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Contribution au développement de politiques publiques de lutte contre les nuisances olfactives au Brésil / Contribution to the development of public policies for odour-nuisance control in BrazilVieira, Magnun Maciel 15 December 2017 (has links)
Les nuisances causées par les odeurs sont devenues un problème environnemental et de santé publique majeur au cours des dernières décennies, surtout dans les zones densément peuplées. Pour cette raison, les odeurs environnementales sont un sujet de préoccupation mondiale et qui reçoivent une attention de plus en plus importante au Brésil. Cependant, il manque aux autorités brésiliennes les instruments réglementaires pour prévenir ou atténuer ces impacts. Plus précisément, au niveau national, aucune législation n’établit des limites d’exposition aux odeurs (critères d’acceptabilité) basé sur les facteurs FIDOL (i.e., fréquence, intensité, durée, offensivité et localisation) qui déterminent l’ampleur de l’effet expérimenté par le récepteur, qui peut être un individu ou un groupe d’individus dans une communauté exposée à des odeurs environnementales. En outre, à l’exception de l’état du Paraná (au sud) et la ville de Uberlândia (au sud-est du pays), aucune méthodologie basée sur l’olfactométrie (i.e., mesure de la réponse d’un jury à un stimulus olfactif), n’est ni standardisée ni reconnue. Dans ce contexte, ce travail de thèse vise à contribuer au développement de politiques publiques de lutte contre les nuisances olfactives au Brésil. Une approche est présentée pour l’évaluation des émissions odorantes d’un site d’équarrissage (une activité à fort potentiel de pollution environnementale) et mettre en évidence la nécessité d’établir un cadre légal et réglementaire pour les odeurs au Brésil, notamment un système d’agrément environnemental avec des critères de conformité spécifiques à chaque secteur de l’industrie. Conscient du besoin de tenir compte des caractéristiques et attributs de la juridiction, comme l’activité économique et la superficie du territoire, l’applicabilité de l’olfactométrie de terrain (en utilisant des appareils portables) a été évaluée pour le relevé d’un contour de panache d’odeur dans l’environnement. De plus, une recherche bibliographique et documentaire a été menée afin de fournir des éléments qui pourront aider les autorités locales dans le développement de solutions adaptées en référence aux expériences et pratiques utilisées à l’échelle internationale. Différents critères de conformité sont discutés et recommandés, sur la base d’une approche réglementaire qui prévoit l’adoption des Meilleures Techniques Disponibles (MTD) et l’établissement de Normes de Distances Minimales (NDM), Normes Maximales d’Emission (NME), Normes Maximales d’Impact (NMI), Normes Maximales de Nuisance (NMN; VIEIRA, 2013). Il est prévu que cette recherche promeut des discussions sur la gestion et la réglementation des odeurs au Brésil (y compris les citoyens, le gouvernement, l’industrie et le milieu académique) et puisse aider à soutenir le développement des structures juridique et réglementaire en vigueur, afin d’assurer un niveau minimum de confort et de protection à la population exposée à ce type de pollution. / Annoying odours have become a major environmental and public health issue in recent decades, especially in densely populated areas. For this reason, environmental odours are a matter of global concern and have received increasing attention in Brazil. However, Brazilian authorities lack the regulatory instruments to prevent or mitigate such impacts. More specifically, at the national level, there is no legislation establishing odour exposure limits (acceptability criteria) based on the FIDOL factors (i.e., frequency, intensity, duration, offensiveness and location) that determine the magnitude of the effect experienced by the receptor, which may be an individual or a group of individuals in a community exposed to environmental odours. Moreover, except for the state of Paraná (in the southern) and the municipality of Uberlândia (in the southeast part of the country), no methodology based on olfactometry (i.e., the measured response of a jury to an olfactory stimulus) is neither standardised nor recognized. In this context, this doctoral thesis aims to contribute to the development of public policies for odour-nuisance control in Brazil. It presents an approach for the evaluation of odour emissions from a rendering plant (an activity with high potential for environmental pollution) and highlights the need to establish a legal and regulatory framework for odours in Brazil, including an environmental permitting system with industry-specific compliance criteria. In light of the necessity of considering jurisdiction-specific characteristics and features such as economy and land area, the applicability of field olfactometry (using portable equipment) was evaluated to outline the contours of an odour plume in the environment. Additionally, bibliographical and documentary research were conducted to provide information that may assist local authorities in developing tailored solutions by reference to experience and practices that have been employed internationally. Different odour compliance criteria are discussed and recommended, based on a regulatory approach that provides for the adoption of the Best Available Techniques (BAT) and the establishment of Minimum Distance Standards (MDS), Maximum Emission Standards (MES), Maximum Impact Standards (MIS) and Maximum Annoyance Standards (MAS; VIEIRA, 2013). It is expected that this research will foster discussions on odour management and regulation in Brazil (involving citizens, government bodies, industry and academia) and may help support the development of the legal and regulatory framework in force, to ensure a minimum level of comfort and protection for the population exposed to this type of pollution.
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The development of yeasts for the optimal production of flavor-active esters and higher alcohols in wine and distillatesLilly, Mariska 12 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Yeasts produce a broad range of aroma-active volatile esters and higher alcohols during
alcoholic fermentation. Some of these esters and higher alcohols are important for the fruity
flavors and therefore the final quality of wine and other fermented beverages. Esters are
produced and hydrolyzed by alcohol acetyltransferases and esterases, respectively. In yeast,
ester-synthesizing activities are represented by two alcohol acetyltransferases encoded by the
ATFI and ATF2 genes, and by an ethanol hexanoyl transferase encoded by the EHTI gene.
Atfl p and Atf2p appear responsible for the production of ethyl acetate and isoamyl acetate,
while Ehtl p synthesizes ethyl hexanoate from ethanol and hexanoyl-CoA. Although a fair
amount of information is available regarding the ATF 1 gene, limited information is available
on the remaining alcohol acetyltransferases. Only two genes that code for esterases have been
identified in yeast, namely lAHI and TIPI. It has also been shown that the balance between
alcohol acetyltransferases and esterases is important for the net rate of ester accumulation.
