Effect of some herbicides on the production of lysine byAzotobacter chroococcum

Summary Production of lysine byAzotobacter chroococcum strain H23 was studied in chemically-defined media amended with different concentrations of alachlor, metolachlor, 2,4-D, 2,4,5-T and 2,3,6-TBA. The presence of 5, 10, and 50g/ml of alachlor or 2,3,6-TBA significantly decreased quantitative production of lysine. However, the presence 2,4-D or 2,4,5-T at concentrations of 10 and 50g/ml enhanced the production of lysine. Quantitative production of lysine was not affected as consequence of the addition of metolachlor to the culture medium, showing that the release lysine to the culture media byA. chroococcum was not affected by that herbicide.     

Effect of benzonitrile ester herbicides on the growth of some soil bacteria

T. CSERHÁTI, Z. ILLÉS AND S. NEMES-KÓSA. 1992. The effect of some benzonitrile ester herbicides on the growth of Bacillus megaterium, B. cereus var. mycoides, B. polymyxa, B. subtilis, Pseudomonas fluorescens and Azotobacter chrooccum was investigated in the concentration range 20–640 ppm by the agar diffusion method. The zones of inhibition, restricted growth and eventual stimulation were determined. The data matrix was evaluated by principal component analysis. Azotobacter chroococcum was the most resistant to the benzonitrile esters. The influence of benzonitrile esters on the growth of micro-organisms depended equally on the species and on the chemical structure of the herbicides. Chloro substitution considerably modified the effect whereas bromo and iodo substitution resulted in similar biological activity.     

The effect of extracellular enzymes of wood-rotting fungi on wood

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Immunoenzyme analysis of decomposition of herbicides by soil and wood-rot fungi

The effect of herbicide atrazine was studied on the growth and development of a number of soil and wood decay fungi: white-rot basidiomycetes (Cerrena maxima, Coriolopsis fulvocenerea, and Coriolus hirsutus), thermophilic micromycetes from self-heating grass composts (cellulolytic fungus Penicillium sp. 13 and noncellulolytic ones Humicola lanuginosa spp. 5 and 12), and mesophilic phenol oxidase-producing micromycete Mycelia sterilia INBI 2-26. Detection of atrazine in liquid fungal cultures was performed by using enzyme immunoassay technique. Both stimulation (Humicola lanuginosa 5) and suppression (Humicola lanuginosa 12 and Penicillium sp. 13) of fungal growth with atrazine were observed on solid agar media. Hyphomycete Mycelia sterilia INBI 2-26 was almost insensitive to the presence of atrazine. Neither of thermophilic strains was capable of atrazine consumption in three-week cultivation. In contrast with that, active laccase producers Cerrena maxima, Coriolopsis fulvocenerea, and Coriolus hirsutus consumed up to 50% atrazine in 5-day cultivation in the presence of the xenobiotic and at least 80-90% in 40 days. Mycelia sterilia INBI 2-26, which also forms extracellular laccase, also consumed up to 70% atrazine in 17 days. The degree of atrazine consumption depended on the term of its addition to the fungal culture medium.     

Effect of aromatic monomers on production of carbohydrate-degrading enzymes by white-rot and brown-rot fungi

Abstract The effects were studied of 12 monomeric aromatic compounds on the production of six carbohydrate-degrading enzymes of two brown-rot fungi, Postia placenta and Gloeophyllum trabeum , and one white-rot fungus, Coriolus versicolor . Most compounds were inhibitory to growth of the decay fungi at concentrations of 0.05%. At lower concentrations, the phenolics often stimulated growth. Relatively high concentrations (> 0.1%) of aromatic monomers were required to inhibit xylanase of P. placenta in situ. The effects of the monomers incorporated in liquid media on enzyme production varied depending on compound and fungal species. Some compounds were quite inhibitory to production of enzyme activities at very low concentrations. For example, catechol and vanillin (50 ppm) caused 100% inhibition of xylanase and β-1,4-endoglucanase production by P. placenta . However, no aromatic monomer was strongly inhibitory to production of all enzyme activities of all fungi.     

