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1.
In the present study, the diversity of rumen methanogens in crossbred Karan Fries cattle was determined by constructing 16S rRNA and mcrA (methyl coenzyme-M reductase α subunit) gene libraries using specific primers. All thirteen OTUs or phylotypes from 16S rRNA library clustered with order Methanobacteriales, twelve of which aligned with Methanobrevibacter spp., whereas one OTU resemble with Methanosphaera stadtmanae. Out of eighteen OTUs identified from mcrA gene library, fifteen clustered with order Methanobacteriales, two resemble with Methanomicrobiales and remaining one grouped with Methanosarcinales. These results revealed that Methanobrevibacter phylotype was predominantly present in Karan Fries crossbred cattle fed on high fibrous diet containing wheat straw. Compared to 16S rRNA gene, mcrA gene OTUs clustered in three orders providing better insights of rumen methanogens diversity in cattle. 相似文献
2.
Molecular identification and dynamics of microbial communities in reactor treating organic household waste 总被引:1,自引:0,他引:1
Juliana Cardinali-Rezende Renan B. Debarry Luis F. D. B. Colturato Eduardo V. Carneiro Edmar Chartone-Souza Andrea M. A. Nascimento 《Applied microbiology and biotechnology》2009,84(4):777-789
The prokaryotic diversity associated with organic household waste (OHW), leachate (start-up inoculum), and mesophilic anaerobic
digestion processes in the degradation of OHW for 44 and 90 days was investigated using a culture-independent approach. Bacterial
and archaeal 16S rRNA and mcrA gene clone libraries were constructed from community DNA preparations. Bacterial clones were affiliated with 13 phyla, of
which Firmicutes, Proteobacteria, and Bacteroidetes were represented in all libraries, whereas Actinobacteria, Thermotogae, Lentisphaerae, Acidobacteria, Chloroflexi, Cyanobacteria, Synergistetes, Spirochaetes, Deferribacteres, and Deinococcus-Thermus were exclusively identified in a single library. Within the Archaea domain, the Euryarchaeota phylum was the only one represented. Corresponding sequences were associated with the following orders of hydrogenotrophic
methanogens: Methanomicrobiales (Methanoculleus genus) and Methanobacteriales (Methanosphaera and Methanobacterium genera). One archaeal clone was not affiliated with any order and may represent a novel taxon. Diversity indices showed greater
diversity of Bacteria when compared to methanogenic Archaea. 相似文献
3.
The phylogenetic diversity and axial distribution of microorganisms in three sections of the gastrointestinal tracts of the
polychaete Neanthes glandicincta was evaluated using both most probable number method and cloning analyses of 16S rRNA genes in this study. Quantification
of the density of microorganisms in the gut showed that aerobic microorganisms decreased from anterior to posterior, while
anaerobic ones showed a reverse trend. The total numbers of microorganisms decreased significantly (p < 0.05, analysis of variance) but more rapidly from the anterior to the middle segment. Phylogenetic analysis showed that
the dominating phylogenetic groups included Methanomicrobiales I: Methanosaetaceae (up to 66% of archaeal clones), δ-Proteobacteria (up to 42% of bacterial clones), and γ-Proteobacteria (up to 30% of bacterial clones) widely distributed throughout the entire gut. Other microbiota distributed in different gut
sections were Methanomicrobiales II: Methanospirillaceae, Methanomicrobiales III, Thermoplasmatales, Crenarchaea, Methanobacteriaceae, and Methanosarcinales for archaea; and α-Proteobacteria, β-Proteobacteria, Fusobacteria, Clostridia, Chloroflexi, and Planctomycetes for bacteria. The results reveal a difference in microbial community structure along the gut of N. glandicincta. The various phylogenetic diversity and axial distribution of microbes along the gut might indicate an environmental gradient
from anterior to posterior sections affecting the structure of the microbial community. 相似文献
4.
The microbial diversity of Japanese- and Chinese-fermented soybean pastes was investigated using nested PCR–denaturing gradient
gel electrophoresis (DGGE). Five Japanese-fermented soybean paste samples and three Chinese-fermented soybean paste samples
were analyzed for bacteria and fungi. Extracted DNA was used as a template for PCR to amplify 16S rRNA and 18S rRNA genes.
