首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The structure of microbial communities of brown algae, red algae, and of the red alga Gracilaria verrucosa, healthy and affected with rotten thallus, were comparatively investigated; 61 strains of heterotrophic bacteria were isolated and characterized. Most of them were identified to the genus level, some Vibrio spp., to the species level according to their phenotypic properties and the fatty acid composition of cellular lipids. The composition of the microflora of two species of brown algae was different. In Chordaria flagelliformis, Pseudomonas spp. prevailed, and in Desmarestia viridis, Bacillus spp. The composition of the microflora of two red algae, G. verrucosa and Camphylaephora hyphaeoides, differed mainly in the ratio of prevailing groups of bacteria. The most abundant were bacteria of the CFB cluster and pseudoalteromonads. In addition, the following bacteria were found on the surface of the algae: Sulfitobacter spp., Halomonas spp., Acinetobacter sp., Planococcus sp., Arthrobacter sp., and Agromyces sp. From tissues of the affected G. verrucosa, only vibrios were isolated, both agarolytic and nonagarolytic. The existence of specific bacterial communities characteristic of different species of algae is suggested and the relation of Vibrio sp. to the pathological process in the tissues of G. verrucosa is supposed.  相似文献   

2.
Mycological studies have been carried out on market samples of gari, a ready-to-use staple fermentation product of cassava ( Manihot esculenta cranz ). Commercial and industrial samples were analysed. The moisture contents of samples varied from 7% to 17% while the water activity ( a w) varied from 0·52 to 0·85 and the pH of samples ranged from 3·9 to 7·26. Several fungi were isolated from the commercial samples while the industrial packaged samples were relatively mould-free. Moulds isolated were mainly Aspergillus spp., Penicillium spp., and several Mucorales, e.g. Rhizopus sp., Syncephalastrum sp., Mucor sp. and Circinella sp.  相似文献   

3.
Abstract The gut microbiota of 7 species of deep-water (300–400 m) invertebrates from the Gulf of Mexico was examined. High populations of Vibrio spp. were observed in crustaceans (ranging from 105 to 7 × 106 cells/g gut content) while relatively low populations of Vibrio spp. were found in annelids, the water column, and sediment. Although saprophytic Vibrio species were isolated, Vibrio fluvialis and Vibrio hollisae , potential human pathogens, were isolated from the crustaceans, Pleoticus robustus, Nematocarcinas sp., Plesionika sp., and Munida sp., and Vibrio vulnificus was isolated from Nereis sp. These observations confirm the finding of Ohwada et al. [18] that the gut of deep-water invertebrates has a bacterial flora abundant in Vibrio spp. These results also suggest that some marine invertebrates may serve as reservoirs for certain potential pathogenic Vibrio species.  相似文献   

4.
One hundred and four strains of heterotrophic bacteria have been isolated and characterized from two species of bivalve mollusks cultivated in the Gulf of Nha Trang (Vietnam) and from the water of a mariculture farm. The isolates have been identified on the basis of morphological, physiological, biochemical, and chemotaxonomic properties, as well as by the content of G+C bases in DNA. In the microflora of mollusks, Vibrio alginolyticus was predominant; the pathogenic species V. harveyi and V. splendidus were found as well. Staphylococci and bacilli occupied the second place in abundance after vibrios. In addition, coryneforms and enterobacteria, as well as Pseudomonas spp. and Pseudoalteromonas spp., were revealed. The composition of the water microflora was more diverse as compared with the microflora of mollusks. In the water, Bacillus spp., Vibrio spp., and Pseudomonas spp. were predominant. Brevibacterium spp. and other coryneform bacteria, as well as enterobacteria, occurred in significant amounts. In addition, Pseudoalteromonas spp., Marinococcus sp., Halobacillus sp., Shewanella sp., Sulfitobacter sp., and bacteria of the CFB cluster were noticed. The presence of pathogenic and conditionally pathogenic bacterial species in the water and mollusks is probably the reason for the high death rate of cultivated animals at the mariculture farm.  相似文献   

