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Search Results: 1 - 10 of 1739 matches for " bacillus megaterium "
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Characterization of the penicillin G acylase from Bacillus megaterium ATCC 14945
Souza, Vanessa Ribeiro de;Silva, Ana C. G.;Pinotti, Laura Marina;Araújo, Heloísa Sobreiro Selistre;Giordano, Raquel de Lima Camargo;
Brazilian Archives of Biology and Technology , 2005, DOI: 10.1590/S1516-89132005000400013
Abstract: the purpose of this work was to characterize the enzyme penicillin g acylase (pga) produced by bacillus megaterium. purification of the enzyme by ultra/diafiltration did not allow the detection of the pga band by sds-page electrophoresis due to the high content of remaining proteins. however, using the dna of the microorganism, it was possible to replicate the genes of the two b. megaterium pga reported in literature, showing that the enzyme consisted of two sub-units, having 245 and 537 amino acids each and an average molecular mass of 26950 and 59070 da, respectively. the parameters studied were: 1) the influence of temperature in the 25-600c range, 2) ph in the 5-10 range and 3) substrate concentration, this was tested to obtain results on the penicillin g hydrolysis reaction rate, using the initial velocities approach. the maximum hydrolysis rate was obtained at 37oc and ph 8.0. the michaelis-menten model fitted well, resulting in estimated km and vmax parameters values of 1.83 mm and 0.165*10-3 mmol/min/ui, respectively.
Rizobactérias no crescimento e na produtividade da cebola
Harthmann, Oscar Emilio Ludtke;Mógor, átila Francisco;Wordell Filho, Jo?o Américo;Luz, Wilmar Cório da;
Ciência Rural , 2010, DOI: 10.1590/S0103-84782009005000256
Abstract: the association of plants with rhizobacteria can enhance plant growth, reducing production costs. benefic rhizobacteria can stimulate plant growth being an alternative for production of onions. this research assesses the impact of applying rhizobacteria in the growth and productivity of cv. bola precoce onions. the study was conducted in the experimental station of epagri, ituporanga, sc, brazil in 2008. the experimental design was in random blocks with five repetitions using pseudomonas spp. w6, b bacillus megaterium w19 e bacillus cereus ufv40 rhizobacteria, microbiolized singly in seeds or in a formula together with non-treated control. the treatments involving rhizobacteria application yielded higher heights, diameter of pseudo-trunk and number of leaves in the plants assessed at 90 days after transplant. all the plants which received treatments with rhizobacteria presented better results considering the fresh weight and yield of bulb in relation to the control. the mass of bulbs were positively affected by the treatments, especially for bacillus megaterium w19.
Kinetics of Petroleum-Contaminated Soil Biodegraded by An Indigenous Bacteria Bacillus megaterium
BAMBANG YUDONO,MUHAMMAD SAID,SABARUDDIN,ADIPATI NAPOLEON
HAYATI Journal of Biosciences , 2010,
Abstract: Bioremediation of petroleum sludge was conducted by using land-farming method in micro scale and by applying an indigenous bacteria Bacillus megaterium. The samples were from PT. Pertamina Musi Banyuasin district of South Sumatra. The research aim was to evaluate the performance of the bacteria in degrading petroleum sludge. The rate of the biodegradation process was determined by using differential method and the data analyses show that the reaction order is 0.74. Then, the rate of biodegradation constant was determined by using an integral method assuming that the biodegradation process was a first reaction order. From the calculation, it was revealed that the biodegradation reaction constant was 0.0204/day. The bioremediation-kinetics model is y = -0.0204X + 2.0365, and by using this model the bioremediation process could be ended after 99.83 days. The qualitative analysis was carried out by using GC-MS to investigate the components of compounds changed during the bioremediation process. The results show that the B. megaterium could degrade 99.32% of alkane compounds.