Pilot-scale production of intracellular and extracellular enzymes

Optimization of pilot-scale enzyme production is described for the case of an extracellular protease and an intracellular esterase. Media optimization was conducted to reduce medium costs and to determine the effect of various defined ingredients as well as complex nitrogen sources on enzyme production. Fermentation conditions such as inoculum transfer timing, agitation rate, and cultivation temperature were evaluated for their effect on enzyme production. Broths were harvested via microfiltration, diafiltered, and in the case of the extracellular enzyme, lysed via homogenization. An improvement in enzyme titer and reduction in medium costs for the extracellular protease was realized through replacement of Sabouraud dextrose broth medium with more reasonably priced complex nitrogen sources such as N-Z-amine A. An improvement in enzyme titer and reduction in medium costs for the intracellular esterase was realized by decreasing the amount of malt extract and omitting glycerol from the medium. An improvement in the harvest conditions for both enzymes was realized by using large-lumen-diameter hollow-fiber membranes (2.7 mm) which seemed wide enough to pass clumps of fungal and filamentous bacterial fermentation broth without clogging.     

Screening for extracellular enzymes of fungi from manufacturing wastes

Summary Three different types of manufacturing waste, dried soybean meal after oil extraction, sesame seed meal after oil extraction, and brewery spent grain from beer production, were plated for fungi with malt extract agar and potato-dextrose agar. Brewery spent grain gave the highest fungal counts and sesame seed meal the least. The more abundant fungi were:Absidia sp.,Aspergillus flavus andAsp. ochraceus in soybean meal;Asp. flavus, Rhizopus oryzae and yeast in sesame seed meal, andAsp. restrictus and yeast in brewery spent grain. Nine fungal isolates were screened for extracellular amylase, protease, cellulase and lipase activity.Aspergillus flavus andFusarium oxysporum were good producers of these enzymes, butAbsidia sp.,Aspergillus ochraceus and the yeasts showed a limited range of enzyme activities.Aspergillus restrictus, an osmophilic fungus, had no activity for the four enzymes.

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Resumen En placas de agar de patata y dextrosa (PDA) y de extracto de malta se sembraron tres tipos de residuos industriales: pulpa de soja, una vez realizada la extracción de aceite, pulpa de semillas de sésamo, después del mismo proceso, y residuos de cereales de fábrica de cerveza. El mayor número de hongos se obtuvo a partir de los residuos de cereales y el menor a partir de la pulpa de semillas de sésamo. Los hongos más abundantes fueron:Absidia sp.,Aspergillus flavus yAsp. ochraceus en pulpa de soja,Asp. flavus, Rhizopus oryzae y levaduras en pulpa de semillas de sésamo, y,Asp. restrictus y levaduras en residuos de fábrica de cerveza. Se estudiaron las actividades extracelulares de amilasa, proteasa, celulasa y lipasa.Aspergillus flavus y Fusarium oxysporum eran buenos productores de estos enzimas, sin embargo,Absidia sp.,Asp. ochraceus y las levaduras mostraron una limitada variedad de actividades enzimáticas.Aspergillus restrictus, hongo de tipo osmofílico, no mostró actividad para niguno de los cuatro enzimas estudiados.

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Résumé Les champignons présents dans trois sortes de déchets industriels (tourteaux délipidés de soja et de sésame, et graines résiduelles de brasserie) ont été cultivés sur milieux gélosés à l'extrait de malt et à la dextrose de pomme de terre. Les graines résiduelles de brasserie ont donné les numérations de champignons les plus élevées, et le tourteau de sésame les plus faibles. Les champignons les plus abondants sont: dans le tourteau de soja,Absidia sp.,Aspergillus flavus etAsp. ochraceus; dans le tourteau de sésame,Asp. flavus, Rhizopus oryzae et la levure; et dans les graines résiduelles de brasserie,Asp. restrictus. Neuf souches de champignons ont été isolées et examinées en ce qui concerne la production extracellulaire des activités amylase, protéase, cellulase et lipase.Aspergillus flavus etFusarium oxysporum sont de bons producteurs de ces enzymes. Par contre,Absidia sp.,Aspergillus ochraceus et les levures ont des activités enzymatiques faibles. Le champignon osmophileAspergillus restrictus ne produit aucun des quatres enzymes.

