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1.
Diversity of bacterial community in freshwater of Woopo wetland 总被引:1,自引:0,他引:1
Keun Sik Baik Seong Chan Park Eun Mi Kim Kyung Sook Bae Jae-Hyung Ann Jong-Ok Ka Jongsik Chun Chi Nam Seong 《Journal of microbiology (Seoul, Korea)》2008,46(6):647-655
Diversity of bacterial community in water layer of Woopo wetland was investigated. Cultivable bacterial strains were isolated
by the standard dilution plating technique and culture-independent 16S rRNA gene clones were obtained directly from DNA extracts
of a water sample. Amplified rDNA restriction analysis (ARDRA) was applied onto both of the isolates and 16S rRNA gene clones.
Rarefaction curves, coverage rate and diversity indices of ARDRA patterns were calculated. Representative isolates and clones
of all the single isolate/clone phylotype were partially sequenced and analyzed phylogenetically. Sixty-four and 125 phylotypes
were obtained from 203 bacterial isolates and 235 culture-independent 16S rRNA gene clones, respectively. Bacterial isolates
were composed of 4 phyla, of which Firmicutes (49.8%) and Actinobacteria (32.0%) were predominant. Isolates were affiliated with 58 species. Culture-independent 16S rRNA gene clones were composed
of 8 phyla, of which Proteobacteria (62.2%), Actinobacteria (15.5%), and Bacteroidetes (13.7%) were predominant. Diversity of 16S rRNA gene clones originated from cultivation-independent DNA extracts was higher
than that of isolated bacteria. 相似文献
2.
Monitoring Bacterial Communities in Raw Milk and Cheese by Culture-Dependent and -Independent 16S rRNA Gene-Based Analyses 总被引:2,自引:0,他引:2
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The diversity and dynamics of bacterial populations in Saint-Nectaire, a raw-milk, semihard cheese, were investigated using a dual culture-dependent and direct molecular approach combining single-strand conformation polymorphism (SSCP) fingerprinting and sequencing of 16S rRNA genes. The dominant clones, among 125 16S rRNA genes isolated from milk, belonged to members of the Firmicutes (58% of the total clones) affiliated mainly with the orders Clostridiales and the Lactobacillales, followed by the phyla Proteobacteria (21.6%), Actinobacteria (16.8%), and Bacteroidetes (4%). Sequencing the 16S rRNA genes of 126 milk isolates collected from four culture media revealed the presence of 36 different species showing a wider diversity in the Gammaproteobacteria phylum and Staphylococcus genus than that found among clones. In cheese, a total of 21 species were obtained from 170 isolates, with dominant species belonging to the Lactobacillales and subdominant species affiliated with the Actinobacteria, Bacteroidetes (Chryseobacterium sp.), or Gammaproteobacteria (Stenotrophomonas sp.). Fingerprinting DNA isolated from milk by SSCP analysis yielded complex patterns, whereas analyzing DNA isolated from cheese resulted in patterns composed of a single peak which corresponded to that of lactic acid bacteria. SSCP fingerprinting of mixtures of all colonies harvested from plate count agar supplemented with crystal violet and vancomycin showed good potential for monitoring the subdominant Proteobacteria and Bacteroidetes (Flavobacteria) organisms in milk and cheese. Likewise, analyzing culturable subcommunities from cheese-ripening bacterial medium permitted assessment of the diversity of halotolerant Actinobacteria and Staphylococcus organisms. Direct and culture-dependent approaches produced complementary information, thus generating a more accurate view of milk and cheese microbial ecology. 相似文献
3.
