Prime time for Bacillus megaterium

Vary, Patricia S.

doi:10.1099/13500872-140-5-1001

Cited by 164 publications

(95 citation statements)

References 11 publications

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“…Thus, we looked for recA and its function in DNA repair in Bacillus megaterium. Interestingly, this biotechnologically relevant species (Vary, 1994) has been reported to resist DNA damage much more efficiently than B. subtilis (English & Vary, 1986). As a result of our work, B. megaterium -unlike several other Bacillus species -was found to harbour two recA genes, both being damage-inducible and functional in DNA repair.…”

Section: Introductionmentioning

confidence: 54%

Evidence for two recA genes mediating DNA repair in Bacillus megaterium

2005

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Isolation and subsequent knockout of a recA-homologous gene in Bacillus megaterium DSM 319 resulted in a mutant displaying increased sensitivity to mitomycin C. However, this mutant did not exhibit UV hypersensitivity, a finding which eventually led to identification of a second functional recA gene. Evidence for recA duplicates was also obtained for two other B. megaterium strains. In agreement with potential DinR boxes located within their promoter regions, expression of both genes (recA1 and recA2) was found to be damage-inducible. Transcription from the recA2 promoter was significantly higher than that of recA1. Since a recA2 knockout could not be achieved, functional complementation studies were performed in Escherichia coli. Heterologous expression in a RecA null mutant resulted in increased survival after UV irradiation and mitomycin C treatment, proving both recA gene products to be functional in DNA repair. Thus, there is evidence for an SOS-like pathway in B. megaterium that differs from that of Bacillus subtilis.

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Section: Introductionmentioning

confidence: 54%

Evidence for two recA genes mediating DNA repair in Bacillus megaterium

2005

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“…The gram-positive bacterium Bacillus megaterium is of great industrial interest because of its production of vitamin B 12 , several useful enzymes, and fungal antibiotics (46). It is an excellent cloning host because of its nonpathogenicity, its secretion of proteins, the absence of alkaline proteases, its ability to stably maintain plasmids, and its ability to produce intact, functional proteins (24,36,39,46,47).…”

mentioning

confidence: 99%

“…It is an excellent cloning host because of its nonpathogenicity, its secretion of proteins, the absence of alkaline proteases, its ability to stably maintain plasmids, and its ability to produce intact, functional proteins (24,36,39,46,47). Our laboratory is interested in the role of plasmids in B. megaterium strain QM B1551 and their replication, stability, and possible horizontal transfer among the gram-positive bacteria.…”

mentioning

confidence: 99%

Molecular Characterization of Plasmid pBM300 from Bacillus megaterium QM B1551

Kunnimalaiyaan

Vary

2005

Appl Environ Microbiol

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Strain QM B1551 of Bacillus megaterium contains seven compatible plasmids: two small rolling circle plasmids and five theta-replicating plasmids with cross-hybridizing replicons. To expand our understanding of these plasmids, the replicon region (6.7 kb) from pBM300 was cloned, sequenced, and functionally characterized. Sequence analysis showed that the replication protein (RepM300) was highly homologous to two other plasmid Rep proteins of the same strain but to no other known proteins. Furthermore, the location of the replication origin was within the RepM300 coding region, and the origin contained three 12-base direct repeats. Deletion analysis of the replicon confirmed the role of the Rep protein and showed that open reading frame 2 (ORF2) was required for stability. However, the protein encoded by ORF2 is entirely different from the replicon stability proteins encoded by the other two replicons. The entire plasmid was isolated from the plasmid array by integrating a spectinomycin resistance gene and transforming a plasmidless strain, PV361. Complete sequencing showed that pBM300 was 26,300 bp long, had a G؉C content of 35.2%, and contained 20 ORFs, two of which encoded proteins that had no similarity to other proteins in the database. The proteins encoded by the plasmid ORFs had similarity to proteins for mobilization and transfer, an integrase, a rifampin resistance protein, a cell wall hydrolase, glutathione synthase, and a biotin carboxylase. The similarities were to several gram-positive genera and a few gram-negative genera and archaea. oriT and ssoT-like regions were detected near two mob genes. These results suggest that pBM300 is a mobilizable hybrid plasmid that confers increased metabolic and germination ability on its host. Its replicon also helps define a new plasmid family.

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“…4b that betulin biotransformation is prone to pH change towards alkalinity. This decrease in biotransformation is because of stress caused on microbial cells due higher alkalinity (Vary 1994;Grishko et al 2013). …”

Section: Effect Of Temperature and Ph On Enhancement Of Biotransformamentioning

confidence: 99%

“…Various biochemical tests were performed for the identification of betulin-tolerant isolates (Vary 1994). The pure cultures were grown on nutrient agar or potato dextrose medium and transferred to Luria-Broth, Mac-conkey agar medium, EMB agar medium, and Mannitol salt agar medium for differentiating and identifying bacteria.…”

Section: Morphological and Biochemical Identification Of Suitable Isomentioning

confidence: 99%

An efficient process for the transformation of betulin to betulinic acid by a strain of Bacillus megaterium

Kumar

Dubey

2017

3 Biotech

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Betulinic acid as a derivative of betulin is widely reported for its anti-HIV and antitumor activities. Betulin has three most significant positions, i.e., primary hydroxyl group at position C-28, secondary hydroxyl group at position C-3, and alkene moiety at position C-20, where chemical modifications were performed to yield pharmacologically more active derivatives. Bioconversion optimization was performed for the enhancement in the percentage of conversion using statistical approach by opting temperature, pH and betulin concentration as independent variables. Three hundred fifty isolates were screened from natural sources under selective medium containing up to 3 g/l of betulin for their tolerance and bioconversion efficiency. Isolate KD235 was found to grow in 3 g/l betulin with 23.34 ± 0.57 g/l biomass and 0.67 ± 0.06 g/l betulinic acid production. New isolate KD235 was characterized by molecular analysis and named as Bacillus megaterium KD235. Molecular characterization of a potentially active isolate for the transformation of betulin to betulinic acid was suggested as isolate Bacillus megaterium KD235. Maximum bioconversion (22 ± 1.5%) was found at optimized conditions, i.e., pH 6.5, temperature 30°C and at 3 g/l betulin. Validations of experiments as *11% more bioconversion i.e., 1 ± 0.1 g/l betulinic acid were obtained using 5 l lab fermenter as compared to shake flask.

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Prime time for Bacillus megaterium

Cited by 164 publications

References 11 publications

Evidence for two recA genes mediating DNA repair in Bacillus megaterium

Evidence for two recA genes mediating DNA repair in Bacillus megaterium

Molecular Characterization of Plasmid pBM300 from Bacillus megaterium QM B1551

An efficient process for the transformation of betulin to betulinic acid by a strain of Bacillus megaterium

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