Expression of alpha-amylase in Bacillus licheniformis.

In Bacillus licheniformis, alpha-amylase production varied more than 100-fold depending on the presence or absence of a catabolite-repressing carbon source in the growth medium. alpha-Amylase was produced during the growth phase and not at the onset of the stationary phase. Induction of alpha-amylase correlated with synthesis of mRNA initiating at the promoter of the alpha-amylase gene.     

微生态系统中地衣芽孢杆菌消长的研究

采用不同接种培养方法,研究了地衣芽孢杆菌在微生态系统的消长状况．结果表明,在健康人体内该菌能迅速增殖,菌数为１．４９×１０８～１．８３×１０８个·ｇ－１,并能较长时间定植下来,３０ｄ后菌数为１．２７×１０７～１．５１×１０７个·ｇ－１．在病人体内增殖相对较慢些,菌数为１．４０×１０８～１．６７×１０８个·ｇ－１,３０ｄ后菌数为１．１５×１０７～１．３１×１０７个·ｇ－１．在人工模拟微生态系统中,当ｐＨ为５．０～９．０,营养物为食物匀浆培养基、牛肉膏蛋白胨培养基时,其菌数为３．０５×１０８、３．４２×１０８个·ｍｌ－１．     

Light-induced inhibition of sporulation in Bacillus licheniformis.

Sporulation of Bacillus licheniformis is inhibited by broad-spectrum light. This phenomenon is intensity dependent and is a near-ultraviolet and blue light effect.     

Peptidoglycan synthesis in L-phase variants of Bacillus licheniformis and Bacillus subtilis.

Stable L-phase variants isolated from Bacillus licheniformis and Bacillus subtilis, when grown in osmotically stabilized media, do not synthesize peptidoglycan but have been found to accumulate the nucleotide precursors of this polymer. The enzymes involved in the synthesis of these precursors and the later membrane-bound stages of peptidoglycan synthesis have been investigated, and the L-phase variants have been shown to contain lesions, which provide a rational explanation for the absence of peptidoglycan and for the nature of the precursor accumulated. The majority of the L-phase variants contained a single enzymic defect, but two strains were isolated with double lesions. Five out of seven strains examined accumulated uridine 5'-diphosphate (UDP)-MurAc-L-ala-D-glu and were unable to synthesize diaminopimelic acid as a consequence of a defect in aspartate-beta-semialdehyde dehydrogenase activity. Two strains were deficient in UDP-MurAc: L-alanine ligase and accumulated UDP-MurAc. One strain accumulated the complete nucleotide precursor UDP-MurAc-L-ala-D-glu-mA2pm-D-ala-D-ala and was deficient in phospho-N-acetylmuramyl pentapeptide translocase. A second strain also had this lesion, together with defective aspartate-beta-semialdehyde dehydrogenase activity. The other enzymes of peptidoglycan synthesis were present in the L-phase variants, with activities similar to those found in the parent bacilli grown under identical conditions. Membrane preparations from certain of the L-phase variants were also capable of synthesizing the secondary polymers poly(glycerol phosphate) teichoic acid and teichuronic acid and also a polymer of N-acetylglucosamine.     

Phosphatidylseryl-transfer RNA in Bacillus licheniformis 749/C.

Phosphatidylserine has been found in extracts of Bacillus licheniformis made under alkaline conditions but not under neutral or acidic ones and was derived from the tRNA fraction. In tRNA preparations kept below neutrality during purification, phosphatidylserine was the only phospholipid released when the pH was raised to 9.0. The amount of bound phosphatidylserine could be increased by incubating tRNA from B. licheniformis or Escherichia coli with CTP and phosphatidic acid in the presence of an S-30 extract from either organism. The tRNA carrying phosphatidylserine has been separated from the bulk of the tRNA by DEAE-Sephadex chromatography in the presence of a detergent. On deaminoacylation of this material and rechromatography on DEAE-Sephadex, a number of peaks were found, indicating that this behavior is not confined to a single isoaccepting species.     

Naturally occurring macrolide-lincosamide-streptogramin B resistance in Bacillus licheniformis.

Resistance to the macrolide-lincosamide-streptogramin B (MLS) group of antibiotics is widespread and of clinical importance. B. Weisblum and his coworkers have demonstrated that this resistance is associated with methylation of the 23S ribosomal ribonucleic acid of the large ribosomal subunit which results in a diminished affinity of this organelle for these antibiotics (Lai et al, J. Mol. Biol. 74:67-72, 1973). We report that 10 of 15 natural isolates of Bacillus licheniformis, a common soil organism, are resistant to the MLS antibiotics. The properties of this resistance (high level of tolerance for erythromycin, broad cross-resistance spectrum, and inducibility) suggest that resistance is conferred as described above. The resistance determinant from one of these strains was cloned onto a B. subtilis plasmid vector, and the resulting hybrid plasmid (pBD90) was used to prepare radioactive probe deoxyribonucleic acid for hybridization studies. All of the resistance B. licheniformis strains studied exhibited homology with the pBD90 insert. Plasmid pBD90 showed no homology to the following staphylococcal and streptococcal MLS-resistance plasmids: pE194, pE5, pAM77, pI258. Plasmids pE194 and pE5, on the other hand, carry homologous MLS genes but showed no detectable homology to one another in their replication genes. pBD90 specified a 35,000-dalton erythromycin-inducible protein, detectable in minicells, which therefore appears different from the 29,000-dalton inducible resistance protein specified by pE194. We conclude that there are at least three distinct MLS resistance determinants to be found among gram-positive bacteria.     