5.
Filamentous fungi were isolated from estuarine sediments collected from two contaminated sites. One site was contaminated mainly by polycyclic aromatic hydrocarbon (PAH) with a concentration around 407?µg g?1 of different PAHs, and the other by different sources of industrial pollutants; both were compared to a pristine site. All three sites were located in the Baixada Santista, São Paulo State, Brazil. The aim of the present investigation was the isolation of filamentous fungi from pristine and industrially polluted sediments in order to assess the mycobiota present in those sites and to evaluate their tolerance to phenanthrene and pyrene. Most of the isolated fungi were mitosporic ascomycetes, including Aspergillus sp., Chrysosporium sp., Cyclothyrium spp., Gliocladium sp., Penicillium spp., Phoma spp., and Trichoderma spp. There were also representatives of sexual Ascomycetes, Basidiomycetes, and Zygomycetes. The results showed that 59% of the evaluated fungi were tolerant to pyrene and 30% to phenanthrene. Representatives of Trichoderma were the most tolerant among the filamentous fungi investigated. A representative of Penicillium simplicissimum was the only isolate tested that had a better growth in the presence of pyrene than in its absence.  相似文献   

6.
The leaf litter microbial community was quantitatively and qualitatively changed when a standard pesticide schedule that comprised an insecticide, a bactericide, and a fungicide was applied to McIntosh apple trees in the summer. Effects were observed for two winters by four indirect assays and three direct methods. Populations were altered qualitatively both years, but the most striking difference was the quantitative impact from year to year. Bacteria, filamentous fungi, and yeasts from treated leaves were reduced 10- to 10 000-fold between November 1976 and April 1977 and did not recover until snow cover had melted in March. Reductions in 1977-1978 were negligible. The marked seasonal difference is attributed to meteorological influences. Fluorescent pseudomonads were among the bacteria depressed by chemicals. Of the 49 genera of fungi and yeasts isolated, Coniothyrium sp., Penicillium spp., Arthrobotrys spp., and Nodulisporium sp. were appreciably reduced, whereas Typhula spp., Pleurophomella sp., Sporobolomyces spp., and Rhodotorula spp. were substantially enhanced by the spray program.  相似文献   

7.
The fungal species isolated from Korean cereals (barley, polished barley, wheat, rye, and malt) were Alternaria spp., Aspergillus spp., Chaetomium spp., Drechslera spp., Epicoccum sp., Fusarium spp., and Penicillium spp., etc. The number of Fusarium strains isolated was 36, and their ability to produce Fusarium mycotoxins on rice was tested. Nivalenol (NIV) was produced by Fusarium graminearum (7 of 9 isolates), Fusarium oxysporum (3 of 10 isolates), and Fusarium spp. (7 of 15 isolates). Of 15 isolates of Fusarium spp., 6 formed deoxynivalenol (DON). Fusarenon-X and 3-acetyl-DON were produced by most NIV- and DON-forming isolates, respectively. Zearalenone was produced by 3 isolates of F. graminearum, 1 isolate of Fusarium equiseti, and 11 isolates of Fusarium spp. T-2 toxin was not produced by any Fusarium isolates. The highest concentrations of mycotoxins produced by Fusarium isolates were 77.4 (NIV), 5.3 (DON), 138.3 (fusarenon-X), 40.6 (3-acetyl-DON), and 23.2 (zearalenone) micrograms/g.  相似文献   

8.
Keratinophilic fungi in the antarctic environment   总被引:1,自引:0,他引:1  
Results of a study on the diffusion of keratinophilic fungi in an Antarctic environment are given. Nine soil samples collected from as many sites along the coast of Ross Sea, and six dust samples inside the Italian scientific base were examined by direct inoculation and hair baiting methods for soil samples and plate dilution method for dust samples. As regards the variety of species isolated and the counting of the numbers of colonies, plate dilution method proved to be very effective.Aspergillus spp.,Cladosporium sp., Dematiaceae,Fusarium sp.,Geomyces pannorum v.pannorum, G. pannorum v.vinaceus, Mycelia sterilia,Penicillium spp. were isolated from soil. From the dust the following moulds were isolated:Aphanoascus fulvescens, Aspergillus sp.,Beauveria sp.,Chrysosporium carmichaelii, Dematiaceae, Geomyces pannorum v.pannorum, G. pannorum v.vinaceus, Malbranchea gypsea, Mycelia sterilia, Nectria inventa, Penicillium spp.,Scopulariopsis brevicaulis, Scopulariopsis sp. andTrichophyton mentagrophytes. The presence of four colonies ofTrichophyton mentagrophytes is emphasized and correlated with the anthropization process.  相似文献   

