Lactic acid bacteria have not only been used to produce various kinds of fermented food, but also used as probiotic products. As lactic acid bacterial group was consisted from diverse genera, a simple inspection metho...Lactic acid bacteria have not only been used to produce various kinds of fermented food, but also used as probiotic products. As lactic acid bacterial group was consisted from diverse genera, a simple inspection method by which numbers and contained microorganisms could be automatically analyzed without any preliminary information was required to use them more effectively. In this manuscript, lactic acid bacterial groups in commercial products of kimuchi, komekouji-miso, and yoghurt were identified and enumerated by our newly developed method [1]-[3], to evaluate whether the method could be used as an inspection method of various food samples. In kimuchi, numerically dominant bacteria were Lactobacillus sakei, and L. casei (1.4 × 104 MPN g<sup>-1</sup>) and Leuconostoc spp. (l.4 × 104 MPN). In kouji-miso, numerically dominant bacteria was Bacillus spp. (3 × 103 MPN), which mainly included B. subtilis group and B. cereus group. Lactic acid bacteria such as Lactobacillus spp., or Lactococcus spp., included in the komekouji-miso, could be enumerated after 3 days incubation (1.24 × 104 MPN), but not detected after 7 days incubation. In yoghurt A and C, Lactococcus lactis was detected as numerically dominant lactic acid bacteria (3.0 × 105 MPN). In yoghurt B, Lactobacillus spp., or Lactococcus spp., was detected not only by a culturebased method but also by an unculture-based method, although there was a difference between the both estimated numbers. The present results suggested that the method might become useful as a simple inspection method of food microorganisms, because time and labor of the analysis could be reduced by using an unculture-based method and MCE-202 MultiNA. In this study, Bifidobacteriium spp. was not detected in B and C yoghurt, in spite of indicating their existence, and numbers of lactic acid bacteria were lower than the level of the daily product regulation, because 16S rDNA of Bifidobacteriium spp. might not be amplified by the used PCR condition. The PCR condition must be changed so as to amplify Bifidobacterium spp., before the method will be used as an inspection method for lactic acid bacteria.展开更多
A total of 80 piglets (7.9 ± 1.0 kg) were used in a feeding experiment with dried oregano. The diets differed in their oregano content: 0 g, 2 g, 4 g and 8 g oregano/kg feed, corresponding to 0, 23.5, 46.9 and 93...A total of 80 piglets (7.9 ± 1.0 kg) were used in a feeding experiment with dried oregano. The diets differed in their oregano content: 0 g, 2 g, 4 g and 8 g oregano/kg feed, corresponding to 0, 23.5, 46.9 and 93.9 mg carvacrol/kg DM. After the experimental period of 5 weeks, 20 piglets of both extreme feeding groups were slaughtered: 10 animals of the control group and 10 animals of the group that received 8 g oregano/kg. Ingesta samples of jejunum, caecum and colon were collected and analyzed by FISH and PCR RFLP to compare the diversity of microbiota. The results showed no significant changes in microbiota in response to oregano. The patterns of the PCR-RFLP showed a similarity of 61.8% - 91.8% in both feeding groups. In conclusion, an effect of oregano on the in- testinal microbiota could not be shown under the methods used.展开更多
To characterize the effects of pentachlorophenol (PCP) on the performance and microbial community of aerobic granular sludge in sequencing batch reactor (SBR), the web-based terminal restriction fragment length polymo...To characterize the effects of pentachlorophenol (PCP) on the performance and microbial community of aerobic granular sludge in sequencing batch reactor (SBR), the web-based terminal restriction fragment length polymorphism (T-RFLP) and real-time PCR (RT- PCR) techniques were used to explore the bacterial community structure. When PCP increased from 0 to 50 mg/L, the COD removal rate changed little, while the ammonia removal rate dropped from 100% to 64.9%. The results of molecular characterization showed that the quantity of ammonia oxidizing bacteria (AOB) kept constantly, although the number of bacteria species decreased with the increase of PCP concentration. Significant shift in bacterial community structure at different PCP stresses was observed within aerobic granular sludge. When the PCP was absent, there are 69 strains in aerobic granular sludge detected by T-RFLP method. With the increase of PCP, most of bacteria disappeared and only 19 bacteria existed at all five PCP concentrations. These results contributed to comprehensive understanding of the microbial community structure under the PCP stress and its relationship with the performance for wastewater treatment by aerobic granular sludge.展开更多
