共查询到20条相似文献,搜索用时 31 毫秒
1.
Chapelle Frédérique Steiman Regine Seigle-Murandi Françoise Luu-Duc Cuong 《Applied microbiology and biotechnology》1986,23(6):430-433
Summary The ability of 610 strains of micromycetes to introduce a hydroxy-group into benzimidazole substrate has been investigated.
Among them, 232 micromycetes have been selected and cultivated in a liquid synthetic medium. Convenient hydroxylation of benzimidazole
was obtained with 78 fungi. Finally, 8 strains of micromycetes have been chosen for further investigation and optimization
of this bioconversion. 相似文献
2.
Summary One of the factors giving rise to soil sickness in apple orchards is the rhizosphere microflora. The composition of the microbial
coenosis in the rhizosphere changes with increasing age of the apple trees. An increase in the counts of micromycetes and
actinomycetes and a decrease in bacterial counts was found in agreement with the decreasing pH of the rhizosphere soil. The
presence of fluorescent pseudomonads in the rhizosphere of old apple trees was rare, but the planting of apple seedling into
sick soil induced their proliferation. The relative proportion of individual genera of micromycetes changed according to the
tree age; fungi of the genus Mucor were more often found in the rhizosphere of younger trees than in that of older ones while
fungi of the genus Penicillium had an opposite trend. Biological tests showed that Penicillium fungi form the majority of
the phytotoxic microflora. The amount of phytotoxic micromycetes was higher in ‘sick’ soil as compared with control soil in
which apple trees had not been grown for at least 15 years. Higher numbers of phytotoxic micromycetes were isolated also from
the rhizosphere of apple seedlings grown in ‘sick’ soil as compared with those growing in control soil. An increase in the
amount of phytotoxic micromycetes in apple tree rhizosphere could be induced by mere addition of 5% (w/w) ‘sick’ soil to the
soil in which apple trees were grown for the first time. By adding sterilized ‘sick’ soil, the amount of phytotoxic micromycetes
in the apple seedling rhizosphere was not affected. Increased numbers of phytotoxic micromycetes affected negatively the growth
of apple trees and the morphology of apple tree roots. This demonstrated the possibility of transfer of a factor participating
in the etiology of soil sickness in apple orchards. 相似文献
3.
采用香农指数(Shannon-VienerIndex)分别对中国云南省热带及亚热带七个山地系统分布的34属小型真菌的生态位宽度和48个样点的生物多样性进行了计算、并用不加权组平均法对七个山地系统的48个样点及其中分布的34属小型真菌之间的关系进行了聚类分析。结果表明不加权组平均法适用于生境的生物多样性和小型真菌的生态位分析,并能定量地反映它们之间的生态学关系。 相似文献
4.
The radial growth rate of soil micromycetes colonies as a function of mineral nitrogen concentrations in the medium is expressed by a bell-shaped curve. Low nitrogen concentrations are growth-limiting whereas its high concentrations inhibit the growth. Soil micromycetes differ in the absolute values of growth rates and in the ranges of tolerance. 相似文献
5.
Shcherba VV Babitskaia VG Kurchenko VP Ikonnikova NV Kukulianskaia TA 《Prikladnaia biokhimiia i mikrobiologiia》2000,36(5):569-574
Fungal melanin pigments were shown to display a high antioxidant activity. An increase in the number of methyl substituents in benzidine molecules of melanins obtained from micromycetes and macromycetes was accompanied by a decrease in the efficiency of inhibition of peroxidase-catalyzed oxidation. Melanins were found to have considerable gene-protecting properties. Pigments isolated from macromycetes and applied at a much lower concentration than those obtained from micromycetes prevented damage to bacteriophage-lambda DNA induced by products of peroxidase-catalyzed degradation of aminobiphenyls. 相似文献
6.
The nature of melanin pigments from some micro- and macromycetes 总被引:6,自引:0,他引:6
New inhibitors of melanin formation by micromycetes Aspergillus carbonarius, Alternaria alternata, and Paecilomyces variotii and basidiomycetes Inonotus obliquus and Phellinus robustus were found. Precursors of melanin pigments were isolated and identified. p-Hydroxybenzoic acid was identified among the products of alkaline degradation of melanin formed by micromycetes, whereas in the case of macromycetes this was protocatechuic acid. Therefore, melanins of the former were found to belong to the dihydronaphthalene group, whereas those of the latter belong to catechols. 相似文献
7.
Antioxidant properties of fungal melanin pigments 总被引:1,自引:0,他引:1
V. V. Shcherba V. G. Babitskaya V. P. Kurchenko N. V. Ikonnikova T. A. Kukulyanskaya 《Applied Biochemistry and Microbiology》2000,36(5):491-495
Fungal melanin pigments were shown to display a high antioxidant activity. An increase in the number of methyl substituents
in benzidine molecules of melanins obtained from micromycetes and macromycetes was accompanied by a decrease in the efficiency
of inhibition of peroxidase-mediated oxidation. Melanins were found to have considerable gene-protecting properties. Pigments
isolated from macromycetes and applied at a much lower concentration than those obtained from micromycetes prevented damage
to bacteriophage-λ DNA induced by products of peroxidase-mediated degradation of aminobiphenyls. 相似文献
8.