9.
The structure of microbial communities of brown algae, red algae, and of the red alga Gracilaria verrucosa, healthy and affected with thallus rot, were comparatively investigated; 61 strains of heterotrophic bacteria were isolated and characterized. Most of them were identified to the genus level, some Vibrio spp., to the species level according to their phenotypic properties and the fatty acid composition of cellular lipids. The composition of the microflora of two species of brown algae was different. In Chordaria flagelliphormis, Pseudomonas spp. prevailed, and in Desmarestia viridis, Bacillus spp. The composition of the microflora of two red algae, G. verrucosa and Camphylaephora hyphaeoides, differed mainly in the ratio of prevailing groups of bacteria. The most abundant were bacteria of the CFB cluster and pseudoalteromonads. In addition, the following bacteria were found on the surface of the algae: Sulfitobacter spp., Halomonas spp., Acinetobacter sp., Planococcus sp., Arthrobacter sp., and Agromyces sp. From tissues of the affected G. verrucosa, only vibrios were isolated, both agarolytic and nonagarolytic. The existence of specific bacterial communities characteristic of different species of algae is suggested and the relation of Vibrio sp. to the pathological process in the tissues of G. verrucosa is supposed.  相似文献   

10.
The fungal species isolated from Korean cereals (barley, polished barley, wheat, rye, and malt) were Alternaria spp., Aspergillus spp., Chaetomium spp., Drechslera spp., Epicoccum sp., Fusarium spp., and Penicillium spp., etc. The number of Fusarium strains isolated was 36, and their ability to produce Fusarium mycotoxins on rice was tested. Nivalenol (NIV) was produced by Fusarium graminearum (7 of 9 isolates), Fusarium oxysporum (3 of 10 isolates), and Fusarium spp. (7 of 15 isolates). Of 15 isolates of Fusarium spp., 6 formed deoxynivalenol (DON). Fusarenon-X and 3-acetyl-DON were produced by most NIV- and DON-forming isolates, respectively. Zearalenone was produced by 3 isolates of F. graminearum, 1 isolate of Fusarium equiseti, and 11 isolates of Fusarium spp. T-2 toxin was not produced by any Fusarium isolates. The highest concentrations of mycotoxins produced by Fusarium isolates were 77.4 (NIV), 5.3 (DON), 138.3 (fusarenon-X), 40.6 (3-acetyl-DON), and 23.2 (zearalenone) micrograms/g.  相似文献   

11.
The aim of this study was to assess the bacterial diversity associated with a corrosive biofilm in a steel pipeline from the Gulf of Mexico used to inject marine water into the oil reservoir. Several aerobic and heterotrophic bacteria were isolated and identified by 16S rRNA gene sequence analysis. Metagenomic DNA was also extracted to perform a denaturing gradient gel electrophoresis analysis of ribosomal genes and to construct a 16S rRNA gene metagenomic library. Denaturing gradient gel electrophoresis profiles and ribosomal libraries exhibited a limited bacterial diversity. Most of the species detected in the ribosomal library or isolated from the pipeline were assigned to Proteobacteria (Halomonas spp., Idiomarina spp., Marinobacter aquaeolei, Thalassospira sp., Silicibacter sp. and Chromohalobacter sp.) and Bacilli (Bacillus spp. and Exiguobacterium spp.). This is the first report that associates some of these bacteria with a corrosive biofilm. It is relevant that no sulfate-reducing bacteria were isolated or detected by a PCR-based method. The diversity and relative abundance of bacteria from water pipeline biofilms may contribute to an understanding of the complexity and mechanisms of metal corrosion during marine water injection in oil secondary recovery.  相似文献   

