Genetic mapping of catabolite-resistant mutants of Bacillus subtilis

1982 ◽  
Vol 28 (11) ◽  
pp. 1242-1251 ◽  
Author(s):  
Dongxu Sun ◽  
I. Takahashi
Keyword(s):  
Bacillus Subtilis ◽  
Genetic Mapping ◽  
Carbon Sources ◽  
Resistance Mutations ◽  
Resistant Mutants ◽  
High Concentrations

Using mutants of Bacillus subtilis that are able to sporulate in the presence of relatively high concentrations of various carbon sources, catabolite resistance mutations were mapped by PBS1 transduction and transformation. Catabolite resistance mutations were localized at six different loci on the chromosome of B. subtilis. The map positions of our mutants suggest that they are distinct from sacUh, catA, and scoC reported by other investigators. Relations between our findings and initiation of sporulation have been discussed.

A catabolite-resistance mutation is localized in the rpo operon of Bacillus subtilis

1984 ◽  
Vol 30 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Dongxu Sun ◽  
I. Takahashi
Keyword(s):  
Bacillus Subtilis ◽  
Rna Polymerase ◽  
Partial Resistance ◽  
Carbon Sources ◽  
Resistance Mutation ◽  
Inhibitory Effect ◽  
High Concentrations

By transformation analysis, a mutation (crsE1), which makes Bacillus subtilis cells able to sporulate in the presence of relatively high concentrations of glucose and other carbon sources, was mapped in the rpoBC operon. The effect of crsE1 mutation can be suppressed by another mutation in the same operon, rfm11, which confers resistance to rifamycin. Mutants carrying stv or std mutations, which are also located in the rpoBC operon, showed partial resistance to catabolites in sporulation. It appears therefore that a change in the structure or synthesis of RNA polymerase may alter the response of cells to the inhibitory effect of catabolites on sporulation.

Catabolite repression-resistant mutants of Bacillus subtilis

1979 ◽  
Vol 25 (11) ◽  
pp. 1283-1287 ◽  
Author(s):  
I. Takahashi
Keyword(s):  
Bacillus Subtilis ◽  
Carbon Source ◽  
Catabolite Repression ◽  
Minimal Medium ◽  
Carbon Sources ◽  
Close Relation ◽  
Selection Technique ◽  
Source Studies ◽  
Resistant Mutants ◽  
Simple Selection

Mutants of Bacillus subtilis that are able to sporulate under the condition of catabolite repression were isolated by a simple selection technique. The mutants used in the present study were able to grow normally on minimal medium with ammonium sulphate as the nitrogen source and glucose as the carbon source. Studies carried out with these mutants show that there is no close relation between catabolite repression of an inducible enzyme, acetoin dehydrogenase, and that of sporulation. Certain mutants are able to sporulate in the presence of all the carbon sources tested but some mutants are resistant only to the carbon source used in isolation. It is suggested that several metabolic steps may be affected in catabolite repression of sporulation.

scholarly journals Bactobolin Resistance Is Conferred by Mutations in the L2 Ribosomal Protein

mBio ◽  
2012 ◽  
Vol 3 (6) ◽  
Author(s):  
Josephine R. Chandler ◽  
Thao T. Truong ◽  
Patricia M. Silva ◽  
Mohammad R. Seyedsayamdost ◽  
Gavin Carr ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Mammalian Cells ◽  
Ectopic Expression ◽  
Wild Type ◽  
Resistance Mutations ◽  
Sequencing Technology ◽  
Cellular Functions ◽  
Burkholderia Thailandensis ◽  
Content Type ◽  
Resistant Mutants

ABSTRACTBurkholderia thailandensisproduces a family of polyketide-peptide molecules called bactobolins, some of which are potent antibiotics. We found that growth ofB. thailandensisat 30°C versus that at 37°C resulted in increased production of bactobolins. We purified the three most abundant bactobolins and determined their activities against a battery of bacteria and mouse fibroblasts. Two of the three compounds showed strong activities against both bacteria and fibroblasts. The third analog was much less potent in both assays. These results suggested that the target of bactobolins might be conserved across bacteria and mammalian cells. To learn about the mechanism of bactobolin activity, we isolated four spontaneous bactobolin-resistantBacillus subtilismutants. We used genomic sequencing technology to show that each of the four resistant variants had mutations inrplB, which codes for the 50S ribosome-associated L2 protein. Ectopic expression of a mutantrplBgene in wild-typeB. subtilisconferred bactobolin resistance. Finally, the L2 mutations did not confer resistance to other antibiotics known to interfere with ribosome function. Our data indicate that bactobolins target the L2 protein or a nearby site and that this is not the target of other antibiotics. We presume that the mammalian target of bactobolins involves the eukaryotic homolog of L2 (L8e).IMPORTANCECurrently available antibiotics target surprisingly few cellular functions, and there is a need to identify novel antibiotic targets. We have been interested in theBurkholderia thailandensisbactobolins, and we sought to learn about the target of bactobolin activity by mapping spontaneous resistance mutations in the bactobolin-sensitiveBacillus subtilis. Our results indicate that the bactobolin target is the 50S ribosome-associated L2 protein or a region of the ribosome affected by L2. Bactobolin-resistant mutants are not resistant to other known ribosome inhibitors. Our evidence indicates that bactobolins interact with a novel antibiotic target.

