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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Degradation of n-alkane fractions of Omani crude oil by bacteria

Al-Hadhrami, Mohamed Nasser January 1995 (has links)
No description available.
12

Décoloration d’effluents de distillerie par un consortium microbien / Decolorization of molasses wastewater from distilleries using bacterial consortium

Jiranuntipon, Suhuttaya 06 March 2009 (has links)
Les effluents de distillerie de mélasse de canne à sucre génèrent une pollution environnementale due à, d’une part de grands volumes et d’autres part à la présence de composés de couleur brune foncée, connus sous le nom de mélanoïdines. Dans cette étude, un consortium bactérien CONS8 isolé dans des sédiments de chute d'eau a été choisi comme consortium apte à la décoloration de la mélasse. On a montré que le consortium CONS8 pouvait décolorer, trois eaux usées synthétiques différentes, élaborées respectivement à base de Viandox (13,48% v/v), d’eau usée de mélasse de betterave (41,5% v/v) ou d’eau usée de mélasse de canne à sucre (20% v/v). Les décolorations obtenues en 2 jours seulement, en fioles d’Erlenmeyer sont respectivement de 9,5, à 8,02 et à 17,5%. Quatre bactéries prédominantes ont été identifiées dans le consortium CONS8 par l'analyse de l'rADN 16S. Sur la base de cette identification, et afin de réaliser la décoloration la plus élevée, un consortium bactérien artificiel MMP1 a été reconstruit avec Klebsiella oxytoca, Serratia mercescens (T2) et la bactérie inconnue DQ817737 (T4). Dans des conditions optimisées (aération, pH) le consortium bactérien MMP1 a permis de décolorer l'eau usée synthétique contenant de la mélanoidine à 18,3% en 2 jours. La comparaison de la décoloration par le consortium MMP1 avec un milieu abiotique a démontré que la décoloration était principalement due à l'activité biotique des cellules bactériennes, sans aucun phénomène d'adsorption. Un complément en minéraux et vitamines B n'a pas amélioré la décoloration de mélanoïdines avec le consortium bactérien MMP1. Enfin, les performances d'un bioréacteur à membrane pour traiter les eaux résiduaires synthétiques contenant de la mélanoïdine ont été évaluées à l’échelle du laboratoire. L'ensemencement du réacteur a été réalisé avec un inoculum sur la base du consortium MMP1. Le réacteur a fonctionné sous plusieurs conditions de temps de séjour hydrauliques (HRT) de 15, 20, et 40 heures. Les performances ont été analysées en termes de DCO (demande chimique en oxygène), décoloration et croissance de biomasse. Les résultats ont indiqué qu’une efficacité accrue d’élimination de la DCO et de la couleur ont été obtenues avec le HRT le plus long. / Distillery effluent from sugarcane molasses leads to an environmental pollution due to its large volume and the presence of dark brown colored compounds, known as melanoidins. In this study, a bacterial consortium CONS8 isolated from waterfall sediments in Maehongsorn province was selected as a molasses-decolorizing consortium. Consortium CONS8 was able to decolorize, only within 2 days, in Erlenmeyer flasks, three different synthetic wastewaters containing either Viandox sauce (13.5% v/v), beet molasses wastewater (41.5% v/v) or sugarcane molasses wastewater (20% v/v) at 9.5, 8.0 and 17.5%, respectively. Four predominant bacteria present in the consortium CONS8 were identified by the 16S rDNA analysis. To achieve the highest decolorization, the artificial bacterial consortium MMP1 comprising Klebsiella oxytoca, Serratia mercescens (T2) and unknown bacterium DQ817737 (T4), was constructed. Under optimized conditions (aeration, pH), the bacterial consortium MMP1 was able to decolorize the synthetic melanoidins-containing wastewater at 18.3% within 2 days. The comparison of decolorization by the consortium MMP1 with abiotic control proved that the color removal for synthetic melanoidins-containing wastewater medium was mainly due to biotic activity of bacterial cells, without any adsorption phenomena. Supplement of nutrients and vitamin B did not promote melanoidins decolorization by bacterial consortium MMP1. Finally, the performance of a membrane bioreactor (MBR) for synthetic melanoidins-containing wastewater treatment was investigated at laboratory scale, with a mineral membrane. The reactor seeding was made with the MMP1 bacterial consortium inoculum. The reactor was performed with several hydraulic retention times (HRT) of 15, 20, and 40 hours. The performances were analyzed in terms of COD, color removal and biomass in the reactor. The results indicated that the higher COD and color removal efficiency were achieved with the longer HRT.
13

