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1.
The biosynthesis of extracellular alkaline phosphatase in the streptomycin-resistant strains Bacillus intermedius S3-19 and S7 in the presence in the medium of 5'-nucleoside monophosphates and different sources of carbon--glucose, sodium pyruvate, sodium lactate, or glycerol--was studied. It was established that, in the presence of mononucleotides, the content of extracellular alkaline phosphatase in both strains increased; the maximal effect was caused by 5'-AMP at a concentration of 20 micrograms/ml. In medium with a low orthophosphate content, where active biosynthesis of alkaline phosphatase occurred, 1% glucose and 0.5% pyruvate stimulated this process 2.5-4 times, and 2% sodium lactate and sodium pyruvate, on the contrary, inhibited it by 20-40%. Analysis of the dynamics of growth and accumulation of extracellular phosphatase in the presence of different sources of carbon in the medium gives evidence of an interrelationship between the biosynthesis of alkaline phosphatase and carbon metabolism in Bacillus intermedius. 相似文献
2.
Alkaline phosphatase, an enzyme secreted byBacillus intermedius S3-19 cells to the medium, was also detected in the cell wall, membrane, and cytoplasm. The relative content of alkaline
phosphatase in these cell compartments depended on the culture age and cultivation medium. The vegetative growth ofB. intermedius on 0.3% lactate was characterized by increased activity of extracellular and membrane-bound phosphatases. The increase in
lactate concentration to 3% did not affect the activity of membrane-bound phosphatase but led to a decrease in the activity
of the extracellular enzyme. Na2HPO4 at a concentration of 0.01 % diminished the activity of membrane-bound and extracellular phosphatases. CoCl2 at a concentration of 0.1 mM released membrane-bound phosphatase into the medium. By the onset of sporulation, phosphatase
was predominantly localized in the medium and in the cell wall. As is evident from zymograms, the multiple molecular forms
of phosphatase varied depending on its cellular localization and growth phase. 相似文献
3.
M. R. Sharipova E. V. Shakirov N. P. Balaban L. A. Gabdrakhmanova M. A. Shilova G. N. Rudenskaya I. B. Leshchinskaya 《Microbiology》2000,69(5):552-558
The activities of proteinases in the culture fluid and cellular fractions ofBacillus intermedius 3–19 grown under various conditions were studied. Thiol-dependent serine proteinase was the prevalent enzyme in the total
pool of extracellular proteinases (70%); its catalytically active form was also detected in the cell membrane and, during
active enzyme production, in the cell wall. Another enzyme, glutamyl endopeptidase (10% of the total pool), was detected in
the cell membrane; it was also found in the cell wall and cytoplasm during active enzyme secretion into the growth medium.
The production of these enzymes was maximal on medium containing inorganic phosphate and gelatin and decreased 2-to 4-fold
on medium with glucose and lactate. The level of activity of extracellular enzymes correlated with that of corresponding membrane-bound
proteins. The addition of C0Cl2 (2 mM) into the medium caused an essential increase in extracellular glutamyl endopeptidase activity and promoted the release
of the membrane-bound enzyme into the culture fluid. Proteolytic activity towards casein was also detected in the cytoplasm.
The proteinases localized in the cytoplasm were shown to differ in their properties from those secreted. 相似文献
4.
Membrane-bound alkaline phosphatase of Bacillus licheniformis 749/c is derepressed by glucose in complex and chemically defined media. In the presence of lactate, pyruvate, or succinate the synthesis is repressed. The lactate repression neither affects total protein synthesis nor inhibits penicillinase synthesis. Thus, carbon sources specifically influence alkaline phosphatase synthesis. Although variations in the inorganic phosphate content of the growth media directly affect alkaline phosphatase synthesis, the intracellular inorganic and total phosphate pools appear to be unrelated to its repression or derepression. During lactate repression there is preferential incorporation of lactate molecules into glycogen, whereas no such incorporation could be detected from glucose. Net glycogen synthesis remains the same in glucose- or lactate-grown cells. It is postulated that, in phosphate-deficient growth medium, gluconeogenic metabolism regulates alkaline phosphatase synthesis. 相似文献
5.