STUDIES ON ENZYMATIC SYNTHESIS OF CEPHALEXIN BY IMMOBILIZED PENICILLIN G ACYLASE FROM BACILLUS MEGATERIUM
固定化巨大芽孢杆菌青霉素G酰化酶酶促合成头孢氨苄的研究

Cui Fumian Zhu Lizhao Han Wenzhen Wu Min Wang Zhenxiang,
崔福绵
,朱丽钊,韩文珍,吴敏,王祯祥

微生物学报 , 1996,
Abstract: β—内酰胺系列抗菌素抗菌谱广、疗效高、毒副作用小,国际上研究与应用日渐广泛深入。头孢氨苄(Cephalexin)是重要的半合成抗菌素之一,由头孢霉素母核7—氨基脱乙酰氧基头孢烷酸(简称7-ADCA)和侧链结构物苯甘氨酸或其甲酯(PGME)经酰化而生成。酰化有化学法和酶法两种。采用青霉素G酰化酶或a—氨基酸酯酶或,a—氨酰转移酶的酶法,具有工艺操作简单、无需基团保护、环境污染轻等优点。继日本人于70年代初试验成功酶法之后,80年代初我们开展了这方面研究。制备方面,胞外酶优于胞内酶;使用方面,固定化酶优于固定化细胞。在用具有青霉素G酰化酶活性的固定化大肠杆菌(Escherichia coli)细胞合成头孢氨苄的基础上,又研究了用固定化巨大芽孢杆菌(Bacillus megaterium)BP931胞外青霉素G酰化酶酰化合成头孢氨苄的条件。本文报道这一研究结果。
Bioconversion of cassava starch by-product into Bacillus and related bacteria polyhydroxyalkanoates
Krueger,Cristhiane L; Radetski,Claudemir M; Bendia,Amanda G; Oliveira,Ida M; Castro-Silva,Marcus A; Rambo,Carlos R; Antonio,Regina V; Lima,André O.S.;
Electronic Journal of Biotechnology , 2012,
Abstract: background: unlike petroleum-based synthetic plastics, biodegradable biopolymer generation from industrial residue is a key strategy to reduce costs in the production process, as well as in the waste management, since efficient industrial wastewater treatment could be costly. in this context, the present work describes the prospection and use of bacterial strains capable to bioconvert cassava starch by-product into biodegradable polyhydroxyalkanoates (phas). results: the first step of this study was the bacterial competence screening which was conducted with 72 strains covering 21 bacillus and related species. the microorganism growth in a medium with a starch substrate was measured by an innovative mtt assay, while the ability of the bacteria to secrete amylase and produce pha was evaluated by the nile red dye method. based on growth and potential for pha production, four isolates were selected and identified as bacillus megaterium by 16s rrna sequencing. when cultivated in hydrolyzed cassava starch by-product, maximum production reached 4.97 g dry biomass/l with 29.7% of poly-(3-hydroxybutyrate) (characterized by ftir). conclusions: mtt assay proved to be a reliable methodology for monitoring bacterial growth in insoluble media. selected amylolytic strains could be used as an alternative industrial process for biodegradable plastics production from starchy residues, reducing costs for biodegradable biopolymer production and wastewater treatment operations.