The bacterial diversity of activated sludge from submerged membrane bioreactor (SMBR) was investigated. A 16S rDNA clone library was generated, and 150 clones were screened using restriction fragment length polymorphi...The bacterial diversity of activated sludge from submerged membrane bioreactor (SMBR) was investigated. A 16S rDNA clone library was generated, and 150 clones were screened using restriction fragment length polymorphism (RFLP). Of the screened clones, almost full-length 16S rDNA sequences of 64 clones were sequenced. Phylogenetic tree was constructed with a database containing clone sequences from this study and bacterial rDNA sequences from NCBI for identification purposes. The 90.6% of the clones were a?liated with the two phyla Bacteroidetes (50%) and Proteobacteria (40%), and β-, γ-, and δ-Proteobacteria accounted for 7.8%, 28.1%, and 4.7%, respectively. Minor portions were a?liated with the Actinobacteria and Firmicutes (both 3.1%). Only 6 out of 64 16S rDNA sequences exhibited similarities of more than 97% to classified bacterial species, which indicated that a substantial fraction of the clone sequences were derived from unknown taxa. Rarefaction analysis of operational taxonomic units (OTUs) clusters demonstrated that 150 clones screened were still insu?cient to describe the whole bacterial diversity. Measurement of water quality parameter demonstrated that performance of the SMBR maintained high level, and the SMBR system remained stable during this study.展开更多
The method to analyze both eukaryotic and prokaryotic microorganisms without preliminary microbial information of sample seemed to be useful not only for research and investigation of microorganisms but also for indus...The method to analyze both eukaryotic and prokaryotic microorganisms without preliminary microbial information of sample seemed to be useful not only for research and investigation of microorganisms but also for industry using microorganisms. In the present manuscript, preparation of a new DNA primers, new reference database for 18S rDNA for our newly developed method [1]- [3], and analyses of eukaryotic and prokaryotic microorganisms in fermentation products were presented. In komekouji, Aspergillus spp., was enumerated to be 46.5 × 106 MPN g<sup>-1</sup>, and Penicillium spp., was enumerated to be 1.5 × 106 MPN g<sup>-1</sup>. In dry yeast, Saccharomyces group, were enumerated to be 8600 × 106 MPN g<sup>-1</sup>. In komekouji-miso, no eukaryotic microorganism was detected, while the other Bacillus spp., was numerically dominant (21.5 × 106 MPN g<sup>-1</sup>) as prokaryotic microorganisms, followed by B. subtilis group (4.65 × 106 MPN g<sup>-1</sup>), and the other Firmicutes (3.7 × 106 MPN g<sup>-1</sup>). The komekouji-miso included lower number of Actinobacteria (0.15 × 106 MPN g<sup>-1</sup>), Burkhokderia sp. (1.5 × 106 MPN g<sup>-1</sup>), and the other α,β,γ-proteobacteria (0.12 × 106 MPN g<sup>-1</sup>). In sake-kasu, both prokaryote and eukaryote were not detected by the method. Present results indicated that using both universal primers for eukaryotic and prokaryotic microorganisms, each groups of prokaryotic and eukaryotic microorganisms were enumerated without any preliminary information nor setting up standard curve, which were required for real time PCR.展开更多