A. B. Duzhak Z. I. Panfilova E. A. Vasyunina 《Applied Biochemistry and Microbiology》2000,36(4):344-352
—The cultivation conditions of wild-type strain V-10 and mutant strain M-l (overproducer of endonuclease and chitinase) ofSerratia marcescens optimal for extracellular lipase biosynthesis were determined. The strain V-10 displayed the maximum lipase yield (840 AU/ml)
after 10–12 h of cultivation; the strain M-l (330 AU/ml), after 25–30 h. The data showed that extracellular lipases from V-10
and M-1 can be precipitated in a weakly acidic medium (pH 5.0 and 4.5, respectively). This property was used to obtain partially
purified lipase preparations. The effect of the ionic composition of the reaction mixture on the activities of these enzymatic
preparations was studied. Both preparations displayed the highest activities in weakly alkaline media (pH 8.0); however, the
wild-type strain lipase displayed higher thermal stability and stability at alkaline pH compared with M-1 lipase. Both lipases
were activated by various anionic and nonionic surfactants and were inactive in the presence of cetyltrimethylammonium bromide. 相似文献
6.
Metabolic engineering of a Lactobacillus plantarum double ldh knockout strain for enhanced ethanol production 总被引:1,自引:0,他引:1
Liu S Nichols NN Dien BS Cotta MA 《Journal of industrial microbiology & biotechnology》2006,33(1):1-7
Lactobacillus plantarum ferments glucose through the Embden–Meyerhof–Parnas pathway: the central metabolite pyruvate is converted into lactate via
lactate dehydrogenase (LDH). By substituting LDH with pyruvate decarboxylase (PDC) activity, pyruvate may be redirected toward
ethanol production instead of lactic acid fermentation. A PDC gene from the Gram-positive bacterium Sarcina ventriculi (Spdc) was introduced into an LDH-deficient strain, L. plantarum TF103, in which both the ldhL and ldhD genes were inactivated. Four different fusion genes between Spdc and either the S. ventriculi promoter or three Lactococcus lactis promoters in pTRKH2 were introduced into TF103. PDC activity was detected in all four recombinant strains. The engineered
strains were examined for production of ethanol and other metabolites in flask fermentations. The recombinant strains grew
slightly faster than the parent TF103 and produced 90–130 mM ethanol. Although slightly more ethanol was observed, carbon
flow was not significantly improved toward ethanol, suggesting that a further understanding of this organism’s metabolism
is necessary. 相似文献
7.
The production of α-ketoglutarate, adenine, thuringiensin production rate and thuringiensin yield on glucose consumed increased by 22%, 36%,
40% and 40%, respectively, in presence of 2 g citrate/l. However, citrate decreased pyruvate production, poly-β-hydroxybutyrate (PHB) production rate and PHB yield by 62%, 31% and 45%, respectively. The activities of pyruvate kinase
and glucose-6-phosphate dehydrogenase were 36%–45% lower and 50%–120% higher than those of the control, respectively. The
results suggest that citrate regulated the carbon flux to synthesis of adenine present in thuringiensin with a higher efficiency
of utilization of glucose by decreasing PHB synthesis. 相似文献
8.
