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1.
Summary By employing wide ranges in vitamin concentrations in biotin basal mineral synthetic medium, it was demonstrated that vitamin B12 markedly stimulated the growth ofCandida albicans, the organism showing a partial dependency upon this vitamin. Growth inhibition by 5-fluorouracil was reversed non-competitively by vitamin B12, suggesting that B12 has a role in nucleic acid biosynthesis of the organism. Thiamine was growth stimulatory, the organism being partially dependent upon this vitamin as well. Neopyrithiamine and oxythiamine were growth inhibitory in thiamine-free biotin basal mineral synthetic medium although the halves of each inhibitor compound were non-inhibitory. Neopyrithiamine inhibition was reversed by intact thiamine but not by pyrimidine thiamine or thiazole thiamine; while oxythiamine inhibition was reversed by thiamine and pyrimidine thiamine but not by thiazole thiamine, the inference being drawn that oxythiamine selectively blocks utilization of pyrimidine thiamine. Twenty-seven different substituted pyrimidines, thiazoles and related thiamine compounds were all utilizable byC. albicans in thiamine-free basal synthetic mineral medium, the organism presumably synthesizing thiamine when presented with the constituent parts of these thiamine analogues. Substitution of sulfur of the thiazole ring with oxygen, as in -methyloxazolium, failed to produce an inhibitory compound forC. albicans. Acetylthiamine, allithiamine, cocarboxylase, tetrahydrothiamine and dihydrothiamine were equally as growth stimulatory as thiamine. 相似文献
2.
Saccharomyces carlsbergensis 4228, an organism widely used for determination of vitamin B6, grows well without this vitamin if thiamine is also omitted from the basal medium, and an inoculum grown in a thiamine-low medium is used. Thiamine inhibits growth when added to such a medium. The thiazole moiety of thiamine, but not the pyrimidine, is also inhibitory, but less so than thiamine itself.Growth inhibition by thiamine is prevented by vitamin B6. At low concentrations of thiamine, the amount of vitamin B6 required for growth increases with the thiamine concentration; at concentrations of thiamine above 1 μg./10 ml. the vitamin B6 requirement for growth remains essentially constant. Since these higher concentrations of thiamine have been used in methods that utilize this organism for determination of vitamin B6 (1,2), the validity of these methods is confirmed.In the presence of thiamine, growth was also permitted by additions of the thiamine antagonist, neopyrithiamine. In this case, however, the relationship was fully competitive; i.e., the amount of neopyrithiamine required for growth increased regularly with the thiamine concentration. At concentrations considerably higher than those required for growth, neopyrithiamine again inhibited growth, and this inhibition was prevented by an increase in the thiamine concentration. Thus neopyrithiamine acts by lowering the effective thiamine concentration to subinhibitory levels; if excessive amounts are used, it prevents essential metabolic functions of thiamine and itself becomes toxic. The mechanism by which vitamin B6 prevents thiamine toxicity is not known.The appearance of a requirement for certain growth factors because of inhibitory effects of other metabolically important compounds, rather than because of an intrinsic inability of the organism to synthesize the growth factor, may be much more common than the few recorded instances of this phenomenon indicate. 相似文献
3.
Inhibition of Thiamine Pyrophosphate Utilization by Thiamine or Its Monophosphate in Escherichia coli
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The growth of a thiamine pyrophosphate auxotroph of Escherichi coli was inhibited by either thiamine or thiamine monophosphate, and the growth of a thiamine monophosphate auxotroph was inhibited by thiamine. The thiamine pyrophosphate-dependent oxidation of pyruvate was inhibited by thiamine with whole cells of the thiamine pyrophosphate auxotroph but not with cell extracts prepared from the same organism. In addition, the thiamine pyrophosphate uptake of the thiamine pyrophosphate auxotroph was inhibited by either thiamine or thiamine monophosphate. Although the thiamine pyrophosphate uptake of a revertant, selected for prototrophy from the thiamine monophosphate auxotroph, was inhibited by thiamine to an extent comparable to that observed with the thiamine monophosphate auxotroph, its growth was no longer inhibited by thiamine. A possible mechanism for the inhibition by thiamine and thiamine monophosphate in the utilization of thiamine pyrophosphate is discussed. 相似文献
4.