Higher alcohols are synthesized from the a-keto-acids in the branched-chain amino acid
metabolic pathway by decarboxylation and reduction. The transamination of the amino acid to
the respective a-keto-acid is catalyzed by mitochondrial and cytosolic branched-chain amino
acid transferases, which are encoded by the BATI and BAT2 genes, respectively.
In recent years, a strong scientific and industrial interest in the metabolism of flavoractive
compounds has emerged, but information regarding the roles of specific enzymes and
the physiological relevance of their metabolism remains limited. The aim of this project was
to investigate the physiological and metabolic consequences of changes in the expression
levels of some of the key enzymes involved in aroma compound production. The
consequences of these changes on the chemical composition and the fermentation bouquet of
wines and distillates were also investigated.
The first part of the section on the results in this dissertation reports on the role and
relative importance of the Saccharomyces cerevisiae enzymes involved in ester metabolism,
namely Atflp, Atf2p, Ehtlp, Iahlp and Tiplp. The corresponding genes were overexpressed
in a laboratory strain of S. cerevisiae, BY4742, and in a widely used commercial wine yeast
strain, VIN13. Table wine and base wines for distillation were prepared with these VIN13
transformed strains. The ester concentrations and aroma profiles of the wines and distillates
were analyzed and compared. The data indicated that the overexpression of ATF 1 and ATF2
increased the concentrations of ethyl acetate, isoamyl acetate, 2-pheylethyl acetate and ethyl
caproate, while the overexpression of JAHI resulted in a significant decrease in the
concentrations of ethyl acetate, isoamyl acetate, hexyl acetate and 2-phenylethyl acetate. The
overexpression of EHTI resulted in a marked increase in the concentrations of ethyl caproate,
ethyl caprylate and ethyl caprate, while the overexpression of TJP1 did not decrease the
concentrations of any of the esters. In most cases, there was a correlation between the increase
in esters and the decrease in higher alcohols. The data suggest that yeast balances the amount
of different esters produced through alcohol acetyltransferases and esterases, and that, in some
cases, these enzymes appear to overlap in function and/or influence each other's activity. In the second part of the results section, the consequences of the deletion and the
overexpression of two genes, BATl and BAT2, which encode transaminases that contribute to
the metabolism of higher alcohols, were investigated. The genes were both disrupted in a
S. cerevisiae BY4742, and overexpressed in both this laboratory strain and in the VIN13 wine
yeast strain. The effects of these modifications on the general physiology of the corresponding
yeast strains and on higher alcohol metabolism were assessed in a range of growth conditions,
including aerobic and anaerobic growth conditions, in the presence of glucose or raffinose as
sole carbon source and growth in the presence of various concentrations of amino acids. Table
wine and base wines for distillation were prepared with the modified industrial strains and the
concentrations of the higher alcohols and the aroma profiles of the wine and distillates were
analyzed and compared. Batl deletion seemed to be lethal under the conditions that were
created, and therefore only the bat2!:!.strain, together with the BATI and BAT2 overexpression
strains, were investigated. These modifications did not appear to significantly affect the
general physiology of the strains. The results obtained indicated that the overexpression of
BATI increased the concentrations of isoamyl alcohol and isoamyl acetate, and, to a lesser
extent, the concentrations of isobutanol and isobutyric acid. The overexpression of the BAT2
gene resulted in a substantial increase in the levels of isobutanol, isobutyric acid and
propionic acid production, and a modest increase in the level of propanol and isovaleric acid.
Interestingly, the overexpression of BAT2 led to a decrease in isoamyl alcohol and isoamyl
acetate concentrations. Sensory analyses indicated that the wines and distillates produced with
the strains in which the BATl and BAT2 genes were overexpressed had more fruity
characteristics (peach and apricot aromas) than the wines produced by the wild-type strains.
This study offers new prospects for the development of wine yeast starter strains with
optimized ester and higher alcohol-producing capability that could assist winemakers in their
efforts to consistently produce wine to definable specifications and styles and a predetermined
flavor profile. / AFRIKAANSE OPSOMMING: Gedurende fermentasie produseer giste 'n wye verskeidenheid vlugtige aromatiese esters en
hoër alkohole. Sommige van hierdie esters en hoër alkohole is belangrik vir die vrugtige
geure en dra dus by tot die finale kwaliteit van wyn en ander gefermenteerde drankies. Esters
word onderskeidelik deur alkoholasetieltranferases en esterases geproduseer en gehidroliseer.
In giste word die ester-sintetiserende aktiwiteite deur twee alkoholasetieltransferases
verteenwoordig wat deur die ATFI-en ATF2-gene, asook 'n etanolheksanoïeltransferase wat
deur die EHTl-geen, gekodeer word. Dit blyk dat ATFlp en ATF2p verantwoordelik is vir
die produksie van etielasetaat en isoamielasetaat, terwyl Ehtl p-etielheksanoaat vanaf etanol
en heksanoïel-CoA sintetiseer. Alhoewel daar 'n redelike hoeveelheid inligting t.o.v die
ATF I-geen beskikbaar is, is daar weinig inligting oor die res van die aloholasetieltransferases.
Slegs twee gene wat vir esterases kodeer, is in gis geïdentifiseer, naamlik IAHI en TIPI.
Daar is ook bewys dat 'n balans tussen die alkoholasetieltransferases en esterases baie
belangrik is vir die netto-tempo van ester-akkumulasie. Hoër alkohole word gesintetiseer
vanaf a-keto sure in die vertakte-ketting aminosuur metaboliese pad deur dekarboksilasie en
reduksie. Die transaminasie van die aminosuur na die onderkeidelike a-ketosuur word deur
vertakte-ketting aminosuur transferases, geleë in die mitochondrion en sitosol, en gekodeer
deur BATl- en BAT2-gene, gekataliseer.
