Sporulation and regulation of homoserine dehydrogenase in Bacillus subtilis

1980 ◽  
Vol 26 (12) ◽  
pp. 1386-1391 ◽  
Author(s):  
James P. Yeggy ◽  
Donald P. Stahly
Keyword(s):  
Bacillus Subtilis ◽  
Specific Activity ◽  
Dipicolinic Acid ◽  
Forward Direction ◽  
Diaminopimelic Acid ◽  
Homoserine Dehydrogenase ◽  
Stage Of Development ◽  
Cell Extracts ◽  
Casamino Acids ◽  
Potential Inhibitors

Homoserine dehydrogenase in dialyzed cell extracts of Bacillus subtilis 168 was studied, particularly with regard to inhibition, repression, and level of activity as a function of stage of development (growth and sporulation). It was assayed in the "forward direction" using L-aspartic semialdehyde and NADPH as substrates. Of the potential inhibitors tested, only cysteine and NADP were found to be effective. Both L- and D-cysteine were equally effective. Therefore, the physiological significance of cysteine as an inhibitor is somewhat questionable. Amino acids involved in repression of homoserine dehydrogenase included methionine, isoleucine, possibly threonine, and one or more unidentified components of Casamino acids. The specific activity of homoserine dehydrogenase was highest during the exponential phase of growth and declined steadily during the stationary phase of growth. The low specific activity during late sporulation may favor preferential funneling of L-aspartic semialdehyde into the lysine pathway, where it is needed for synthesis of large amounts of dipicolinic acid and diaminopimelic acid.

scholarly journals Methanococci Use the Diaminopimelate Aminotransferase (DapL) Pathway for Lysine Biosynthesis

2010 ◽  
Vol 192 (13) ◽  
pp. 3304-3310 ◽  
Author(s):  
Yuchen Liu ◽  
Robert H. White ◽  
William B. Whitman
Keyword(s):  
Specific Activity ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Direct Conversion ◽  
Maximum Activity ◽  
Lysine Biosynthesis ◽  
Diaminopimelic Acid ◽  
Reading Frame ◽  
Cell Extracts ◽  
Methanothermobacter Thermautotrophicus

ABSTRACT The pathway of lysine biosynthesis in the methanococci has not been identified previously. A variant of the diaminopimelic acid (DAP) pathway uses diaminopimelate aminotransferase (DapL) to catalyze the direct conversion of tetrahydrodipicolinate (THDPA) to ll-DAP. Recently, the enzyme DapL (MTH52) was identified in Methanothermobacter thermautotrophicus and shown to belong to the DapL1 group. Although the Methanococcus maripaludis genome lacks a gene that can be unambiguously assigned a DapL function based on sequence similarity, the open reading frame MMP1527 product shares 30% amino acid sequence identity with MTH52. A Δmmp1527 deletion mutant was constructed and found to be a lysine auxotroph, suggesting that this DapL homolog in methanococci is required for lysine biosynthesis. In cell extracts of the M. maripaludis wild-type strain, the specific activity of DapL using ll-DAP and α-ketoglutarate as substrates was 24.3 ± 2.0 nmol min−1 mg of protein−1. The gene encoding the DapL homolog in Methanocaldococcus jannaschii (MJ1391) was cloned and expressed in Escherichia coli, and the protein was purified. The maximum activity of MJ1391 was observed at 70°C and pH 8.0 to 9.0. The apparent Km s of MJ1391 for ll-DAP and α-ketoglutarate were 82.8 ± 10 μM and 0.42 ± 0.02 mM, respectively. MJ1391 was not able to use succinyl-DAP or acetyl-DAP as a substrate. Phylogenetic analyses suggested that two lateral gene transfers occurred in the DapL genes, one from the archaea to the bacteria in the DapL2 group and one from the bacteria to the archaea in the DapL1 group. These results demonstrated that the DapL pathway is present in marine methanogens belonging to the Methanococcales.

In vivo Production of Soluble Inorganic Pyrophosphatases in Two Strains of Vibrio cholerae

1970 ◽  
Vol 24 (1) ◽  
pp. 38-41
Author(s):  
Taslima Taher Lina ◽  
Mohammad Ilias
Keyword(s):  
Vibrio Cholerae ◽  
Specific Activity ◽  
Experimental Conditions ◽  
Environmental Strain ◽  
Cell Extracts ◽  
Atcc Strain ◽  
The Family ◽  
Effects Of Ph ◽  
Vibrio Cholerae O1