Avinash Sharma Kunal Jani Vishal Thite Sunil Kumar Dhar Yogesh Shouche 《Geomicrobiology journal》2019,36(2):179-187
Culture-dependent and independent approaches were used to understand the microbiota thriving in tertiary coalbed, located in Jammu and Kashmir, India. We observed changes in physicochemical properties of the surface sediment (CM1) and coalbed (CM2) which detailed the influence of environmental factors on the structure and capabilities of bacterial communities. A total of 316 bacterial isolates representing 35 genera were isolated. We noted comparable difference in uncultivable bacterial communities which revealed the predominance of Proteobacteria in both the study sites. Moreover, we observed differential abundance of phyla Actinobacteria (49.6%), Firmicutes (4.2%), and Bacteroidetes (0.8%) in CM1, whereas Actinobacteria (11%), Firmicutes (37.8%), and Bacteroidetes (2.3%) in CM2. Additionally, functional imputations using PICRUSt depicted ~30% higher assemblage of major gene families in CM1 in comparison to CM2. Bacterial communities residing at CM1 were predominantly involved in methane oxidation, whereas CM2 communities found to play a vital process of conversion of coal to biogenic-methane enabling microbes to survive under constraints of high sulfur content, salt precipitation, and low nutrients and also provide clues to understand the potential of methanogenesis. 相似文献
4.
The Eastern Mediterranean deep sea is one of the most oligotrophic regions in the world’s ocean. With the aim to classify
bacteria from this special environment we isolated 107 strains affiliating to the Gammaproteobacteria, Alphaproteobacteria, Firmicutes, Actinobacteria and Bacteroidetes from sediments of the Eastern Mediterranean Sea. As determined by 16S rRNA gene sequence analysis, Actinobacteria and Firmicutes, in particular members of the genus Bacillus, were dominant and represented a remarkable diversity with 27 out of a total of 33 operational taxonomic units obtained from
the untreated sediment. The considerable percentage of operational taxonomic units (42%) which may be considered to be new
species underlines the uniqueness of the studied environment. In order to selectively enrich bacteria which are adapted to
the deep-sea conditions and tolerate broad pressure ranges, enrichments were set up with a sediment sample under in situ pressure
and temperature (28 MPa, 13.5°C) using N-acetyl-d-glucosamine as substrate. Interestingly Gammaproteobacteria were significantly enriched and dominant among the strains isolated after pressure pre-incubation. Obviously, Gammaproteobacteria have a selective advantage under the enrichment conditions applied mimicking nutrient supply under pressure conditions and
cope well with sudden changes of hydrostatic pressure. However, under the continued low nutrient situation in the Eastern
Mediterranean deep-sea sediments apparently Firmicutes and Actinobacteria have a clear adaptative advantage. 相似文献
5.
In this work, the results of microbiological and molecular genetic investigation of the microorganisms inhabiting the Kara Sea and the adjacent Yenisei and Gydanskii Bays are presented. The microorganisms isolated from the samples collected in the studied area belonged to 4 phyla and 11 genera. Bacteria of two phyla, Firmicutes and Actinobacteria, prevailed; representatives of the Gammaproteobacteria and Bacteroidetes were isolated as well. According to their phenotypic properties, the obtained pure cultures were classified with the genera Streptomyces, Rhodococcus, Micrococcus, Bacillus, Pseudomonas, Acinetobacter, Flavobacterium, and Marinococcus. Analysis of the obtained nucleotide sequences of the 16S rRNA genes confirmed that the isolates belonged to the genus Bacillus. One strain was reidentified as Brevibacillus laterosporus, and two strains were identified Aeromonas piscicola and Plantibacter sp. The results of the study of the enzymatic activity of the obtained pure psychrotolerant cultures suggest that the microbial community is actively involved in the destruction processes occurring in the studied area. 相似文献
6.
Yoshiaki Maejima Koya Kushimoto Yusuke Muraguchi Kohei Fukuda Takamasa Miura Atsushi Yamazoe 《Bioscience, biotechnology, and biochemistry》2018,82(7):1260-1263
141 filterable bacteria that passed through a 0.22 μm pore size filter were isolated from Lake Sanaru in Hamamatsu, Japan. These belonged to Proteobacteria, Bacteroidetes, Firmicutes, or Actinobacteria among which the first two phyla comprised the majority of the isolates. 48 isolates (12 taxa) are candidates assignable to new bacterial species or genera of Proteobacteria or Bacteroidetes. 相似文献
7.