The nearly complete 16S rRNA and 18S rRNA genes were amplified using universal primers, and the resulting products were subsequently
used as a template in a nested PCR to obtain suitable fragments for DGGE. Tetragenococcus halophilus and Staphylococcus gallinarum were found to dominate the bacterial microbiota in Japanese samples, whereas Bacillus sp. was detected as the predominant species in Chinese samples. DGGE analysis of fungi in soybean pastes determined the presence
of Aspergillus oryzae and Zygosaccharomyces rouxii in most of the Chinese and Japanese samples. Some differences were observed in the bacterial diversity of Japanese- and Chinese-fermented
soybean pastes. 相似文献
5.
Sediments from Xuanwu Lake have been dredged in the past 3 years to improve the water quality, but methanogenesis should still
exist in the newly settled sediment. Methane production, methanogens, and physiochemical parameters were detected in the surface
sediments (0–5 cm) and/or vertical sediments (0–21 cm, segmented at interval of 3 cm). Methane flux at water–air interface
varied among five detected sites. Principal component analysis showed that CH4 flux, content of water and the concentration of total nitrogen (TN), CH4 and organic matters (OM) weighed most heavily on the component I in surface sediments while different patterns were observed
for vertical sediments. The copy number of the 16S rRNA gene for bacteria was lower in the surface sediment (0–6 cm) than
that in deeper sediments (12–21 cm), while 16S rRNA genes of Archaea were almost evenly distributed in the vertical sediments.
Representatives belonging to the orders Methanobacteriales, Methanomicrobiales, and Methanosarcinales were detected in all samples of the vertical sediments, except that no members of the Methanococcales were detected in the samples at 0–6 cm. The level of Methanobacteriales reached a highest density at 18.1 × 104 copies g−1 dry weight (dw) at 6–9 cm; for Methanosarcinales (76.89 × 106 copies g−1 dw) and Methanococcales (82.70 × 103 copies g−1 dw) at 12–15 cm, whereas for Methanomicrobiales (43.37 × 106 copies g−1 dw) at 9–12 cm. Methanosarcinaceae and Methanosaetaceae reached to their highest densities at 6–9 and 9–12 cm, respectively. These data provided useful information for better understanding
the methanogenesis in the newly settled sediments of a recently dredged lake. 相似文献
6.
Culture-independent techniques, denaturing gradient gel electrophoresis (DGGE) analysis, and random cloning of 16S rRNA gene sequences amplified from community DNA were used to determine the diversity of microbial communities in gas industry pipelines. Samples obtained from natural gas pipelines were used directly for DNA extraction, inoculated into sulfate-reducing bacterium medium, or used to inoculate a reactor that simulated a natural gas pipeline environment. The variable V2-V3 (average size, 384 bp) and V3-V6 (average size, 648 bp) regions of bacterial and archaeal 16S rRNA genes, respectively, were amplified from genomic DNA isolated from nine natural gas pipeline samples and analyzed. A total of 106 bacterial 16S rDNA sequences were derived from DGGE bands, and these formed three major clusters: beta and gamma subdivisions of Proteobacteria and gram-positive bacteria. The most frequently encountered bacterial species was Comamonas denitrificans, which was not previously reported to be associated with microbial communities found in gas pipelines or with microbially influenced corrosion. The 31 archaeal 16S rDNA sequences obtained in this study were all related to those of methanogens and phylogenetically fall into three clusters: order I, Methanobacteriales; order III, Methanomicrobiales; and order IV, Methanosarcinales. Further microbial ecology studies are needed to better understand the relationship among bacterial and archaeal groups and the involvement of these groups in the process of microbially influenced corrosion in order to develop improved ways of monitoring and controlling microbially influenced corrosion. 相似文献
7.