In die laaste paar jare het daar 'n sterk wetenskaplike, asook industrïele, belangstelling in
die metabolisme van aroma-aktiewe komponente te voorskyn gekom, maar inligting in
verband met die rol van spesifieke ensieme en die fisiologiese belangrikheid van hul
metabolisme is egter beperk. Die doel van hierdie projek was om die fisiologiese en
metaboliese gevolge van veranderinge in die ekspressievlakke van sommige sleutelensieme
betrokke by aromakomponent-produksie te ondersoek. Die gevolge van hierdie veranderinge
op chemiese vlakke, asook hoe die fermentasie-aroma van die wyne en distillate beïnvloed
word, is ook bestudeer.
Die eerste gedeelte van die resultate rapporteer oor die rol en relatiewe belangrikheid van
die Saccharomyces cerevisiae-ensieme betrokke by estermetabolisme, naamlik Atfl p, Atf2p,
Ehtlp, Iahlp en Tiplp. Die gene was ooruitgedruk in 'n laboratoriurnras van S. cerevisiae,
BY4742, asook in 'n kommersïele wyngisras, VIN13. Tafelwyne en basiswyne vir distillasie
is gemaak met die getransformeerde VIN13-rasse. Die esterkonsentrasies en aromaprofiele
van die wyne en distillate is ontleed en vergelyk. Die data het gewys dat die ooruitdrukking
van ATFI- en ATF2-gene 'n verhoging in etielasetaat, isoamielasetaat, 2-fenieletielasetaat en
etielkaproaat veroorsaak het, terwyl ooruitdrukking van !AHI 'n betekenisvolle afname in
etielasetaat-, isoamielasetaat-, heksielasetaat- en 2-fenieletielasetaat-konsentrasies veroorsaak
het. Die ooruitdrukking van EHTI het 'n duidelike verhoging in etielkaproaat, etielkaprilaat
en etielkapraat veroorsaak en die ooruitdrukking van TIPIhet geen van die esterkonsentrasies
verander nie. In die meeste gevalle was daar nie 'n korrelasie tussen die toename in esters en
afname in hoër alkohole nie. Die data stelook voor dat die gis 'n balans tussen die
verskillende esters handhaaf deur middel van die alkoholasetieltrasferases en esterases, en in sommige gevalle blyk dit dat die ensieme dieselfde funksies het en/of mekaar se aktiwiteit
beïnvloed.
In die tweede gedeelte van die resultate is die oorsake van delesie en ooruitdrukking van
twee gene, BAT1 en BAT2, wat kodeer vir transaminases wat tot hoër alkohol metabolisme
bydra, bestudeer. Die gene is uitgeslaan in S. cerevisiae BY4742 en ooruitgedruk in BY4742
en in die wyngisras VIN13. Die effekte van hierdie modifikasies op die algemene fisiologie
van die verskillende gisrasse en op hoëralkoholmetabolisme is onder 'n verskeidenheid
kondisies bestudeer, naamlik aërobies en anaërobiese groeikondisies, in die teenwoordigheid
van glukose of raffinose as die enigste koolstofbron, asook in die teenwoordigheid van 'n
verskeidenheid konsentrasies aminosure. Tafelwyne en basiswyne vir distillasie is gemaak
met die gemodifiseerde industrïele rasse en die konsentrasies van die hoër alkohole en
aromaprofiele van die wyne en distillate is ontleed en vergelyk. Bat1-delesie was dodelik
onder die kondisies, daarom is slegs die batlts-tes tesame met die BAT1 en BAT2 wat in die
rasse ooruitgedruk is, bestudeer. Die modifikasies het nie 'n beduidende effek op die
algemene fisiologie van die rasse getoon nie. Die data het wel getoon dat die ooruitdrukking
van BAT1 'n verhoging in isoamielalkohol- en isoamielasetaatkonsentrasies, en tot 'n mindere
mate isobutielalkohol- en isobottersuur-konsentrasies, veroorsaak het. Die ooruitdrukking
van BAT2 het 'n beduidende toename in isobutanol-, isobottersuur- en propioonsuurkonsentrasies
en 'n kleinere toename in propanol- en isovaleriaansuur veroorsaak. Die
ooruitdrukking van BAT2 het ook gelei tot 'n afname in isoamielalkohol- en isoamielasetaatkonsentrasies.
Sensoriese analises het getoon dat die wyne en distillate wat geproduseer is
met die rasse waarin die BAT1 en BAT2 gene ooruitgedruk is meer vrugtige eienskappe
(perske- en appelkoos-aromas) getoon het as die wyne wat deur die wildetipe rasse
geproduseer is.
Die studie lewer nuwe vooruitsigte vir die ontwikkeling van wyngiste met geoptimiseerde
ester en hoër alkohol produserende eienskappe wat die wynmakers in staat kan stelom wyne
te produseer met gedefinieerde spesifikasies en style en 'n voorafbepaalde aromaprofiel.
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An investigation into lactic acid bacteria as a possible cause of bitterness in wineKrieling, Shannon Janine 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Spoilage, be it due to microbial actions, chemical reactions or both, poses a serious
threat to the food and beverage industries. Not only can spoilage lead to great
economic losses, but it can also cause industries to lose their competitive edge in the
economic and consumer market. Considering all the modern technologies and the
range of preservation techniques that are available, it is surprising that spoilage is still
an economic problem. Wine spoilage due to unpalatable bitterness, and the role of
lactic acid bacteria (LAB) in causing this bitterness, have received much attention
over the years, but no definite understanding has yet emerged.