The in vivo production of soluble inorganic pyrophosphatases (PPases) was investigated in two strains, namely, Vibrio cholerae EM 004 (environmental strain) and Vibrio cholerae O1 757 (ATCC strain). V. cholerae is known to contain both family I and family II PPase coding sequences. The production of family I and family II PPases were determined by measuring the enzyme activity in cell extracts. The effects of pH, temperature, salinity of the growth medium on the production of soluble PPases were studied. In case of family I PPase, V. cholerae EM 004 gave the highest specific activity at pH 9.0, with 2% NaCl + 0.011% NaF and at 37°C. The strain V. cholerae O1 757 gave the highest specific activity at pH 9.0, with media containing 0% NaCl and at 37°C. On the other hand, under all the conditions family II PPase did not give any significant specific activity, suggesting that the family II PPase was not produced in vivo in either strains of V. cholerae under different experimental conditions. Keywords: Vibrio cholerae, Pyrophosphatases (PPases), Specific activityDOI: http://dx.doi.org/10.3329/bjm.v24i1.1235 Bangladesh J Microbiol, Volume 24, Number 1, June 2007, pp 38-41

scholarly journals Molecular Physiological Characterization of a High Heat Resistant Spore Forming Bacillus subtilis Food Isolate

2021 ◽  
Vol 9 (3) ◽  
pp. 667
Author(s):  
Zhiwei Tu ◽  
Peter Setlow ◽  
Stanley Brul ◽  
Gertjan Kramer
Keyword(s):  
Bacillus Subtilis ◽  
Heat Resistance ◽  
Dipicolinic Acid ◽  
Laboratory Strain ◽  
High Heat ◽  
High Heat Resistance ◽  
Vegetative Cells ◽  
Heat Resistant ◽  
Food Isolate ◽  
Wet Heat

Bacterial endospores (spores) are among the most resistant living forms on earth. Spores of Bacillus subtilis A163 show extremely high resistance to wet heat compared to spores of laboratory strains. In this study, we found that spores of B. subtilis A163 were indeed very wet heat resistant and released dipicolinic acid (DPA) very slowly during heat treatment. We also determined the proteome of vegetative cells and spores of B. subtilis A163 and the differences in these proteomes from those of the laboratory strain PY79, spores of which are much less heat resistant. This proteomic characterization identified 2011 proteins in spores and 1901 proteins in vegetative cells of B. subtilis A163. Surprisingly, spore morphogenic protein SpoVM had no homologs in B. subtilis A163. Comparing protein expression between these two strains uncovered 108 proteins that were differentially present in spores and 93 proteins differentially present in cells. In addition, five of the seven proteins on an operon in strain A163, which is thought to be primarily responsible for this strain’s spores high heat resistance, were also identified. These findings reveal proteomic differences of the two strains exhibiting different resistance to heat and form a basis for further mechanistic analysis of the high heat resistance of B. subtilis A163 spores.

scholarly journals Role of SpoVA Proteins in Release of Dipicolinic Acid during Germination of Bacillus subtilis Spores Triggered by Dodecylamine or Lysozyme

2006 ◽  
Vol 189 (5) ◽  
pp. 1565-1572 ◽  
Author(s):  
Venkata Ramana Vepachedu ◽  
Peter Setlow
Keyword(s):  
Bacillus Subtilis ◽  
Small Molecules ◽  
Spore Germination ◽  
Dipicolinic Acid ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Ph Optimum ◽  
Inner Membrane ◽  
Temperature Sensitive Mutants

ABSTRACT The release of dipicolinic acid (DPA) during the germination of Bacillus subtilis spores by the cationic surfactant dodecylamine exhibited a pH optimum of ∼9 and a temperature optimum of 60°C. DPA release during dodecylamine germination of B. subtilis spores with fourfold-elevated levels of the SpoVA proteins that have been suggested to be involved in the release of DPA during nutrient germination was about fourfold faster than DPA release during dodecylamine germination of wild-type spores and was inhibited by HgCl2. Spores carrying temperature-sensitive mutants in the spoVA operon were also temperature sensitive in DPA release during dodecylamine germination as well as in lysozyme germination of decoated spores. In addition to DPA, dodecylamine triggered the release of amounts of Ca2+ almost equivalent to those of DPA, and at least one other abundant spore small molecule, glutamic acid, was released in parallel with Ca2+ and DPA. These data indicate that (i) dodecylamine triggers spore germination by opening a channel in the inner membrane for Ca2+-DPA and other small molecules, (ii) this channel is composed at least in part of proteins, and (iii) SpoVA proteins are involved in the release of Ca2+-DPA and other small molecules during spore germination, perhaps by being a part of a channel in the spore's inner membrane.