Isolation and Partial Characterization of a Bacteriocin Produced by a Newly Isolated Bacillus megaterium 19 Strain
Rowaida Khalil,Yasser Elbahloul,Fatima Djadouni,Sanaa Omar
Pakistan Journal of Nutrition , 2009,
Abstract: A Bacillus megaterium 19 strain isolated from a mixture of fermented vegetable wastes, produced a bacteriocin that displayed a wide spectrum antimicrobial activity against food-spoilage microorganisms and possessed a bactericidal mode of action. The bacteriocin activity against Salmonella typhimurium and Staphylococcus aureus attained its maximum value during the mid stationary phase. Maximal bacteriocin activity (93% growth reduction) was achieved using MRS broth, at initial pH of 5.5-6.5 and at 30°C incubation temperature. High levels of bacteriocin activity (up to 85% growth reduction) were detected under limited or reduced oxygen levels. The inhibitory activity increased in mMRS broth with 4% sucrose and (0.10%) beef extract. The bacteriocin was thermally stable over a wide temperature range up to 100°C for 15 min and retained its activity at acidic and neutral pH values, but not at alkaline pHs. Full bacteriocin activity was expressed after 30 days of storage at 4°C, for 15 min of exposure to UV light. The bacteriocin was amylase and lipase sensitive, however, treatment with proteolytic enzymes resulted in a remarkable stability. SDS-PAGE analysis of the partially purified bacteriocin revealed an apparent molecular weight ranging from 3.496 to 6.512 kDa. The strain may have a potential use as food biopreservative, because of its promising thermostable technological properties and broad antimicrobial spectrum.
Screening and Evaluation of Antimicrobial Activity of Tannery Fleshing Utilizing Fish Gut Bacteria
C. Sumathi,S. Jayashree,G. Sekaran
International Journal of Pharmacology , 2012,
Abstract: The focal theme of the present investigation is to explore the antimicrobial activity of Tannery Fleshing (TF) utilizing Labeo rohita gut bacteria against common microbial pathogens. The study involves isolation of the bacteria through culture technique, biochemical characterization, Scanning Electron Microscopic and phylogenetic cluster analysis. Antimicrobial activities were determined through agar diffusion technique. Partial 16S-rRNA gene sequencing analysis shows that the isolate exhibited homology with Bacillus megaterium. Among the bacterial pathogens maximum inhibition was observed against Salmonella typhi and Bacillus subtilis when compared to standard antibiotic followed by Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris. Minimum inhibitory effect was observed with Staphylococcus aureus and Pseudomonas aeruginosa. Most susceptible fungal pathogens include Microsporum canis and Aspergillus fumigatus whereas Trichophyton mentagrophytes and Penicillium chrysogenum were least susceptible. Antifungal activity of Bacillus megaterium remained almost similar to standard drug in Fusarium moniliforme, Aspergillus niger, Candida albicans. The in vitro studies indicate that Bacillus megaterium ANFLR1 isolated from Labeo rohita can inactivate pathogenic Gram-positive and Gram-negative bacteria as well as fungi and can be of potential use as an antibiotic and probiotic.
Enterotoxigenic gene profiles of Bacillus cereus and Bacillus megaterium isolates recovered from honey Búsqueda de factores de virulencia en cepas de Bacillus cereus y de Bacillus megaterium aisladas de miel
A. C. López,A. M. Alippi
Revista argentina de microbiolog?-a , 2010,
Abstract: One hundred and thirty two Bacillus cereus and 52 Bacillus megaterium isolates from honeys were evaluated for the presence of genes encoding enterotoxin HBL, enterotoxin-T, cytotoxin K and the NHE complex, respectively. The relationship between hemolytic and coagulase activity and its correlation with the presence of the four mentioned enterotoxins was determined by principal component analysis (PCA). PCA in B. cereus revealed a positive correlation among free coagulase, hemolysis and the presence of genes hblA, hblB, hblC, hblD (HBL complex) and bceT (enterotoxin-T), but no correlation with the clumping factor (bound coagulase) and the presence of sequences of the NHE complex. On the other hand, PCA in B. megaterium showed a high positive correlation between coagulase (bound and free) and the haemolytic activity but no correlation in relation to the presence of genes of the HBL complex, cytotoxin K, enterotoxin T and the NHE complex. To our knowledge, this is the first report of the detection of cytotoxin K and of the NHE complex genes in B. megaterium. The