Influence of cane molasses inclusion to dairy cow diets during the transition period on rumen epithelial development and a proposed mechanism of rumen epithelial development

Miller, William Frederick January 1900 (has links)
Doctor of Philosophy / Department of Animal Sciences and Industry / Bradley J. Johnson / Research regarding rumen epithelial adaptation and potential mechanisms during the transition period of the dairy cow is lacking. The rumen epithelium has a tremendous capacity for the absorption of volatile fatty acids (VFA) produced from microbial fermentation in the rumen. Absorption of VFA from the rumen pool delivers energy substrates to the animal and provides stability to the rumen environment. Increased epithelial surface area from the development and adaptation of rumen papillae facilitates VFA absorption. Manipulation of the diet to alter rumen fermentation can have positive effects upon the rumen papillae development supporting VFA absorption. We hypothesized that enhancing rumen epithelial surface area through dietary alterations could lead to greater VFA absorption and improve rumen stability. Experiments were conducted to determine the effects of diets formulated with cane molasses to stimulate the production of ruminal butyrate and thereby increase rumen epithelial surface area and to investigate a potential mechanism for glucagon-like peptide-2 (GLP-2) to impact epithelial development. Feeding cane molasses in the dry period improved dry matter intake during the close-up period and during lactation. Milk production was increased for cows that were fed cane molasses during the dry period. Ruminal absorption of valerate was greater during the close-up period than the far-off period but was not influenced by the addition of cane molasses. Total VFA concentration measured during the dry period was not affected by the addition of cane molasses to the diet. The presence of glucagon-like peptide receptor (GLP-2R) mRNA was confirmed in bovine tissue obtained from rumen epithelium, omasum, abomasum, duodenum, jejunum, ileum, large intestine, and pancreas. The greatest level of expression of mRNA for GLP-2R was in the small intestine and large intestine. Expression of GLP-2R mRNA during the prepartum period tended to be increased with the addition of cane molasses. Postpartum expression of GLP-2R was not increased by supplementing cane molasses in the dry cow diet. Results from these experiments indicate that dry cow diets formulated to contain cane molasses can positively influence transition cow performance and that the presence of glucagonlike peptide-2 receptor could play a pivotal role in rumen epithelial development.
14

Effect of sugar supplementation in lactating dairy cows

Vargas Rodriguez, Claudio Fabian January 1900 (has links)
Master of Science / Department of Animal Science and Industry / Barry Bradford / During the past decades, the dairy industry has been challenged to find alternative approaches in order to feed cows without affecting their performance or increasing production costs. To accomplish these objectives, some options that have been implemented are the inclusion of short chain carbohydrates to replace starch and the addition of synthetic supplements to increase feed efficiency. In order to assess the impact of these strategies, an experiment was conducted to evaluate productive responses of lactating dairy cattle when they received sucrose and/or exogenous amylase in low starch diets. The results indicated that milk production, milk component profile, and feed efficiency were not significantly altered by the use of the enzyme, sucrose inclusion, or the combination of both. Comparing these results with the literature revealed apparent inconsistencies in responses to the inclusion of sugar in dairy rations. For that reason, a meta-analysis was performed to determine the impact of different sugar sources on milk production, and also to evaluate the impact of other dietary factors on response to dietary sugar. The results indicated that dry matter intake responses were significantly (P < 0.05) affected by an interaction between added sugar and dietary forage neutral detergent fiber content, but overall, dry matter intake tended to increase when sugar replaced corn grain in diets. Energy corrected milk was not affected by dietary sugar, but milk production showed a tendency to respond to treatment, dependent on an interaction between added sugar and rumen undegradable protein. In summary, sugar inclusion may promote small increases in dry matter intake, but the impact on milk production is inconsistent; both factors may be influenced by the diet to which sugar is added.
15