Cultivable Bacterial Community from South China Sea Sponge as Revealed by DGGE Fingerprinting and 16S rDNA Phylogenetic Analysis 总被引:2,自引:0,他引:2
The cultivable bacterial communities associated with four South China Sea sponges—Stelletta tenuis, Halichondria rugosa, Dysidea avara, and Craniella australiensis in mixed cultures—were investigated by microbial community DNA-based DGGE fingerprinting and 16S rDNA phylogenetic analysis.
Diverse bacteria such as α-, γ-, δ-Proteobacteria, Bacteroidetes, and Firmicutes were cultured, some of which were previously uncultivable bacteria, potential novel strains with less than 95% similarity
to their closest relatives and sponge symbionts growing only in the medium with the addition of sponge extract. According
to 16S rDNA BLAST analysis, most of the bacteria were cultured from sponge for the first time, although similar phyla of bacteria
have been previously recognized. The selective pressure of sponge extract on the cultured bacterial species was suggested,
although the effect of sponge extract on bacterial community in high nutrient medium is not significant. Although α- and γ-Proteobacteria appeared to form the majority of the dominant cultivable bacterial communities of the four sponges, the composition of the
cultivable bacterial community in the mixed culture was different, depending on the medium and sponge species. Greater bacterial
diversity was observed in media C and CS for Stelletta tenuis, in media F and FS for Halichondria rugosa and Craniella australiensis. S. tenuis was found to have the highest cultivable bacterial diversity including α-, γ-, δ-Proteobacteria, Bacteroidetes, and Firmicutes, followed by sponge Dysidea avara without δ-Proteobacteria, sponge Halichondria rugosa with only α-, γ-Proteobacteria and Bacteroidetes, and sponge C. australiensis with only α-, γ-Proteobacteria and Firmicutes. Based on this study, by the strategy of mixed cultivation integrated with microbial community DNA-based DGGE fingerprinting
and phylogenetic analysis, the cultivable bacterial community of sponge could be revealed effectively. 相似文献
8.
9.
Gurdeep Rastogi Dilip R. Ranade Tulshiram Y. Yeole Arvind K. Gupta Milind S. Patole Yogesh S. Shouche 《World journal of microbiology & biotechnology》2008,24(12):2973-2979
Methanogen communities were characterized in cattle dung of different ages by using a culture-independent approach. Community
structures were determined by the phylogenetic analyses of methyl-coenzyme M reductase A (mcrA) clones of fresh, 8-month-old, and 24-month-old-dry dung samples. The clones in the mcrA libraries of fresh and 8-month old dung samples were identified as belonging to Methanomicrobiales, Methanobacteriales, and Methanosarcinales. However, clones in the library of 24-month-old dung were not affiliated to Methanomicrobiales. Anaerobic digestion of 2-month-old dung produced only 15% less methane compared to fresh dung which indicated the possibility
of using dry dung to fuel the biogas plants in areas where unavailability of fresh dung hinders their continuous functioning.
Our results first time showed the presence of viable methanogens in dry cattle dung stored for prolonged periods of time. 相似文献
10.
Culture-independent PCR–denaturing gradient gel electrophoresis (DGGE) was employed to assess the composition of diazotroph
species from the sediments of three mangrove ecosystem sites in Sanya, Hainan Island, China. A strategy of removing humic
acids prior to DNA extraction was conducted, then total community DNA was extracted using the soil DNA kit successfully for
nifH PCR amplification, which simplified the current procedure and resulted in good DGGE profiles. The results revealed a novel
nitrogen-fixing bacterial profile and fundamental diazotrophic biodiversity in mangrove sediments, as reflected by the numerous
bands present DGGE patterns. Canonical correspondence analysis (CCA) revealed that the sediments organic carbon concentration
and available soil potassium accounted for a significant amount of the variability in the nitrogen-fixing bacterial community
composition. The predominant DGGE bands were sequenced, yielding 31 different nifH sequences, which were used in phylogenetic reconstructions. Most sequences were from Proteobacteria, e.g. α, γ, β, δ-subdivisions, and characterized by sequences of members of genera Azotobacter, Desulfuromonas, Sphingomonas, Geobacter, Pseudomonas, Bradyrhizobium and Derxia. These results significantly expand our knowledge of the nitrogen-fixing bacterial diversity of the mangrove environment. 相似文献
11.
