Showing papers in "Canadian Journal of Microbiology in 1982"
TL;DR: Trichoderma harzianum excreted β-1, 3-glucanase and chitinase into the medium when grown on laminarin and Chitin, respectively, or on cell walls of the pathogen Sclerotium rolfsii as discussed by the authors.
Abstract: Trichoderma harzianum excreted β-1, 3-glucanase and chitinase into the medium when grown on laminarin and chitin, respectively, or on cell walls of the pathogen Sclerotium rolfsii, as sole carbon s...
479 citations
TL;DR: Using the OsO4 isolation method, Frankia strains were obtained from 27 provenances of the two alder species represented in Quebec and the sporulating or nonsporulating endophytic character was recognized as one of the valid criteria that should be used in the awaited species definition in the genus Frankia.
Abstract: Using the OsO4 isolation method, more than 200 Frankia strains were obtained from 27 provenances of the two alder species represented in Quebec, i.e., Alnus crispa (Ait.) Pursh. and Alnus rugosa (D...
204 citations
TL;DR: It is suggested that the C2H2-sensitive step is associated with the ammonia oxygenase, and the oxidation of hydroxylamine to NO2− by Nitrosomonas europaea is affected.
Abstract: Acetylene (C2H2) strongly inhibited (Ki 0.25 μM or 0.66 Pa) the oxidation of ammonia (NH4+) to nitrite (NO2−) by Nitrosomonas europaea but did not affect the oxidation of hydroxylamine (NH2OH) to N...
163 citations
TL;DR: The composition of the N2-fixing microflora of a rice rhizosphere was studied by a new enrichment and isolation procedure: rather than using an artificial C source, the exudates from a germinating seed ("the spermosphere model") are used.
Abstract: The composition of the N2-fixing microflora of a rice rhizosphere was studied by a new enrichment and isolation procedure: rather than using an artificial C source, the exudates from a germinating ...
127 citations
TL;DR: The intracellular peptide hydrolase activities of Lactobacillus helveticus, L. lactis, and L. bulgaricus were determined using various aminopeptidase, dipeptid enzyme, and carboxypeptid...
Abstract: The intracellular peptide hydrolase activities of Lactobacillus helveticus, L. acidophilus, L. lactis, and L. bulgaricus were determined using various aminopeptidase, dipeptidase, and carboxypeptidase substrates in addition to casein and whey protein fractions. The different activities were then separated using disc gel electrophoresis. Each bacterium had aminopeptidase activity towards various amino acid beta-naphthylamides and dipeptides. The four species also showed bands of true dipeptidase activities on a large number of dipeptides. Intracellular enzymes from thermophilic lactobacilli also hydrolysed the whey proteins (alpha-lactalbumin and beta-lactoglobulin). From the results of electrophoresis on beta-casein and alpha s1-casein it was shown that beta-casein was totally hydrolysed by L. lactis while it was only partially hydrolysed by the intracellular enzymes of L. acidophilus and L. bulgaricus. On the other hand, alpha s1-casein was only partially hydrolysed by L. helveticus, L. lactis, and L. bulgaricus.
114 citations
TL;DR: Inhibition and retardation of growth were similar for yeast and mycelial forms, but germ tube formation was inhibited at concentrations lower than those which inhibited growth.
Abstract: Eugenol and vanillin were examined for in vitro antifungal activity against the medically important yeasts, Candida albicans and Cryptococcus neoformans. Minimal inhibitory concentrations (MIC) and...
106 citations
TL;DR: In six of the seven genera investigated the conversion was enhanced when air had access to the medium, suggesting that the ability to convert D-xylose to ethanol under these conditions is probably common among yeasts.