Immunoelectron microscopic localization of penicillinase in Bacillus licheniformis.

Penicillinase was localized in log-phase cells of Bacillus licheniformis 749/C by labeling with ferritin-anti-penicillinase immunoglobulin G conjugate. Mildly fixed homogenized cells, isolated subcellular fractions, and frozen thin sections were labeled. The label was distributed in discrete patches in the cell envelope. The patches extended from the inside part of the membrane to the outside part of the wall. The inside part of the membrane was labeled more extensively than the outside part. The cytoplasm also bound some ferritin-immunoglobulin G conjugate. Immunoelectrophoresis and biochemical assay of cytosol material suggest that the cytoplasmic antigenic sites are a protease-sensitive form of penicillinase.     

Biosynthesis of Bacillus licheniformis penicillinase in Escherichia coli and in Bacillus subtilis.

Modified prepenicillinase was accumulated in both Escherichia coli and Bacillus subtilis treated with globomycin. Although the inhibitions of processings of prepenicillinase and prolipoprotein by globomycin in E. coli are qualitatively similar, they differ in the degree of inhibition at given concentrations of globomycin. The processing of prepenicillinase proceeds much more rapidly in E. coli than in B. subtilis.     

Site-specific restriction endonucleases in Bacillus licheniformis

Abstract We systematically studied site-specific restriction endonucleases in Bacillus licheniformis strains and detected endonuclease activity in 25 of 217 strains tested. Three different activities were obtained. One of these activities detected in 21 strains was the most representative within the species and produced a banding pattern, after digestion of A DNA, identical to that seen with Cla I. Two other strains isolated from soil samples from China and USA were found to produce a DNA-cleaving enzyme with the same recognition sequence as Bsa I. One producer strain, isolated from a Peruvian soil sample, showed to possess a mixture of two isoschizomers, Cla I and Bsa I. Finally, one strain produced an endonuclease activity, not previously described in B. licheniformis , that showed the same recognition sites as Bsu 361.     

Characterization of the glucose transport systems in Neurospora crassa sl.

Neurospora crassa sl, a mutant that lacks a rigid cell wall, exhibits transport systems for glucose similar to those of wild-type strain 1A. When the orgnism is grown in a medium containing 50 mM glucose as the carbon source, glucose is transported primarily by a glucose-facilitated diffusion system (GluI). When it is grown in a medium with little or no glucose present, a glucose active transport system (Glu II) is expressed. Both of these systems are similar kinetically to those in the wild type. Significant differences do exist between strains sl and 1A with respect to genetic regulation of the glucose active transport system.     

Nutrient-stimulated methylation of a membrane protein in Bacillus licheniformis.

When nitrogen-starved vegetative cells of Bacillus licheniformis A5 were presented with a good nitrogen source in the presence of chloramphenicol and methyl-labeled methionine, a 40-kilodalton (kDa) protein was found to be reversibly methylated, with a half-life of approximately 10 to 15 min. The 40-kDa protein was strongly methylated in response to the addition of ammonia, glutamine, or sodium glutamate nitrogen sources that produce generation times of less than or equal to 90 min) but was very poorly methylated in the absence of a nitrogen source or in the presence of potassium glutamate or histidine (generation times of greater than 150 min). The methylated protein was found to be membrane associated, but the methylation reaction did not appear to be related to chemotaxis, because the spectrum of nutrients that promoted methylation was different from that which prompted a chemotactic response. In addition, the methyl residue on the 40-kDa protein was found to be alkali stable. Approximately 180 to 640 molecules of the methylated protein were found per cell. The characteristics of this methylated protein were consistent with the hypothesis that the reversible methylation of the protein functions in nutrient sensing to regulate growth, cell division, and the initiation of sporulation.     

Major sites of metal binding in Bacillus licheniformis walls.

Isolated and purified walls of Bacillus licheniformis NCTC 6346 his contained peptidoglycan, teichoic acid, and teichuronic acid (0.36 mumol of diaminopimelic acid, 0.85 mumol of organic phosphorus, and 0.43 mumol of glucuronic acid per mg [dry weight] of walls, respectively). The walls also contained a total of 0.208 mumol of metal per mg. When these walls were subjected to metal-binding conditions (T. J. Beveridge and R. G. E. Murray, J. Bacteriol. 127:1502-1518, 1976) for nine metals, the amount of bound metal above background ranged from 0.910 mumol of Na to 0.031 mumol of Au per mg of walls. Most were in the 0.500-mumol mg-1 range. Electron-scattering profiles from unstained thin sections indicated that the metal was dispersed throughout the wall fabric. Mild alkali treatment extracted teichoic acid from the walls (97% based on phosphorus) but left the peptidoglycan and teichuronic acid intact. This treatment reduced their capacity for all metals but Au. Thin sections revealed that the wall thickness had been reduced by one-third, but metal was still dispersed throughout the wall fabric. Trichloroacetic acid treatment of the teichoic acid-less walls removed 95% of the teichuronic acid (based on glucuronic acid) but left the peptidoglycan intact (based on sedimentable diaminopimelic acid). The thickness of these walls was not further reduced, but little binding capacity remained (usually less than 10% of the original binding). The staining of these walls with Au produced a 14.4-nm repeat frequency within the peptidoglycan fabric. Sedimentation velocity experiments with the extracted teichuronic acid in the presence of metal confirmed it to be a potent metal-complexing polymer. These results indicated that teichoic and teichuronic acids are the prime sites of metal binding in B. licheniformis walls.