Effects of Cold Atmospheric Pressure Plasma Jeton the Viability of Bacillus subtilis Endospores

2013 ◽  
Vol 647 ◽  
pp. 524-531
Author(s):  
Vinita Sharma ◽  
Katsuhiko Hosoi ◽  
Tamio Mori ◽  
Shin-ichi Kuroda
Keyword(s):  
Bacillus Subtilis ◽  
Atmospheric Pressure ◽  
Dipicolinic Acid ◽  
Atmospheric Pressure Plasma ◽  
Dilution Method ◽  
Pressure Plasma ◽  
Agar Disc ◽  
Bacterial Endospores ◽  
Cold Atmospheric Pressure Plasma ◽  
Ar Gas

In this study, we conducted experiments to investigate the effectiveness of a non-equilibrium Ar-N2 plasma jet generated by a Cold Atmospheric Pressure Plasma Torch (CAPPLAT) at a sinusoidal voltage of 20 kV, frequency of 30 kHz with 10 slm of Ar gas and 100 sccm of N2 gas. Highly environmental stress resistant bacterial endospores of Bacillus subtilis, dried on an agar disc were exposed to the plasma discharge from the CAPPLAT for different durations. The viability of spores after plasma exposure was checked by counting CFUs by serial dilution method. We also measured the amount of released DPA (dipicolinic acid, pyridine-2, 6-dicarboxylic acid), which is exclusively found in endospore protoplast (cortex), to confirm the disintegration of the cortex. We could successfully inactivate a population of Bacillus endospores of about 1.0 × 107 to 4.0 × 107 spores/ml.

Degradation of zearalenone in swine feed and feed ingredients by Bacillus subtilis ANSB01G

2014 ◽  
Vol 7 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Y.P. Lei ◽  
L.H. Zhao ◽  
Q.G. Ma ◽  
J.Y. Zhang ◽  
T. Zhou ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Culture Supernatant ◽  
Antimicrobial Activities ◽  
Proteinase K ◽  
Rrna Gene ◽  
Distillers Grains With Solubles ◽  
Dried Distillers Grains ◽  
Cell Extracts ◽  
Gene Sequence Analysis ◽  
And Staphylococcus Aureus

Zearalenone (ZEA) and its derivatives are mycotoxins that can cause oestrogenic effects and impair the reproductive physiology of animals, especially in female swine. Strategies to reduce or eliminate ZEA contamination in foods and feeds are very much needed. Among 36 bacterial isolates obtained from a variety of animal intestinal chyme, mouldy foods and feeds, soils, etc., five isolates demonstrated the ability to reduce more than 50% of ZEA in a liquid medium; ANSB01G isolate taken from normal broiler intestinal chyme reduced ZEA the most, by 88.65%. Using physiological, biochemical, and 16S rRNA gene sequence analysis methods, the ANSB01G isolate was identified as Bacillus subtilis. Under simulated intestinal tract conditions, the ANSB01G B. subtilis isolate degraded 84.58, 66.34 and 83.04% of ZEA in naturally contaminated maize, dried distillers’ grains with solubles, and swine complete feed, respectively. The highest degradation of ZEA occurred when the mycotoxin was co-incubated with the whole bacterial culture, resulting in a reduction of 88.65%, followed by 75.60% using culture supernatant, 26.11% using cell extracts, and 15.06% using viable cells. Treatments consisting of both heating and addition of proteinase K significantly reduced the rate of ZEA degradation in the culture supernatant, indicating that the ZEA degradation might be enzymatic. B. subtilis ANSB01G displayed resistance to simulated gastrointestinal tract environments and antimicrobial activities against several common bacterial pathogens, including Escherichia coli, Salmonella typhimurium and Staphylococcus aureus. These properties of B. subtilis ANSB01G suggest the possibility of its potential to effectively degrade ZEA in feed and to develop functional feed products for livestock industries.

Characterization of a factor that stimulates hydrolysis of GTP bound to ras gene product p21 (GTPase-activating protein) and correlation of its activity to cell density

1988 ◽  
Vol 8 (10) ◽  
pp. 4169-4173
Author(s):  
M Hoshino ◽  
M Kawakita ◽  
S Hattori
Keyword(s):  
Gene Product ◽  
Cell Density ◽  
Cultured Cells ◽  
Specific Activity ◽  
Gtpase Activating Protein ◽  
Ras Gene ◽  
Cell Extracts ◽  
Mouse Tissues ◽  
Almost All ◽  
Hydrolysis Of

The postmicrosomal fraction of the extract from NIH 3T3 and BALB/c 3T3 cells stimulated the hydrolysis of GTP bound to H-ras gene product p21 by severalfold. The stimulation was observed with normal p21 but not with p21 with valine as the 12th residue. This specificity is similar to that of GTPase-activating protein (GAP) for N-ras p21 described by M. Trahey and F. McCormick (Science 238:542-545, 1987). Consistent with this specificity, analysis of p21-bound nucleotides in living cells revealed that almost all normal p21 bound GDP, whereas oncogenic mutant p21s bound both GTP and GDP. Similar activity was also found in various mouse tissues, with brain tissue showing the highest specific activity. When cell extracts were prepared from cultured cells, there was a linear relationship between GAP activity and cell density. These results suggest the factor is involved in the regulation of cell proliferation.

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