摘要:

Several fungi (Aspergillus niger,A.terreus,Cochliobolus specifer,Myrothecium verrucaria.Rhizoctonia solani,Spicaria fusispora.Penicilliumsp., andGliocladiumsp.) were isolated from decomposing wheat straw and tested for their ability to utilize whole straw and its components, holocellulose (hemicellulose and cellulose) and cellulose, for the production of single-cell protein (SCP). It was found thatC.speciferwas the most efficient fungus for protein synthesis with the three substrates. Using potassium nitrate as N source in mixtures of 0.04 g N/g substrate (0.04% wt./vol.) at pH 4.5, it was found that incubation periods of 3. 4, and 5 days were optimal for protein production on cellulose and holocellulose fractions, and whole straw, respectively. Whole native straw was found to be the most recalcitrant to bioconversion into SCP; however, protein production was almost doubled when the lignin component was removed using a mixture of sodium chlorite and acetic acid.

ISSN:0008-4166    

DOI:10.1139/m79-116

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The artificial electron-donor system, phenazine methosulfate (PMS) ascorbate, inhibited active transport of glucose byPseudomonas aeruginosairrespective of whether the incubation systems were in air, flushed with oxygen, or gassed with nitrogen under anaerobic denitrifying conditions. Active transport of glucose byP.aeruginosawas also inhibited by reduced 5-N-methyl-phenazonium-3-sulfonate, a membrane-impermeable electron donor. PMS–ascorbate caused rapid depletion of intracellular adenosine triphosphate (ATP) when added to respiring cell suspensions ofP.aeruginosaeither in the presence or absence of glucose or succinate as oxidizable energy sources. In contrast, under identical conditions,Escherichia coliformed ATP with PMS–ascorbate as the sole oxidizable energy source and ATP formation continued when glucose or succinate was present in addition to PMS–ascorbate in the incubation system.

ISSN:0008-4166    

DOI:10.1139/m79-117

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Total cellular DNA fromRhizobium trifolii,R.meliloti, andR.japonicumstrains 110 and 117 were prepared. DNA fragments generated with restriction endonucleaseEcoRI from these DNA samples were compared in agarose gels after electrophoresis. DNA cleavage patterns generated fromR.japonicumstrain 110,R.trifolii, andR.melilotiwere clearly distinguishable from each other. Restriction endonuclease cleavage patterns of DNA fromR.japonicumstrain 110 and presumptiveR.trifoliimutant strains that nodulate soybean were found to be similar.Rhizobium trifoliimutant strains were also lysed by a phage specific forR.japonicumstrain 110. These results show that "R.trifoliimutant strains" are indeed derivatives ofR.japonicumstrain 110 and notR.trifolii.

ISSN:0008-4166    

DOI:10.1139/m79-118

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

A number of features not described previously has been revealed in electron-microscope studies of mature chlamydospores ofFusarium oxysporum. On the maturation of one isolate, many spores formed a thick matrix-like layer containing electron-dense particles on the exterior surface of the spore wall. In thin sections of mature chlamydospores of the same isolate, cisternae of endoplasmic reticulum surrounding, and in close apposition to, the limiting boundary of the lipid bodies were revealed.The germination of chlamydospores was accompanied by (a) the rapid appearance of polysaccharide deposits and changes in the configuration of some subcellular organelles, (b) the formation of a new wall layer between the plasma membrane and the innermost layer of the spore Wall, (c) the rupture of the outermost coats of the spore wall, and (d) the emergence of the germ tube as an extension of the new wall layer.

ISSN:0008-4166    

DOI:10.1139/m79-119

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The susceptibility ofCephalosporium acremoniumto selected amino acid analogues was markedly influenced by the carbon source used in the test media. Lysine hydroxamate, β-hydroxy norvaline, and hexafluorovaline were toxic when tested with ribose, ribose or fructose, and ribose or galactose, respectively. In contrast, thialysine and thiaisoleucine inhibitedC.acremoniumwith glucose, fructose, galactose, sucrose, mannitol, sorbitol, and soluble starch. Neither of these analogues was toxic at levels tested when glycerol was used as a carbon source. The minimal inhibitory concentrations (MIC) of thialysine, homoserine, and α-methylserine were > 1000, > 1000, and 250 μg/mL, respectively, with glycerol. In contrast, the MIC values for the same three analogues were 31, 62, and 125 μg/mL, respectively, with mannitol. The matching of the carbon sources with the specific amino acid analogues expands the number of analogues useful for selecting derepressed mutants. Thialysine-resistant mutants (tlysR) ofC.acremoniumwhich excrete lysine were isolated on a medium containing mannitol.