Abstract: Fifteen yeasts which can assimilate D-xylose were examined for the ability to convert this pentose to ethanol. In six of the seven genera investigated the conversion was enhanced when air had access to the medium. Therefore, the ability to convert D-xylose to ethanol under these conditions is probably common among yeasts. Growth under the same conditions on xylitol, a putative catabolite of D-xylose, led to only traces of ethanol. The effects of growth on another putative catabolite, D-xylose, were complex, but some of the strains which were among the better producers of ethanol from D-xylose produced less from D-xylulose.
96 citations
TL;DR: Acetylene-reducing bacteria isolated from the setts and roots of two sugar cane varieties propagated aseptically from stem cuttings and roots were identified using a computer-assisted scheme based on 75 biochemical tests, suggesting that the root is the site of bacterial multiplication.
Abstract: Acetylene-reducing bacteria isolated from the setts (stem cuttings used as seed pieces) and roots of two sugar cane varieties propagated aseptically from stem cuttings were identified using a computer-assisted scheme based on 75 biochemical tests. Because 106 to 108 acetylene-reducing bacteria per gram (fresh weight basis) were found in the roots, while 10 to 100 times fewer were present in the sett, we suggest that the root is the site of bacterial multiplication. Sterilization of the sett surface before planting or root sterilization at harvest reduced or completely removed acetylene-reducing bacteria and associated whole plant acetylene-reducing activity. This indicates that most of the active bacteria were on the sett and root exteriors. Setts did not exhibit acetylene-reducing activity until after emergence of the roots. Since shoot emergence was not necessary for acetylene-reducing activity, the extensive carbohydrate supply of the sett itself must have provided the carbon substrate for bacterial N2...
95 citations
TL;DR: The properties of halocin H4, produced by strain R-4, were studied using Halobacterium halobium as an indicator organism and it is shown that it is a high molecular weight substance, destroyed by heat or exposure to low salt concentrations or treatment with a protease.
Abstract: Strains of halophilic rods, presumably halobacteria, produce substances that inhibit the growth of other halobacteria but not halococci or moderate halophiles. The spectrum of action of these subst...
94 citations
TL;DR: Using the simple serial dilution technique, five strains of actinomycetes were isolated from nodules of Casuarina equisetifolia and were assumed to belong to the genus Frankia because they possessed the morphological and cultural characteristics now admitted as specific to this genus.
Abstract: Using the simple serial dilution technique, five strains of actinomycetes were isolated from nodules of Casuarina equisetifolia. In spite of the fact that these strains did not nodulate the host pl...
86 citations
TL;DR: Xylanases A and B have been partially characterized with respect to their main physicochemical parameters and β-D-xylosidase to a lesser extent on account of its low stability.
Abstract: Bacillus circulans WL-12 secretes two endo-β-D-xylanases (A and B, respectively) (EC 3218) and one β-D-xylosidase (EC 32137) when cultured in liquid media with xylan as the sole carbon sourc
TL;DR: Eight strains of lactobacilli isolated from conventional mice, rats, fowls, and pigs were tested for their ability to colonize squamous epithelia in the gastrointestinal tracts of gnotobiotic animals.
Abstract: Eight strains of lactobacilli isolated from conventional mice, rats, fowls, and pigs were tested for their ability to colonize squamous epithelia in the gastrointestinal tracts of gnotobiotic animals. Two of the strains isolated from rodents could colonize the nonsecretory epithelium of the stomach of gnotobiotic rodents, and one strain isolated from a fowl could colonize the crop epithelium of gnotobiotic chickens. The specificity of colonization of squamous epithelia by lactobacilli was demonstrated by these in vivo studies: strains of lactobacilli isolated from rodents could only colonize rodent epithelium; the strain from a fowl could only colonize crop epithelium.
TL;DR: The results of detecting indicator bacteria following the analysis of 53 130 samples over a 2-year period were arranged by water source (well, lake, river, mixed, mixed) and water type (raw or drinking) to determine the influence of these parameters on the recovery of indicator bacteria.