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Paper presented at the VII International Conference on the Global Impacts of Applied Microbiology, Helsinki, 12–18 August 1985     

Carbon assimilation and extracellular antigens of some yeast-like fungi

Many yeast-like fungi assimilated n-hexadecane, butylamine and putrescine as sole carbon sources. Methanol was not assimilated. This points to a physiological similarity to endomycetous, hydrocarbon-utilizing yeasts. Stephanoascus ciferrii assimilated uric acid, adenine and allantoin as sole source of carbon and nitrogen. All strains of Geotrichum candidum and many other yeast-like fungi assimilated acetoin and butan-2,3-diol. Assimilation tests for adenine, uric acid, allantoin, acetoin and butan-2,3-diol were found to be suitable for taxonomic purposes.Extracellular antigens immunologically related to those produced by Geotrichum candidum were detected in the cell-free culture liquids of several yeast-like fungi. The extracellular antigen excreted by Stephanoascus ciferrii was species-specific.     

Cellulolytic activity of some soil fungi

The cellulolytic activity of some soil fungi isolated from soil and decomposing pieces of plant material was observed to depend upon the genera of fungi, the nature of substrate and the temperature, The cellulase produced in the presence of cellulose powder was active against CMC and vice versa.     

Studies on mevinolin production by some fungi

The potentiality of 25 fungal species, belonging to fourteen genera isolated from Egyptian soils, to produce mevinolin, a hypocholesterolaemic agent, when grown on selected substrates was tested. Samples of culture filtrates were tested by thin layer chromatography and the positive results were further assessed by high pressure liquid chromatography analysis. It was found that nearly one-third of the fungi showed positive results for production of mevinolin. Aspergillus terreus was distinguished by its capacity to produce mevinolin when cultivated on selected media. Some factors influencing mevinolin production and the growth of A. terreus were also studied. The maximal mevinolin yields were achieved after 8 days incubation at 30 degrees C. An initial pH value of 5-6 was the optimum for growth of A. terreus and mevinolin production.     

Mevinolin production by some fungi

The potentiality of twenty-five fungal species belonging to 14 genera isolated from Egyptian soils to produce mevinolin, a hypocholesterolemic agent, when grown on selected substrates was tested. For the first screening samples of culture filtrates were tested by TLC and the positive results were further estimated by HPLC analysis. It was found that nearly one-third of the tested fungi showed positive results as to production of mevinolin.Aspergillus terreus was distinguished by its capacity to produce mevinolin when cultivated on a selected medium. The maximum mevinolin yields were achieved after on 8-d incubation at 30°C. An initial pH value of 5–6 was found to be the optimum for growth ofA. terreus and mevinolin production.     

Hyphal interactions among some soil fungi

Summary Hyphal interactions amongRhizopus oryzae, a dominant soil inhabiting fungus and soil fungi with potential antagonistic characters, were studiedin vitro. Results depict that diameter of the hyphae of interacting fungi plays an important role in hyperparasitic interactions. None of the hyphae with wide diam. could penetrate inside and coil around the hyphae ofR. oryzae, while most of the hyphae with narrow diam. did so.     

Rhizosphere soil fungi of some vegetable plants

Summary The fungi from the rhizosphere and non-rhizosphere soils of some important vegetable crop plants, viz.,Lycopersicon esculentum, Allium cepa, Trigonella foenum-graecum, Daucus carota, Hibiscus esculentus, Raphanus sativus, andBrassica oleradcea were isolated. Some members of Phycomycetes, Acsomycetes and Fungi Imperfecti were isolated.It has also been observed that the pH in the region of the rhizosphere was lower and the moisture content was higher than in the soil away from it. Further, the maximum number of fungi was found in the rhizosphere of young plants. The present studies also supported the view that the number of fungi in the rhizosphere is greater than in the soil away from it. The largest number of fungi was obtained from the rhizosphere ofTrigonella foenum-graecum.