Peiying Yan Shugui Hou Tuo Chen Xiaojun Ma Shuhong Zhang 《Extremophiles : life under extreme conditions》2012,16(2):345-354
The abundance and community composition of culturable bacteria in four snow cores along the 1300 km traverse from Zhongshan
Station to Dome A, East Antarctica, were investigated through the combination of liquid and solid media and small subunit
16S rRNA sequences. Under aerobic cultivation conditions, the average concentrations of bacterial colonies from each snow
core varied from 0.008 to 0.32 CFU mL−1. A total of 37 and 15 isolates with different morphologic characteristics were recovered from solid and liquid media PYGV,
respectively. The phylogenetic analysis of 14 representatives with different ARDRA patterns from RFLP showed that all the
isolates were affiliated with five phylogenetic groups: Firmicutes, Actinobacteria, Alphaproteobacteria, Gammaproteobacteria and Bacteroidetes. Actinobacteria represented the largest cluster with 43% of strains, and these strains exhibited unique phenotypic properties. The community
compositions of culturable bacteria in the four snow cores were distinctly different from each other and the concentrations
and community sizes of culturable bacteria along the traverse decreased with increases of latitude, altitude and distance
from coast, which likely reflected the different bacterial sources and biogeographies under the different regional climate
conditions in the snow cover of East Antarctica. 相似文献
8.
Bacterial community composition and chitinase gene diversity of vermicompost with antifungal activity 总被引:1,自引:0,他引:1
Muhammad Yasir Zubair Aslam Seon Won Kim Seon-Woo Lee Che Ok Jeon Young Ryun Chung 《Bioresource technology》2009,100(19):4396-4403
Bacterial communities and chitinase gene diversity of vermicompost (VC) were investigated to clarify the influence of earthworms on the inhibition of plant pathogenic fungi in VC. The spore germination of Fusarium moniliforme was reduced in VC aqueous extracts prepared from paper sludge and dairy sludge (fresh sludge, FS). The bacterial communities were examined by culture-dependent and -independent analyses. Unique clones selected from 16S rRNA libraries of FS and VC on the basis of restriction fragment length polymorphism (RFLP) fell into the major lineages of the domain bacteria Proteobacteria, Bacteroidetes, Verrucomicrobia, Actinobacteria and Firmicutes. Among culture isolates, Actinobacteria dominated in VC, while almost equal numbers of Actinobacteria and Proteobacteria were present in FS. Analysis of chitinolytic isolates and chitinase gene diversity revealed that chitinolytic bacterial communities were enriched in VC. Populations of bacteria that inhibited plant fungal pathogens were higher in VC than in FS and particularly chitinolytic isolates were most active against the target fungi. 相似文献
9.
Diversity and Activity of Cellulose-Decomposing Bacteria,Isolated from a Sandy and a Loamy Soil after Long-Term Manure Application 总被引:1,自引:0,他引:1
The community of culturable cellulolytic bacteria was analyzed in two long-term experimental field sites on Albic Luvisol
(silty sand) and Haplic Phaeozem (loam), with and without farmyard manure treatment. Against the backdrop of significant differences
in soil properties, the bacterial community structure differed clearly between sites and was affected by manure application
as analyzed by T-RFLP of 16S rDNA. The population densities of cellulolytic bacteria were significantly increased by manure
application in Phaeozem. Cellulose decomposing potentials of 537 isolates were tested on soluble, colloidal, and crystalline
cellulose. The results showed some evidence of a greater proportion of isolates with high decomposition activity in Luvisol,
but no impact from manure application could be observed in both soils. Restriction analysis and sequencing of 16S rDNA of
isolates revealed a rather simple community composition that was dominated by Streptomyces (67%). The composition of the RFLP groups was affected by manure application, which was most evident in Luvisol, whereas
an effect of the soil type could not be found. Although abundant RFLP groups were assigned to phylogenetically different bacterial
classes (Actinobacteria, Betaproteobacteria, and Gammaproteobacteria), cellulolytic activity could not consistently be differentiated. All in all, cellulolytic capabilities of the isolates were
highly variable and did not map to phylogenetic affiliation. 相似文献
10.
