This study is concerned with the metabolism of L-asparagine in Lactobacillus plantarum (ATCC 8014). Theprimary area of investigation is the preliminary characterization of a previously unreported L-asparaginase enzyme in L. plantarum. This L-asparaginase was determined to be an inducible enzyme with variations in its activity level according to the L-asparagine level in the growth medium. L-Glutaminase could not be induced in this organism by L-glutamine, nor would L-glutamine induce the asparaginase activity. These and other studies with amino acid analogs demonstrated the high specificity of both induction and enzymic activity of the asparaginase. Various physical properties of the enzyme were studied. The enzyme was found to be inhibited by adenosine triphosphate (ATP). This inhibition appears to be cooperative in nature and of the type exhibited by allosteric enzymes. These studies should be confirmed on a highly purified enzyme as these preliminary experiments were performed using a crude cell-free extract.

Graduation date: 1993

Diss. (sammanfattning) Göteborg : Göteborgs universitet. / Härtill 4 uppsatser.

No description available.

This investigation concerned determining certain factors which affect the activity of cyclopropane synthetase in L. plantarum. In vitro experiments showed the enzme to be sensitive to ionic strength and subject to product inhibition by S-adenosylhomocysteine nucleusidase, which relieves this inhibition by degrading SAH to adenine and ribosylhomocysteine.

Salmonellosis is a foodborne disease, poultry and poultry products are the main source of the disease. Many countries including Iraq still use antibiotics to control Salmonella. The increase in antibiotic resistant bacteria putatively caused by the overuse of antibiotics in agriculture has provided the incentive to look for alterna-tives to antibiotic to control diseases in livestock. Lactic acid bacteria with probiotic characteristics have the potential to beneficially affect the gut microflora of chick-ens and help reduce the incidence of Salmonella infection. In this study, Lactobacillus plantarum NCIMB 41607 was examined in vitro for in-hibitory effects against Salmonella and in vivo for its effects on the gut microflora and on the incidence of Salmonella infection. In separate studies Lb. plantarum was administered to chicks as fermented moist feed (containing 175 mmol/L lactic acid and 1x109 CFU/g of Lb. plantarum), in drinking water or applied to dry feed. Rifampicin resistance was used as a biomarker for the Lb. plantarum NCIMB 41607. Traditional and molecular microbiology including DGGE, RISA, and FISH were used with electron microscopy to assess the effect of Lb. plantarum on bac-terial population in the digestive system of chicks. Lactobacillus plantarum (NCIMB 41607) was found to reduce the growth of Salmonella Typhimurium and Salmonella Enteritidis by 4 Log CFU/g in a chicken simulated digestive system in vitro. The presence of rifampicine resistant Lactobacillus plantarum in the gut was con-firmed by replica plating and fluorescent in situ hybridisation with a strain specific probe. In general, the bacterial population in the guts of chicks fed Lactobacillus plantarum was more diverse in the guts of chicks fed control feed. There was no significant effect on Salmonella infection in Ross chicks compared with control. However, with specific pathogen free chicks the Salmonella infection was reduced. The intestinal villi lengths in FMF group were increased. These studies demonstrate that probiotics can affect the microflora in the chicken gut. Lactobacillus plantarum NCIMB 41607 may have the potential to control of Salmonella Typhimurium infection in chicken and continued research is advised.

That Lactobacillus arabinosus 17-5, ATCC 8014, can supply its own requirement for the amino acid, lysine, is demonstrated by the fact that the organism is capable of growth in media devoid of lysine. Since the final biosynthetic step in lysine formation in all bacteria studied to date involves the decarboxylation of meso-dlaminopimelic acid (DAP) to produce lysine, it was of interest to determine whether an enzyme catalyzing such a reaction (DAP decarboxylase) is present in L. arabinosus.

Thesis (Ph. D)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xvi, 196 p.: ill. Includes abstract and vita. Advisor: Herbert W. Ockerman, Dept. of Animal Science. Includes bibliographical references (p. 185-196).