Abstract: Municipal water samples were analyzed by membrane filter (MF) and presence–absence (P-A) tests for pollution indicator bacteria. In four years, 11 514 bacterial cultures were isolated from either raw water, drinking water, or new main water samples submitted to three environmental laboratories. The bacterial species occurring most often in all types of water samples were Escherichia coli (11.6–39.7%), Enterobacter aerogenes (18.1–26.3%), Aeromonas hydrophila (8.8–17.0%), Klebsiella pneumoniae (7.7–10.3%), and Citrobacter freundii (5.09–22.7%). A lactose – lauryl tryptose – tryptone broth was examined as an alternative medium to modified MacConkey broth in the presumptive portion of the P-A test. The intensity of acid and gas production in presumptive positive P-A bottles was compared with the types and frequencies of indicator bacteria shown by confirmatory tests. The results of detecting indicator bacteria following the analysis of 53 130 samples over a 2-year period were arranged by water source (well, ...
TL;DR: A working model for methane formation from acetate by the consortium is presented and bears resemblance to a pseudoparenchyma and consists of "macrocysts" and coccoid cells, resembling Methanosarcina cells.
Abstract: The ultrastructure of a thermophilic methanogenic consortium appearing as morphologically distinct bacterial granules (up to approximately 3 mm in diameter) has been studied. The consortium was enriched and maintained at 60 °C in continuous culture in a defined mineral – vitamin – acetic acid medium at a hydraulic retention time of 44 h. Thin-section electron microscopy showed three morphologically distinct layers of the granules. (1) The outer division zone bears resemblance to a pseudoparenchyma and consists of "macrocysts" and coccoid cells, resembling Methanosarcina cells. (2) The inner zone is built up of loosely packed ovoid cells and (3) internal cavities containing rods.The cavities were the exclusive site of gas formation, as shown with a specially designed minifermenter allowing direct light microscopic observation of gassing granules. Based on labeling studies with cationic ferritin and scanning electron microscopy a working model for methane formation from acetate by the consortium is presented.
TL;DR: The data presented indicate that ferric iron can serve as a terminal electron acceptor for cytochrome-associated respiratory processes of this corrosive pseudomonad.
Abstract: Cells of a pseudomonad associated with pipeline corrosion grown on a complex medium were orange in color and vigorously reduced ferric iron. The intensity of orange color of cells grown on a synthetic medium and their ability to reduce ferric iron was directly related to the iron content of the medium. Absorption spectrophotometric data show a direct relationship between color of cells, cytochrome content, and ability to reduce ferric iron. Carbon monoxide markedly, but not completely, inhibits the reduction of ferric iron. The data presented indicate that ferric iron can serve as a terminal electron acceptor for cytochrome-associated respiratory processes of this corrosive pseudomonad.
TL;DR: The densities of filamentous fungal colonies, together with physicochemical and bacteriological parameters, were assessed in a chlorinated and unchlorinated drinking water distribution system at eight separate times over a period of 1 year.
Abstract: The densities of filamentous fungal colonies, together with physicochemical and bacteriological parameters, were assessed in a chlorinated and unchlorinated drinking water distribution system at eight separate times over a period of 1 year. Filamentous fungal colonies were enumerated by membrane filtration on Czapek–Dox agar. The mean number of filamentous fungal colony-forming units per 100 mL of drinking water was 18 in the unchlorinated and 34 in the chlorinated system. The majority of filamentous fungi isolated were saprophytic Deuteromycotina. The four most frequently occurring genera were Penicillium, Sporocybe, Acremonium, and Paecilomyces. In the chlorinated system, only physicochemical parameters correlated with observed fungal frequencies, whereas in the unchlorinated system, none of the parameters exhibited significant correlations with fungal numbers.
TL;DR: Ultraviolet-induced fluorescence was observed with the same filtering system used to detect fluorescein staining in vesicular–arbuscular mycorrhizal (VAM) infections in untreated roots autofluoresced when viewed with an epifluorescence microscope.