Previously, we reported that pyruvate production was markedly improved in TBLA-1, an H+-ATPase-defective Escherichia coli mutant derived from W1485lip2, a pyruvate-producing E. coli K-12 strain. TBLA-1 produced more than 30 g/l pyruvate from 50 g/l glucose by jar fermentation, while W1485lip2 produced only 25 g/l pyruvate (Yokota et al. in Biosci Biotechnol Biochem 58:2164–2167, 1994b). In this study, we tested
the ability of TBLA-1 to produce alanine by fermentation. The alanine dehydrogenase (ADH) gene from Bacillus stearothermophilus was introduced into TBLA-1, and direct fermentation of alanine from glucose was carried out. However, a considerable amount
of lactate was also produced. To reduce lactate accumulation, we knocked out the lactate dehydrogenase gene (ldhA) in TBLA-1. This alanine dehydrogenase-expressing and lactate dehydrogenase-defective mutant of TBLA-1 produced 20 g/l alanine
from 50 g/l glucose after 24 h of fermentation. The molar conversion ratio of glucose to alanine was 41%, which is the highest
level of alanine production reported to date. This is the first report to show that an H+-ATPase-defective mutant of E. coli can be used for amino acid production. Our results further indicate that H+-ATPase-defective mutants may be used for fermentative production of various compounds, including alanine. 相似文献
9.
Addition of different concentrations of sodium arsenite to the fermentation medium vised for the production of mitomycin antibiotics
byStreptomyces caespitosus hindered the biosynthesis of mitomycins and led to the accumulation of 2-oxoglutarate, pyruvate and acetone. Mitomycin C
isolated and purified using thin-layer chromatography in low concentration of about 0.1 μg/ml did not affect the RNA, DNA
and protein biosynthesis of the growingBacillus subtilis, while at 10 μg/ml mitomycin C markedly affected RUA, DNA and protein biosynthesis. 相似文献
10.
Hou Shuyu Zhang Qingmin Duo Miao Zhang Yang Sun Hongwen 《Frontiers of Biology in China》2007,2(4):387-390
Two bacterial strains, Py1 and Py4, have been tamed and isolated through long cultivation with polycyclic aromatic hydrocarbon—pyrene
as the single carbon source. It has been proven that they are both highly-efficient pyrene degrading bacteria and both Bacillus sp.. The pyrene degradation ability of separated Py1, Py4 and the consortium of equal Py1 and Py4 was studied in this project.
It is shown that pyrene degradation rates were 88% in 10hr by Py1, 84% in 14hr by Py4, and 88% in 8hr by the consortium. It
was also determined that the best degradation temperatures were 37°C and pH 7.0 respectively. The influence of different nutrient
substrates added in the degradation experiments was also studied. It was shown that sodium salicylate, sodium acetate and
yeast extract had obvious simulative effect, but glucose had no obvious effect.
__________
Translated from Acta Scientiarum Naturalium Universitatis Nankaiensis (Natural Science Edition) 2006, 39: 71–74 [译自: 南开大学学报 (自然科学版)] 相似文献
11.
Bacillus subtilis 115 grew in a medium with amino acids and glucose with the maximum specific growth rates μ of 1.20-1.10/h in the temperature
range of 45–48°C. Activity of the extracellular neutral proteinase excreted by 1.3 mg/mL dry mass during 8 h of the postexponential
and stationary growth phases decreased from its maximum value of 0.23 TU/mL at 40°C to 0.13 and 0.06 TU/mL at 45 and 48°C,
respectively. Formation of the extracellular serine proteinase decreased even more—from 0.18 TU/mL at 40°C to 0.06 and 0.03
TU/mL at 45 at 48°C, respectively. Sporulation, expressed as the portion of sporangia rith refractile spores at the 6th h
of the stationary phase decreased from 46% at 40°C to 17 and 3% at 45 and 48°C, respectively. 相似文献
12.
The regulatory link between biosynthesis of Bacillus intermedius subtilisin-like serine proteinase and nitrogen metabolism in B. intermedius cells was determined. The level of the enzyme biosynthesis by the recombinant strain of Bacillus subtilis in the medium containing ammonium ions was three- to fivefold less than that in the medium with poorly utilized sodium nitrate.
