~ Azospirillum iipoferurn strain D-2 produces the phenolate siderophores 2,3-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid and salicylic acid under iron-starved conditions. Lysine and leucine were identified as the amino acid conjugates of the siderophores. The concentration of siderophores in the culture supernatant was maximal after 20 h growth. Iron-binding proteins were present in membranes of cultures grown under iron starvation. Iron uptake was enhanced in the presence of each of the siderophores.
We reported (1) that amino acid incorporation into liver proteins was reduced markedly in biotin-deficient rats and chicks. In these experiments biotin deficiency was produced on a regime where glucose was the sole source of the carbohydrate. Substitution of 10% of the glucose in the diet by sodium succinate restored amino acid incorporation to the normal level. We suggested that biotin deficiency might be accompanied by an impairment of glucose metabolism resulting in a decreased supply of energy for synthetic processes such as protein synthesis. An exogenous supply of succinate by making itself available for energy production ameliorated this defect.There are conflicting reports (2, 3) about the alleviation of biotin deficiency by sorbitol when it partially replaced glucose in the diet. Using amino acid incorporation ( 1 ) into liver proteins as an index we o h d that sorbitol as well as fructose s h o d a definite beneficial effect. These data and 'the results of a study of oxidative phosphorylaticm in biotin deficiency are given in this paper.Animals and basal diet. Using 35-40 gm weanling male Sprague-Dawley rats, biotin deficiency was produced in 6-7 weeks on a 71% glucose, 20% raw egg-white basal diet which was complete in all nutrients except biotin. Since in biotin deficiency r a b are unable to synthesize ascorbic acid (4) it was included in the basal diet. Normal animals were given parenterally 100 pg of biotin twice a week. Dietary conditions are described under each table.Materials. Fructose, mbitol, ATP, NAD,
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.