Abstract: Arbuscules in vesicular–arbuscular mycorrhizal (VAM) infections in untreated roots autofluoresced when viewed with an epifluorescence microscope. Ultraviolet-induced fluorescence was observed with ...
TL;DR: The lipids of eight strains of a new group of extreme halophiles isolated from Spanish salt ponds have been studied in comparison with those of Halobacterium cutirubrum, H. halobium, and H. salinarium.
Abstract: The lipids of eight strains of a new group of extreme halophiles isolated from Spanish salt ponds have been studied in comparison with those of Halobacterium cutirubrum, H. halobium, H. salinarium,...
TL;DR: Comparisons are made between the structure of the vesicle envelope in cultured Frankia and the strikingly similar innermost laminated layer in the dinitrogen-fixing heterocysts of the cyanobacterium Anabaena.
Abstract: The filamentous bacterium Frankia sp. CpI1 of the Actinomycetales, responsible for symbiotic nitrogen fixation in the nodules of certain woody dicots, also fixes dinitrogen when grown independently...
TL;DR: It is demonstrated that oligolignols, thought to be refractory under anaerobic conditions, can be degraded to lower molecular weight compounds and to methane and carbon dioxide.
Abstract: Soluble fragments of lignin origin obtained by thermochemical treatment of [14C]lignin-labeled lignocellulose served as substrate for anaerobic enrichment cultures. This study demonstrates that oli...
TL;DR: Freshly compared cell suspensions of clostridia converted leucine to isovaleric (iV) and isocaproic (iC) acids in the absence of other amino acids, implying that leukine was primarily a proton donor in the presence of proton acceptors.
Abstract: Freshly prepared cell suspensions of Clostridia (Clostridium bifermentans, C. botulinum proteolytic type A, C. difficile, C. sordellii, and C. sporogenes) and Peptostreptococcus anaerobius converte...
TL;DR: The importance of the pretreatment conditions and ensuing chemical extractions of the cellulosic substrates was demonstrated by the range of sugar and ethanol values obtained after saccharification and fermentation of the liberated sugars.
Abstract: Several highly cellulolytic fungi were initially screened for their cellulase and β-glucosidase activities. Culture filtrates from Trichoderma E58 demonstrated the highest β-glucosidase activity, giving a value of 1.0 IU/mg protein. A variety of different cellulose and pretreated wood substrates were hydrolysed by various cellulase preparations. The importance of the pretreatment conditions and ensuing chemical extractions of the cellulosic substrates was demonstrated by the range of sugar and ethanol values obtained after saccharification and fermentation of the liberated sugars. The rate of hydrolysis of the cellulosic substrate by Trichoderma E58 culture filtrates, concentrated culture filtrates, and whole cell cultures was compared. An ethanol value of 2.2% (w/v) could be obtained after hydrolysis of 5% Solka floe by concentrated culture filtrates of Trichoderma E58 and fermentation of the liberated sugars by Zymomonas mobilis or Saccharomyces cerevisiae.
TL;DR: Actively growing Zostera marina plants had a greater rhizosphere inorganic phosphate solubilizing potential than dormant plants and it is suggested that acetic acid, a product of glucose metabolism in the Rhizosphere flora, is responsible for phosphatesolubilization in the environment.
Abstract: Actively growing Zostera marina plants had a greater rhizosphere inorganic phosphate solubilizing potential than dormant plants. Rhizosphere bacteria that were capable of calcium phosphate solubilization were obligate aerobes and numbered approximately 4 × 108 colony-forming units/g dry weight root. Bacterial isolates solubilized calcium phosphate when cultured with glucose as the sole carbon and energy source but not when cultured with amino acids. Both calcium phosphate (hydroxyapatite) and glucose were found in sea grass bed sediment. Acetic acid was also detected from roots plus clinging sediment, from sediment, and from cultured bacterial isolates in a glucose-supplemented medium. The minimum concentration of acetic acid that showed detectable solubilization of calcium phosphate was 10−5 M. It is suggested that acetic acid, a product of glucose metabolism in the rhizosphere flora, is responsible for phosphate solubilization in the environment.