Accumulation of glutamyl endopeptidase in a culture liquid of this microorganism did not depend on the source of nitrogen
present in the medium. During cultivation in the rich medium, the productivity of subtilisin-like proteinase in the recombinant
B. subtilis strain carrying a mutation in the NrgB sensor protein was demonstrated to increase threefold compared to that of the control
strain. In the minimal culture medium, mutation in the nrgB gene abolished the effect of a nitrogen source on the level of the subtilisin-like proteinase gene expression. At the same
time, this mutation did not affect glutamyl endopeptidase biosynthesis. Thus, expression of the gene coding for subtilisin-like
proteinase from B.intermedius is suggested to be positively regulated by the regulatory system of nitrogen metabolism. 相似文献
13.
J. G. Roddick G. Melchers 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1985,70(6):655-660
Summary Analyses of leaves and ‘tubers’ from somatic hybrids of potato and tomato (‘pomato’ with plastids of potato, ‘topato’ with
plastids of tomato) produced by fusion of protoplasts from liquid cultures of dihaploid potato and mesophyll of tomato revealed
the presence of the two major potato glycoalkaloids (α-solanine and α-chaconine) as well as the tomato glycoalkaloid (αtomatine). The total alkaloid content of leaves was greater than that of ‘tubers’ and similar to levels in the foliage of
parent plants. However, glycoalkaloids were more abundant in hybrid ‘tubers’ than in normal potato tubers by a factor of 5–15.
In hybrid foliage, approximately 98% of the alkaloid present was of potato origin whereas in ‘tubers’ the reverse was the
case, with tomatine comprising 60–70% of the total alkaloid. The similarities in alkaloid content and ratios between the pomato
and the topato lines indicate that plastomes do not influence the biosynthesis and distribution of these alkaloids. The results
indicate that major secondary metabolites may prove useful for assessing the hybrid nature of such plants. 相似文献
14.
Cell death after cerebral ischemia is mediated by the accumulation of excitatory amino acids, calcium influx into cells and the generation of free radicals. The aim of this study was to evaluate changes in energy-related metabolites in the striatum of gerbils subjected to focal cerebral ischemia after pretreatment withGinkgo biloba extract (EGb761), a well-known antioxidant, and FK506, a calcium-dependent phosphatase calcineurin inhibitor. Ischemia was induced by occlusion of the right common carotid artery and the right middle cerebral artery for 60 min. A microdialysis probe was inserted into the right striatum to monitor extracellular glucose, lactate and pyruvate levels. This study showed decreases in glucose (10% of the baseline), pyruvate (20% of the baseline) and lactate (60% of the baseline), and a 5-fold increase in the lactate to pyruvate ratio during ischemia in the control group. Both EGb761 treatment and the combination (EGb761 and FK506) therapy significantly preserved glucose (50% of the baseline) and pyruvate (60% of the baseline) levels during ischemia. The marked increase in the lactate to pyruvate ratio was not observed in the combination group. These results suggest that preservation of cellular energy metabolism during cerebral ischemia and after restoration with reperfusion may contribute to the neuroprotective effects of EGb761 and FK506. 相似文献
15.
16.
Sandra Regina B. R. Sella Belquis P. Guizelini Luciana P. S. Vandenberghe Adriane B. P. Medeiros Carlos Ricardo Soccol 《Applied microbiology and biotechnology》2009,82(6):1019-1026
Bacillus atrophaeus’ spores are used in the preparation of bioindicators to monitor the dry heat, ethylene oxide, and plasma sterilization processes
and in tests to assess sterilizing products. Earlier production methods involved culture in chemically defined medium to support
sporulation with the disadvantage of requiring an extended period of time (14 days) besides high cost of substrates. The effect
of cultivation conditions by solid-state fermentation (SSF) was investigated aiming at improving the cost–productivity relation.
Initial SSF parameters such as the type of substrate were tested. Process optimization was carried out using factorial experimental
designs and response surface methodology in which the influence of different variables—particle size, moisture content, incubation
time, pH, inoculum size, calcium sources, and medium composition—was studied. The results have suggested that soybean molasses
and sugarcane bagasse are potential substrate and support, respectively, contributing to a 5-day reduction in incubation time.
