Seizi Igarasi

Asparaginase and Glutaminase Activities of Micro-organisms

Summary: l-Asparaginase and l-glutaminase activities were detected in many microorganisms and the distribution of these activities was found to be related to the classification of micro-organisms. Among 464 bacteria, the activities occurred in many Gram-negative bacteria and in a few Gram-positive bacteria. Most members of the family Enterobacteri-aceae possessed l-asparaginase. l-Asparaginase and l-glutaminase occurred together in a large proportion of pseudomonads. Among Gram-positive bacteria many strains of Bacillus pumilus showed strong l-asparaginase activity. Amidase activities were also observed in several strains in other families. l-Asparaginase activity was not detected in culture filtrates of 261 strains of species of the genera Streptomyces and Nocardia, but l-asparaginase and l-glutaminase were detected when these organisms were sonicated. The amidase activities in culture filtrates of 4158 fungal strains were tested. All the strains of Fusarium species formed l-asparaginase. Organisms of the genera Hypomyces and Nectria, which are regarded as the perfect stage of the genus Fusarium, also formed l-asparaginase. Several Penicillium species formed l-asparaginase. Two organisms of the family Moniliaceae formed l-glutaminase together with l-asparaginase, and a fewascomycetous fungi formed l-asparaginase or l-glutaminase. Among 1326 yeasts, l-asparaginase or l-glutaminase occurred frequently in certain serological groups of yeasts: VI (Hansenula) group, Cryptococcus group and Rhodotorula group. Many strains of Sporobolomyces species also showed l-asparaginase activity. Several strains of Cryptococcus and Rhodotorula group possessed l-glutaminase and l-asparaginase. l-Glutaminase alone was formed in many strains of Candida scottii and Cryptococcus albidus, both of which are related to Basidiomycetes.

Formation of L-Asparaginase by Fusarium Species

SUMMARY: L-Asparaginase was formed in the culture filtrates of a number of Fusarium species, as well as in those of ascomycetous fungi having a Fusarium imperfect state, such as species of Hypomyces and Nectria. Species of Gibberella, though having a Fusarium state, formed little L-asparaginase. The distribution of the ability to form the enzyme was related to taxonomic position.

Chemical structure of an acidic polysaccharide produced by serratia piscatorum

Abstract The acidic polysaccharide of Serratia piscatorum consists of L -rhamnopyranosyl, D -galactopyranosyl, and D -galactopyranosyluronic acid residues in the molar ratio of 2:1:1. Some of the D -galactopyranosyluronic acid residues are acetylated at O-2 or O-3, or both. Smith degradation and methylation analysis indicated that the L -rhamnopyranosyl, D -galactopyranosyl, and D -galactopyranosyluronic acid residues are substituted with glycosidic linkages at O-3, O-3, and O-4, respectively. Partial acid hydrolysis of the native polysaccharide gave four acidic oligosaccharides, each of which was isolated and characterized, suggesting the following tetrasaccharide repeating unit: →3)- L -Rha p -(1→4)- D -GalA p -(1→3)- L -Rha p -(1→3)- D -Gal p -(1→.

A bacteriolytic enzyme from Chaetomium globosum, a marine-isolate

SummaryWhen a marine-isolate, Chaetomium globosum was cultivated in a medium with an increased MgCl2 content, a bacteriolytic enzyme was extracellularly produced. The enzyme was purified approximately 130-fold. It lyzed Staphylococcus aureus, Micrococcus lysodeikticus and several other Gram-positive bacteria. Optimal pH and temperature for the lysis were 8.0 and 37°C, respectively. The enzyme was heat-labile with maximum stability at neutral pH. Enzymatic activity was greatly stimulated by NaCl and CaCl2 with maximum activity obtained in the presence of 0.1 M NaCl and 0.003 M to 0.005 M CaCl2. The activity was stimulated by SH-compounds and was inhibited by SH-reactants.The enzyme is an N-acetylhexosaminidase.

Degradation of Nucleic Acids and Related Compounds by Microbial Enzymes

The culture filtrate of a strain of Bacillus subtilis decomposed ribonucleic acid into 5′-nucleotides and into other intermediates which released orthophosphate by an arsenate-resistant phosphatase. Under the best conditions examined in these experiments, about 50 per cent of ribonucleic acid was converted into 5′-nucleotides.The culture filtrate of a strain of Bacillus brevis showed slight activities of ribonuclease and/or phosphodiesterase which produced 5′-nucleotides from ribonucleic acid, but showed predominant activity of 5′-adenylic acid degrading phosphatase.