Yinxin Zeng Yang Zou Jacqueline M. Grebmeier Jianfeng He Tianling Zheng 《Polar Biology》2012,35(1):117-129
Planktonic bacteria are abundant in the Bering Sea. However, very little is known about their diversity and the roles of various
bacteria in the ocean. Bacterioplankton diversity in the northern Bering Sea was investigated using a combination of molecular
and cultivation-based methods. Community fingerprint analysis using polymerase chain reaction-denaturing gradient gel electrophoresis
revealed an apparent difference in the bacterioplankton community composition between sampling locations in the area. The
bacterial communities were characterized by two 16S rRNA gene clone libraries for surface and bottom water at shallow station
NEC5 (<60 m in depth) on the continental shelf. Sequences fell into 21 major lineages of the domain Bacteria, including Proteobacteria (Alpha, Beta, Gamma, and Delta), Bacteroidetes, Actinobacteria, Firmicutes, Acidobacteria, Planctomycetes, Verrucomicrobia, Fusobacteria, Chlamydiae, Chloroflexi, Chlorobi, Spirochaetes, Cyanobacteria (or algal chloroplasts), and candidate divisions OP8, OP11, TM6, TM7, and WS3. Significant differences were found between
the two clone libraries. Actinobacteria formed the dominant bacterial lineage in both surface and bottom water, and the Alphaproteobacteria was another dominant fraction in surface water. A total of 232 heterotrophic bacterial strains were isolated and 81% showed
extracellular proteolytic activity. Phylogenetic analysis revealed that the isolates fell into three bacterial groups, including
the Gammaproteobacteria, Actinobacteria, and Firmicutes. The most common genus in both the bacterial isolates and protease-producing bacteria was Pseudoalteromonas. Divergence of bacterial community composition in the northern Bering Sea was mainly characterized by the dominance of Actinobacteria and reflected a bacterial community different from that currently known for marine bacterioplankton communities in other
polar regions. 相似文献
11.
During ODP Leg 201 microbial communities in Eastern Equatorial Pacific Ocean and Peru Margin sediments were investigated. The sediment layers sampled extended down to 420 m below the sea floor, with estimated ages of up to 40 million years. Contamination-free anoxic slurries were inoculated into media containing different substrate combinations, all at micromolar concentration. These culture media were designed for a broad spectrum of physiological groups. A total of 162 pure cultures were isolated that could be grouped into 19 different phylotypes based on 16S rRNA gene analysis. The isolates belonged to the Alpha-, Gamma- and Deltaproteobacteria, the Firmicutes, Actinobacteria, and Bacteroidetes. The genera most frequently isolated were Bacillus (68 isolates) and Rhizobium (40 isolates). Comparison of strains with the same phylotypes by enterobacterial repetitive intergenic consensus (ERIC-PCR) analysis revealed the presence of several subgroups that did not correlate with medium, sediment depth or sampling site. The majority of the isolates, although obtained from anoxic environments and isolated under strictly anoxic conditions, turned out to be facultativly aerobic. Physiologically, the isolates were characterized as generalists, able to utilize a broad variety of electron donors with either oxygen, nitrate and in some cases manganese oxides as electron acceptors. The diversity inferred from physiological tests was even higher than that on the phylogenetic or genomic level. The outcome of the contamination tests, the isolation of close relatives of already known subsurface bacteria, the repeated finding of the same phylotype from different sites and the level of diversity present in the culture collection strongly suggest that indigenous deep-biosphere bacteria had been isolated. 相似文献
12.