Scale Up Of Panel Photobioreactors For Hydrogen Production By Pns Bacteria

Avcioglu, Sevler Gokce 01 September 2010 (has links) (PDF)
Production of hydrogen from biomass through the use of dark and photofermentative bacteria will be applicable in the future and a promising route. The aim of this study is to develop and to scale-up solar panel photobioreactors for the biological hydrogen production by photosynthetic purple non sulfur (PNS) bacteria on artificial substrates and on real dark fermentation effluent of molasses. The parameters studied are light intensity, temperature, feed stock, feed rate, pH, cell density, light and dark cycle and carbon to nitrogen ratio on hydrogen production. Continuous hydrogen production has been achieved on artificial medium and dark fermentor effluent of molasses containing acetate and lactate by Rhodobacter capsulatus wild type and (hup-) mutant strains in panel photobioreactors in indoor and outdoor conditions by fed batch operation. Laboratory (from 4 to 8 liters) and large scale (20 L) panel photobioreactors by using various designs and construction materials were developed. In this photobioreactors continuous hydrogen production was achieved by feeding. Na2CO3 can be used as buffer to keep the pH stable during long term operation on molasses dark fermentor effluent. The adjustment of the feedstock by dilution and buffer addition were found to be essential for the long term stability of pH, biomass and H2 production for both in indoor and outdoor applications.
16

Produção do bioaroma acetoína a partir de hidrolisado de melaço por bactérias do gênero bacillus isolados do sedimento de mangue