A. A. Osmolovskiy V. G. Kreier A. V. Kurakov N. . Baranova N. S. Egorov 《Applied Biochemistry and Microbiology》2012,48(5):488-492
Natural isolates of Aspergillus ochraceus micromycetes from soil and plant remains from various regions have been screened. The isolated strains were characterized by similar cultural and morphological features and an identical nucleotide sequence in the ITS1-5,8S-ITS2 region of rDNA. The ability of the extracellular proteinases of A. ochraceus micromycetes to activate protein C of blood plasma has been established. Differences are revealed in the accumulation of proteinases activating protein C and proteinases with thrombinand plasmin-like activities in the growth dynamics of producers. 相似文献
9.
We investigated the interactions between micromycetes and basidiomycete mycelium on plant substrates in the course of their 3-year incubation in the litter of ecologically intact spruce forests of the Central State Biosphere Forest Sanctuary (Nelidovo District, Tver oblast). Only 40-60% of the micromycetes were involved in direct antagonistic interactions with basidiomycetous fungi. In terms of the ratio between physiologically active strains and those which did not interact with basidiomycete mycelium, we revealed differences in the structure of micromycete communities developing on various types of substrates (xylem, bark, sphagnum, leaves, needles, litter, and cotton grass). The micromycetes tested belonged to 49 species. At the end of the observation period, the fraction of microscopic fungi that actively influenced basidiomycete mycelium was four times lower in the inactive litter fraction (lignin-containing xylem debris) than in the active fraction (grass substrates). The mechanisms of indirect regulation of the structure and functions of micromycete communities are discussed, which may be based on the accumulation of phenolic compounds in the medium and changes in the enzyme activities of basidiomycete mycelium. 相似文献
10.
Investigation of the crude extracellular chitinase of Bacillus sp. 739, an antagonist of phytopathogenic fungi, discerned a relationship between the chitinase and antifungal activities of this bacterium. Purified chitinase lost its ability to inhibit the growth of micromycetes. The antagonistic (antifungal) activity of crude chitinase was found to be located in a low-molecular-weight fraction of the enzyme, which does not possess chitinase activity. Both crude and purified chitinase were able to lyse the cell walls of intact mycelium. Accordingly, it may be inferred that the antagonistic activity of Bacillus sp. 739 against micromycetes is largely determined by low-molecular-weight nonenzymatic substances whereas the role of chitinase is to utilize chitin, which is ubiquitously present in soil. 相似文献
11.
Investigation of the crude extracellular chitinase of Bacillussp. 739, an antagonist of phytopathogenic fungi, discerned a relationship between the chitinase and antifungal activities of this bacterium. Purified chitinase lost its ability to inhibit the growth of micromycetes. The antagonistic (antifungal) activity of crude chitinase was found to be located in a low-molecular-weight fraction of the enzyme, which does not possess chitinase activity. Both crude and purified chitinase were able to lyse the cell walls of intact mycelium. Accordingly, it may be inferred that the antagonistic activity of Bacillussp. 739 against micromycetes is largely determined by low-molecular-weight nonenzymatic substances, whereas the role of chitinase is to utilize chitin, which is ubiquitously present in soil. 相似文献
12.
V. Čatská 《Biologia Plantarum》1994,36(1):99-104
Phytotoxic micromycetes appear to be responsible for the apple replant disease (ARD). This was suppressed by the inoculation of apple-tree seedlings with some species of vesicular-arbuscular mycorrhizal (VAM) fungi—Glomus fasciculatum andG. macrocarpum. After the inoculation, growth of apple-tree seedlings improved in dependence on the type of soil, on VAM fungus species and on the ARD appearance. After 12-month cultivation, plant biomass (height, shoot and root dry masses) was markedly increased by inoculation withG. fasciculatum. Similarly, the numbers of colony forming units per unit soil (CFU) of phytotoxic micromycetes and of diazotroph bacteria (associative dinitrogen-fixing bacteria) in the rhizosphere was affected; CFU of phytotoxic micromycetes decreased, whereas CFU of the genusAzospirillum was higher. These bacteria could also serve as antagonists against phytotoxic micromycetes. It is also suggested that the ratio of CFU of diazotroph bacteria to CFU of phytotoxic micromycetes can be used as an indicator of the degree of ARD. It may be assumed that the use of some VAM fungi can replace the chemcial treatment of the soil with ARD. 相似文献
13.
I. G. Vorob’eva V. A. Chulkina A. B. Gorbunov M. A. Tomoshevich 《Contemporary Problems of Ecology》2011,4(3):254-259
The main and auxiliary first- and second-order ecological niches of the pathogenic micromycetes parasitizing on the berry
plants of subfamily Vaccinioideae subfamily is analyzed in this paper. 相似文献
14.