Palmitic acid was inhibitory to the growth of Brochothrix thermosphacta in liquid culture at 0.5 mmol/l. Uptake of [1-14 C]-palmitic acid by the organism has been demonstrated, and was reduced at acid pH. These findings are discussed in relation to the known effects of fatty acids on bacteria. 相似文献
5.
G. E. Wessman 《Applied microbiology》1965,13(3):426-431
The growth of Pasteurella haemolytica strain H44L was studied under aerobic conditions in a medium of acid-hydrolyzed casein, supplementary cysteine, inorganic salts, vitamins, and a carbon source. The concentration of casein hydrolysate necessary for optimal growth was 1.5 or 2.0%, depending upon the carbon source employed. Essential vitamins were calcium pantothenate, nicotinamide, and thiamine. Concentrations as low as 0.01 mug/ml of thiamine monophosphate or thiamine pyrophosphate supported maximal growth, but thiamine hydrochloride or thiamine nitrate were active only at the unusually high levels of 10 to 20 mug/ml. The best carbon sources were d-galactose or sucrose. Maximal growth resulted from an inoculum containing fewer than 10 cells per milliliter of medium. Cellular yields averaged 6 x 10 to 7 x 10 cells per milliliter for the test organism and five other strains of P. haemolytica isolated from cases of bovine respiratory diseases. 相似文献
6.
Marvin H. Cantor 《Current microbiology》1978,1(6):349-351
The effects of thiamine deprivation on the growth, respiration, and activity of several enzymes of the phytoflagellate protozoanPolytomella agilis were studied. Vitamin deprivation had no effect on the exponential growth rate; the peak population of cultures grown without
thiamine was 50% of the control level. The rates of oxygen consumption in control and thiamine-deprived cultures were not
significantly different from each other. The activities of pyruvate dehydrogenase and oxoglutarate dehydrogenase in vitamin-deprived
cells were 14% and 30%, respectively, of the control values. In these cells, the succinic dehydrogenase activity was 10% and
mitochondrial ATPase activity was twice that of control cells. Vitamin deprivation had no effect on the activities of malate
dehydrogenase and isocitrate lyase, but pyruvic carboxylase activity increased fourfold. These results indicate a complex
role for thiamine in the regulation of growth, respiration, and metabolism in this organism. 相似文献
7.
Stoffel SA Rodenko B Schweingruber AM Mäser P de Koning HP Schweingruber ME 《International journal for parasitology》2006,36(2):229-236
Bloodstream forms of Trypanosoma brucei brucei were cultivated in the presence and absence of thiamine (vitamin B1) and pyridoxine (vitamin B6). The vitamins do not change growth behaviour, indicating that Trypanosoma brucei is prototrophic for the two vitamins even though in silico no bona-fide thiamine-biosynthetic genes could be identified in the T. brucei genome. Intracellularly, thiamine is mainly present in its diphosphate form. We were unable to detect significant uptake of [3H]thiamine and structural thiamine analogues such as pyrithiamine, oxithiamine and amprolium were not toxic for the bloodstream forms of T. brucei, indicating that the organism does not have an efficient uptake system for thiamine and its analogues. We have previously shown that, in the fission yeast Saccharomyces pombe, the toxicity of melarsen oxide, the pharmacologically active derivative of the frontline sleeping sickness drug melarsoprol, is abolished by thiamine and the drug is taken up by a thiamine-regulated membrane protein which is responsible for the utilization of thiamine. We show here that thiamine also has weak effects on melarsen oxide-induced growth inhibition and lysis in T. brucei. These effects were consistent with a low affinity of thiamine for the P2 adenosine transporter that is responsible for uptake of melaminophenyl arsenicals in African trypanosomes. 相似文献
8.
