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.

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.

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.

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.

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.

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.

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.

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.

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.

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.