The first objective of this study was to isolate, enumerate and identify the LAB
from three red grape varieties, viz. Pinotage, Merlot and Cabernet Sauvignon. The
LAB populations on the grapes of all three varieties ranged from 102 to 104 cfu/ml
during the 2001 and 2002 harvest seasons. The Cabernet Sauvignon grapes had
slightly higher numbers than the Pinotage and Merlot. The LAB population in the
Cabernet Sauvignon, Pinotage and Merlot wines after completion of the alcoholic
fermentation ranged from 102 to 105 cfu/ml, while during 2002 the numbers in wine
undergoing malolactic fermentation (MLF) ranged from 104 to 108 cfu/ml. The
isolated LAB were divided into the three metabolic groups, with 59% belonging to the
facultatively heterofermentative group, 26% to the obligately heterofermentative
group and 15% to the obligately homofermentative group. The isolates were
identified by means of species-specific primers as Leuconostoc mesenteroides (4),
Oenococcus oeni (28), Lactobacillus brevis (15), Lb. hilgardii (15), Lb. plantarum
(98), Lb. pentosus (12), Lb. paraplantarum (3), Lb. paracasei (28),
Pediococcus acidilactici (2) and Pediococcus spp. (35). The most predominant
species isolated was Lb. plantarum, followed by Pediococcus spp. The results
suggest that Pinotage carries a more diverse LAB population in comparison to Merlot
and Cabernet Sauvignon.
The second objective of this study was to determine the presence of the glycerol
dehydratase gene in the LAB strains by using the G01 and G02 primers. Twenty-six
strains tested positive, namely Lb. plantarum (15), Lb. pentosus (1), Lb. hilgardii (5),
Lb. paracasei (2), Lb. brevis (2) and a Pediococcus spp. (1). Interestingly, 62% of
these strains were isolated from Pinotage. The strains all had the ability to degrade
glycerol by more than 90%, and no significant differences were observed between
the species. The GO-possessing strains exhibited varying degrees of inhibition
towards Gram-positive and Gram-negative bacteria, and the results suggest that this
inhibition activity may be similar to that of reuterin, which is produced by Lb. reuteri.
This study can form the foundation for unravelling the causes of bitterness in red
wines. Combining the results of this study with analytical, sensory and molecular
data may very well provide the industry with valuable tools with which to combat the
occurrence of bitterness. / AFRIKAANSE OPSOMMING: Bederf as gevolg van mikrobiese aksies, chemiese reaksies of beide, hou 'n groot
bedreiging vir die voedsel- en drankbedrywe in. Nie net kan bederf lei tot groot
ekonomiese verliese nie, maar dit kan ook veroorsaak dat bedrywe hul
kompeterende voordeel in die ekonomiese en verbruikersmarkte verloor. As die
moderne tegnologie en die reeks preserveringstegnieke wat beskikbaar is, in ag
geneem word, is dit verbasend dat bederf steeds 'n ekonomiese probleem is.
Wynbederf as gevolg van oormatige bitterheid en die rol van melksuurbakterieë
(MSB) in die ontwikkeling van hierdie bitterheid het oor die jare heen baie aandag
geniet, maar geen definitiewe verklaring is nog daarvoor gevind nie.
Die eerste doelwit van hierdie studie was om MSB vanaf drie rooidruifvariëteite,
nl. Pinotage, Merlot en Cabernet Sauvignon, te isoleer, te kwantifiseer en te
identifiseer. Die MSB-populasies op die druiwe van al drie variëteite het gedurende
die 2001- en 2002-parsseisoene tussen 102 en 104 kvu/ml gevarieer. Die Cabernet
Sauvignon-druiwe het effens hoër getalle as die Pinotage- en Merlot-druiwe gehad.
Die MSB-populasies in die Cabernet Sauvignon-, Pinotage- en Merlot-wyne aan die
einde van die alkoholiese fermentasie het tussen 102 en 1055 kvu/ml gevarieer.
Gedurende 2002 het die MSB-getalle in die wyne waarin appelmelksuurgisting
(AMG) aan die gang was tussen 104 en 108 kvu/ml gevarieer. Die geïsoleerde MSB
was onderverdeel in die drie metaboliese groepe, met 59% wat behoort aan die
fakultatiewe, heterofermentatiewe groep, 26% aan die obligate, heterofermentatiewe
groep en 15% aan die obligate, homofermentatiewe groep. Die isolate is
geïdentifiseer as Leuconostoc mesenteroides (4), Oenococcus oeni (28),
Lactobacillus brevis (15), Lactobacillus hi/gardii (15, Lactobacillus p/antarum (98),
Lactobacillus pentosus (12), Lactobacillus parap/antarum (3), Lactobacillus paracasei
(28), Pediococcus acidi/actici (2) en Pediococcus spp. (35) deur middel van spes iespesifieke
inleiers. Die mees algemeen geïsoleerde spesies was Lb. p/antarum,
gevolg deur Pediococcus spp. Die resultate impliseer dat Pinotage 'n meer
uiteenlopende MSB-populasie in vergelyking met Merlot en Cabernet Sauvignon dra.
Die tweede doelwit van hierdie studie was om die teenwoordigheid van die
gliseroldehidratase-geen in die MSB-isolate deur middel van die GD1- en GD2-
inleiers te bepaal. Ses-en-twintig isolate was positief, nl. Lb. p/antarum (15), Lb.
pentosus (1), Lb. hi/gard;; (5), Lb. paracasei (2), Lb. brevis (2) en 'n Pediococcus spp.
(1). 'n Interessante resultaat was dat 62% van hierdie isolate vanaf Pinotage
geïsoleer is. Die isolate was almal in staat om meer as 90% van die gliserol te
gebruik en geen noemenswaardige verskille is tussen die isolate waargeneem nie.
Die GD-bevattende isolate het verskillende grade van inhibisie teenoor Grampositiewe
en Gram-negatiewe bakterieë getoon, en die resultate impliseer dat hierdie
inhiberende aktiwiteit dieselfde is as dié van reuterin wat deur Lb. reuteri
geproduseer word. Hierdie studie kan dus die basis vorm vir die ontrafeling van die oorsake van
bitterheid in rooiwyne. Deur die resultate van hierdie studie met analitiese,
sensoriese en molekulêre data te kombineer, kan die wynbedryf voorsien word van
waardevolle metodes om die voorkoms van bitterheid mee te bekamp.
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The impact of amino acids on growth performance and major volatile compound formation by industrial wine yeastMcKinnon, Alexander 12 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Nitrogen composition of grape must is highly variable and impacts on the health of the
fermenting yeast population as well as the formation of aroma and flavour compounds in wine.