CORREIA, Jackelline Larissa Albuquerque 09 December 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-06-21T15:01:16Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação versão final.pdf: 2119371 bytes, checksum: 450a30d2e9d1d1f7c89323a179ac7bea (MD5) / Made available in DSpace on 2016-06-21T15:01:16Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação versão final.pdf: 2119371 bytes, checksum: 450a30d2e9d1d1f7c89323a179ac7bea (MD5) Previous issue date: 2015-12-09 / CAPEs / A aplicação de processos biotecnológicos para a produção de aromas alimentares tem apresentado um crescimento bastante significativo, já que esses aromas são classificados como aromas naturais. Acetoína (3-hidroxi 2-butanona ou metil carbinol acetil) é uma sustância volátil bastante utilizada em produtos alimentícios, com a finalidade de intensificar o sabor e o aroma dos alimentos, deixando-os mais atrativos aos consumidores. Este trabalho tem como objetivo produzir o bioaroma acetoína por via bioquímica a partir de hidrolisado de melaço utilizando as bactérias do gênero Bacillus isoladas do sedimento de mangue da Lagoa do Araçá (Recife-PE). Foi possível identificar nove espécies desse gênero (B.alvei, B. badius, B. circulans “A”, B. circulans “B”, B. coagulans, B. larvae, B. licheniformis, B. polymyxa, B. popilliae e B.subtilis.) sendo cinco espécies (B. subtilis, B. licheniformis, B. polymyxa, B. alvei e B. coagulans)produtoras do bioaroma acetoína. Foi realizado um planejamento fatorial 23com as variáveis independentes: agitação (0 rpm a 200 rpm), pH (6,5 a 8,5), concentração de melaço (60 g·L-1 a 100 g·L-1) e como variáveis dependentes a conversão de substrato em produto por três bactérias (Bacillus licheniformis, Bacillus alvei e Bacillus polymyxa).Com esse estudo foi possível observar que a agitação foi a principal variável que afetou os três processos de conversão de substrato em acetoína e que a interação do pH com agitação mostrou-se bastante significativo favorecendo essa conversão com os três micro-organimos. Os Bacillus licheniformis foi a bactéria queapresentou maior percentual de YP/S (52,88%) com pH 6,5, agitação de 200 rpm e concentração de melaço de 100 g·L-1. A partir deste resultado foi realizado um estudo cinético em reator batelada de 3L, do tipo tanque agitado, com sistema de aeração. O processo foi acompanhado por determinação de açúcares redutores totais (ART), biomassa (Peso seco), produto (Cromatografia Gasosa). A síntese bioquímica foi interrompida em 144 horas com consumo de 54% dos açúcares. No final do processo a concentração de açúcar residual estabilizou-se em 23,44 g·L-1 e a produção máxima de acetoína foi de 16,11 g·L-1. A produtividade de acetoína foi Pv = 0,11 g·L-1·h. A velocidade específica máxima de crescimento do B. licheniformis foi μmáx = 0,025 h-1. Os coeficientes de conversão de substrato em células e substrato em produto foram respectivamente: YX/S = 0,1 g/g e YP/S = 0,58 g/g. Com esse estudo pode-se concluir que a produção de bioaromas, utilizando hidrolisado de melaço por Bacillus pode ser uma alternativa de produção para gerar produtos com baixo custo e alto valor agregado. / The application of biotechnological processes for producing flavoring aromas has shown a significant growth, since these are classified as natural flavors. Acetoin (3-hidroxi 2- butanone or acetyl methyl carbinol) is a volatile substance widely used in food products, in order to intensify the taste and flavor of food, making it more atractive for consumers. This work aims to biochemically produce acetoin aroma from hydrolyzate of molasses,using the bacterias of bacillus genus isolated of the sediment mangrove of the Araçá lagoon (Recife-PE). It was possible to identify nine species of this genus (B.alvei, B. badius, B. circulans “A”, B. circulans “B”, B. coagulans, B. larvae, B. licheniformis, B. polymyxa, B. popilliaee B.subtilis.), but only five among these (B. subtilis, B. licheniformis, B. polymyxa, B. alvei e B. coagulans) are able to produce the acetoin bioaroma. It’s made a factorial planning 23with the independent variables: agitation (0 rpm to 200 rpm), pH (6.5 to 8.5), molasses concentration (60 g·L-1 a 100 g·L-1) and as independent variables the conversion of substrate in product for three bacteria(Bacillus licheniformis, Bacillus alvei e Bacillus polymyxa).With this study, it was possible to notice that the agitation was the main variable to affect the three processes of conversion of substrate into acetoin, and also that the pH interaction along with the agitation has been proven very significant, contributing to this conversion with the three microorganisms. B.licheniformis was the bacteria that showed the highest percentage of YP/S (52.88%) with pH 6.5, agitation of 200 rpm and molasses concentration of 100 g·L-1. Using these results, a kinetic study was performe batch reactor a three-liter, busy type tank with aeration system.The process was accompanied by determination of total reducing sugars (ART), biomass (dry weight), product (gaseous chromatography). The biochemical synthesis was interrupte dater 144 hours, with consumption of 54% of sugars. At the end of the process, the concentration of residual sugar stabilized in 23.44 g·L-1and the maximum production of acetoin was 16.11 g·L-1. The productivity of acetoin was Pv = 0.11 g·L-1·h. The maximum specific speed of increase of B. licheniformis was μmax = 0.025 h-1. The substrate conversion coefficients in cells and substrate in product respectively were: YX/S = 0.1 g/g and YP/S = 0.58 g/g. With this study, it can be understood that the bio-aroma production using hydrolyzate of molasses by Bacillus licheniformis can be an alternative way to generate products with low cost and high aggregate value.
17

