Yeast biotin source

The structural formula (Figure 9-23) contains three asymmetric carbon atoms, and eight different stereoisomers are possible. Only the dextrorotatory D-biotin occurs in nature and has biological activity. Biotin occurs in some products in free form (vegetables, milk, and fruits) and in other products is bound to protein (organ meats, seeds, and yeast). Good sources of the vitamin are meat, liver, kidney, milk, egg yolk, yeast, vegetables, and mushrooms (Table 9-27). 

In terms of amino acids bacterial protein is similar to fish protein. The yeast s protein is almost identical to soya protein fungal protein is lower than yeast protein. In addition, SCP is deficient in amino acids with a sulphur bridge, such as cystine, cysteine and methionine. SCP as a food may require supplements of cysteine and methionine whereas they have high levels of lysine vitamins and other amino acids. The vitamins of microorganisms are primarily of the B type. Vitamin B12 occurs mostly hi bacteria, whereas algae are usually rich in vitamin A. The most common vitamins in SCP are thiamine, riboflavin, niacin, pyridoxine, pantothenic acid, choline, folic acid, inositol, biotin, B12 and P-aminobenzoic acid. Table 14.4 shows the essential amino acid analysis of SCP compared with several sources of protein. 

Vitamins such as thiamin, biotin, and vitamin Bj2 are often added. Once again, the requirements of anaerobes are somewhat greater, and a more extensive range of vitamins that includes pantothenate, folate, and nicotinate is generally employed. In some cases, additions of low concentrations of peptones, yeast extract, casamino acids or rumen fluid may be used, though in higher concentrations, metabolic ambiguities may be introduced since these compounds may serve as additional carbon sources. 

The best food sources of biotin (Fig. 8) include yeast, liver, soy products, rice, egg yolks, nuts, fish, and chocolate (179,180). Although many foods contain biotin, the levels are normally very low. Endogenous biotin in foods is usually protein bound in general there is more free biotin in plant-based foods than in animal-based products. 

Biorphen orphenadrine. biotin [inn, usan] (vitamin H coenzyme R Vitamin B7 Factor S) is a VITAMIN that occurs in yeast, eggs and liver, and is also produced by various other microorganisms and isolated from various higher plant sources, e.g. maize seedlings. A bacterial growth factor for egg white injury , it is an essential coenzyme in fat metabolism and other carboxylation reactions. Deficiency is rare apart from in certain paediatric disorders. It is incorporated into numerous multivitamin preparations. 

Biotin is widely distributed in foods. Beef liver, yeast, peanuts, kidney, chocolate, and egg yolk are especially rich sources. The intestinal flora synthesizes biotin. Fecal excretion reflects this enteric synthesis. Total daily urinary and fecal excretion exceeds the dietary intake. 

Biotin is widely distributed in foods liver, milk, yeast, oilseeds and vegetables are rich sources. However, in some foods, much of the bound vitamin may not be released during digestion and hence may be imavailable. Studies with chicks and pigs have shown that the availability of biotin in barley and wheat is very low, whereas the biotin in maize and certain oilseed meals, such as soya bean meal, is completely available. 

For most Claviceps strains synthetic media can be used. In industry sucrose or sorbitol is used (seldom other C-sources) in concentrations of 70-250 g/1. As a secondary C-source usually citrate in concentration of 5-10 g/1 is used. NH4 salts, asparagine or NOf salts serve as N-source and phosphate—vide supra—and other inorganic salts are supplemented. Inoculation medium differs from the production medium by higher phosphate concentration—up to 10 mM, different N-source, some additional vitamins (biotin, aneurine) and by complex nutrients added— yeast extract, corn steep, malt extract etc. 

His skin rash and hair loss were reminiscent of the signs of biotin deficiency, as caused by excessive consumption of uncooked egg-white (section 11.12). However, his mother said that Barry did not eat raw or undercooked eggs at all, although he was fond of hard-boiled eggs and yeast extract (which are rich sources of biotin). His plasma biotin was 0.2 nmol/L (normal level > 0.8 nmol/L), and he excreted a... 

Biotin is required by all living cells but only biosynthesized by plants, fungi, and the majority of micro-organisms. Sources of exogenous biotin for animals are for instance found in yeast extracts, liver, kidneys, egg yolks, milk, and cereals. 

Also called D-biotin, is one of the more recently discovered vitamins. It belongs to the group of B vitamins and is found in most foods in small amounts. The richest sources are yeast, liver and kidney. Egg yolk, soybeans, nuts and cereals are also good sources. Biotin is found in most feedsmffs because its bioavailability is low it is added to most animal feeds to improve reproductive functions and general health. 

There is no published evidence that biotin can be synthesized by mammals thus, the higher animals must derive biotin from other sources. The ultimate source of biotin appears to be de novo synthesis by bacteria, primitive eukaryotic organisms such as yeast, moulds, and algae, and some plant species. 

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