Identification of products produced by the anaerobic degradation of naringin by Butyrivibrio sp. C3

Butyrivibrio sp. C3 degraded naringin anaerobically yielding naringenin, neohesperidose, phloroglucinol, and p-hydroxyphenylpropionic acid.

Bacteriolytic enzymes from Staphylococcus aureus. Specificity of ction of endo-beta-N-acetylglucosaminidase

The bacteriolytic enzyme with an isoelectric point of 9.5 that is produced by all strains of Staphylococcus aureus investigated was purified from strain M18 (Wadström & Hisatsune, 1970). This enzyme released reducing groups from cell walls of Micrococcus lysodeikticus and was thus shown to be a bacteriolytic hexosaminidase. Although dinitrophenylation and acid hydrolysis of cell walls hydrolysed by a partially purified enzyme gave DNP-alanine and DNP-glycine from staphylococcal peptidoglycan, which indicated the presence of a peptidase and probably also an N-acetylmuramyl-l-alanine amidase, hydrolysis of cell walls by the extensively purified enzyme did not give any DNP-amino acids. The enzyme digest was purified by Amberlite CG-120 and Sephadex G-10 chromatography. Reduction by sodium borohydride of the disaccharide obtained was followed by acid hydrolysis and paper chromatography. Glucosamine completely disappeared after this treatment and a new spot identical with glucosaminitol appeared. The muramic acid spot remained unchanged. The purified enzyme was found to be devoid of exo-beta-N-acetylglucosaminidase activity. These results are compatible with the action of a bacteriolytic endo-beta-N-acetylglucosaminidase. It is also proposed that this enzyme is probably identical with the staphylococcal lysozyme. The mode of action of this has not previously been investigated.

Trehalose phosphate synthesis in Streptomyces hygroscopicus: purification of guanosine diphosphate D-glucose: D-glucose-6-phosphate 1-glucosyl-transferase

Guanosine diphosphate d-glucose:d-glucose-6-phosphate 1-glucosyl-transferase was purified approximately 100-fold from extracts of Streptomyces hygroscopicus. The purified enzyme catalyzed the transfer of glucose from guanosine diphosphate-d-glucose to glucose-6-phosphate to form trehalose phosphate and guanosine diphosphate. The enzyme was specific for these two substrates and was stimulated by the addition of magnesium ions. The product was characterized as alpha-alpha-trehalose-6-phosphate by its physical and chemical properties. The enzyme was present in a large number of Streptomyces species, suggesting that this group of organisms synthesized trehalose phosphate in a unique manner. This enzyme was not detected in fungi, since these organisms utilized uridine diphosphate-d-glucose as the glucosyl donor.

Isolation and characterization of a cellulose-utilizing bacterium

A cellulose-decomposing aerobic and mesophilic bacterium has been isolated from soils of sugar cane fields. The terminal dilution method was adapted to isolate a single clone of cellulolytic organism from closely related contaminants. The cultural and physiological characteristics of the isolate were studied, and the organism was identified as a member of the genus Cellulomonas. The isolate excreted cellulase into the menstruum, and it hydrolyzed various cellulosic materials producing cellobiose as the final breakdown product in the menstruum. When sugar cane bagasse was properly treated with alkali and heat, the organism could decompose up to 90% of the initial substrate within 5 days. Amino acid analysis of the cell crop revealed a high content of lysine, and the essential amino acid pattern compared favorably with that of Food and Agricultural Organization reference protein.

Carbohydrate metabolism in streptomycetes. II. Isolation and enzymatic synthesis of trehalose

A number of streptomycetes were examined for their ability to synthesize trehalose phosphate as well as for the presence of alpha,alpha-trehalose. In each case, an enzyme system was demonstrated which catalyzed the transfer of glucose from guanosine diphosphate-glucose to glucose-6-phosphate to form trehalose phosphate. Thus, this group of organisms appears to synthesize trehalose phosphate by a different mechanism from that described in insects, yeast, and fungi. In addition, trehalose was isolated from each of these organisms. In several of these cases, crystallization of the sugar and determination of the physical properties showed that the sugar was alpha,alpha-trehalose.

Regulation of cockroach fat-body metabolism by the corpus cardiacum in vitro

Incubation in vitro of young, adult, male Leucophaea maderae fat body with extracts of corpora cardiaca or intact corpora cardiaca results in stimulation of oxygen consumption but reduction in carbon dioxide evolved from carbohydrate. The carbohydrate is preferentially used for trehalose synthesis, and the endogenous metabolism of the fat body appears to be supported by increased lipid utilization. A hormone from the corpus cardiacum is most likely responsible for these effects and may act at two points, at least, in the glycolytic pathway.

The biosynthesis of streptomycin. The origin of the C-formyl group of streptose

1. The biosynthesis of streptomycin in Streptomyces griseus has been studied by adding d-[3,4-(14)C(2)]glucose or d-[1,3-(14)C(2)]glucose to the growth medium and degrading the streptomycin produced. 2. The results suggest that the C-3' branch carbon atom of l-streptose arises from C-3 of d-glucose. 3. The mechanism of biosynthesis of streptose from glucose is discussed. It probably involves an intramolecular rearrangement of a 6-deoxy-4-oxyhexose derivative, and it is suggested that the nucleoside diphosphate sugar derivative hitherto recognized as an intermediate in the biosynthesis of l-rhamnose might participate in such a rearrangement.