relationship between the coagulase activity and the presence of virulence factors has not been described before in the genus Bacillus, being this work the first report of this correlation. Interestingly, the presence of the cytK gene was almost independent of the presence of the rest of virulence factors herein analyzed both in B. cereus and B. megaterium populations. Our results suggest that honey could be a possible vehicle for foodborne illness due to the presence of toxigenic B. cereus and B. megaterium strains containing different virulence factors. Se evaluaron 132 aislamientos de Bacillus cereus y 52 de Bacillus megaterium provenientes de mieles de distintos orígenes geográficos para investigar la presencia de secuencias de ADN relacionadas con genes de virulencia y su posible correlación con la actividad hemolítica y coagulasa. Con respecto a los genes de virulencia, se analizaron por PCR secuencias de ADN de los genes nhe (A, B y C), HBL (A, B, C, D), cytK y bceT. La relación entre las variables fue evaluada mediante un análisis de componentes principales, donde se encontró que los aislamientos de B. cereus mostraron una correlación positiva entre actividad de coagulasa (coagulasa libre) y presencia de los genes del complejo HBL y bceT, mientras que en B. megaterium se halló una alta correlación positiva entre actividad de coagulasa (libre y fija) y actividad hemolítica, pero no se observó correlación significativa entre la presencia de genes de virulencia y dichas actividades. Este estudio
Antimicrobial Activity Investigation on Wuyiencin Fractions of Different Polarity
Zengjie Cui,Kecheng Zhang,Gaimei She,Yinni Lin,Lei Sun,Yan Cheng,Beibei Tan
Molecules , 2010, DOI: 10.3390/molecules15053179
Abstract: The aim of this study was to evaluate the antimicrobial activity of Wuyiencin fractions with different polarities against six indicator microorganisms: Rhodotorula rubra, Bacillus subtilis, Bacillus megaterium, Escherichia coli, Cladosporium fulvum and Staphylococcus aureus. The fermentation broth of Wuyiencin was submitted to AB-8 macroporous adsorptive resin and fractionated with solvents of different polarity. The fraction eluted with water had remarkably antimicrobial activity against all the microorganisms investigated except for C. fulvum and S. aureus (MIC ≤ 0.0625 mg/mL), probably due to the presence of active components. The fraction eluted with methanol showed potential antimicrobial activity against all the test microorganisms except for R.rubra, with MIC values of0.5 and 2 mg/mL. In conclusion, fractions eluted with water and methanol, respectively, represent the main active-part of Wuyiencin, and could be emphasized for agricultural applications in the future.
Enterotoxigenic gene profiles of Bacillus cereus and Bacillus megaterium isolates recovered from honey
López,A. C.; Alippi,A. M.;
Revista argentina de microbiolog?-a , 2010,
Abstract: one hundred and thirty two bacillus cereus and 52 bacillus megaterium isolates from honeys were evaluated for the presence of genes encoding enterotoxin hbl, enterotoxin-t, cytotoxin k and the nhe complex, respectively. the relationship between hemolytic and coagulase activity and its correlation with the presence of the four mentioned enterotoxins was determined by principal component analysis (pca). pca in b. cereus revealed a positive correlation among free coagulase, hemolysis and the presence of genes hbla, hblb, hblc, hbld (hbl complex) and bcet (enterotoxin-t), but no correlation with the clumping factor (bound coagulase) and the presence of sequences of the nhe complex. on the other hand, pca in b. megaterium showed a high positive correlation between coagulase (bound and free) and the haemolytic activity but no correlation in relation to the presence of genes of the hbl complex, cytotoxin k, enterotoxin t and the nhe complex. to our knowledge, this is the first report of the detection of cytotoxin k and of the nhe complex genes in b. megaterium. the relationship between the coagulase activity and the presence of virulence factors has not been described before in the genus bacillus, being this work the first report of this correlation. interestingly, the presence of the cytk gene was almost independent of the presence of the rest of virulence factors herein analyzed both in b. cereus and b. megaterium populations. our results suggest that honey could be a possible vehicle for foodborne illness due to the presence of toxigenic b. cereus and b. megaterium strains containing different virulence factors.
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