Factors affecting growth and lipase production by meat lactobacilli strains and Brochothrix thermosphacta 总被引:2,自引:2,他引:0
Lipolytic activity of lactobacilli strains and Brochothrix thermosphacta was cellrelated; no significant activity was found in the supernatant fluids. Most lipase was produced during the logarithmic phase of growth and was greatly affected by growth conditions. The optimal temperatures for growth and lipase production were respectively 24°C for B. thermosphacta and 30°C for lactobacilli. For all strains, an initial pH of around 7-0 for the medium and low glucose concentration stimulated lipase production. Tributyrin inhibited both growth and lipase production at a concentration of 0-1% for B. thermosphacta or 1% for lactobacilli. Butyric acid (0-1%) and anaerobic culture inhibited lipase production by B. thermosphacta while these two factors had no effect on enzyme production by lactobacilli. 相似文献
9.
S.C. Stringer B.J. Chaffey C.E.R. Dodd M.R.A. Morgan W.M. Waites 《Journal of applied microbiology》1995,78(4):335-340
S.C. STRINGER, B.J. CHAFFEY, C.E.R. DODD, M.R.A. MORGAN AND W.M. WAITES. 1995. A rabbit polyclonal antibody-linked probe was developed which detected 76% of 800 food isolates of the spoilage bacterium Brochothrix thermosphacta when cells were bound to nitrocellulose. In slide cross-reaction tests all six environmental isolates tested were stained but the type strain was not. The antibody did not cross-react with Listeria grayi, L. monocytogenes, Lactobacillus plantarum, Lactococcus lactis, Streptococcus mutans, Bacillus cereus or B. subtilis.
The antibody-linked probe detected Br. thermosphacta in thin sections of British fresh sausage when the viable count was greater than 106 g−1 Cells were detected mainly within 1 or 2 mm of the surface on the loose starchy material. They were not detected within muscle blocks or in the centre of the sausage. Such results suggest that growth of this organism occurs close to the surface of the sausage. 相似文献
The antibody-linked probe detected Br. thermosphacta in thin sections of British fresh sausage when the viable count was greater than 10
10.
The effects of different gaseous atmospheres were determined on the maximum specific growth rate (mumax) and end-product formation by Brochothrix thermosphacta ATCC 11509T, Lactobacillus viridescens SMRICC 174 and Lactobacillus sp. SMRICC 173 (homofermentative). The highest mumax-values for Lact. viridescens (0.47/h) and Broc. thermosphacta (0.49/h) were obtained in air. Under anaerobic conditions mumax was reduced, an atmosphere containing CO2 alone giving the greatest reduction. Lactobacillus sp. 173 did not grow in air or N2. Aerobic growth was obtained by adding peroxidase while anaerobic growth occurred in the presence of 5-20% CO2. Carbon dioxide alone reduced the growth rate. All test organisms produced mainly lactic acid anaerobically. Lactobacillus viridescens also produced ethanol while Broc. thermosphacta produced small amounts of ethanol and formic acid. With O2 present, the number of end-products increased for all organisms. Lactobacillus sp. 173 produced small amounts of acetic acid and acetoin together with lactic acid. Oxygen induced acetic acid production in Lact. viridescens and Broc. thermosphacta. Aerobically, Broc. thermosphacta also produced a large amount of acetoin and smaller amounts of 2,3-butanediol, iso-valeric acid and iso-butyric acid. The production of lactic acid by Broc. thermosphacta was completely prevented under strictly aerobic conditions. All test organisms consumed O2 during aerobic growth. Hydrogen peroxide was produced by Lact. viridescens and Lactobacillus sp. 173. 相似文献
11.
Vitreoscilla stercoraria ATCC 15218 was studied to elucidate some of its physiological characteristics. The initial optimal pH for the organism was found to be 7.5 to 7.7. The characteristics of the growth curve of the organism showed that its growth in shake cultures is by increasing trichome number up to approximately 15 hr and by increasing trichome length after 15 hr. Nutritional studies indicated that it is auxotrophic for biotin, thiamine, and l-arginine, and it appears to be an obligate amino acid utilizer because only protein hydrolysates or known amino acid mixtures would support growth. 相似文献
12.