Effects of various inhibitory agents on sporulation of Bacillus subtilis

1982 ◽  
Vol 28 (1) ◽  
pp. 80-86 ◽  
Author(s):  
I. Takahashi ◽  
L. W. MacKenzie
Keyword(s):  
Bacillus Subtilis ◽  
Acridine Orange ◽  
Nalidixic Acid ◽  
Exponential Growth ◽  
Morphological Changes ◽  
Carbon Sources ◽  
Stage Iv ◽  
Electron Microscopic ◽  
High Concentrations ◽  
Inhibitory Agents

Electron microscopic examinations of Bacillus subtilis cells revealed that relatively high concentrations of carbon sources blocked sporulation at stage 0 in most cells. Both nalidixic acid and novobiocin blocked sporulation at stage 0. The cells treated with acridine orange showed the morphology of stage IV 5 h after the end of exponential growth, but no further progression was observed. Mutants that are able to sporulate in the presence of these agents had the characteristic morphological changes observed in uninhibited cultures.

Cloning and genetic mapping of SNF1, a gene required for expression of glucose-repressible genes in Saccharomyces cerevisiae

1984 ◽  
Vol 4 (1) ◽  
pp. 49-53
Author(s):  
J L Celenza ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Mapping ◽  
Gene Product ◽  
Structural Gene ◽  
Glucose Repression ◽  
Carbon Sources ◽  
Recombinant Plasmids ◽  
The Right ◽  
Integrating Vector

A functional SNF1 gene product is required to derepress expression of many glucose-repressible genes in Saccharomyces cerevisiae. Strains carrying a snf1 mutation are unable to grow on sucrose, galactose, maltose, melibiose, or nonfermentable carbon sources; utilization of these carbon sources is regulated by glucose repression. The inability of snf1 mutants to utilize sucrose results from failure to derepress expression of the structural gene for invertase at the RNA level. We isolated recombinant plasmids carrying the SNF1 gene by complementation of the snf1 defect in S. cerevisiae. A 3.5-kilobase region is common to the DNA segments cloned in five different plasmids. Transformation of S. cerevisiae with an integrating vector carrying a segment of the cloned DNA resulted in integration of the plasmid at the SNF1 locus. This result indicates that the cloned DNA is homologous to sequences at the SNF1 locus. By mapping a plasmid marker linked to SNF1 in this transformant, we showed that the SNF1 gene is located on chromosome IV. We then mapped snf1 to a position 5.6 centimorgans distal to rna3 on the right arm; snf1 is not extremely closely linked to any previously mapped mutation.

scholarly journals Antibacterial Peptides Resistance in Staphylococcus aureus: Various Mechanisms and the Association with Pathogenicity

Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1527
Author(s):  
Miki Kawada-Matsuo ◽  
Mi Nguyen-Tra Le ◽  
Hitoshi Komatsuzawa
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Antibacterial Peptides ◽  
Low Concentrations ◽  
Component Systems ◽  
Two Component Systems ◽  
Resistant Strains ◽  
Resistant Mutants ◽  
High Concentrations

Staphylococcus aureus is a bacterium that mainly colonizes the nasal cavity and skin. To colonize the host, it is necessary for S. aureus to resist many antibacterial factors derived from human and commensal bacteria. Among them are the bacteria-derived antimicrobial peptides (AMPs) called bacteriocins. It was reported that some two-component systems (TCSs), which are signal transduction systems specific to bacteria, are involved in the resistance to several bacteriocins in S. aureus. However, the TCS-mediated resistance is limited to relatively low concentrations of bacteriocins, while high concentrations of bacteriocins still exhibit antibacterial activity against S. aureus. To determine whether we could obtain highly bacteriocin-resistant mutants, we tried to isolate highly nisin A-resistant mutants by exposing the cells to sub-minimum inhibitory concentrations (MICs) of nisin A. Nisin A is one of the bacteriocins produced by Lactococcus lactis and is utilized as a food preservative worldwide. Finally, we obtained highly nisin A-resistant mutants with mutations in one TCS, BraRS, and in PmtR, which is involved in the expression of pmtABCD. Notably, some highly resistant strains also showed increased pathogenicity. Based on our findings, this review provides up-to-date information on the role of TCSs in the susceptibility to antibacterial peptides. Additionally, the mechanism for high antimicrobial peptides resistance and its association with pathogenicity in S. aureus is elucidated.

scholarly journals Draft Genome Sequence ofBacillus subtilisIa1a, a New Strain for Poly-γ-Glutamic Acid and Exopolysaccharide Production

2016 ◽  
Vol 4 (6) ◽  
Author(s):  
Mohammad H. A. Ibrahim ◽  
Brady F. Cress ◽  
Robert J. Linhardt ◽  
Mattheos A. G. Koffas ◽  
Richard A. Gross
Keyword(s):  
Bacillus Subtilis ◽  
Glutamic Acid ◽  
Genome Sequence ◽  
Genome Assembly ◽  
Draft Genome ◽  
Carbon Sources ◽  
Draft Genome Sequence ◽  
High Quality ◽  
Exopolysaccharide Production ◽  
Draft Genome Assembly

We report here the 4.092-Mb high-quality draft genome assembly of a newly isolated poly-γ-glutamic acid–producing strain,Bacillus subtilisIa1a. The genome sequence is considered a critical tool to facilitate the engineering of improved production strains. Exopolysaccharides and many industrially important enzymes can be produced by this new strain utilizing different carbon sources.

Sign in / Sign up

Export Citation Format

Share Document