A. Šimonovičová 《Folia microbiologica》1990,35(6):561-569
Examination of the total biomass of soil micromycetes and their abundance in four soil types in the Furkota Valley (High Tatra
Mountains) modified by adding plant waste at 1 and 5% revealed the following. The effect of the addition of organic matter
was manifested by increased values of both the total biomass of soil micromycetes and their abundance. The highest values
were always detected in soils to which the waste was added at 5%. The effect of organic matter was most pronounced during
the first phase of the experiment (from the beginning of the experiment up to 2–3 months). A gradual exhaustion of nutrients
and energy resulted in decreased values. 相似文献
15.
The structure of micromycete communities and their synecologic interactions with basidiomycetes during plant debris decomposition 总被引:1,自引:0,他引:1
We investigated the interactions between micromycetes and basidiomycete mycelium on plant substrates in the course of their 3-year incubation in the litter of ecologically intact spruce forests of the Central Forest State Biosphere Reservoir (Nelidovo district, Tver oblast). Only 40–60% of the micromycetes were involved in direct antagonistic interactions with basidiomycetous fungi. In terms of the ratio between physiologically active strains and those that did not interact with basidiomycete mycelium, we revealed differences in the structure of micromycete communities developing on various types of substrates (wood, bark, sphagnum moss, leaves, needles, litter, and cotton grass). The micromycetes tested belonged to 49 species. At the end of the observation period, the fraction of microscopic fungi that actively influenced basidiomycete mycelium was four times lower in the inactive litter fraction (lignin-containing wood debris) than in the active fraction (grass substrates). The mechanisms of indirect regulation of the structure and functions of micromycete communities are discussed, which may be based on the accumulation of phenolic compounds in the medium and changes in the enzyme activities of basidiomycete mycelium.Translated from Mikrobiologiya, Vol. 74, No. 1, 2005, pp. 104–110.Original Russian Text Copyright © 2005 by Terekhova, Semenova. 相似文献
16.
New inhibitors of melanin formation by micromycetes Aspergillus carbonarius, Alternaria alternata, and Paecilomyces variotii and basidiomycetes Inonotus obliquus and Phellinus robustus were found. Precursors of melanin pigments were isolated and identified. p-Hydroxybenzoic acid was identified among the products of alkaline degradation of melanin formed by micromycetes, whereas in the case of macromycetes this was protocatechuic acid. Therefore, melanins of the former were found to belong to the dihydronaphthalene group, whereas those of the latter belong to catechols. 相似文献
17.
Kuvarina A. E. Roshka Yu. A. Rogozhin E. A. Nikitin D. A. Kurakov A. V. Sadykova V. S. 《Applied Biochemistry and Microbiology》2022,58(3):243-250
Applied Biochemistry and Microbiology - The ability of representatives of psychrotolerant micromycetes to produce antimicrobial compounds was studied. A promising producer of antibiotics,... 相似文献
18.
A. V. Alexandrova I. I. Aldobaeva K. A. Kalashnikova A. N. Kuznetsov 《Contemporary Problems of Ecology》2018,11(5):472-483
Results of a multiyear complex study of species diversity, features and patterns of distribution, substrate colonization, and ecology of soil microscopic fungi in the lowland, piedmont, and mountain monsoon rain forests of Vietnam are presented for the first time. In 97 forest habitats studied within 13 specially protected areas of Vietnam in the Northern, Central, and Southern parts of the country, 510 species of micromycetes from 148 genera have been identified. The influence of environmental factors (climatic features, relief, soils, forest types, etc.) on the formation of complexes of micromycetes has been analyzed. As a result, the dependence of the number of colony-forming units (CFUs) on the type of the substrate and the season (wet/dry) is established: significantly more species are detected in the dry season (October–March) (p < 0.05) in comparison with the wet one; many species are associated with certain plant species. Indicators of species diversity decrease with an increase above sea level altitude (p < 0.01). Herewith, the ratio of the taxonomic groups of micromycetes also consistently changes. A latitudinal–zonal trend of the change of the species composition of microscopic fungi, determined by a combination of environmental factors, has been revealed. 相似文献
19.
A. Lettl 《Folia microbiologica》1983,28(3):187-194
In regions highly influenced by immissions the concentrations of serobic and ammonifying bacteria and yeasts on the surface of apical shoots of spruce were 10–30 times higher in summer than in regions that were relatively less influenced; concentrations of micromycetes were almost two-fold. Deterioration by immissions eliminated the autotrophic oxidizers of sulphur and decreased the number of asymbiotic nitrogen-fixing bacteria to zero. Counts of proteolytic bacteria decreased pronoucedly. On the other hand, the number of bacteria capable of multiplication at pH 4.0 in the presence of 10 mM sulphite increased. The proportion of lipolytic bacteria, micromycetes and mainly of yeasts increased considerably. A similar trend was observed in the case of amylolytic bacteria. Heterotrophic sulphur oxidizers could not be detected. The possible significance of this phenomenon for senescence of conifer needle is discussed. 相似文献
20.
Microbiology - Adaptive reactions of Arctic and Antarctic strains of psychrophilic micromycetes Geomyces pannorum and Thelebolus microsporus to growth within a broad temperature range were studied.... 相似文献