TL;DR: Two distinct phages infecting extremely halophilic bacteria of the genus Halobacterium, isolated from fermented anchovy sauce, have been characterized and suggest that the halophages are well adapted to survival in environments in which the salinity is subject to rapid changes of considerable magnitude.
Abstract: Bacteriophages infecting extremely halophilic bacteria of the genus Halobacterium have been isolated from fermented anchovy sauce Two distinct phages, designated Hh-1 and Hh-3, have been character
TL;DR: Strains of Acremonium roseum and Chaetomium globosum were tested for their ability to attack the protein components of wool by culturing the fungi in basal medium containing wool and monitoring changes in pH and soluble protein levels occurring in the medium.
Abstract: Strains of Acremonium roseum and Chaetomium globosum were tested for their ability to attack the protein components of wool by culturing the fungi in basal medium containing wool and monitoring cha...
TL;DR: Seven marine bacteria, which degraded carrageenan from Eucheuma spinosum, a hybrid ι–κ-carrageenan, were isolated and the specificity of the bacterialCarrageenases synthesized was determined.
Abstract: Seven marine bacteria, which degraded carrageenan from Eucheuma spinosum, a hybrid ι–κ-carrageenan, were isolated and the specificity of the bacterial carrageenases synthesized was determined. An e...
TL;DR: Grain dust from four large grain elevators along the Mississippi River near New Orleans, Louisiana, were analyzed for the presence of Bacillus thuringiensis, a pathogen of lepidopterous insects, and showed 94.9% of them to be variety aizawai.
Abstract: Grain dust from four large grain elevators along the Mississippi River near New Orleans, Louisiana, were analyzed for the presence of Bacillus thuringiensis, a pathogen of lepidopterous insects. Bo...
TL;DR: Azospirilla associated with wetland rice were isolated and characterized by employing immunodiffusion and immunofluorescence techniques and species specific antisera and fluorescent antibodies was further demonstrated with bacteria other than Azospirillum.
Abstract: Azospirilla associated with wetland rice were isolated and characterized by employing immunodiffusion and immunofluorescence techniques. Antisera against two strains belonging to Azospirillum lipoferum produced at least one heat-labile precipitation band with most isolates of A. lipoferum and A. brasilense. Antisera against two strains belonging to A. lipoferum and one strain belonging to A. brasilense produced one band only with strains of their respective species. Fluorescent antibody reactions with Azospirillum were species specific. Specificity of these antisera and fluorescent antibodies was further demonstrated with bacteria other than Azospirillum.
TL;DR: Fifteen specific bacteriophages, each active on particular strains of Rhizobium meliloti, have been selected from those isolated by enrichment of local soils.
Abstract: Fifteen specific bacteriophages, each active on particular strains of Rhizobium meliloti, have been selected from those isolated by enrichment of local soils. Variables affecting phage–host interaction have been examined and standardized. The differential susceptibility of individual R. meliloti strains to each phage produces a distinctive pattern of response which allows the segregation of each strain into one of the 80 different groups identified to date. Discrimination between strains with this typing system is reproducible with no change in phage type following extended subculture or plant infection and reisolation of strains from root nodules of alfalfa. The large number of different strains recognized by the system should make it very useful in experimentally controlled tests of selected strains in the nodulation of alfalfa plants.
TL;DR: A marine oil-degrading population grown at 8 °C showed a selective sensitivity regarding utilization of compounds in Prudhoe Bay oil in the presence of the dispersant Corexit 9527, which may indeed be stimulatory in the case of select compounds.
Abstract: A marine oil-degrading population grown at 8 °C showed a selective sensitivity regarding utilization of compounds in Prudhoe Bay oil in the presence of the dispersant Corexit 9527. The response was...