12.
A survey was conducted to determine the nematodes associated with the soil, substratum and roots of the ornamental plant, Pseuderanthemum atropurpureum, grown in the Aligarh district of western Uttar Pradesh, India. Ten genera of plant parasitic nematodes, viz. Meloidogyne spp., Helicotylenchus sp., Hemicriconemoides sp., Hoplolaimus sp., Xiphinema sp., Pratylenchus sp., Trichodorus sp., Tylenchorhynchus sp., Aphelenchoides sp. and Rotylenchus sp., were isolated from 345 soil samples collected from 15 different localities. Our study indicates that among the 10 genera of the plant parasitic nematodes, Meloidogyne spp. was widely spread in all the examined localities of Aligarh district, except at Khair. It was observed that the population density and diversity of nematodes in all the soil samples was not uniform. Meloidogyne spp. showed the highest absolute frequency and relative frequency followed by Helicotylenchus sp., Hemicriconemoides sp., Xiphinema sp., Hoplolaimus sp., Pratylenchus sp., Trichodorus sp., Tylenchorhynchus sp., Aphelenchoides sp. and Rotylenchus sp. Since no records are available in the literature related to the association of root-knot nematode in P. atropurpureum, it is worthy to note that this study may be considered as a new hope towards further study of the interaction between the root-knot nematode and ornamental plant P. atropurpureum if any.  相似文献   

13.
Ground beef samples prepared from electrically stimulated and nonstimulated biceps femoris and infraspinatus muscles were inoculated with Lactobacillus sp., Pseudomonas sp., Acinetobacter sp., or a mixture of Lactobacillus spp., Pseudomonas spp., Acinetobacter spp., Moraxella sp., Microbacterium thermosphactum, and Erwinia herbicola. There were no significant differences in growth of various bacteria in ground beef made from electrically stimulated and nonstimulated muscles.  相似文献   

14.
In the present study, 10 soil samples were collected aseptically from an equal number of areas of the Antarctic in the zone occupied by the 1986–1987 Italian expedition for research on keratinophilic fungi.Of particular interest was the isolation of a pathogenic fungus, Microsporum gypseum, from two sites in the base camp occupied by men and by skuas. Trichophyton terrestre was isolated from a site in which people worked and through which penguins and skuas passed.The most widespread fungal species were members of the genus Chrysosporium. Some of these species were isolated but not identified and this part of the study was still be completed.Another significant finding was the absence of fungi in one sample, while in another the widespread and abundant growth in all the seeded dishes of a single species of Chrysosporium.Other species in genera of general diffusion in many environments were also isolated : Aspergillus spp., Malbranchea sp., Mycelia sterilia spp., Paecilomyces sp., Penicillium spp. and Scopulariopsis spp.  相似文献   

15.
Endophytic fungi were isolated from healthy, living, and symptomless tissues of inner bark, leaf, and roots of Aegle marmelos, a well-known medicinal plant, growing in different parts of India including Varanasi. A total of 79 isolates of endophytic fungi were isolated, representing 21 genera, adopting a standard isolation protocol. Members of the deuteromycotina were more prevalent than ascomycotina and others. The result was quite encouraging in terms of maximum isolates recovery from hyphomycetes (78.5%) followed by ascomycetes (8.9%) and coelomycetes (7.6%) respectively, which corroborates previous studies in same area. However, 5.1% isolates remained unidentified and were classified under Mycelia Sterilia. No isolate was obtained from either basidiomycotina or from zygomycotina. Fusarium spp. had maximum colonization frequency (8.00%) in this plant. The other dominant endophytic genera were Aspergillus spp., Alternaria sp., Drechslera sp., Rhizoctonia sp., Curvularia sp., Nigrospora sp., and Stenella sp. Only two ascomycetous members Chaetomium globosum and Emericella sp. (perfect state of Aspergillus sp.) were obtained from the bark sample. These results indicated that distribution of endophytic fungi within the A. marmelos is not even. Bark harbors more endophytic fungi than leaf and root.  相似文献   