Insufficient yeast assimilable nitrogen (YAN), mostly consisting of amino acids and ammonium,
can lead to stuck or sluggish fermentations as well as the formation of undesirable compounds
such as H2S. Furthermore, it is well established that the total concentration of YAN and the
specific amino acid composition have a significant impact on the final aroma and flavour of
wines. However, the impact of individual amino acids and of specific amino acid compositions
on fermentation kinetics and on the production of aroma and flavour impact compounds under
winemaking conditions is not well understood.
The first goal of this study was to evaluate the effect of single amino acids on growth
kinetics and major volatile production of two industrial wine yeast strains under conditions
resembling wine fermentations. To facilitate these fermentation conditions while also allowing
for easy reproducibility and manipulation of the initial components, a synthetic grape media was
utilized. Biomass formation, exponential growth rate, lag phase, and fermentation duration were
utilized to evaluate the efficiency of single amino acids.
The data show that previously observed trends in laboratory strains mostly apply to these
conditions and strains. In general, the efficiency of amino acids to be used as nitrogen sources
and the production of major volatiles due to their presence followed the same patterns for both
industrial yeast strains. However, the production of the secondary metabolites butanol,
propanol, acetic acid, and ethyl acetate were found to be produced in different final
concentrations dependent upon the yeast strain.
The branched-chained and aromatic amino acids (BCAAs) treatments were observed to
have the most dramatic effects on major volatile production. Investigating the relationships
between the initial concentration of the BCAAs and the final concentrations of major volatile
compounds, it was found that the production of fusel alcohols and fusel acids due to the
degradation of BCAAs by S. cerevisiae could be predicted from the initial concentration of
BCAAs. While under simple nitrogen conditions the production of several other secondary metabolites such as butanol, propionic acid, valeric acid, decanoic acid and 2-phenylethyl
acetate were found to be correlated to the initial concentration of BCAAs in the media.
Future studies should focus on the validation of these trends in aroma production in real
grape musts under various fermentation temperatures for a number of industrial wine yeast
strains. / AFRIKAANSE OPSOMMING: Die stikstof samestelling van druiwemos is hoogs veranderlik en impakteer op die
kerngesondheid van die fermenterende gis populasie asook die produksie van aroma- en
geurverbindings in wyn. Onvoldoende assimileerbare stikstof (ook genoem “yeast assimilable
nitrogen” (YAN)), wat meestal bestaan uit aminosure en ammonium, kan aanleiding gee tot
steek- of slepende fermentasies, asook die vorming van ongewensde verbindings soos H2S. Dit
is alombekend dat die totale konsentrasie van YAN en dan ook die spesifieke aminosuur
samestelling ‘n noemenswaardige impak op die finale aroma en smaak van wyn het. Die
invloed van individuele am inosure en spesifieke aminosuur samestellings op die fermentasie
kinetika, asook die produksie van verbindings met ‘n impak op die wyn aroma en smaak, word
egter nie deeglik verstaan nie.
Die eerste doelwit van die studie was om twee industriële gisrasse te gebruik om die effek
van enkel aminosure op die groei-kinetika en produksie van die vername vlugtige verbindings
onder wynmaak toestande te bepaal. Kunsmatige, gedefinieerde druiwermosmedium is gebruik
om wynmaak toestande te simuleer en ook herhaalbaarheid en manipulering van die
aanvanklike samestelling van die medium te verseker.
Die studie het vorige tendense wat opgemerk is in die evaluasie van laboratorium rasse
onder soortgelyke toestande bevestig. Die doeltreffendheid waarmee aminosure oor die
algemeen gebruik word as stikstofbron, asook die produksie van die vernaamste vlugtige
verbindings wat gekoppel is aan hulle teenwoordigheid, het ‘n vergelykbare patroon vir beide
rasse gevolg. Die sekondêre metaboliete butanol, propanol, asetaat en etiel-asetaat is egter wel
in verskillende eindkonsentrasies geproduseer deur die verskillende gisrasse. Die vertakte-ketting en aromatiese aminosuur (“branched-chained and aromatic amino
acids” (BCAAs)) behandelings het die mees dramatiese effek op die produksie van die
vernaamste vlugtige komponente gehad. Ondersoek na die verwantskap tussen die
aanvanklike konsentraies van die BCAAs en die finale konsentrasies van dié verbindings het
aangedui dat die produksie van hoër alkohole en sure, as gevolg van die afbraak van BCAAs
deur S. cerevisiae, met behulp van die aanvanklike konsentrasie van die BCAAs voorspel kon
word. Terselfdertyd is gevind dat onder eenvoudige stikstoftoestande, verskeie ander sekondêre metaboliete soos butanol, propionaat, valeriaat, dekanoësuur en 2-fenieletielasetaat,
gekorreleer kan word met die aanvanklike BCAAs in die media.
Verdere studies moet poog om hierdie tendense ten opsigte van aromaproduksie te bevestig en
wel deur gebruik te maak van ware druiwemos, verskeie fermentasietemperature, asook ’n
verskeidenheid van wyngisrasse.