Fitoplâncton e protozooplâncton em viveiros de cultivo de camarão

Teixeira, Priscila da Fonseca January 2011 (has links)
Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2011 / Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-12-16T03:06:44Z No. of bitstreams: 1 Priscila da Fonseca Teixeira.pdf: 335923 bytes, checksum: 69841da63959745c00a7a0e8b7859194 (MD5) / Approved for entry into archive by Sabrina Andrade (sabrinabeatriz@ibest.com.br) on 2013-12-18T18:10:59Z (GMT) No. of bitstreams: 1 Priscila da Fonseca Teixeira.pdf: 335923 bytes, checksum: 69841da63959745c00a7a0e8b7859194 (MD5) / Made available in DSpace on 2013-12-18T18:10:59Z (GMT). No. of bitstreams: 1 Priscila da Fonseca Teixeira.pdf: 335923 bytes, checksum: 69841da63959745c00a7a0e8b7859194 (MD5) Previous issue date: 2011 / Na aqüicultura, o sistema sem trocas de água é eficiente e sustentável, permite manejar o balanço entre carbono e nitrogênio, e o desenvolvimento de microorganismos que contribuem na boa qualidade da água, alimentação e sobrevivência do organismo alvo do cultivo. No presente estudo, a composição e densidade de fitoplâncton e protozooplâncton em conjunto com variáveis físico-químicas foram avaliados em viveiros de cultivo de camarão Litopenaeus vannamei (Boone) em sistema sem troca de água em dois tratamentos, com e sem a adição de melaço como fertilizante de carbono. As amostras de água foram coletadas por um período de 70 dias (janeiro a abril de 2009) e os tratamentos apresentaram diferença significativa para o teor dos nutrientes fosfato, silicato e clorofila <20 μm. A clorofila foi dominada pela fração <20μm (>80%) nos dois tratamentos e alcançou os maiores valores (~400 μg L-1) no final do experimento. No viveiro com melaço houve um maior crescimento de cianobactérias filamentosas (Pseudoanabaena spp. e Spirulina sp.), de diatomáceas especialmente Pleurosigma sp. e de ciliados, além da presença de Oxyrrhis marina Dujardin e de Anabaena sp.. No viveiro sem melaço os flagelados e dinoflagelados, especialmente Protoperidinium sp. e outros da ordem Peridiniales foram mais freqüentes e abundantes. Em ambos os tratamentos foi observada uma alta densidade de cianobactérias cocóides e de dinoflagelados (Gymnodiniales e Gyrodinium sp.). Apesar de não terem sido encontradas diferenças estatísticas entre os tratamentos, ficaram claras tendências distintas de composição e densidade do fitoplâncton e protozooplâncton entre os viveiros, indicando a influência da adição de melaço. / In aquaculture the zero water exchange system is efficient, sustainable, and allows the management to balance the carbon and nitrogen compounds through the development of microorganisms contributing to good water quality, feeding and survival of the target organism. In this study, the composition and density phytoplankton and protozooplâncton together with physical and chemical variables were evaluated in shrimp ponds (Litopenaeus vannamei Boone) without water exchange in two treatments with and without the addition of molasses as carbon fertilizer. Water samples were collected during 70 days (January- April 2009). The treatments differed significantly in dissolved inorganic phosphate, silicate and chlorophyll <20 μm. Chlorophyll, dominated by the fraction <20 μm (> 80%), reached the highest values (~400 μg L-1) at the end of the experiment in both treatments. In the pond with molasses, the filamentous cyanobacteria (Pseudoanabaena spp., Spirulina sp.), the diatom Pleurosigma sp. and ciliates reached highest density and the dinoflagellate Oxyrrhis marina Dujardin and the cyanobacteria Anabaena sp. were present. In the pond without molasses, flagellates, and dinoflagellates Protoperidinium sp. and other Peridiniales were more frequent and abundant. In both treatments coccoid cyanobacteria and dinoflagellates (Gyrodinium sp. and other Gymnodiniales) were abundant. Although the differences were not statistically significant, the composition and abundance of phytoplankton and protozooplankton differed over time in both treatments, indicating the influence of the molasses addition.
18

