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.

Made available in DSpace on 2015-03-26T13:55:22Z (GMT). No. of bitstreams: 1 texto completo.pdf: 379133 bytes, checksum: 4d3ccf481d9a605e1a1405e097dec6c9 (MD5) Previous issue date: 2013-12-04 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study was conducted to evaluate the use of sugarcane silage or traditional forage sources (corn silage or fresh sugarcane) on intake and milk production of Holstein cows. Twenty five Holstein cows were used, with an average initial body weight of 600 kg, the trial was implemented as a randomized block design with 5 blocks, 5 experimental periods lasting 14 days and 5 treatments each, in a repeated measurements scheme. The treatments were given corn silage (SM), fresh sugarcane, unadulterated sugarcane silage, sugarcane silage with Lactobacillus plantarum and Pediococcus pentosaceus (2.5 × 1010 CFU / g forage) and sugarcane silage with Propionibacterium acidipropionici + sucrase + cellulase (5 × 109 CFU / g of forage). The forage:concentrate ratio was 60:40, in the dry matter (DM) basis, for treatment based on corn silage and 40:60 for the treatments based on sugarcane. Similarities regarding consumption of (kg / day) of DM, organic matter (OM) was observed among SM and sugarcane treatments. A lower consumption (kg / day) of crude protein (CP), non fibrous carbohydrates (NFC) and total digestible nutrients (TDN) and lower digestibility of DM, OM, CP , NFC and TDN for corn silage treatment compared to the other sugarcane based diets. The production of milk, protein, fat, lactose, dry nonfat extract were similar among all treatments. However, it was observed that milk production based on pure sugarcane was higher compared to treatments based on sugarcane silage. The average daily gain (ADG) was similar among treatments based on SM compared with treatments based on sugarcane. It is concluded that diets based on sugarcane silage with forage:concentrate ratio of 40:60 in DM, provide milk production of up to 20 kg/day and an ADG of up to 650 g/day. / Este trabalho foi conduzido com o objetivo de avaliar o uso da silagem de cana-de-açúcar ou fontes tradicionais de volumosos (silagem de milho ou cana-de-açúcar in natura) sobre o consumo e a produção de leite de vacas holandesas. Foram utilizadas 25 vacas da raça Holandesa, com peso médio inicial de 600 kg e adotado o delineamento em blocos casualizados, com cinco blocos, cinco períodos com duração de 14 dias e cinco tratamentos, em esquema de medidas repetidas no tempo. As dietas à base de silagem de milho (SM), cana-de-açúcar in natura, silagem de cana-de-açúcar sem aditivo, silagem de cana-de-açúcar com Lactobacillus plantarum + Pediococcus pentosaceus (2,5 × 1010 UFC/g de forragem) e silagem de cana-de-açúcar com Propionibacterium acidipropionici + sacarase + celulase (5 × 109 UFC/g de forragem). A relação volumoso: concentrado foi de 60:40 na matéria seca (MS) para a dieta à base de silagem de milho e de 40:60 para dietas à base de cana-de-açúcar in natura ou ensilada. Observou-se consumo (kg/dia) de MS e matéria orgânica (MO) semelhante entre os tratamentos à base de SM e aqueles à base de cana-de-açúcar. Verificou-se menor consumo (kg/dia) de proteína bruta (PB), carboidratos não fibrosos (CNF) e nutrientes digestíveis totais (NDT) e menores digestibilidade da MS, MO, PB, CNF e NDT para a dieta à base de silagem de milho em relação às dietas à base de cana-de-açúcar. A produção de leite, e os teores de proteína, gordura, lactose e extrato seco desengordurado foram semelhantes entre os tratamentos à base de SM em comparação com os tratamentos à base de cana-de-açúcar. No entanto, verificou-se que a produção de leite do tratamento à base de cana in natura foi maior, comparada com a dos tratamentos à base de silagem de cana-de-açúcar. O ganho médio diário (GMD) foi semelhante entre os tratamentos à base de SM em comparação com os tratamentos à base de cana-de-açúcar. Conclui-se que dietas à base de cana-de-açúcar ensilada, com relação volumoso: concentrado de 40:60 na MS, proporcionam produção de até 20 kg de leite /dia, além de um ganho medio diario de até 650 g/dia.

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.

This study is concerned with the regulation of Lasparaginase (LA) in the cell-free crude extracts from Lactobacillus plantarum (ATCC8014). A previously reported finding that adenosine triphosphate (ATP) inhibits the action of LA in crude extracts was confirmed. The study was extended to include the mono-, di-, and triphosphates of adenosine, guanosine, cytidine, and uridine. These compounds were also shown to inhibit LA activity. These andother studies revealed that LA appears to be an allosteric type enzyme exhibiting positive homotropism with respect to substrate and heterotropism with respect to the nucleotides tested. The regulation of LA activity by high energy compounds, when coupled with asparagine synthetaseL suggests a relationship between amide synthesis-amide degradation and the energy levels of the cell.

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).