scholarly journals Sinorhizobium meliloti Cells Require Biotin and either Cobalt or Methionine for Growth

2001 ◽  
Vol 67 (8) ◽  
pp. 3767-3770 ◽  
Author(s):  
Robert J. Watson ◽  
Roselyn Heys ◽  
Teresa Martin ◽  
Marc Savard
Keyword(s):  
Growth Factors ◽  
Yeast Extract ◽  
Sinorhizobium Meliloti ◽  
Minimal Medium ◽  
Vitamin B ◽  
Methionine Biosynthesis ◽  
Rich Media ◽  
Homocysteine Methyltransferase

ABSTRACT Sinorhizobium meliloti is usually cultured in rich media containing yeast extract. It has been suggested that some components of yeast extract are also required for growth in minimal medium. We tested 27 strains of this bacterium and found that none were able to grow in minimal medium when methods to limit carryover of yeast extract were used during inoculation. By fractionation of yeast extract, two required growth factors were identified. Biotin was found to be absolutely required for growth, whereas previously the need for this vitamin was considered to be strain specific. All strains also required supplementation with cobalt or methionine, consistent with the requirement for a vitamin B12-dependent homocysteine methyltransferase for methionine biosynthesis.

scholarly journals Interrelations between Glycine Betaine Catabolism and Methionine Biosynthesis in Sinorhizobium meliloti Strain 102F34

2006 ◽  
Vol 188 (20) ◽  
pp. 7195-7204 ◽  
Author(s):  
Lise Barra ◽  
Catherine Fontenelle ◽  
Gwennola Ermel ◽  
Annie Trautwetter ◽  
Graham C. Walker ◽  
...  
Keyword(s):  
Glycine Betaine ◽  
Sinorhizobium Meliloti ◽  
Wild Type Strain ◽  
Methionine Synthase ◽  
Vitamin B ◽  
Wild Type ◽  
Methionine Biosynthesis ◽  
Catabolic Pathway ◽  
Methyl Transferase ◽  
Meliloti Strain

ABSTRACT Methionine is produced by methylation of homocysteine. Sinorhizobium meliloti 102F34 possesses only one methionine synthase, which catalyzes the transfer of a methyl group from methyl tetrahydrofolate to homocysteine. This vitamin B12-dependent enzyme is encoded by the metH gene. Glycine betaine can also serve as an alternative methyl donor for homocysteine. This reaction is catalyzed by betaine-homocysteine methyl transferase (BHMT), an enzyme that has been characterized in humans and rats. An S. meliloti gene whose product is related to the human BHMT enzyme has been identified and named bmt. This enzyme is closely related to mammalian BHMTs but has no homology with previously described bacterial betaine methyl transferases. Glycine betaine inhibits the growth of an S. meliloti bmt mutant in low- and high-osmotic strength media, an effect that correlates with a decrease in the catabolism of glycine betaine. This inhibition was not observed with other betaines, like homobetaine, dimethylsulfoniopropionate, and trigonelline. The addition of methionine to the growth medium allowed a bmt mutant to recover growth despite the presence of glycine betaine. Methionine also stimulated glycine betaine catabolism in a bmt strain, suggesting the existence of another catabolic pathway. Inactivation of metH or bmt did not affect the nodulation efficiency of the mutants in the 102F34 strain background. Nevertheless, a metH strain was severely defective in competing with the wild-type strain in a coinoculation experiment.

Croissance et activité cellulaire du Brevibacterium casei NCDO 2049 dans du perméat de lactosérum

1997 ◽  
Vol 43 (12) ◽  
pp. 1180-1188
Author(s):  
K. M. Oulé ◽  
G. Turcotte ◽  
Y. Beaulieu
Keyword(s):  
Growth Factors ◽  
Yeast Extract ◽  
Culture Medium ◽  
Nitrogen Sources ◽  
Inhibitory Effect ◽  
Vitamin B ◽  
Cellular Activity ◽  
Whey Permeate ◽  
The Media ◽  
Influence Of Ph