Bakteriell Cellulosa-tillverkning från Melass genom Kombucha-fermentering / Production of Bacterial Cellulose from Molasses by Kombucha Fermentation

Engström, Adina January 2019 (has links)
As the global plastic consumption is increasing, an innovative substitute for petroleum-based product must be developed towards a more sustainable society. Cellulose is the most abundant biopolymer on earth having potential because of its biodegradability and is produced from renewable resources. However, purification of plant cellulose is costly and limit the application development where bacterial cellulose have gained more focus. Bacterial cellulose can be obtained as a by-product from Kombucha fermentation on commercial sugars such as sucrose. Replacing commercial sugars with molasses, a by-product from the sugarcane industry, as a substrate could be a low-cost alternative. The purpose of the study is to investigate and evaluate the properties of bacterial cellulose obtained from Kombucha microorganisms fermented in molasses medium using different fermenting conditions. Biofilms containing bacterial cellulose were obtained by fermenting with three types of molasses inoculated with two types of Kombucha cultures. Two of the three molasses used came from PT. Andalan Furnindo in Indonesia from two different sugar production batches and one type from Nordic Sugar AB in Sweden. The culture was obtained from previously fermented Kombucha, one from Tujju Kombucha, Indonesia and one from Roots AB, Sweden. Fermentation was carried out with one of the molasses from PT. Andalan Furnindo together with coffee waste, containing different concentrations of the substrates. The obtained biofilms were compared to biofilms produced with the ingredients of a conventional Kombucha setup. The other molasses from PT. Andalan Furnindo was fermented with or without the addition of pure caffeine, using culture with adapted microorganisms. Obtained films were either dried under pressure, without pressure in oven or purified with 1 M NaOH and air-dried. Optimum fermentation conditions with the molasses from Nordic Sugar AB were analysed. Regarding the fermentation with molasses from PT. Andalan Furnindo and coffee waste, the highest yield of biomass after fermentation could be seen in the system containing the highest amount of total sugars (100 g/l) and highest amount of caffeine deriving from coffee waste (200 mg/l). However, the membrane produced from conventional Kombucha exhibited a more flexible character, having superior elongation at break, stretching 46 % more than the sample produced in molasses medium. Using culture with adapted microorganisms in the fermentation with molasses from PT. Andalan Furnindo proved to increase the biomass yield with roughly 40 % compared to the biofilms produced without adapted microorganisms, but no effect of higher caffeine concentration was detected for the setups. All biofilms obtained from fermenting with adapted culture possessed superior mechanical-thermal properties. The highest elongation at break of 48.7 % was observed for the sample dried under normal conditions and the highest tensile strength was observed for the purified samples of 43.5 MPa. Furthermore, the purified samples possessed a higher thermal stability and had the highest cellulose content of 64 %. Adaptation was vital to obtain any bacterial cellulose fermenting in medium containing molasses from Nordic Sugar AB.
19