Variables which presented significant effects and optimum values were mean particle size (1.0 mm), moisture content (93%),
initial substrate pH (8.0), and water as a solution base. The high-yield spore production was about 3 logs higher than the
control and no significant difference in dry heat resistance was observed. 相似文献
17.
L. A. Gabdrakhmanova E. V. Shakirov N. P. Balaban M. R. Sharipova G. N. Rudenskaya S. V. Kostrov T. V. Akimkina I. B. Leshchinskaya 《Microbiology》2000,69(5):546-551
A nutrient medium was elaborated for the efficient production of glutamyl endopeptidase by the recombinantBacillus subtilis strain AJ73 bearing theBacillus intermedius 3–19 glutamyl endopeptidase gene within a multicopy plasmid. Optimal concentrations of the main nutrients, peptone and inorganic
phosphate, were found using a multifactor approach. To provide for active growth and efficient glutamyl endopeptidase production,
the cultivation medium of the recombinant strain should be enriched in phosphorus, organic and inorganic nitrogen sources,
and yeast extract. Complex protein substrates, such as casein and gelatin, enhanced the biosynthesis of glutamyl endopeptidase.
At the same time, easily metabolizable carbon sources suppressed it. The production of glutamyl endopeptidase was stimulated
by the bivalent cations Ca2+, Mg2+, and Co2+. 相似文献
18.
V. P. Zambare S. S. Nilegaonkar P. P. Kanekar 《World journal of microbiology & biotechnology》2007,23(11):1569-1574
The present investigation describes microbial production of an alkaline protease and its use in dehairing of buffalo hide.
Bacillus cereus produced extracellular protease when grown on a medium containing starch, wheat bran and soya flour (SWS). The ammonium sulphate
precipitated (ASP) enzyme was applied for dehairing of buffalo hide. Microscopic observation of longitudinal section of buffalo
hide revealed that the epidermis was completely removed and hair was uprooted leaving empty follicles in the hide. The ASP
enzyme was stable for one month at ambient temperature between 25–35 °C. Enzymatic dehairing may be a promising shift towards
an environment-friendly leather processing method. 相似文献
19.
Alkaline phosphatase, an enzyme secreted by Bacillus intermedius S3-19 cells to the medium, was also detected in the cell wall, membrane, and cytoplasm. The relative content of alkaline phosphatase in these cell compartments depended on the culture age and cultivation medium. The vegetative growth of B. intermedius on 0.3% lactate was characterized by increased activity of extracellular and membrane-bound phosphatases. The increase in lactate concentration to 3% did not affect the activity of membrane-bound phosphatase but led to a decrease in the activity of the extracellular enzyme. Na2HPO4 at a concentration of 0.01% diminished the activity of membrane-bound and extracellular phosphatases. CoCl2 at a concentration of 0.1 mM released membrane-bound phosphatase into the medium. By the onset of sporulation, phosphatase was predominantly localized in the medium and in the cell wall. As is evident from zymograms, the multiple molecular forms of phosphatase varied depending on its cellular localization and growth phase. 相似文献
20.
Guanyl-specific ribonucleases from Bacillus intermedius and Bacillus pumilus are actively secreted under phosphate starvation by recombinant strains of Bacillus subtilis with native regulatory systems and by strains defective in some proteins of the Spo0A phosphorylation pathway. The level
of expression of ribonuclease genes has been shown to increase approximately sixfold in recombinant strains with mutation
in the spo0A gene and threefold in the spo0A/abrB mutants, as compared with native strains. These results demonstrate that the Spo0A protein regulates the production of ribonucleases
and thus acts as a repressor, while the AbrB protein is an activator of expression of the genes encoding ribonucleases from
Bacillus intermedius and Bacillus pumilus in Bacillus subtilis cells.
Original Russian Text ? V.V. Ul’yanova, V.I. Vershinina, M.A. Kharitonova, M.R. Sharipova, 2007, published in Mikrobiologiya,
2007, Vol. 76, No. 5, pp. 639–644. 相似文献