Brian P. Hedlund Jeremy A. Dodsworth Jessica K. Cole Hovik H. Panosyan 《Antonie van Leeuwenhoek》2013,104(1):71-82
Culture-independent and enrichment techniques, with an emphasis on members of the Archaea, were used to determine the composition and structure of microbial communities inhabiting microbial mats in the source pools of two geothermal springs near the towns of Arzakan and Jermuk in Armenia. Amplification of small-subunit rRNA genes using “universal” primers followed by pyrosequencing (pyrotags) revealed highly diverse microbial communities in both springs, with >99 % of pyrosequences corresponding to members of the domain Bacteria. The spring in Arzakan was colonized by a photosynthetic mat dominated by Cyanobacteria, in addition to Proteobacteria, Bacteroidetes, Chloroflexi, Spirochaeta and a diversity of other Bacteria. The spring in Jermuk was colonized by phylotypes related to sulfur, iron, and hydrogen chemolithotrophs in the Betaproteobacteria and Epsilonproteobacteria, along with a diversity of other Bacteria. Analysis of near full-length small subunit rRNA genes amplified using Archaea-specific primers showed that both springs are inhabited by a diversity of methanogens, including Methanomicrobiales and Methanosarcinales and relatives of Methanomassiliicoccus luminyensis, close relatives of the ammonia-oxidizing archaeon (AOA) “Candidatus Nitrososphaera gargensis”, and the yet-uncultivated Miscellaneous Crenarchaeotal Group and Deep Hydrothermal Vent Crenarchaeota group 1. Methanogenic enrichments confirmed the predicted physiological diversity, revealing methylotrophic, acetoclastic, and hydrogenotrophic methanogenesis at 45 and 55 °C, but not 65 °C. This is one of only a few studies combining cultivation-independent and -dependent approaches to study archaea in moderate-temperature (37–73 °C) terrestrial geothermal environments and suggests important roles for methanogenic archaea and AOA in the carbon and nitrogen biogeochemical cycles in these environments. 相似文献
12.
This study aimed to detect differences in the richness of total supragingival plaque microbiota as well as the species composition
of oral streptococci involved in the different stages of dental caries. Forty-five plaque samples were collected from caries-moderate
(CM, 4 ≤ dmfs ≤ 6), caries-susceptible (CS, dmfs ≥ 10), and age-matched caries-free children separately. Total DNA was isolated
directly from each sample, and polymerase chain reaction–denaturing gradient gel electrophoresis (PCR-DGGE) analyses using
universal and primers specific for oral streptococci were carried out. Using 16S rDNA PCR-DGGE, 34 different species of bacteria
were identified in a culture-independent manner and classified into 11 genera according to phylogenetic analysis. Among them,
Mitis group streptococci and Campylobacter, which were present in health status, no longer appeared in caries-susceptible samples. In addition, Capnocytophaga, Burkholderia, and Prevotella were found significantly less frequently in the CS group samples (P < 0.05), while there were no significant differences among the prevalence of Neisseria, Leptotrichia, Haemophilus, Mutans group streptococci, Corynebacterium, and Actinomyces in the three groups. Further DGGE analysis of rnpB gene amplicons obtained with oral streptococci species-specific primers showed that a total of 23 species of oral streptococci
were identified. Streptococcus sanguinis, Streptococcus mitis, and Streptococcus oralis showed a significantly higher prevalence in healthy children (P < 0.05), while that of Streptococcus mutans and Streptococcus sobrinus did not vary among the three groups. Overall, these results suggest that supragingival plaque microbiota as a whole undergoes
a more complicated shift in the caries process. 相似文献
13.