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Pollinator-mediated selection, reproductive isolation and the evolution of floral traits in Ophrys (Orchidaceae)Vereecken, Nicolas J 15 May 2008 (has links)
Cette thèse aborde l’écologie et l’évolution des relations qu’entretiennent les orchidées du genre Ophrys avec leurs pollinisateurs. L’approche comparative et la combinaison (i)
d’analyses chimiques de phéromones sexuelles et de parfums floraux, (ii) d’analyses génétiques avec des outils moléculaires, et (ii) de tests de comportement réalisés sur les insectes in situ nous ont permis d’éclairer certains aspects méconnus de ces interactions inter-spécifiques. La pollinisation des orchidées du genre Ophrys est assurée par des mâles d'abeilles ou de guêpes solitaires qui opèrent une tentative d’accouplement (pseudocopulation) sur le labelle des fleurs. L'attraction des pollinisateurs est généralement hautement spécifique, régie par un mimétisme des signaux (chimiques, visuels, tactiles) des femelles des espèces d'insectes concernés. Malgré cette spécificité, des hybrides se forment occasionnellement en conditions naturelles, témoignant de la perméabilité partielle des barrières d'isolement reproductif entre espèces. Au cours de
ce programme de recherche, nous avons entrepris l’étude des interactions Ophryspollinisateurs en mettant l’accent sur trois aspects spécifiques, à savoir (i) la sélection des caractères floraux par les pollinisateurs, (ii) l'isolement reproductif entre espèces d'Ophrys sympatriques, et enfin (iii) l'évolution des caractères floraux au sein d'un complexe d'espèces-soeurs d'Ophrys associées à différents pollinisateurs. Les principaux
résultats de ce travail sont repris ci-dessous, ponctués de références aux articles qui rassemblent l’intégralité des études réalisées.
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Prediction, management and control of odour from landfill sites.Laister, Guy. January 2002 (has links)
Due to the spread of urbanisation and increased environmental awareness,
odour has become a major problem in communities surrounding landfills. The aim
of this research was to investigate odour emissions from landfills and develop a
management tool that operators could use to assist in minimising the impacts of
odour. The management tool would be in the form of real-time predictions of
odour concentrations in the vicinity of a source. The Bisasar Road landfill in
Springfield, Durban was a case study site for the research.
The methodologies used in this project can be divided into three broad
categories. Firstly, flow visualisation experiments were conducted on the case
study site to investigate the effects of complex terrain and the results compared
to predictions from a dispersion model. Secondly, source characterisation was
done on-site. Sources of odour were identified using a portable odour monitor
(Electronic nose). Sources of odour were then sampled using sorbent tubes and
analysis done using Gas Chromatography - Mass Spectrometry. Thirdly,
numerical dispersion modelling was done. Five available dispersion models were
assessed and compared against one another in order to select the most suitable
model for this application. A software management tool or 'Odour Management
System' (OMS), was designed and implemented on a computer at the Bisasar
Road landfill.
Qualitative results of the flow visualisation experiments show that terrain does
have an effect on a dispersing plume path for short-range predictions.
Comparisons between the flow experiments and model predictions are
qualitatively consistent. Quantitative results were not obtained for the emission
flow rate and emission concentration of landfill gas. The chemical composition of
the fresh waste gas was determined. ADMSTM(Advanced Dispersion Modelling
System) was found to be the most suitable dispersion model for this application.
The OMS has been installed on-site to produce odour concentration graphics
every ten minutes. A fence line odour control misting system has been installed
along approximately 600 metres of the landfill border based on work done as part
of this project. Weather conditions and information provided by the OMS, assist in
running the odour control system economically. / Thesis (M.Sc.Eng.)-University of Natal,Durban, 2002.
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Following a cleaner production approach to guide the permitting process of odour producing industries : an assessment of case studies.Nzimande, Bawinile. January 2011 (has links)
The eThekwini Municipality is facing two major challenges in controlling odorous emissions by various
industries in the South Durban Basin; firstly, getting industry to manage their onsite odorous emissions and,
secondly regulating these odorous emissions. This study focused on the Jacobs’s Industrial Complex (JIC)
which comprises various industries releasing air emissions which impact on the local air quality. The impact of
these emissions is supported by the number of odour complaints reported to the eThekwini Environmental
Health Department by the public.
Cleaner production (CP) is an integrated approach aimed at continuously reducing environmental impacts of
processes, products and services through applying preventive approaches rather than controlling and managing
pollution once it has been created. This dissertation has assessed the application of CP as a concept to prevent
and reduce emissions of odours by industries in the JIC that are an impacting on the environment and
neighbouring communities. Three CP case studies are analysed to demonstrate the applicability of the approach.
These are a CP project for drum reprocessing company based in the South Durban Basin and two waste
minimisation clubs which operated from 1998 to 2000 in Durban.
The key findings, outcomes, experiences and lessons learnt from these case studies underpin the
recommendation of an approach that can be applied by eThekwini Municipality to incorporate CP in the
scheduled trade (ST) permitting of odour producing industries. This research has applied a multi-case study
design implying both qualitative and quantitative approaches. A qualitative approach was used in the detailed
analyses of case studies whilst the quantitative one was applied in the graphical analyses of the odour
complaints statistics for the JIC.
The study concludes by drawing two major recommendations from the lessons leant. Recommendation 1: The
general CP strategy that can be applied by eThekwini Municipality in regulating, promoting, enforcing,
monitoring and evaluating application of CP practices among stakeholders. The recommended objectives for
the general strategy include:
· Enforcement of uniform regulatory standards.
· Development of a policy or guidelines.
· Effective compliance monitoring and enforcement.
· Develop a local Cleaner Production Centre (LCPC).
· Ensure co-operative governance.
· Provide adequate financial resources.
· Monitoring and evaluation.
Recommendation 2: Strategy for incorporating CP in the ST permitting of odour producing industries. It is
recommended that the ST permit holder for an odour producing industry comply with the following:
· Prioritisation of odour like the other priority pollutants.
· Industry to perform an audit to map odour emitting areas.
· Permit holder to development a CP based odour management plan.
· Investigate possible CP projects that can be undertaken to prevent and mitigate odour emissions.
· Incorporate an odour management plan into a 5 year environmental improvement plan.
· Develop and appropriately manage an odour complaints management system.
· Set odour management performance indicators and baselines for targets and reporting.
· The permit holder should include odour management performance including odour complaints
management in the annual report. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.
