摘要:

In well-aerated submerged cultures ofFusarium diversisporumSherb. withn-hexadecanol orn-heptadecanol (which are virtually water insoluble) as the sole carbon source, the alkanols do not undergo extracellular chemical changes before assimilation but move, unchanged, through the cell wall faster than they can be metabolized by the organism and thus may constitute up to one-half of the total lipids in the cells. The alkanols are initially oxidized at the hydroxylated terminal carbon atom to fatty acids without loss of carbon. The fatty acids are subject to further metabolic action. Apparently carbon, not needed immediately for energy and for synthesis of cell components, is transformed into triglycerides as a reserve material. In these triglycerides, the distribution of the saturated and the unsaturated fatty acids between the primary and the secondary positions of the glycerol moiety is one typical of a vegetable lipid. Interesting differences exist, particularly in the sterol ester and phospho- or glyco-lipid contents, between mycelia grown on sucrose, hexadecanol, or heptadecanol. These cell constituents may possibly be involved in alkanol transport across the cell wall. The mold also assimilates cholesterol but has difficulty in metabolizing it.

ISSN:0008-4166    

DOI:10.1139/m67-018

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The chemical components of the sclerotial and hyphal walls of the fungusSclerotium rolfsiiSacc. are compared. Sclerotial walls contain a melanin-like pigment which is absent from hyphal walls. They are also higher in non-hydro-lyzable residue, in lipids, and in ash content. In both walls, glucose, mannose, and glucosamine are found after acid hydrolysis. Acid hydrolysates of sclerotial and hyphal walls contain 10 and 13 amino acids, respectively,L-arginine,L-serine, andL-proline being absent from sclerotial walls. The possible role of some of these components in the resistance of the sclerotia to biological and chemical degradation is discussed.

ISSN:0008-4166    

DOI:10.1139/m67-019

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Peptococcus aerogenesferments histidine-α-14C to acetic, butyric, and formic acids. The distribution of carbon-14 in acetic and butyric acids was consistent with that expected if the urocanic acid pathway was used for the metabolism of histidine. Radioactive glutaconic acid also was isolated from such reaction mixtures. Glutamic acid accumulated when histidine was fermented under sodium-deficient conditions.

ISSN:0008-4166    

DOI:10.1139/m67-020

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

APseudomonasspecies adapted to grow on phenylacetic acid is simultaneously adapted to the utilization of phenylacetic acid,p-hydroxyphenylacetic acid, and 3,4-dihydroxyphenylacetic acid. Extracts of the organism catalyze the oxidation ofp-hydroxyphenylacetic acid and 3,4-dihydroxyphenylacetic acid, but not phenylacetic acid. The addition of NAD or NADH to extracts is required for maximum utilization ofp-hydroxyphenylacetic acid; ferrous ion is required for maximum utilization of 3,4-dihydroxyphenylacetic acid. The oxidation of 3,4-dihydroxyphenylacetic acid results in the production of a compound having an absorption maximum at 318 mμ in acid and at 380 mμ in alkali, which was identified as δ-carboxymethyl-α-hydroxymuconic semialdehyde. The degradation of phenylacetic acid by this organism follows a pathway that utilizesp-hydroxyphenylacetic acid and 3,4-dihydroxyphenylacetic acid as intermediates.

ISSN:0008-4166    

DOI:10.1139/m67-021

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Suspensions ofPseudomonasgrown on phenylacetic acid oxidized 3,4-dihydroxy-phenylacetic acid to δ-carboxymethyl-α-hydroxymuconic semialdehyde. The compound was characterized by conversion to 2,5-pyridine dicarboxylic acid. The results show that cleavage of the aromatic ring occurs between carbons 2 and 3. δ-Carboxymethyl-α-hydroxymuconic semialdehyde is relatively unstable. Maximum absorption of the compound is obtained in acid at 318 mμ and in alkali at 380 mμ. The ratio of optical densities (380/318) is 1.8. In 2% sodium carbonate solution the molar extinction coefficient at 380 mμ is 2.7 × 104. Other chemical properties of the cleavage product are described.

