Synthesis of vitamin B12 and B12-like compound by Streptomyces olivaceus.
01 Sep 1956-Archives of Biochemistry and Biophysics (Arch Biochem Biophys)-Vol. 64, Iss: 1, pp 67-73
TL;DR: Phenylenediamine has been found to stimulate the synthesis of compounds with vitamin B 12 activity by S. olivaceus in both the synthetic and the nonsynthetic media, and implications in relation to the biosynthetic formation of vitamin B12 and its analog have been discussed.
About: This article is published in Archives of Biochemistry and Biophysics.The article was published on 1956-09-01. It has received 5 citations till now. The article focuses on the topics: Vitamin B12 & Cyanocobalamin.
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TL;DR: Ochromonas malhamensis (Pringsheim strain) can be grown above 35°C; below 35°, the previous chemically defined medium supports dense growth; the B12 and thiamine requirements rise steeply with temperature, and growth promotion by folic acid emerges; folic Acid spares the enhanced B12 requirement.
Abstract: SUMMARY. Ochromonas malhamensis (Pringsheim strain) can be grown above 35.5°C.; below 35°, the previous chemically defined medium supports dense growth. The B12 and thiamine requirements rise steeply with temperature, and growth promotion by folic acid emerges; folic acid spares the enhanced B12 requirement. B12 is spared also, perhaps wholly bypassed, by purines + pyrimidines + amino acids (below 35°, exogenous purines, pyrimidines, and folic acid have little effect). Requirements also emerge for glycine (spared by serine), valine and isoleucine (their ratio is critical; leucine and threonine assist in maintaining a good balance), and, at very slightly higher temperatures, phenylalanine, tryptophan, cystine, and lysine. Requirements for Mg, Fe, Zn, and Mn appear to rise steeply with temperature; metal toxicities have to be circumvented carefully. The proportion of histidine + arginine to carbohydrate has to be increased, and a Krebs-cycle component such as succinic acid becomes stimulatory. At 36.3–36.7°, a further supplement of crude natural materials such as an autoclaved suspension of Ochromonas cells is needed. Relevance of these findings to fever stress in vertebrates, general mitochondrial function, and repair of radiation damage, is discussed.
71 citations
TL;DR: The ability of cobamides to form colored dicyanides has been the basis of a very useful method that gave results in good agreement with bio-assays using E. gracilis as the test organism in one series of experiments.
Abstract: Publisher Summary This chapter discusses the microbial synthesis of cobamides. The chapter discusses the usefulness and value of microbiological assays in studying the biosynthesis of cobamides and for the detection of cobamides in natural materials. A number of chemical methods applicable to the estimation of the cobamide content of fermentation samples have been developed, but only a few have apparently been used for this purpose. These chemical methods have been based on either the separation of the cobamides from other substances in fermentation samples and the subsequent measurement of the absorption of the extract at certain wavelengths or the determination of a specific portion of the molecule dimethylbenzimidazole or the red acid fragment formed by the acid hydrolysis of cobamides. The ability of cobamides to form colored dicyanides has been the basis of a very useful method that gave results in good agreement with bio-assays using E. gracilis as the test organism in one series of experiments.
46 citations
TL;DR: Both riboflavin and vitamin B, have in common a I,2-dimethyl-4,5-diaminobenzene moiety (substance I), which could well be a biogenetic precursor of these two vitamins.
Abstract: In micro-organisms, substance I exhibited some small degree of riboflavin activity for Lactobacillus casei and also had some vitamin B,, potency for Euglena gran'lis, as well as for some other organisms requiring vitamin B,, (Woolley, 1950, 1951). Addition of substance I to cultures of Bacillus megatherium stimulated vitamin B,, synthesis (Woolley, 1950). The precursor activity of substance I has been further suggested by the observation that an analogue, I ,2-dichloro-4,5-diaminobenzene, competitively inhibited synthesis by B. megatherium of riboflavin and vitamin B,, from substance I (Woolley, 1950). Addition of cobalt, which would normally stimulate synthesis of vitamin B,, by B. megatherium, with this analogue was found to aggravate the inhibition of the synthesis (Woolley, 1950). Addition of substance I, or of the substances that closely resemble it, 5,6-dimethylbenziminazole and o-phenylenediamine, is known to stimulate synthesis of vitamin B,, by Streptomyces olivaceous (Ganguly & Roy, 1956) and by Streptomyces griseus (Dulaney & Williams, 1953). Riboflavin and 5,6dimethylbenziminazole have been shown to cause a small but significant increase in synthesis of vitamin B,, by Escherichia coli (cf. Ford & Hutner, 1955). Added support for the view that biosynthesis of riboflavin and vitamin B,, may involve a common precursor is provided by observations that in media supplemented with cobalt there is an increased synthesis of riboflavin by Ashbya gossypii (Hickey, I 954), and that flavinogenesis by various micro-organisms synthesizing riboflavin was stimulated by additions of certain purines and amino acids (Ford & Hutner, 1955). Since single-carbon fragments may take part in the biosynthesis of riboflavin much in
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01 Jan 1963
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TL;DR: A method of assay with the protozoan Ochromonas malhamemis (Pringsheim isolate) and its application to the measurement of cobalamins in crude extracts and in the presence of vitamin %-like compounds is described.
Abstract: It is known that certain natural materials contain substances related to vitamin B, active as the vitamin for a number of micro-organisms but not for animals: these substances are not in the strict sense cobalamins and cannot be converted into cyanocobalamin by treatment with cyanide. We have studied the identity of several of these vitamin B12-like compounds, isolated by ourselves or by other workers, and concluded that the substances examined were each composed of one or more of five distinct compounds: factors A (vitamin B,), B and C, cyanocobalamin and pseudovitamin B, (Ford, 1953; Holdsworth, 1953; Ford, Holdsworth, Kon & Porter, 1953). We have further shown that the vitamin B, activities (for micro-organisms) of a variety of natural materials, extracted in the presence of cyanide, were contributed by one or more of these five compounds. Clearly, the presence in such test extracts of these vitamin B,,-like compounds, singly or in combination, can greatly complicate the assessment of cyanocobalamin itself by the available non-specific techniques of assay. There is an evident need for a method of assay capable of measuring cobalamins in the presence of these other related compounds. Hutner and co-workers (Hamilton, Hutner & Provasoli, 1952 ; Hutner, Provasoli & Filfus, 1953) have shown that certain chrysomonads require vitamin B,, and respond linearly to the vitamin over a wide ratio of concentrations. They drew attention to the potentialities of these phagotrophic protozoa as reagents for high-molecular conjugates of the vitamin and indicated that they might display a specificity for vitamin h2 similar to that of birds and mammals. The present paper describes a method of assay with the protozoan Ochromonas malhamemis (Pringsheim isolate) and its application to the measurement of cobalamins in crude extracts and in the presence of vitamin %-like compounds. The method was developed from that described by Hutner et al. (1953). For comparison, tests were also carried out with Euglena gracilis, Bacterium coli and Lactobacillus leichmannii.
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