ISSN:0008-4166    

DOI:10.1139/m79-120

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The ability of microbes to metabolize the N–N bond seems rare.Pseudomonas sp. from soil can utilize 1,4,5,6-tetrahydro-6-oxo-3-pyridazinecarboxylic acid as C and N source. This appears to be the first report that a microbe can cleave a nitrogen–nitrogen bond in an organic compound and use the products for growth.

ISSN:0008-4166    

DOI:10.1139/m79-121

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

The ultrastructure of the cells of the major component of an enriched culture of a presumed methanogen which utilized acetic acid was studied by transmission and scanning election microscopy. The filaments were composed of Gram-positive, rod-shaped cells, 1–2 μm in length and about 0.5 μm in breadth, attached end to end. Septa between cells were complex, with a central, electron-dense sheet which had a spherical enlargement in the center separating the cell walls. The cells walls themselves were of variable thickness with a light, fluffy, thin portion on the outside and a denser, thicker portion within. They contain a series of rings stacked side by side which are composed of material that stains strongly and positively with phosphotungstate ion. The cytoplasmic membrane of these cells had an outer leaflet which stains more densely with uranium and lead ions than the inner leaflet. There were no recognizable organelles in the cytoplasm other than ribosomes. It is shown in these observations that the presumed methanogen may likely be a new species.

ISSN:0008-4166    

DOI:10.1139/m79-122

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

Synthesis of β-galactosidase byStreptomyces violaceuswas induced byD-galactose andL-arabinose, and to a lesser extent by lactose,D-arabinose, and methyl-β-D-galactopyranoside. The synthesis of the enzyme was linear and started to increase 2–3 h after induction by galactose, reaching a maximum after 5–7 h. The highest level of specific activity was observed in 2% galactose, with an increase of 45 times over the basal level in glycerol. Isopropyl-β-D-thiogalactopyranoside (IPTG) and methyl-β-D-thiogalactopyranoside (TMG) inhibited induction byD-galactose, but did not influence enzymatic activity. Cellular extracts hydrolyzedo-nitrophenyl-β-D-galactopyranoside, but did not significantly hydrolyze lactose, melibiose,p-nitrophenyl-α-D-galactopyranoside,p-nitrophenyl-β-D-fucoside, orp-nitrophenyl-β-D-glucopyranoside. Rifampicin and chloramphenicol inhibited β-galactosidase synthesis in non-preinduced and in pre-induced cells. The inhibition by chloramphenicol was reversible.

ISSN:0008-4166    

DOI:10.1139/m79-123

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

We report a procedure for the purification of Chilo iridescent virus (Iridovirustype 6), an evaluation of the purification procedure, and the results of analyses of the virion proteins by acrylamide gel electrophoresis. Purity was evaluated in three ways, i.e., by analysis of purified virions from artificial mixtures of infected and labeled uninfected larvae, electrophoresis at neutral pH, and electron-microscopic examination. Analysis of the polypeptides of purified CIV gave the following results: (i) after solubilization with SDS-B-mercaptoethanol, 16 polypeptides could be resolved in Coomassie brillant blue-stained electrophoretograms with molecular weights ranging from 18 000 to 115 000; (ii) after solubilization with SDS-urea, 26 polypeptides could be resolved with molecular weights ranging from 10 000 to 230 000 daltons.

ISSN:0008-4166    

DOI:10.1139/m79-124

出版商:NRC Research Press    

年代:1979

数据来源: NRC

摘要:

A comparison was made of results obtained with aBrucellaagar–gel immunodiffusion (AGID) test and the standard tube-agglutination test on 612 human sera. Agreement between the tests was 97% when the titer was 1:160 or higher. Of 448 sera that showed no agglutination titer, 447 were negative with the AGID test. Results of the AGID test were also compared to those obtained with the 2-mercaptoethanol (2-ME) agglutination test on 148 sera that demonstrated a standard tube-agglutination titer of 1:20 or higher. All sera with a 2-ME-agglutination titer of 1:40 or higher were positive with the AGID test. Of 123 sera that showed no 2-ME-agglutination titer. 21 were positive with the AGID test. Two of these 21 sera were obtained from patients with bacteriologically proven brucellosis, and eight were from abattoir employees with suspected but not bacteriologically proven brucellosis.

ISSN:0008-4166    

DOI:10.1139/m79-125

出版商:NRC Research Press    

年代:1979

数据来源: NRC