Molasses as a possible cause of "endocrine disruptive syndrome" in cattle

Masgoret Cuellar, Maria Sol 06 November 2007 (has links)
The objective of this study was to evaluate the suspected endocrine disruptive effect of molasses included in cattle feed. During the mid 1990's a potentially serious, chronic syndrome was reported in well-managed beef and dairy herds from unrelated parts of South Africa. Farmers reported that it manifested as various combinations of seriously decreased production, increased reproductive disorders, apparent immune incompetence in previously immune competent animals, various mineral imbalances in non¬deficient areas and goitre, perceptible by enlarged thyroids. Farmers related this syndrome to certain batches of sugarcane molasses and molasses¬based products. Their opinion was based on observations that dramatic improvements in health and productivity often followed the withdrawal of the molasses component of the diet. The syndrome had all the characteristics of an "endocrine disruptive syndrome". Endocrine disrupting compounds (EDCs) are exogenous substances that have the potential to alter the functions of the endocrine system and consequently cause ill health. The EDCs comprise a diverse group of compounds that are widely used in detergents, in the paint and plastics industries and as wetting agents in agricultural remedies. Contamination of molasses with these compounds could occur as a result of uptake of chemicals by growing sugarcane or by the use of contaminated river water in the extraction of sugar from chopped sugarcane. It was essential to investigate the safety of molasses, currently available as stock feed in South Africa and the rest of the world, to allay any fears created by the farmers. Four batches of molasses previously collected from four different sugar mills located in different parts of the country were screened for potential endocrine disruptive activity, including oestrogen and thyroid activity and immune suppression. Two batches of molasses were selected to be used in a calf feeding trial. Thirty-two, 4 to 6 week-old Holstein bull calves of approximately the same weight, and supplied by the same rearing facility, were included in a single phase, three treatment, parallel design experiment. Calves from the three experimental groups were housed in the same facilities, under the same conditions and fed diets with similar composition. Two of the groups had molasses (Umzimkulu and Komatipoort) included in their rations and the control group was fed a ration where no molasses was added, but fermentable sugars and minerals were included. The weight gain of the calves was recorded over a six-month study period. Regular clinical examinations were conducted and clinical pathology parameters, immune responses and endocrine effects were evaluated. Even though endocrine disrupting effects were detected in in vitro screening tests, these could not be reproduced in calves under experimental conditions. The two batches of molasses utilized in the calf feeding trial did not induce major differences in any of the parameters measured, except a lower weight gain in the Umzimkulu molasses fed group which tended towards significance. It appears improbable that these two batches of molasses had any endocrine disruptive or immunosuppressive effects. Therefore, these two batches of molasses per se were not deleterious when fed to calves. / Dissertation (MSc (Veterinary Sciences))--University of Pretoria, 2006. / Paraclinical Sciences / unrestricted
20

The production of oxalic, citric, and gluconic acids from plantation molasses

Ruth, John A. 01 January 1934 (has links)
This research was undertaken for the purpose of developing a process for producing citric and gluconic acids from plantation molasses. There is an evident need for such a process. At the present time, these acids are being produced by processes in which refined sugar is the principal raw material. If molasses could be used in place of refined sugar, the cost of raw materials would be reduced by approximately ninety percent. In addition, a waste product would be utilized. The scope of this problem is very broad. Its solution will involve the solving of many problems of widely varying natures. In this work it is the aim of the writer to survey the entire field, touching lightly on each of its various phases, rather than to attempt to work out the complete solution of any particular phase of the problem. Since this is the initial research such a course of action seems prudent. It would be useless to solve one phase of the problem without making certain that some other one does not present a serious barrier to the process as a whole. Also, it is only by doing this survey work that the relative importance of the various problems can be determined. In order that he may be acquainted with the economic aspects of the problem, the reader should have some knowledge of the uses of the acids to be produced. The uses of citric acid are well known and need not be discussed here. Gluconic acid, however, has only recently become of any commercial importance. A brief discussion of some of its possible uses will be in order. Many of the uses of gluconic acid are based on its ability to form inner anhydrides, known as lactones, which will regenerate gluconic acid when dissolved in water. The rate of formation of the acid from the lactone may be controlled within certain limits by varying the conditions of temperature and concentration. This property makes it desirable to use gluconic lactone in fruit powders for jelly making, in baking powders, in the manufacture of cell concrete and insulating brick, and, in short, wherever the slow and controllable formation of an acid is wanted. Gluconates are used in the preparation of homogeneous pastes such as dentifrices. Calcium and magnesium gluconates are quite satisfactory polishing agents. The gluconate is the most satisfactory calcium salt for use in medicine, being assimilable, practically tasteless, and non-irritating to tissues. It may be administered by the mouth or by subcutaneous injection. A colloidal suspension of hydrated aluminum oxide in gluconic acid finds use in tanning, furnishing a white, flexible, and durable leather, which is not leached out or stiffened by prolonged treatment with hot water.

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