16.
One hundred and four strains of heterotrophic bacteria have been isolated and characterized from two species of bivalve mollusks cultivated in the Gulf of Nha Trang (Vietnam) and from the water of a mariculture farm. The isolates have been identified on the basis of morphological, physiological, biochemical, and chemotaxonomic properties, as well as by the content of G+C bases in DNA. In the microflora of mollusks, Vibrio alginolyticus was predominant; the pathogenic species V. harveyi and V. splendidus were found as well. Staphylococci and bacilli occupied the second place in abundance after vibrios. In addition, coryneforms and enterobacteria, as well as Pseudomonas spp. and Pseudoalteromonas spp., were revealed. The composition of the water microflora was more diverse as compared with the microflora of mollusks. In the water, Bacillus spp., Vibrio spp., and Pseudomonas spp. were predominant. Brevibacterium spp. and other coryneform bacteria, as well as enterobacteria, occurred in significant amounts. In addition, Pseudoalteromonas spp., Marinococcus sp., Halobacillus sp., Shewanella sp., Sulfitobacter sp., and bacteria of the CFB cluster were noticed. The presence of pathogenic and conditionally pathogenic bacterial species in the water and mollusks is probably the reason for the high death rate of cultivated animals at the mariculture farm.  相似文献   

17.
A halophilic alkaline phosphatase was highly purified (about 510-fold with about 21% yield) from a moderate halophile, Halomonas sp. 593. The N-terminal 35 amino acid sequence of this enzyme was found to be more acidic than those previously isolated from Vibrio spp., and this enzyme was partially resistant to SDS. Several enzymatic properties demonstrated that it showed higher halophilicity than those enzymes from Vibrio spp.  相似文献   

18.
从马兜铃内生真菌Colletotrichum sp.的大米发酵产物中分离得到6个化合物,经波谱数据分析分别鉴定为7-hydroxy-10-oxodehydrodihydrobotrydial(1)、格链孢酚(2)、5-甲氧基格链孢酚(3)、链格孢毒素I(4)、腾毒素(5)和二氢腾毒素(6)。以上化合物均为从该菌属中首次分离得到,其中化合物1~4对肺癌细胞和乳腺癌细胞有一定的细胞毒活性。  相似文献   

19.
A total of 331 aerobic heterotrophic bacterial strains were isolated from various ecosystems of Finnish Lapland (68-69 degrees N) including forest soil, arctic alpine-tundra soil, stream water, lake and mire sediments, lichen and snow algae. Whole cell fatty acid and 16S rRNA gene sequence analysis and microscopy indicated that the isolates were dominated by Gram-negative bacteria, while only 20 Gram-positive strains were isolated. Based on 16S rRNA gene sequences the isolates were members of alpha-, beta-, gamma-Proteobacteria, Gram-positives with low G+C content, Actinobacteria and the Cytophaga/Flexibacter/Bacteroides group. More than one-third of the isolates could be tentatively identified as Pseudomonas spp. which were particularly abundant in the alpine-tundra soils where they represented 60% of all isolates. Other frequently isolated Gram-negative taxa were Burkholderia sp., Collimonas sp., Pedobacter sp., Janthinobacter sp., Duganella sp., Dyella sp. and Sphingomonas sp. Growth temperature ranges and hydrolytic enzyme activities of selected ca.100 strains were screened. The strains were psychrotolerant growing generally at temperatures ranging from 0 to 30 degrees C, as 82% of the isolates grew at 0 degrees C while only 7% grew at 35 degrees C. Protease and lipase activities at 5 degrees C were detected in more than half of the strains while approximately 20% of the strains possessed amylase and/or cellulase activities.  相似文献   

20.
Fungi isolated from field-collected egg masses of the European corn borer, Ostrinia nubilalis, were identified as Alternaria spp., A. porri, Fusarium spp., Fusarium oxysporum, Beauveria bassiana, Mucor spp., and an unidentified yeast. Most fungi were associated with predator injury to the egg mass. Bioassay of fungi on egg masses, however, showed that Alternaria spp. and A. porri reduced the hatch of both injured and uninjured egg masses, and Mucor sp. reduced the hatch only when the egg mass was injured.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号