Phylogenetic composition of Arctic Ocean archaeal assemblages and comparison with Antarctic assemblages 总被引:2,自引:0,他引:2
Archaea assemblages from the Arctic Ocean and Antarctic waters were compared by PCR-denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA genes amplified using the Archaea-specific primers 344f and 517r. Inspection of the DGGE fingerprints of 33 samples from the Arctic Ocean (from SCICEX submarine cruises in 1995, 1996, and 1997) and 7 Antarctic samples from Gerlache Strait and Dallman Bay revealed that the richness of Archaea assemblages was greater in samples from deep water than in those from the upper water column in both polar oceans. DGGE banding patterns suggested that most of the Archaea ribotypes were common to both the Arctic Ocean and the Antarctic Ocean. However, some of the Euryarchaeota ribotypes were unique to each system. Cluster analysis of DGGE fingerprints revealed no seasonal variation but supported depth-related differences in the composition of the Arctic Ocean Archaea assemblage. The phylogenetic composition of the Archaea assemblage was determined by cloning and then sequencing amplicons obtained from the Archaea-specific primers 21f and 958r. Sequences of 198 clones from nine samples covering three seasons and all depths grouped with marine group I Crenarchaeota (111 clones), marine group II Euryarchaeota (86 clones), and group IV Euryarchaeota (1 clone). A sequence obtained only from a DGGE band was similar to those of the marine group III Euryarchaeota: 相似文献
14.
Characterization and comparison of microbial community of different typical Chinese liquor Daqus by PCR-DGGE 总被引:3,自引:0,他引:3
Aims: To identify and compare microbiota in Chinese liquor Daqu, which were produced in the different regions using different production process. Methods and Results: The DNA exacted from Daqu samples was used as a template for PCR with universal primers of 16S rRNA, 26S rRNA and 18S rRNA, respectively. The amplicons were analysed using denaturing gradient gel electrophoresis (DGGE). It was observed that the bacterial DGGE profile indicated high diversity and predominance of lactic acid bacteria. The results showed that Saccharomycopsis fibuligera and Pichia anomal were dominant yeast species and that several non‐Saccharomyces yeasts including Hanseniaspora guilliermondii, Debaryomyces hansenii, Issatchenkia orientalis and Trichosporon asahii were also detected. As for fungal DGGE, Aspergillus oryzae and Absidia blakesleeana were the most common species amongst different samples. Based on the DGGE analysis, a few differences in community structure were found between Daqu samples. Conclusions: A variety of bacteria, yeast and moulds were identified in Daqu samples, in addition to the present knowledge obtained mainly through the traditional culture‐dependent methods. Moreover, production temperature played a more decisive role on the formation of micro‐organism composition in Daqu than geographical region. Significance and Impact of the Study: PCR–DGGE technique was used in this study to fully observe and asses all microbial community (including bacteria, yeast and mould) in Chinese liquor Daqu for the first time and proved to be effective in profiling Daqu microbial diversity. 相似文献
15.
Diversity of bovine rumen methanogens In vitro in the presence of condensed tannins, as determined by sequence analysis of 16S rRNA gene library 总被引:1,自引:0,他引:1
Tan HY Sieo CC Lee CM Abdullah N Liang JB Ho YW 《Journal of microbiology (Seoul, Korea)》2011,49(3):492-498
Molecular diversity of rumen archaeal populations from bovine rumen fluid incubated with or without condensed tannins was
investigated using 16S rRNA gene libraries. The predominant order of rumen archaea in the 16S rRNA gene libraries of the control
and condensed tannins treatment was found to belong to a novel group of rumen archaea that is distantly related to the order
Thermoplasmatales, with 59.5% (15 phylotypes) and 81.43% (21 phylotypes) of the total clones from the control and treatment clone libraries,
respectively. The 16S rRNA gene library of the control was found to have higher proportions of methanogens from the orders
Methanomicrobiales (32%) and Methanobacteriales (8.5%) as compared to those found in the condensed tannins treatment clone library in both orders (16.88% and 1.68% respectively).
The phylotype distributed in the order Methanosarcinales was only found in the control clone library. The study indicated that condensed tannins could alter the diversity of bovine
rumen methanogens. 相似文献
16.