Kennedy J Baker P Piper C Cotter PD Walsh M Mooij MJ Bourke MB Rea MC O'Connor PM Ross RP Hill C O'Gara F Marchesi JR Dobson AD 《Marine biotechnology (New York, N.Y.)》2009,11(3):384-396
Samples of the marine sponge Haliclona simulans were collected from Irish coastal waters, and bacteria were isolated from these samples. Phylogenetic analyses of the cultured
isolates showed that four different bacterial phyla were represented; Bacteriodetes, Actinobacteria, Proteobacteria, and Firmicutes. The sponge bacterial isolates were assayed for the production of antimicrobial substances, and biological activities against
Gram-positive and Gram-negative bacteria and fungi were demonstrated, with 50% of isolates showing antimicrobial activity
against at least one of the test strains. Further testing showed that the antimicrobial activities extended to the important
pathogens Pseudomonas aeruginosa, Clostridium difficile, multi-drug-resistant Staphylococcus aureus, and pathogenic yeast strains. The Actinomycetes were numerically the most abundant producers of antimicrobial activities, although activities were also noted from Bacilli and Pseudovibrio isolates. Surveys for the presence of potential antibiotic encoding polyketide synthase and nonribosomal peptide synthetase
genes also revealed that genes for the biosynthesis of these secondary metabolites were present in most bacterial phyla but
were particularly prevalent among the Actinobacteria and Proteobacteria. This study demonstrates that the culturable fraction of bacteria from the sponge H. simulans is diverse and appears to possess much potential as a source for the discovery of new medically relevant biological active
agents. 相似文献
13.
Cultivation based and culture independent molecular approaches were used to characterize the composition and structure of
bacterial community from a natural warm spring in the Western Ghats, a biodiversity ‘hotspot’. Dilution plating was done on
three types of media with varying nutrient levels. Relatively nutritionally poor medium supported growth of highest number
of bacteria (4.98 × 103 ml−1) compared to nutritionally rich media. On the basis of different morphological features on the plate, 62 aerobic and heterotrophic
bacterial strains were isolated and their 16S rRNA genes were sequenced and analyzed. On the basis of sequence similarity
these isolates were found to be distributed in 21 different genera belonging to Proteobacteria (58%) followed by Firmicutes (26%), Actinobacteria (13%) and Bacteroidetes (3%). Amplification of 16S rRNA gene of the community DNA using eubacterial primers, followed by cloning and sequencing revealed
that predominant members of the habitat belong to the phylum Cyanobacteria (60%) followed by Proteobacteria (19.5%), Bacteroidetes (6.67%), Actinobacteria (4.4%) and Firmicutes (2.2%) and small ribosomal subunit of a plastid (of Chlorophyta, 2.2%). 相似文献
14.
Fifty-one heterotrophic bacterial strains were isolated from the marine cyanobacterial cultures of heterocystous Nodularia harveyana strain Bo53 and non-heterocystous Oscillatoria brevis strain Bo10. Fluorescence in situ hybridisation and fingerprinting methods were used for a preliminary taxonomical classification of 44 of the 51 isolates. The strains obtained from Bo53 were mostly Alphaproteobacteria (10/24), followed by Bacteroidetes (7/24), and Gammaproteobacteria (3/24). The affiliation of the isolates originating from Bo10 was dominated by Alphaproteobacteria (8/20) and Bacteroidetes (7/20), followed by Gammaproteobacteria (3/20). The 16S rRNA genes of four selected isolates were sequenced. A red-coloured bacterium from Bo53 grouped with the alphaproteobacterial genus Porphyrobacter, while the other three strains, obtained from Bo10, belonged to the alphaproteobacterial genera Roseobacter (pink) and Rhodobacter (colourless), and to the genus Muricauda (yellow) of Bacteroidetes. The findings indicated that the aerobic anoxygenic phototroph Porphyrobacter and its relatives only occurred in Bo10 culture, whereas members of the Roseobacter clade and the Bacteroidetes bacterium Muricauda sp. seemed to be more ubiquitous. 相似文献
15.
Samir Radwan Huda Mahmoud Majida Khanafer Aamar Al-Habib Redha Al-Hasan 《Microbial ecology》2010,60(2):354-363
Gravel particles from four sites along the Arabian Gulf coast in autumn, winter, and spring were naturally colonized with
microbial consortia containing between 7 and 400 × 102 cm−2 of cultivable oil-utilizing bacteria. The 16S rRNA gene sequences of 70 representatives of oil-utilizing bacteria revealed
that they were predominantly affiliated with the Gammaproteobacteria and the Actinobacteria. The Gammaproteobacteria comprised among others, the genera Pseudomonas, Pseudoalteromonas, Shewanella, Marinobacter, Psychrobacter, Idiomarina, Alcanivorax, Cobetia, and others. Actinobacteria comprised the genera Dietzia, Kocuria, Isoptericola, Rhodococcus, Microbacterium, and others. In autumn, Firmicutes members were isolated from bay and nonbay stations while Alphaproteobacteria were detected only during winter from Anjefa bay station. Fingerprinting by denaturing gradient gel electrophoresis of amplified
16S rRNA genes of whole microbial consortia confirmed the culture-based bacterial diversities in the various epilithons in
various sites and seasons. Most of the representative oil-utilizing bacteria isolated from the epilithons were diazotrophic
and could attenuate oil also in nitrogen-rich (7.9–62%) and nitrogen-free (4–54%) cultures, which, makes the microbial consortia
suitable for oil bioremediation in situ, without need for nitrogen supplementation. This was confirmed in bench-scale experiments
in which unfertilized oily seawater was bioremediated by epilithon-coated gravel particles. 相似文献
16.