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Effect of sensory enrichments on the behaviour of captive Northern lynx (Lynx lynx lynx) and assessment of automated behaviour monitoring technologiesJEAN-LOUIS, Uranie January 2019 (has links)
Captive environments like zoo exhibits offer limited space, lacking many of the environmental stimuli that are present in the wild. This may reduce animal welfare and potentially lead to the development of stereotypic behaviour like pacing. Environmental enrichment is used to prevent and reduce pacing and enhance animal well-being. The aim of this project was to evaluate sensory enrichments, and the effect of such enrichment on pacing in a group of Northern lynx by means of new, automated monitoring technologies in combination with traditional visual observations. The lynxes were exposed to valerian, catnip and cinnamon as olfactory enrichment. The acoustic enrichments were play-backed mouse squeals, roe deer barking and lynx vocalizations, and live crickets. The responses of the lynx were recorded by logging their subcutaneous HDX pit tags, and Bluetooth Low Energy (BLE) tags mounted on collars and using a wildlife camera. The results showed that catnip elicited clear “catnip responses” i.e sniffing, rubbing, biting and licking. The sounds were found to attract the lynxes and increase their arousal. One of the sounds, the lynx calls, elicited social behaviour. However, none of the sensory treatments reduced pacing. The combination of these automated technologies with visual observation was powerful to evaluate the effect of enrichment on captive lynxes and to monitor their activity patterns and stereotypic behaviours. Sensory enrichment could also be used in the wild as lures to attract lynxes to BLE or HDX PIT tag logging stations and to wildlife cameras, as part of monitoring a lynx population.
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Coabitação com um parceiro doente: avaliações das alterações neuroimunes e da forma de comunicação / Cohabitation with a sick cage mate: evaluations of neuroimune changes and of the way of communicationAlves, Glaucie Jussilane 01 July 2010 (has links)
Os trabalhos na área de neuroimunomodulação vêm contribuindo de forma marcante para o entendimento da regulação/modulação das respostas adaptativas dos organismos frente ao estresse ou às doenças. A integração de modelos biológicos e psicológicos surge e torna-se cada vez mais importante para a neuroimunologia. Cada animal comunica-se com outros de sua ou de outra espécie através de mecanismos que são característicos dentro de seus respectivos grupos; sabe-se que a comunicação entre os animais pode ser visual, táctil, química e sonora. Procuramos neste trabalho identificar o(s) tipo(s) de comunicação mais relevante(s) entre camundongas saudáveis e conspecíficas doentes. Mais especificamente, avaliamos efeitos neuroimunes decorrentes da convivência por 14 dias com companheiras inoculadas com tumor ascítico de Ehrlich e buscamos caracterizar o tipo de comunicação envolvida com este processo. Os resultados obtidos mostraram que a simples convivência com um portador do tumor de Ehrlich produziu em camundongas: 1) redução do peso e celulariedade do baço; 2) redução na contagem diferencial de blastos, eritrócitos jovens e linfócitos no esplenograma; 3) redução da porcentagem de linfócitos B e T helper e na proporção CD4/CD8 no baço; 4) aumento da atividade citotóxica de células NK; 5) aumento da celulariedade total da medula; 6) aumento na contagem absoluta de blastos e redução de eritrócitos jovens e de linfócitos no mielograma; na contagem relativa observamos um aumento dos blastos; 7) aumento de células na fase G1 e redução na fase G2 do ciclo celular da medula; 8) aumento de células tumorais de Ehrlich na fase G1 e redução destas na fase G2, 9) aumento de permanência na zona animal estranho e redução de tempo na zona companheiro doente em um labirinto em T, 10) aumento de interação social; 11) redução do burst oxidativo basal de neutrófilos provenientes de animais que conviveram com dois doentes, e reversão destas alterações quanto da convivência com dois sadios. Observamos, ainda que: 12) a convivência não modificou os níveis de corticosterona dos animais desafiados ou não por contenção; 13) a ausência de contato físico não foi relevante para reverter as alterações induzidas pela convivência; 14) a falta de contato visual também não foi relevante para reverter as alterações observadas; 15) os estímulos olfativos foram relevantes para as alterações induzidas pela convivência sobre o burst oxidativo e fagocitose de neutrófilos, crescimento tumoral, alterações comportamentais, dosagem plasmática de noradrenalina e de adrenalina e níveis hipotalâmicos de noradrenalina. Em seu conjunto observamos que a convivência por 14 dias com um animal portador de um tumor de Ehrlich produziu relevantes alterações no comportamento, em parâmetros neuroquímicos e de atividade imune inata de camundongas. Nossos resultados sugerem que a percepção do odor da doente esteja diretamente relacionada com as alterações relatadas. / Several papers are showing relevant neuroimmune regulation and/or modulation during stress or diseases. The incorporation of biological and psychological models of humans conditions are of high relevance in neuroscience. Animals exhibit a variety of adaptative behaviors for communicating with conspecifics; communication between animals can be visual, tactile, chemical and sound induced. The present experiment was designed to analyze the effects induced by cohabitation with a sick cage mate and some aspects of communication between sick mice and their companions. Specifically, we analyzed some neuroimmune effects induced by cohabitation with a sick cage-mate for 14 days (mice bearing an ascitic Ehrlich tumor), looking also for the type of communication related to this process. Our results showed that cohabitation with a sick cage-mate induced, in female mice 1) decreased spleen weight and total cellullarity; 2) decreased the number of blast, young erythrocytes and lymphocytes in spleen 3) decreased percentage of B and T helper cells, and decreased proportion of CD4/CD8 cells in the spleen; 4) increased NK cells cytotoxicity; 5) increased bone marrow total celullarity; 6) increased absolute number of blasts, and decreased the number of young erythrocytes and lymphocytes; in the relative count, an increase of blast cells in bone marrow was observed; 7) increased amount of cells on G1 cellular cycle phase, and a decreased population of cells on G2 cellular cycle phase in the bone marrow; 8) increased amount of Ehrlich tumor cells in G0-G1 cellular cycle phases, and decreased population of tumor cells in S/G2/M phases; 9) increased time spent with an strange animal and decreased time spent will sick companion in a T maze and increased locomotion in this apparatus; 10) increased social interaction; 11) decreased neutrophil basal oxidative burst in animals that lived with two sick companions. We also observed that: 12) cohabitation with a sick partner was unable to modify serum corticosterone levels with or without an immobilization stress challenge; 13) physical contact was not relevant for the neuroimune changes induced by cohabitation; 14) visual cues were not relevant for the present contextual immune changes; 15) odor cues were effective mechanisms of communication used by the mice in the present experiment; because it removal abrogated or reversed the neuroimmune changes reported above for cohabitation. The present findings showed that cohabitation with an ascitic Ehrlich tumor bearing mice produced behavioral, neurochemical, and immunological changes. The present results strongly suggest that volatile compounds released by the sick companion are directly relationed to the neuroimmune changes now reported in mice for cohabitation with a sick companion.