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Aquicultura, Florianópolis, 2011 / Made available in DSpace on 2012-10-26T04:18:02Z (GMT). No. of bitstreams: 1 294815.pdf: 393747 bytes, checksum: 54fd2a5da055c3d8d5184275a8d7caa8 (MD5) / O objetivo deste trabalho foi avaliar o uso de prebiótico (inulina), probiótico (Lactobacillus plantarum) e simbiótico (Lactobacillus plantarum + inulina) no crescimento, microbiota intestinal, reposta imune e resistência ao desafio experimental com Vibrio alginolyticus em camarões Litopenaeus vannamei. A concentração de Vibrio spp. no trato digestório foi significativamente menor em camarões alimentados com dieta suplementada com prebiótico, probiótico e simbiótico, enquanto que a concentração de bactérias ácido lácticas foi significativamente superior somente nos camarões alimentados com probiótico e simbiótico. O valor aglutinante do soro frente à Vibrio alginolyticus foi significativamente maior no grupo probiótico e simbiótico antes da infecção, e maior em todos os tratamentos após infecção em relação ao controle. O número de hemócitos, a atividade da fenolixidase e a atividade antibacteriana do soro dos camarões não apresentaram diferenças significativas nos tratamentos comparados com o controle. Igualmente, não houve diferença no crescimento ou na sobrevivência dos camarões ao desafio por V. alginolyticus. Conclui-se que dietas probióticas, prebióticas e simbióticas, alteram a microbiota intestinal aumentando o título aglutinante do soro contra V. alginolyticus, contudo sem alterar o crescimento dos camarões ou a sobrevivência ao desafio por V. alginolyticus.

1. Ištirtos registruotos Lactobacillus plantarum U-14, kuri išskirta iš sveikos karvės makšties ir Lactobacillus fermentum U-5, kuri išskirta iš sveiko veršelių fekalijų, padermės, nustatytos jų optimalios kultivavimo temperatūros, įvertintos jų probiotinės savybės, nustatytas antagonistinis aktyvumas, atsparumas antibiotikams bei įvertinta liofilizacijos įtaka šioms laktobacilų padermėms. 2. Liofilizacijos būdu pagamintas probiotikas, sudarytas iš Lactobacillus plantarum U-14 ir Lactobacillus fermentum U-5 padermių, nustatytas laktobacilų gyvybingumas preparate laikant vienus metus +4oC temperatūroje. 3. Nustatyta probiotiko profilaktinė dozė naujagimiams veršeliams girdant su krekenomis arba pienu pirmas 10 gyvenimo dienų, stebint veršelių klinikinius požymius, įvertinant paros priesvorį, įtaką bendram enterobakterijų ir laktobacilų kiekiui bei nustatant laktobacilų rūšinę sudėtį fekalijose įvertinant kraujo morfologinius ir biocheminius parametrus.4. Nustatyta probiotiko profilaktinė dozė veršeliams, kuri buvo – 4g/d. ir ji palyginta su probiotiko Yeasture profilaktine doze. / 1.The registered strains of Lactobacillus plantarum U-14 isolated from the vagina of healthy cow and Lactobacillus fermentum U-5 isolated from the faeces of healthy calve were studied, the optimal temperature for the cultivation was defined, were evaluated their probiotic properties, the antagonistic activity, resistance to antibiotics and the effect of lyophilization on these strains of lactobacillus were studied. 2.The probiotic preparation, consisting of Lactobacillus plantarum U-14 and Lactobacillus fermentum U-5 strains was produced by the method of lyophilization and the viability of lactobacillus during the period of 1 year storage at +4oC temperature was defined. 3.The preventive dose of probiotic preparation for neonate calves given with colostrum or milk was defined during the first 10 days, the clinical signs of calves, daily weight gain, effect on the total number of enterobacteria and lactobacillus were studied and the lactobacillus species composition in the faeces together evaluating morphological and biochemical indicators of blood was investigated. 4.The defined dose of probiotic preparation for calves was – 4g/d. and it was compared to the preventive dose of the preparation Yeasture.