Analyses of microbial properties in soil and manure had always included the problem that there was no available standard method to evaluate microbial property. The one of the major problems was the vast diversity and ...Analyses of microbial properties in soil and manure had always included the problem that there was no available standard method to evaluate microbial property. The one of the major problems was the vast diversity and the enormous population of soil microorganisms [1], the other was an existence of numerically dominant unculturable microorganisms which comprise 99% of soil habitat [2]. We evaluated whether our newly developed method, by which taxonomies and their number of each bacterial groups were estimated, could be used as evaluation method of microbial properties of soils and manures. In the forest soil, β-Proteobacteria, which included Burkholderia sp., Ralstonia sp., and Alcaligenes sp., was numerically dominant bacteria (3.64 × 10<sup>6</sup> MPN g<sup>-1</sup> dry soil), followed by γ-Proteobacteria (1.32 × 10<sup>6</sup> MPN), δ-Proteobacteria (0.006 × 10<sup>6</sup> MPN), and the other gram negative bacteria (0.006 × 10<sup>6</sup> MPN). In the commercial manure, Actinobacteria, which included Streptoverticillium salmonis, Mycrococcus sp., Streptomyces bikiniensis, and Microbacterium ulmi, was numerically dominant bacterial group (30.8 × 10<sup>6</sup> MPN), followed by α-Proteobacteria (26.0 × 10<sup>6</sup> MPN), β-Proteobacteria (17.1 × 10<sup>6</sup> MPN), δ-Proteobacteria (11.2 × 10<sup>6</sup> MPN), the other Firmicutes (1.71 × 10<sup>6</sup> MPN), γ-Proteobacteria (0.5 × 10<sup>6</sup> MPN), and the other gram negative bacteria (0.05 × 10<sup>6</sup> MPN). In the upland field, the other Firmicutes, which included Paenibacillus sp., was numerically dominant bacteria (4.41 × 10<sup>6</sup> MPN), followed by Actinobacteria (2.14 × 10<sup>6</sup> MPN), Bacillus sp. (2.14 × 10<sup>6</sup> MPN), and γ-Proteobacteria (0.35 × 10<sup>6</sup> MPN). Although the precision of the affiliations became lower because of higher diversity of samples and the number of some Antinobacteria and Firmicutes might be underestimated by the used PCR condition, the method was found suitable as a candidate of a new evaluation system of soil and manure.展开更多
In the present manuscript it was presented whether spreading of antibiotic resistant bacterial groups in environment could be monitored by our newly developed method by enumerating antibiotic resistant bacterial group...In the present manuscript it was presented whether spreading of antibiotic resistant bacterial groups in environment could be monitored by our newly developed method by enumerating antibiotic resistant bacterial groups in various biological wastes and composts. Although the numbers were not so high, diverse kinds of colistin resistant bacteria (25 mg·L<sup>-1</sup><sup></sup>) were included in row cattle feces (1.78 × 10<sup>4</sup> MPN g<sup>-1</sup>) and cattle feces manure (>3.84 × 10<sup>4</sup> MPN g<sup>-1</sup>). Compost originated from leftover food (>44.8 × 10<sup>4</sup> MPN g<sup>-1</sup>) and shochu lee (>320 × 10<sup>4</sup> MPN g<sup>-1</sup>) included higher numbers of chlortetracycline resistant Pseudomonas sp., (25 mg·L<sup>-1</sup><sup></sup>), and row cattle feces included higher numbers of chlortetracycline resistant Enterobacteriacea (15.7 × 10<sup>4</sup> MPN g<sup>-1</sup>), which mostly consisted from Pantoea sp. or Xenorhobdus doucetiae. Numbers of multi drug resistant bacteria, resistant to 25 mg·L<sup>-1 </sup>of<sup> </sup>ciprofloxacin, streptomycin, chloramphenicol, and ampicillin, were the highest in row cattle feces (>143.6 × 10<sup>4</sup> MPN g<sup>-1</sup>), followed by cattle feces manure (4.19 × 10<sup>4</sup> MPN g<sup>-1</sup>), and shochu lee (0.36 × 10<sup>4</sup> MPN g<sup>-1</sup>), which included diverse kinds of bacterial group. The present results indicated that higher numbers of multi drug resistant bacteria were typically found in row cattle feces, and the method was found suitable to enumerate and identify them. These results suggested that the method might become their environmental risk evaluation method.展开更多