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Coabitação com um parceiro doente: avaliações das alterações neuroimunes e da forma de comunicação / Cohabitation with a sick cage mate: evaluations of neuroimune changes and of the way of communicationGlaucie Jussilane Alves 01 July 2010 (has links)
Os trabalhos na área de neuroimunomodulação vêm contribuindo de forma marcante para o entendimento da regulação/modulação das respostas adaptativas dos organismos frente ao estresse ou às doenças. A integração de modelos biológicos e psicológicos surge e torna-se cada vez mais importante para a neuroimunologia. Cada animal comunica-se com outros de sua ou de outra espécie através de mecanismos que são característicos dentro de seus respectivos grupos; sabe-se que a comunicação entre os animais pode ser visual, táctil, química e sonora. Procuramos neste trabalho identificar o(s) tipo(s) de comunicação mais relevante(s) entre camundongas saudáveis e conspecíficas doentes. Mais especificamente, avaliamos efeitos neuroimunes decorrentes da convivência por 14 dias com companheiras inoculadas com tumor ascítico de Ehrlich e buscamos caracterizar o tipo de comunicação envolvida com este processo. Os resultados obtidos mostraram que a simples convivência com um portador do tumor de Ehrlich produziu em camundongas: 1) redução do peso e celulariedade do baço; 2) redução na contagem diferencial de blastos, eritrócitos jovens e linfócitos no esplenograma; 3) redução da porcentagem de linfócitos B e T helper e na proporção CD4/CD8 no baço; 4) aumento da atividade citotóxica de células NK; 5) aumento da celulariedade total da medula; 6) aumento na contagem absoluta de blastos e redução de eritrócitos jovens e de linfócitos no mielograma; na contagem relativa observamos um aumento dos blastos; 7) aumento de células na fase G1 e redução na fase G2 do ciclo celular da medula; 8) aumento de células tumorais de Ehrlich na fase G1 e redução destas na fase G2, 9) aumento de permanência na zona animal estranho e redução de tempo na zona companheiro doente em um labirinto em T, 10) aumento de interação social; 11) redução do burst oxidativo basal de neutrófilos provenientes de animais que conviveram com dois doentes, e reversão destas alterações quanto da convivência com dois sadios. Observamos, ainda que: 12) a convivência não modificou os níveis de corticosterona dos animais desafiados ou não por contenção; 13) a ausência de contato físico não foi relevante para reverter as alterações induzidas pela convivência; 14) a falta de contato visual também não foi relevante para reverter as alterações observadas; 15) os estímulos olfativos foram relevantes para as alterações induzidas pela convivência sobre o burst oxidativo e fagocitose de neutrófilos, crescimento tumoral, alterações comportamentais, dosagem plasmática de noradrenalina e de adrenalina e níveis hipotalâmicos de noradrenalina. Em seu conjunto observamos que a convivência por 14 dias com um animal portador de um tumor de Ehrlich produziu relevantes alterações no comportamento, em parâmetros neuroquímicos e de atividade imune inata de camundongas. Nossos resultados sugerem que a percepção do odor da doente esteja diretamente relacionada com as alterações relatadas. / Several papers are showing relevant neuroimmune regulation and/or modulation during stress or diseases. The incorporation of biological and psychological models of humans conditions are of high relevance in neuroscience. Animals exhibit a variety of adaptative behaviors for communicating with conspecifics; communication between animals can be visual, tactile, chemical and sound induced. The present experiment was designed to analyze the effects induced by cohabitation with a sick cage mate and some aspects of communication between sick mice and their companions. Specifically, we analyzed some neuroimmune effects induced by cohabitation with a sick cage-mate for 14 days (mice bearing an ascitic Ehrlich tumor), looking also for the type of communication related to this process. Our results showed that cohabitation with a sick cage-mate induced, in female mice 1) decreased spleen weight and total cellullarity; 2) decreased the number of blast, young erythrocytes and lymphocytes in spleen 3) decreased percentage of B and T helper cells, and decreased proportion of CD4/CD8 cells in the spleen; 4) increased NK cells cytotoxicity; 5) increased bone marrow total celullarity; 6) increased absolute number of blasts, and decreased the number of young erythrocytes and lymphocytes; in the relative count, an increase of blast cells in bone marrow was observed; 7) increased amount of cells on G1 cellular cycle phase, and a decreased population of cells on G2 cellular cycle phase in the bone marrow; 8) increased amount of Ehrlich tumor cells in G0-G1 cellular cycle phases, and decreased population of tumor cells in S/G2/M phases; 9) increased time spent with an strange animal and decreased time spent will sick companion in a T maze and increased locomotion in this apparatus; 10) increased social interaction; 11) decreased neutrophil basal oxidative burst in animals that lived with two sick companions. We also observed that: 12) cohabitation with a sick partner was unable to modify serum corticosterone levels with or without an immobilization stress challenge; 13) physical contact was not relevant for the neuroimune changes induced by cohabitation; 14) visual cues were not relevant for the present contextual immune changes; 15) odor cues were effective mechanisms of communication used by the mice in the present experiment; because it removal abrogated or reversed the neuroimmune changes reported above for cohabitation. The present findings showed that cohabitation with an ascitic Ehrlich tumor bearing mice produced behavioral, neurochemical, and immunological changes. The present results strongly suggest that volatile compounds released by the sick companion are directly relationed to the neuroimmune changes now reported in mice for cohabitation with a sick companion.
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