Karolien?Peeters Elie?Verleyen Dominic?A.?Hodgson Peter?Convey Damien?Ertz Wim?Vyverman Anne?Willems
Heterotrophic bacteria isolated from five aquatic microbial mat samples from different locations in continental Antarctica
and the Antarctic Peninsula were compared to assess their biodiversity. A total of 2,225 isolates obtained on different media
and at different temperatures were included. After an initial grouping by whole-genome fingerprinting, partial 16S rRNA gene
sequence analysis was used for further identification. These results were compared with previously published data obtained
with the same methodology from terrestrial and aquatic microbial mat samples from two additional Antarctic regions. The phylotypes
recovered in all these samples belonged to five major phyla, Actinobacteria, Bacteroidetes, Proteobacteria, Firmicutes and Deinococcus-Thermus, and included several potentially new taxa. Ordination analyses were performed in order to explore the variance in the diversity
of the samples at genus level. Habitat type (terrestrial vs. aquatic) and specific conductivity in the lacustrine systems
significantly explained the variation in bacterial community structure. Comparison of the phylotypes with sequences from public
databases showed that a considerable proportion (36.9%) is currently known only from Antarctica. This suggests that in Antarctica,
both cosmopolitan taxa and taxa with limited dispersal and a history of long-term isolated evolution occur. 相似文献
17.
Lakes in the McMurdo Dry Valleys of Antarctica are characterized by a permanent ice cover and little or no anthropogenic influence.
Although bacterial cultures have been obtained from these habitats, recent culture-independent studies indicate that the most
abundant microbes in these systems are not yet cultivated. By using dilution-to-extinction cultivation methods with sterilized
and nutrient-amended lake water as media, we isolated 148 chemotrophic psychrotolerant bacterial cultures from fresh surface
water of Lake Fryxell and the east lobe of Lake Bonney and the hypersaline, suboxic bottom water from the west lobes of Lake
Bonney. Screening of the 16S ribosomal ribonucleic acid (rRNA) genes of the cultures by restriction fragment length polymorphism
(RFLP) yielded 57 putatively pure psychrotolerant, slow growing cultures grouped into 18 clusters. The sequencing of 16S rRNA
genes of randomly selected representatives of each RFLP cluster revealed that the corresponding isolates belong to the Alphaproteobacteria (six RFLP patterns), Betaproteobacteria (six RFLP patterns), Bacteroidetes (four RFLP patterns), and Actinobacteria (two RFLP patterns). Phylogenetic analysis of the sequences showed that the vast majority of the isolates were not closely
related to previously described species. Thirteen of 18 RFLP patterns shared a 16S ribosomal deoxyribonucleic acid sequence
similarity of 97% or less with the closest described species, and four isolates had a sequence similarity of 93% or less with
the nearest described species. Phylogenetic analysis showed that these sequences were representatives of deeply branching
organisms in the respective phylum. A comparison of the isolates with 16S rRNA clone libraries prepared from the same environments
showed substantial overlap, indicating that dilution-to-extinction culturing in natural lake water media can help isolate
some of the most abundant organisms in these perennially ice-covered lakes. 相似文献
18.