Growth and cellular activity of Brevibacterium casei NCDO 2049 were studied in a whey permeate as basic culture medium. The possible inhibitory effect of the carbone substrate (undiluted or diluted permeate) on growth was investigated as well as the influence of pH of the media (controlled or not) and of the addition of nitrogen sources (organic or inorganic) or growth factors such as yeast extract or vitamin B12. Growth in undiluted permeate produced a maximal biomass (6.5 × 109 cfu/mL) that was nearly twice as much as that in diluted permeate (3.8 × 109 cfu/mL). The carbone substrate (lactose) had no inhibitory effect on growth. In undiluted permeate and an uncontrolled pH, maximal biomass was reached after 36 h of incubation, while in a pH controlled medium, twice as much time was required to obtain an equivalent biomass. In undiluted permeate and an uncontrolled pH, growth in the presence of peptone reached 22.6 × 109 cfu/mL and, in the presence of (NH4)2SO4, 12.4 × 109 cfu/mL. Adding growth factors to media with peptone resulted in the reduction of 90% of initial lactose in the presence of yeast extract and of 75% in the presence of B12 vitamin. This study indicates the possibility of reducing lactose in whey permeate when cultivating strains of the genus Brevibacterium used as maturing bacteria for certain cheese types.Key words: whey permeate, Brevibacterium casei, lactose.[Journal translation]

scholarly journals The Lipid Lysyl-Phosphatidylglycerol Is Present in Membranes of Rhizobium tropici CIAT899 and Confers Increased Resistance to Polymyxin B Under Acidic Growth Conditions

2007 ◽  
Vol 20 (11) ◽  
pp. 1421-1430 ◽  
Author(s):  
Christian Sohlenkamp ◽  
Kanaan A. Galindo-Lagunas ◽  
Ziqiang Guan ◽  
Pablo Vinuesa ◽  
Sally Robinson ◽  
...  
Keyword(s):  
Sinorhizobium Meliloti ◽  
Minimal Medium ◽  
Polymyxin B ◽  
Growth Conditions ◽  
Membrane Lipid ◽  
Low Ph ◽  
Wild Type ◽  
Rhizobium Tropici ◽  
Gram Negative ◽  
Inducible Genes

Lysyl-phosphatidylglycerol (LPG) is a well-known membrane lipid in several gram-positive bacteria but is almost unheard of in gram-negative bacteria. In Staphylococcus aureus, the gene product of mprF is responsible for LPG formation. Low pH-inducible genes, termed lpiA, have been identified in the gram-negative α-proteobacteria Rhizobium tropici and Sinorhizobium medicae in screens for acid-sensitive mutants and they encode homologs of MprF. An analysis of the sequenced bacterial genomes reveals that genes coding for homologs of MprF from S. aureus are present in several classes of organisms throughout the bacterial kingdom. In this study, we show that the expression of lpiA from R. tropici in the heterologous hosts Escherichia coli and Sinorhizobium meliloti causes formation of LPG. A wild-type strain of R. tropici forms LPG (about 1% of the total lipids) when the cells are grown in minimal medium at pH 4.5 but not when grown in minimal medium at neutral pH or in complex tryptone yeast (TY) medium at either pH. LPG biosynthesis does not occur when lpiA is deleted and is restored upon complementation of lpiA-deficient mutants with a functional copy of the lpiA gene. When grown in the low-pH medium, lpiA-deficient rhizobial mutants are over four times more susceptible to the cationic peptide polymyxin B than the wild type.

Betaine: a key modulator of one-carbon metabolism and homocysteine status

2005 ◽  
Vol 43 (10) ◽  
Author(s):  
Per Magne Ueland ◽  
Pål I. Holm ◽  
Steinar Hustad
Keyword(s):  
Carbon Metabolism ◽  
Individual Variability ◽  
Vitamin B ◽  
Total Homocysteine ◽  
Altered Metabolism ◽  
One Carbon Metabolism ◽  
And Gender ◽  
Betaine Homocysteine Methyltransferase ◽  
Plasma Total Homocysteine ◽  
Homocysteine Methyltransferase

AbstractBetaine serves as a methyl donor in a reaction converting homocysteine to methionine, catalysed by the enzyme betaine-homocysteine methyltransferase. It has been used for years to lower the concentration of plasma total homocysteine (tHcy) in patients with homocystinuria, and has recently been shown to reduce fasting and in particular post-methionine load (PML) tHcy in healthy subjects.Betaine exists in plasma at concentrations of about 30μmol/L; it varies 10-fold (from 9 to 90μmol/L) between individuals, but the intra-individual variability is small. Major determinants are choline, dimethylglycine and folate in plasma, folic acid intake and gender.Recent studies have demonstrated that plasma betaine is a stronger determinant of PML tHcy than are vitamin BTo conclude, betaine status is a component of an individual's biochemical make-up with ramifications to one-carbon metabolism. Betaine status should be investigated in pathologies related to altered metabolism of homocysteine and folate, including cardiovascular disease, cancer and neural tube defects.

scholarly journals The growth of Paracoccus halodenitrificans in a defined medium