Factors affecting growth and lipase production by meat lactobacilli strains and Brochothrix thermosphacta 总被引:2,自引:0,他引:2
Lipolytic activity of lactobacilli strains and Brochothrix thermosphacta was cell-related; no significant activity was found in the supernatant fluids. Most lipase was produced during the logarithmic phase of growth and was greatly affected by growth conditions. The optimal temperatures for growth and lipase production were respectively 24 degrees C for B. thermosphacta and 30 degrees C for lactobacilli. For all strains, an initial pH of around 7.0 for the medium and low glucose concentration stimulated lipase production. Tributyrin inhibited both growth and lipase production at a concentration of 0.1% for B. thermosphacta or 1% for lactobacilli. Butyric acid (0.1%) and anaerobic culture inhibited lipase production by B. thermosphacta while these two factors had no effect on enzyme production by lactobacilli. 相似文献
13.
Bartnicki-Garcia, S. (Rutgers, the State University, New Brunswick, N. J.), and Walter J. Nickerson. Thiamine and nicotinic acid: Anaerobic growth factors for Mucor rouxii. J. Bacteriol. 82:142-148. 1961.-Mucor rouxii requires preformed thiamine and nicotinic acid for anaerobic growth. Such requirements are not manifested during aerobic incubation. Aerobically, the fungus was shown to be able to synthesize both vitamins.The yeastlike form and the filamentous form of anaerobically grown M. rouxii exhibit the same vitamin requirements.Thiamine can be substituted by its thiazole moiety. Under certain conditions, nicotinic acid was partly substituted by tryptophan, kynurenine, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid.Anaerobically. the fungus (thiamine requiring) was about ten times more susceptible to pyrithiamine antagonism than the same organism grown aerobically (thiamine independent). 相似文献
14.
Thiamine participates in neuromuscular transmission. This transmission is depressed when thiamine level in organism decreases and it is normalized in animals after thiamine injection. 相似文献
15.
The effects of different gaseous atmospheres were determined on the maximum specific growth rate (μmax ) and end-product formation by Brochothrix thermosphacta ATCC 11509T , Lactobacillus viridescens SMRICC 174 and Lactobacillus sp. SMRICC 173 (homofermentative). The highest μmax -values for Lact. viridescens (0.47/h) and Broc. thermosphacta (0.49/h) were obtained in air. Under anaerobic conditions μmax was reduced, an atmosphere containing CO2 alone giving the greatest reduction. Lactobacillus sp. 173 did not grow in air or N2 . Aerobic growth was obtained by adding peroxidase while anaerobic growth occurred in the presence of 5–20% CO2 . Carbon dioxide alone reduced the growth rate. All test organisms produced mainly lactic acid anaerobically. Lactobacillus viridescens also produced ethanol while Broc. thermosphacta produced small amounts of ethanol and formic acid. With O2 present, the number of end-products increased for all organisms. Lactobacillus sp. 173 produced small amounts of acetic acid and acetoin together with lactic acid. Oxygen induced acetic acid production in Lact. viridescens and Broc. thermosphacta . Aerobically, Broc. thermosphacta also produced a large amount of acetoin and smaller amounts of 2,3-butanediol, iso -valeric acid and iso -butyric acid. The production of lactic acid by Broc. thermosphacta was completely prevented under strictly aerobic conditions. All test organisms consumed O2 during aerobic growth. Hydrogen peroxide was produced by Lact. viridescens and Lactobacillus sp. 173. 相似文献
16.
Grau FH 《Applied and environmental microbiology》1980,40(3):433-436
Brochothrix thermosphacta can grow aerobically in the presence of 210 mM l-lactate and anaerobically in its absence at pH values down to at least 5.5. Anaerobic growth is, however, inhibited by l-lactate, the concentration of undissociated lactic acid being the governing factor. Postrigor meat usually contains sufficient lactic acid to select against the anaerobic growth of B. thermosphacta. At least some Lactobacillaceae strains are more resistant to lactic acid and so their growth is favored on vacuum-packaged meat. 相似文献
17.
Penetration of thiamine and its metabolites through the liver mitochondria and blood cells of white rats has been studied. It is shown that the catabolic forms of thiamine, thiochrome and 4-methyl-5 oxyethylthiasole penetrate through the mitochondria membranes at a larger extent than thiamine and its phosphoric esters. An increase in concentration of thiamine and its metabolites in the incubation medium from 0.1 mM to 3.2 mM leads to intensification of this process. The larger permeability of thiochrome and 4-methyl-5 oxyethylthiasole through biological membranes permits explaining the principles of catabolic thiamine forms removal from the tissues and organism. 相似文献
18.