ISSN:0008-4166    

DOI:10.1139/m67-022

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Propagation of coxsackievirus B5 on cell lines revealed two variants, one that yields small plaques and is stable and another that is large but variable in size. Multiple-burst studies on the large-plaque pool showed the existence of two different population sections. Analysis of a sample from a plaque belonging to the small population section showed a progeny of small plaques while a similar analysis from a plaque in the large population section produced plaques of varying size but whose mean plaque diameter resembled that of the parent culture. Repeated selection for smallness from plaques in the large population section resulted in small plaques and a shift from the large to the small population section. Analysis of the small pool virus on monkey kidney monolayers revealed the presence of a few typical monkey kidney plaques which differed from normal monkey kidney plaques by producing only small plaques on HEp-2 monolayers.

ISSN:0008-4166    

DOI:10.1139/m67-023

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The effect of additions of the gamma-isomer of benzene hexachloride (gamma-BHC) upon algal populations in two submerged tropical rice soils was studied. Additions of the insecticide to the floodwaters of the soils at 5, 6, and 50 kg/ha active compound resulted in a marked stimulation of growth of the indigenous algae. The stimulation was attributed to the elimination by the insecticide of small animals which feed on the algae. No detrimental effect upon total algal populations was found when gamma-BHC was applied at 50 kg/ha, which is 10 times the rate recommended to control the rice stem borer. Qualitative changes were detected in the incidence of major algal groups. Blue-green algae were more abundant in treated soils whereas the green algae and diatoms were more abundant in the untreated soils. Much larger amounts of algal tissue were produced in the floodwaters treated with gamma-BHC. The possible effects of increased algal development on the fertility of the soil and the persistence of gamma-BHC in submerged soils are discussed.

ISSN:0008-4166    

DOI:10.1139/m67-024

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Growth and metabolite production byPolyporus tumulosusCooke were shown to be markedly influenced by (a) the nature of the carbon source, (b) the carbon mitrogen ratio, and (c) the pH of the medium at the time of inoculation. Whereas in some instances growth and metabolite production could be altered independently, production of phenols was more usually correlated with a high growth rate. Further, variations in the conditions of culture were shown to alter the relative proportions of the several phenolic acids as well as the gross yield.The biochemical interrelationships of the metabolites were also investigated. Isotope incorporation experiments demonstrated that these compounds have their biosynthetic origin in the shikimic acid pathway rather than by that of acetate condensation. The primary shunt metabolites were located on two similar pathways and a probable relationship for the secondary shunt metabolites is suggested. The investigation has shown that the well-known fungal metabolite gentisic acid is produced in a biochemical sequence alternative to that usually described for this compound in microorganisms.

ISSN:0008-4166    

DOI:10.1139/m67-025

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The root microflora of Bison flax, resistant to wilt caused byFusarium oxysporumf.lini, was compared with that of the wilt-susceptible variety Novelty. Plants grown in "disease-free" soil show that the susceptible variety harbors not only the most numerous, but also the most metabolically active bacterial flora on its roots. Generic classification of bacterial isolates shows a higher incidence of more active organisms, represented byPseudomonasandFlavobacteriumon roots of the susceptible crop, whereas the more slowly growing pleomorphic types such asArthrobacterwere most abundant on roots of the resistant variety. Fungi were also more numerous on roots of the susceptible crop, but the generic composition of rhizosphere populations of both varieties was similar to that of the soil itself.Fusarium oxysporumdominated the flora occurring in an active mycelial state on roots of the susceptible variety, whereasF.oxysporumandPhomasp. were codominants in the active flora of the resistant crop. Tests with other soils showed that dominance of specific genera varies with soil type. The results indicate a selective action on the root microflora, particularly the bacteria, and suggest both quantitative and qualitative differences in root environments of the two flax varieties.

ISSN:0008-4166    

DOI:10.1139/m67-026

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Bacterial isolates from a number of different soils were screened by growth observation and microscopic examination forArthrobacterspp. Incidence of arthrobacter in the total population varied, but averaged around 15% in the soils investigated. One hundred and thirty arthrobacter isolates were tested for their ability to utilize aromatic hydrocarbons as their sole carbon source. Seventy-seven percent of these organisms were able to grow on at least two aromatic substrates and many were capable of growth on a wide range of these compounds. Nutritional studies indicated that arthrobacter with simple requirements were able to utilize the greatest number of aromatic hydrocarbons as their sole carbon source. The ability of the arthrobacter to metabolize aromatic compounds is discussed in terms of their possible role in the formation and turnover of residual soil organic matter.

ISSN:0008-4166    

DOI:10.1139/m67-027

出版商:NRC Research Press    

年代:1967

数据来源: NRC