Molecular Diversity of Methanogens in Feedlot Cattle from Ontario and Prince Edward Island, Canada 总被引:2,自引:1,他引:1
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The molecular diversity of rumen methanogens in feedlot cattle and the composition of the methanogen populations in these animals from two geographic locations were investigated using 16S rRNA gene libraries prepared from pooled PCR products from 10 animals in Ontario (127 clones) and 10 animals from Prince Edward Island (114 clones). A total of 241 clones were examined, with Methanobrevibacter ruminantium accounting for more than one-third (85 clones) of the clones identified. From these 241 clones, 23 different 16S rRNA phylotypes were identified. Feedlot cattle from Ontario, which were fed a corn-based diet, revealed 11 phylotypes (38 clones) not found in feedlot cattle from Prince Edward Island, whereas the Prince Edward Island cattle, which were fed potato by-products as a finishing diet, had 7 phylotypes (42 clones) not found in cattle from Ontario. Five sequences, representing the remaining 161 clones (67% of the clones), were common in both herds. Of the 23 different sequences, 10 sequences (136 clones) were 89.8 to 100% similar to those from cultivated methanogens belonging to the orders Methanobacteriales, Methanomicrobiales, and Methanosarcinales, and the remaining 13 sequences (105 clones) were 74.1 to 75.8% similar to those from Thermoplasma volcanium and Thermoplasma acidophilum. Overall, nine possible new species were identified from the two clone libraries, including two new species belonging to the order Methanobacteriales and a new genus/species within the order Methanosarcinales. From the present survey, it is difficult to conclude whether the geographical isolation between these two herds or differences between the two finishing diets directly influenced community structure in the rumen. Further studies are warranted to properly assess the differences between these two finishing diets. 相似文献
17.
Nested PCR-Denaturing Gradient Gel Electrophoresis Approach To Determine the Diversity of Sulfate-Reducing Bacteria in Complex Microbial Communities 总被引:4,自引:0,他引:4
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Here, we describe a three-step nested-PCR-denaturing gradient gel electrophoresis (DGGE) strategy to detect sulfate-reducing bacteria (SRB) in complex microbial communities from industrial bioreactors. In the first step, the nearly complete 16S rRNA gene was amplified using bacterial primers. Subsequently, this product was used as a template in a second PCR with group-specific SRB primers. A third round of amplification was conducted to obtain fragments suitable for DGGE. The largest number of bands was observed in DGGE patterns of products obtained with primers specific for the Desulfovibrio-Desulfomicrobium group, indicating a large diversity of these SRBs. In addition, members of other phylogenetic SRB groups, i.e., Desulfotomaculum, Desulfobulbus, and Desulfococcus-Desulfonema-Desulfosarcina, were detected. Bands corresponding to Desulfobacterium and Desulfobacter were not detected in the bioreactor samples. Comparative sequence analysis of excised DGGE bands revealed the identity of the community members. The developed three-step PCR-DGGE strategy is a welcome tool for studying the diversity of sulfate-reducing bacteria. 相似文献
18.
Jemaneh Zeleke Shui-Long Lu Jian-Gong Wang Jing-Xin Huang Bo Li Andrew V. Ogram Zhe-Xue Quan 《Microbial ecology》2013,66(2):257-267
Methanogen populations of an intertidal mudflat in the Yangtze River estuary of China were investigated based on the methyl coenzyme M reductase A (mcrA) gene using 454-pyrosequencing and quantitative real-time polymerase chain reaction (qPCR). Samples were collected at six depths from three locations. In the qPCR analyses, a mean depth-wise change of mcrA gene abundance was observed from (1.23?±?0.13)×107 to (1.16?±?0.29)×108 per g dried soil, which was inversely correlated with the depletion of sulfate (R 2?=0.74; α?=?0.05) and salinity (R 2?=?0.66; α?=?0.05). The copy numbers of mcrA was at least 1 order of magnitude higher than dissimilatory sulfate reductase B (dsrB) genes, likely indicating the importance of methanogenesis at the mudflat. Sequences related to the orders Methanomicrobiales, Methanosarcinales, Methanobacteriales, Methanococcales and the uncultured methanogens; Rice Cluster I (RC-I), Zoige cluster I (ZC-I) and anaerobic methane oxidizing archaeal lineage-1 (ANME-1) were detected. Methanomicrobiales and Methanosarcinales dominated the entire sediment layers, but detectable changes of proportions were observed with depth. The hydrogenotrophic methanogens Methanomicrobiales slightly increased with depth while Methanosarcinales showed the reverse. Chao1 and ACE richness estimators revealed higher diversity of methanogens near the surface (0–10 cm) when compared with the bottom sediments. The near-surface sediments were mainly dominated by the family Methanosarcinaceae (45 %), which has members that can utilize substrates that cannot be used by sulfate-reducing bacteria. Overall, current data indicate that Methanosarcinales and Methanomicrobiales are the most dominant methanogens within the entire depth profile down to 100 cm, with higher abundance and diversity of methanogens in the deeper and upper sediment layers, respectively. 相似文献
19.
