摘要:

Homogenized suspensions ofStreptomyces scabiesmycelium derived from young cultures were shown to oxidize a number of organic acids. Data indicate that the high autorespiration rate encountered was supported, at least in part, by nitrogenous substances. Manometric data support the concept of tyrosine oxidation through dihydroxyphenylalanine with subsequent melanin formation. The possible role of cell permeability in contributing to the anomalous rate of α-ketoglutarate oxidation is discussed.

ISSN:0008-4166    

DOI:10.1139/m56-048

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

A proteinaceous toxin has been extracted from sporulated cultures ofBacillus sottoIshiwata. The toxin is similar in amino acid composition and biological activity to the crystalline inclusions produced by this microorganism and it appears that the toxic protein is associated with the crystals. The toxin is stable, and causes paralysis and death in the larvae ofBombyx moriL. (the silkworm) and other lepidopterous insects. The symptoms caused by the toxin are identical with those caused by ingestion of the whole microorganism.

ISSN:0008-4166    

DOI:10.1139/m56-049

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Using a manometric or a dehydrogenase assay, activity for most of the intermediates of the tricarboxylic acid cycle was demonstrated in extracts fromRhodo spirillum rubrumgrown photosynthetically (anaerobic light), heterotrophically (aerobic dark), or a combination of both (aerobic light). Dehydrogenases for succinate and α-ketoglutarate were more active in extracts from cells grown photosynthetically. Extracts from cells grown heterotrophically had the greatest oxidative activity. Succinic dehydrogenase was associated with larger macromolecular units in all extracts while the other dehydrogenases behaved as soluble enzymes. Conditions of cultivation affected the rate at which keto acids were formed from citrate.Rhodopseudomonas palustrisalso possessed tricarboxylic acid dehydrogenases whether grown photosynthetically or heterotrophically.

ISSN:0008-4166    

DOI:10.1139/m56-050

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

It was demonstrated thatPseudomonas aeruginosapossesses all the enzymes necessary for the oxidation of pyruvate to CO2and water without passing through the conventional intermediates oxalosuccinate and α-ketoglutarate. These intermediates are bypassed by the action of the enzyme isocitratase which splitsd-isocitrateto succinate plus glyoxylate. This reaction was shown to be readily reversible. The malic acid dehydrogenase content was low and in addition this enzyme required a high pH for optimum activity. In fresh cell extracts at pH 7.4 its activity was only 10% that of the other enzymes of the cycle. The malic andisocitricdehydrogenases were TPN specific. The organism was also shown to possess all the enzymes necessary for the operation of the conventional tricarboxylic acid cycle.

ISSN:0008-4166    

DOI:10.1139/m56-051

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Zinc, manganese, and iron were shown to be essential for good growth ofHelminthosporium sativum, whereas copper, cobalt, molybdenum, boron, and calcium apparently were not required. One milligram each of zinc sulphate, manganese chloride, and ferrous sulphate per liter was considered adequate to ensure maximum growth ofH.sativumin simple media.H.biforme,H.halodes, andH.setariaealso produced maximum growth in response to a combination of zinc, manganese, and iron.

ISSN:0008-4166    

DOI:10.1139/m56-052

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Fresh cell suspensions of glucose-grownSerratia marcescensoxidize glucose, gluconic acid, and 2-ketoglneonate with an uptake of 3.0, 2.5, and 2.0 μmoles of oxygen per μM. substrate, respectively. Approximately two μM. of CO2per μM. of each substrate are evolved. 6-Phosphogluconate, glucose-6-phosphate, and hexose diphosphate do not appear to be intermediates in the normal pathway of glucose oxidation. Dried-cell preparations ofS.marcescensoxidize glucose and gluconate in a two-stage pattern, with an initial uptake of 1.0 and 0.5 μM. O2/μM. substrate, respectively. 2-Ketogluconate was identified chromatographically in these solutions. In the second stage, both added and metabolically formed 2-ketogluconate are further oxidized to the same oxidation level attained with the whole cell, i.e., 3.0, 2.5, and 2.0 μM. O2/μM. glucose, gluconate, and 2-ketogluconate, respectively. An as yet unidentified acidic compound has been isolated from the solution of metabolites of a glucose oxidation by these organisms.

ISSN:0008-4166    

DOI:10.1139/m56-053

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

It was demonstrated that yeast extract is capable of reversing the inhibition ofS.cerevisiaeby a quaternary ammonium surface active agent. A reversing factor representing a 25-fold increase in activity was obtained by chemical fractionation of the yeast extract, and the chemical nature of this reversing factor was partially characterized. It was observed that the growth response of cells which had been inhibited and then reversed was the same as that of uninhibited cells. Mechanisms of reversal compatible with the experimental results have been suggested.

ISSN:0008-4166    

DOI:10.1139/m56-054

出版商:NRC Research Press    

年代:1956

数据来源: NRC