Incorporation of nisin into a meat binding system to inhibit bacteria on beef surfaces 总被引:1,自引:0,他引:1
In two separate experiments, the bacteriocin, nisin, was incorporated into a commercially available meat binding system (Fibrimex® ) and applied to meat surfaces as a way of inhibiting the meat spoilage organism, Brochothrix thermosphacta during extended refrigerated storage. In experiment 1, pre-rigor lean beef carcass tissue (BCT) was inoculated with B. thermosphacta , left untreated (U), treated with 10 μg ml−1 nisin (N), Fibrimex® (F) or Fibrimex® containing 10 μg ml−1 nisin (FN), held aerobically at 4 °C for up to 7 d, and populations of B. thermosphacta and nisin activity determined. Experiment 2 determined the effects of the same treatments but on post-rigor, frozen and thawed lean BCT that was inoculated, vacuum-packaged, and stored at 4 °C for up to 14 d. In both experiments, N- and FN-treated tissues exhibited significantly lower populations of B. thermosphacta compared to U- and F-treated tissues, for the duration of refrigerated storage. Nisin activity was detected up to 7 d in N- and FN-treated samples from experiment 1. However, activity was detected only to days 0 and 2 in FN- and N-treated samples, respectively, from experiment 2. These studies indicate that the addition of a bacteriocin to a meat binding system and application to meat surfaces may be useful in reducing undesirable bacteria in restructured meat products. 相似文献
19.
The influence of glucose concentration and culture incubation time on end-product formation during aerobic growth of Brochothrix thermosphacta 总被引:3,自引:3,他引:0
Fifteen strains of Brochothrix thermosphacta , isolated from various meat sources, produced the same end-products during aerobic growth in a tryptone-based medium containing 0.2% (w/v) glucose. Growth of one strain at different glucose concentrations showed that 2-methylpropanol and 2,3-butanediol were also produced. Formation of the branched chain acids was favoured by low glucose concentrations, that of the alcohols and the diol by higher concentrations. The traces of the diol, but not those of the alcohols, produced during the early stages of growth at low, limiting concentrations of glucose, gradually disappeared following glucose depletion. These findings provide adequate explanations for the observed differences in end-product formation during growth of Broc. thermosphacta on non-processed and corned beef. 相似文献
20.
E Blickstad 《Applied and environmental microbiology》1983,46(6):1345-1350
Lactobacillus viridescens, Lactobacillus sp. strain 173 (homofermentative), and Brochothrix thermosphacta ATCC 11509T were studied at different pH values and temperatures in aerobic and anaerobic batch cultures. The growth rates were higher in aerobic than in anaerobic cultures. L. viridescens grew faster at pH 5.8 than at pH 6.3, whereas the opposite was true for B. thermosphacta. Lactobacillus sp. strain 173 was inhibited in air or at 8 degrees C in anaerobic culture. B. thermosphacta did not grow in anaerobic culture at pH 5.3. The following variations in growth yields were found in the different environments studied: Lactobacillus sp. strain 173, 23 to 25 g (dry weight) per mol of glucose consumed; L. viridescens, 11 to 23 g/mol; B. thermosphacta, 16 to 38 g/mol. In air, L. viridescens produced D-lactic acid, ethanol, and acetic acid, whereas no acetic acid was produced anaerobically. Acetic acid and ethanol together constituted 41 to 48% of the total product yield irrespective of pH and temperature. Lactobacillus sp. strain 173 produced a racemic mixture of D- and L-lactic acid at pH 6.3, whereas the proportion of L-lactic acid was higher than that of D-lactic acid at pH 5.3. In air, product formation of B. thermosphacta varied from a domination of L-lactic acid to increasing yields of acetoin, acetic acid, 2,3-butanediol and isovaleric acid. The effect of pH and temperature on product formation was difficult to separate from the effect of O2 availability in aerobic cultures. However, it was indicated that more 2,3-butanediol and less acetoin were produced with a decreasing temperature.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献