1984 ◽  
Vol 30 (6) ◽  
pp. 837-840 ◽  
Author(s):  
Lawrence I. Hochstein ◽  
Geraldine A. Tomlinson
Keyword(s):  
Synthetic Medium ◽  
Carbon Sources ◽  
Defined Medium ◽  
Anaerobic Growth ◽  
Inorganic Salts ◽  
Vitamin B ◽  
Aerobic Growth ◽  
Methionine Biosynthesis ◽  
Dependent Pathway

A synthetic medium, consisting of inorganic salts and any of a number of carbon sources, supported the aerobic growth of Paracoccus halodenitrificans when supplemented with thiamine. The same medium plus an appropriate nitrogenous oxide supported anaerobic growth when additionally supplemented with methionine. The observation that vitamin B12 or betaine replaced methionine suggested that P. halodenitrificans had a defect in the cobalamin-dependent pathway for methionine biosynthesis, as well as the inability to synthesize betaine when growing anaerobically.

DECOMPOSITION OF CHLORO-SUBSTITUTED ALIPHATIC ACIDS BY SOIL BACTERIA

1957 ◽  
Vol 3 (2) ◽  
pp. 151-164 ◽  
Author(s):  
H. L. Jensen
Keyword(s):  
Amino Acids ◽  
Yeast Extract ◽  
Soil Bacteria ◽  
Basal Medium ◽  
Soil Extract ◽  
Taxonomic Position ◽  
Vitamin B ◽  
Selective Media ◽  
Aliphatic Acids

Three groups of bacteria capable of decomposing chloro-substituted aliphatic acids were isolated from soil by means of selective media. A group of Pseudomonas-like bacteria (A) decomposed monochloroacetate (and monobromoacetate) readily in media with yeast extract, peptone, or amino acids. They also decomposed α-monochloropropionate with moderate vigor, but had little effect on dichloro-acetate and -propionate, and none on trichloroacetate. A non-sporeforming bacterium of uncertain taxonomic position (B) was able to decompose trichloroacetate in media containing soil extract or vitamin B12, and also in basal medium when associated with vitamin B12-producing strains of Streptomyces. Dichloroacetate was only slightly attacked, and monochloroacetate and α-dichloropropionate not at all. A group of bacteria (C) apparently belonging to Agrobacterium decomposed α-dichloropropionate and dichloroacetate, but was less active towards α-monochloropropionate, and did not attack mono- and tri-chloroacetate. The organisms of groups B and C grew only feebly in ordinary media. The decomposition of monochloroacetate, trichloroacetate, and α-dichloropropionate in soil was accelerated by addition of cell suspensions of groups A, B, and C, respectively. The organisms seemed to be more active in the soil than in vitro.

Citrus Residues Isolates Improve Astaxanthin Production by Xanthophyllomyces dendrorhous

2010 ◽  
Vol 65 (9-10) ◽  
pp. 594-598 ◽  
Author(s):  
Wei Wu ◽  
Mingbo Lu ◽  
Longjiang Yu
Keyword(s):  
Carbon Source ◽  
Yeast Extract ◽  
Minimal Medium ◽  
Wild Strain ◽  
Xanthophyllomyces Dendrorhous ◽  
Citrus Juice ◽  
Astaxanthin Production ◽  
Mutant Strains

The wild strain and two astaxanthin-overproducing mutant strains, W618 and GNG274, of Xanthophyllomyces dendrorhous were analyzed in order to assess their ability to grow and synthesize astaxanthin in a minimal medium containing (per liter): 2 g KH2PO4, 0.5 g MgSO4, 2 g KNO3, and 1 g yeast extract, and supplemented with citrus residues isolates as a carbon source (citrus medium). The selected strain W618 was evaluated under various contents of citrus juice. At the content of 20% (v/v), the highest astaxanthin production reached 22.63 mg L-1, which was two-fold more than that observed in yeast malt medium. Addition of 8% (v/v) n-hexadecane to the citrus medium was found to be optimal, increasing the astaxanthin yield by 21.7%.

scholarly journals Effects of Epiphytic Enterobacteriaceae and Pseudomonads on the Growth of Listeria monocytogenes in Model Media

2001 ◽  
Vol 64 (5) ◽  
pp. 721-724 ◽  
Author(s):  
J. DEL CAMPO ◽  
F. CARLIN ◽  
C. NGUYEN-THE
Keyword(s):  
Amino Acids ◽  
Listeria Monocytogenes ◽  
Yeast Extract ◽  
Inhibitory Activity ◽  
Minimal Medium ◽  
Pseudomonas Chlororaphis ◽  
Enterobacter Agglomerans ◽  
Minimally Processed ◽  
Yeast Extract Medium ◽  
Extract Medium