Mieczysław Śmiech Zbigniew Rusinowski Stefan Malepszy Katarzyna Niemirowicz-Szczytt 《Acta Physiologiae Plantarum》2000,22(3):299-303
The selection of TSWV resistant individuals can be facilitated by molecular markers. RAPD analysis was carried out on three
forms (Stevens × Rodade — resistant; Rey de los Tempranos — moderately tolerant; Potentat — susceptible) with the use of 271
primers. Out of 271 primers 28 generated stable polymorphism and so they were tested for linkage to resistance gene. Bulk
segregant analysis (BSA) was applied to F2 segregating progeny developed from resistant × susceptible parents. As a result, 5 primers enabling us to distinguish between
resistant and susceptible forms were detected. Only one of them had previously been reported by Chague et al. (1996). The analysis should be repeated on a larger population to confirm the results obtained. 相似文献
20.
Xinqing Zhao Liuyan Yang Can Chen Lin Xiao Lijuan Jiang Zhe Ma Haowei Zhu Zhenyang Yu Daqiang Yin 《Frontiers of Biology in China》2008,3(3):293-299
In this study, PCR-denaturing gradient gel electrophoresis (DGGE) was applied to analyze the microbial communities in lake
sediments from Lake Xuanwu, Lake Mochou in Nanjing and Lake Taihu in Wuxi. Sediment samples from seven locations in three
lakes were collected and their genomic DNAs were extracted. The DNA yields of the sediments of Lake Xuanwu and Lake Mochou
were high (10 μg/g), while that of sediments in Lake Taihu was relatively low. After DNA purification, the 16S rDNA genes
(V3 to V5 region) were amplified and the amplified DNA fragments were separated by parallel DGGE. The DGGE profiles showed
that there were five common bands in all the lake sediment samples indicating that there were similarities among the populations
of microorganisms in all the lake sediments. The DGGE profiles of Lake Xuanwu and Lake Mochou were similar and about 20 types
of microorganisms were identified in the sediment samples of both lakes. These results suggest that the sediment samples of
these two city lakes (Xuanwu, Mochou) have similar microbial communities. However, the DGGE profiles of sediment samples in
Lake Taihu were significantly different from these two lakes. Furthermore, the DGGE profiles of sediment samples in different
locations in Lake Taihu were also different, suggesting that the microbial communities in Lake Taihu are more diversified
than those in Lake Xuanwu and Lake Mochou. The differences in microbial diversity may be caused by the different environmental
conditions, such as redox potential, pH, and the concentrations of organic matters. Seven major bands of 16S rDNA genes fragments
from the DGGE profiles of sediment samples were further re-amplified and sequenced. The results of sequencing analysis indicate
that five sequences shared 99%–100% homology with known sequences (Bacillus and Brevibacillus, uncultured bacteria), while the other two sequences shared 93%–96% homology with known sequences (Acinetobacter, and Bacillus). The study shows that the PCR-DGGE technique combined with sequence analysis is a feasible and efficient method for the
determination of microbial communities in sediment samples.
__________
Translated from Acta Ecologica Sinica, 2006, 26(11): 3610–3616 [译自: 生态学报] 相似文献