We investigated the bacterial diversity of microbial communities in water-filled, human-made and natural container habitats
of the mosquitoes Aedes aegypti and Aedes albopictus in suburban landscapes of New Orleans, Louisiana in 2003. We collected water samples from three classes of containers, including
tires (n = 12), cemetery urns (n = 23), and miscellaneous containers that included two tree holes (n = 19). Total genomic DNA was extracted from water samples, and 16S ribosomal DNA fragments (operational taxonomic units,
OTUs) were amplified by PCR and separated by denaturing gradient gel electrophoresis (DGGE). The bacterial communities in
containers represented diverse DGGE-DNA banding patterns that were not related to the class of container or to the local spatial
distribution of containers. Mean richness and evenness of OTUs were highest in water samples from tires. Bacterial phylotypes
were identified by comparative sequence analysis of 90 16S rDNA DGGE band amplicons. The majority of sequences were placed
in five major taxa: Alpha-, Beta- and Gammaproteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, and an unclassified group; Proteobacteria and Bacteroidetes were the predominant heterotrophic bacteria in containers. The bacterial communities in human-made containers consisted mainly
of undescribed species, and a phylogenetic analysis based on 16S rRNA sequences suggested that species composition was independent
of both container type and the spatial distribution of containers. Comparative PCR-based, cultivation-independent rRNA surveys
of microbial communities associated with mosquito habitats can provide significant insight into community organization and
dynamics of bacterial species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
Cultivation techniques were used to study the heterotrophic bacterial diversity in two microbial mat samples originating from
the littoral zone of two continental Antarctic lakes (Forlidas Pond and Lundstr?m Lake) in the Dufek Massif (within the Pensacola
Mountains group of the Transantarctic Mountains) and Shackleton Range, respectively. Nearly 800 isolates were picked after
incubation on several growth media at different temperatures. They were grouped using a whole-genome fingerprinting technique,
repetitive element palindromic PCR and partial 16S rRNA gene sequencing. Phylogenetic analysis of the complete 16S rRNA gene
sequences of 82 representatives showed that the isolates belonged to four major phylogenetic groups: Actinobacteria, Bacteroidetes, Proteobacteria and Firmicutes. A relatively large difference between the samples was apparent. Forlidas Pond is a completely frozen water body underlain
by hypersaline brine, with summer thaw forming a slightly saline littoral moat. This was reflected in the bacterial diversity
with a dominance of isolates belonging to Firmicutes, whereas isolates from the freshwater Lundstr?m Lake revealed a dominance of Actinobacteria. A total of 42 different genera were recovered, including first records from Antarctica for Albidiferax, Bosea, Curvibacter, Luteimonas, Ornithinibacillus, Pseudoxanthomonas, Sphingopyxis and Spirosoma. Additionally, a considerable number of potential new species and new genera were recovered distributed over different phylogenetic
groups. For several species where previously only the type strain was available in cultivation, we report additional strains.
Comparison with public databases showed that overall, 72% of the phylotypes are cosmopolitan whereas 23% are currently only
known from Antarctica. However, for the Bacteroidetes, the majority of the phylotypes recovered are at present known only from Antarctica and many of these represent previously
unknown species. 相似文献
20.
《Bioscience, biotechnology, and biochemistry》2013,77(2):232-239
Sugarcane bagasse is an important lignocellulosic by-product with potential for conversion to biofuels and chemicals in biorefinery. As a step towards an understanding of microbial diversity and the processes existing in bagasse collection sites, the microbial community in industrial bagasse feedstock piles was investigated. Molecular biodiversity analysis of 16S rDNA sequences revealed the presence of a complex bacterial community. A diverse group of mainly aerobic and facultative anaerobic bacteria was identified reflecting the aerobic and high temperature microenvironmental conditions under the pile surface. The major bacterial taxa present were identified as Firmicutes, Alpha- and Gammaproteobacteria, Acidobacteria, Bacteroidetes, and Actinobacteria. Analysis of the eukaryotic microbial assemblage based on an internal transcribed spacer revealed the predominance of diverse cellulolytic and hemicellulolytic ascomycota. A microbial interaction model is proposed, focusing on lignocellulose degradation and methane metabolism. The insights into the microbial community in this study provide a basis for efficient utilization of bagasse in lignocellulosic biomass-based industries. 相似文献