Four Enterobacteriaceae (Enterobacter agglomerans and Rhanella aquatilis) and six pseudomonads (Pseudomonas fluorescens, Pseudomonas chlororaphis, Pseudomonas putida) isolated from minimally processed green endive were coinoculated at 10°C with Listeria monocytogenes in a minimal medium. Pseudomonads did not modify the growth of L. monocytogenes, whereas Enterobacteriaceae reduced its maximal population by 2 to 3 log CFU/ml. The same effect was observed in a diluted yeast extract medium supplemented with amino acids and glucose, in which L. monocytogenes grown alone reached 109 to 1010 CFU/ml. In the same diluted yeast extract medium, not supplemented with glucose and amino acids, the maximal population of L. monocytogenes in the presence of both Enterobacteriaceae and pseudomonads was only slightly reduced (less than 0.5 log CFU/ml). Culture filtrates of the Enterobacteriaceae had no inhibitory activity on L. monocytogenes. The effect of the Enterobacteriaceae on L. monocytogenes growth was presumably due to a competition for glucose and/or amino acids.

scholarly journals De novo cobalamin biosynthesis, transport and assimilation and cobalamin-mediated regulation of methionine biosynthesis in Mycobacterium smegmatis

2020 ◽  
Author(s):  
Terry Kipkorir ◽  
Gabriel T. Mashabela ◽  
Timothy J. De Wet ◽  
Anastasia Koch ◽  
Lubbe Wiesner ◽  
...  
Keyword(s):  
Mycobacterium Smegmatis ◽  
De Novo ◽  
Time Lapse ◽  
Methionine Synthase ◽  
Vitamin B ◽  
Human Pathogen ◽  
Methionine Biosynthesis ◽  
Gene And Protein Expression ◽  
Cobalamin Biosynthesis

ABSTRACTCobalamin is an essential co-factor in all domains of life, yet its biosynthesis is restricted to some bacteria and archaea. Mycobacterium smegmatis, an environmental saprophyte frequently used as surrogate for the obligate human pathogen, M. tuberculosis, carries approximately 30 genes predicted to be involved in de novo cobalamin biosynthesis. M. smegmatis also encodes multiple cobalamin-dependent enzymes, including MetH, a methionine synthase which catalyses the final reaction in methionine biosynthesis. In addition to metH, M. smegmatis possesses a cobalamin-independent methionine synthase, metE, suggesting that enzyme selection – MetH or MetE – is regulated by cobalamin availability. Consistent with this notion, we previously described a cobalamin-sensing riboswitch controlling metE expression in M. tuberculosis. Here, we apply a targeted mass spectrometry-based approach to confirm de novo cobalamin biosynthesis in M. smegmatis during aerobic growth in vitro. We also demonstrate that M. smegmatis transports and assimilates exogenous cyanocobalamin (CNCbl; a.k.a. vitamin B12) and its precursor, dicyanocobinamide ((CN)2Cbi). Interestingly, the uptake of CNCbl and (CN)2Cbi appears restricted in M. smegmatis and dependent on the conditional essentiality of the cobalamin-dependent methionine synthase. Using gene and protein expression analyses combined with single-cell growth kinetics and live-cell time-lapse microscopy, we show that transcription and translation of metE are strongly attenuated by endogenous cobalamin. These results support the inference that metH essentiality in M. smegmatis results from riboswitch-mediated repression of MetE expression. Moreover, differences observed in cobalamin-dependent metabolism between M. smegmatis and M. tuberculosis provide some insight into the selective pressures which might have shaped mycobacterial metabolism for pathogenicity.IMPORTANCEAccumulating evidence suggests that alterations in cobalamin-dependent metabolism marked the evolution of Mycobacterium tuberculosis from an environmental ancestor to an obligate human pathogen. However, the roles of cobalamin in mycobacterial physiology and pathogenicity remain poorly understood. We used the non-pathogenic saprophyte, M. smegmatis, to investigate the production of cobalamin, transport and assimilation of cobalamin precursors, and the potential role of cobalamin in regulating methionine biosynthesis. We provide biochemical and genetic evidence confirming constitutive de novo cobalamin biosynthesis in M. smegmatis under standard laboratory conditions, in contrast with M. tuberculosis, which appears to lack de novo cobalamin biosynthetic capacity. We also demonstrate that the uptake of cyanocobalamin (vitamin B12) and its precursors is restricted in M. smegmatis, apparently depending on the need to service the co-factor requirements of the cobalamin-dependent methionine synthase. These observations support the utility of M. smegmatis as a model to elucidate key metabolic adaptations enabling mycobacterial pathogenicity.

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