Four typical coastal sites(rocky shore,sandy shore,mud flat shore,and artificial harbor)at the Yellow Sea were chosen to investigate the spatial and seasonal variations in bacterial communities.This was accomplished b...Four typical coastal sites(rocky shore,sandy shore,mud flat shore,and artificial harbor)at the Yellow Sea were chosen to investigate the spatial and seasonal variations in bacterial communities.This was accomplished by using terminal restriction fragment length polymorphism(T-RFLP)analysis of PCR amplified 16S rDNA fragments.Two kinds of tetrameric restriction enzymes,HhaI and MspI,were used in the experiment to depict the bacterial community diversity in different marine environments.It was found that the community compositions digested by the two enzymes separately were different.However,the results of bacterial community diversity derived from them were similar.The MDA analysis results of T-RFLP profiles coming from HhaI and MspI both exhibited a significant seasonal community shift for bacteria and a relatively low spatial variation among the four locations.With HhaI as the sample,the pair wise Ttests also revealed that variations were minor between each pair of marine environments,with R ranging from 0.198 to 0.349.However,the bacterial community structure in the mud flat site depicted a larger difference than each of the other three sites(R ranging from 0.282 to 0.349).展开更多
To determine whether the functional stability of nitrification was correlated to a stable community structure of ammonia oxidizing bacteria(AOB)in a fullscale wastewater treatment plant,the AOB community dynamics in a...To determine whether the functional stability of nitrification was correlated to a stable community structure of ammonia oxidizing bacteria(AOB)in a fullscale wastewater treatment plant,the AOB community dynamics in a wastewater treatment system was monitored over one year.The community dynamics were investigated using specific PCR followed by terminal restriction fragment length polymorphism(T-RFLP)analysis of the amoA gene.The T-RFLP results indicated that during the period of nitrification stability,the AOB community structure in the full-scale wastewater treatment system was relatively stable,and the average change rate every 15 d of the system was 6.6%±5.8%.The phylogenetic analysis of the cloned amoA gene showed clearly that the dominant AOB in the system was Nitrosomonas spp.The results of this study indicated that throughout the study period,the AOB community structure was relatively stable in the full-scale wastewater treatment system with functional stability of nitrification.展开更多
文摘Lactic acid bacteria have not only been used to produce various kinds of fermented food, but also used as probiotic products. As lactic acid bacterial group was consisted from diverse genera, a simple inspection method by which numbers and contained microorganisms could be automatically analyzed without any preliminary information was required to use them more effectively. In this manuscript, lactic acid bacterial groups in commercial products of kimuchi, komekouji-miso, and yoghurt were identified and enumerated by our newly developed method [1]-[3], to evaluate whether the method could be used as an inspection method of various food samples. In kimuchi, numerically dominant bacteria were Lactobacillus sakei, and L. casei (1.4 × 104 MPN g<sup>-1</sup>) and Leuconostoc spp. (l.4 × 104 MPN). In kouji-miso, numerically dominant bacteria was Bacillus spp. (3 × 103 MPN), which mainly included B. subtilis group and B. cereus group. Lactic acid bacteria such as Lactobacillus spp., or Lactococcus spp., included in the komekouji-miso, could be enumerated after 3 days incubation (1.24 × 104 MPN), but not detected after 7 days incubation. In yoghurt A and C, Lactococcus lactis was detected as numerically dominant lactic acid bacteria (3.0 × 105 MPN). In yoghurt B, Lactobacillus spp., or Lactococcus spp., was detected not only by a culturebased method but also by an unculture-based method, although there was a difference between the both estimated numbers. The present results suggested that the method might become useful as a simple inspection method of food microorganisms, because time and labor of the analysis could be reduced by using an unculture-based method and MCE-202 MultiNA. In this study, Bifidobacteriium spp. was not detected in B and C yoghurt, in spite of indicating their existence, and numbers of lactic acid bacteria were lower than the level of the daily product regulation, because 16S rDNA of Bifidobacteriium spp. might not be amplified by the used PCR condition. The PCR condition must be changed so as to amplify Bifidobacterium spp., before the method will be used as an inspection method for lactic acid bacteria.
文摘A total of 80 piglets (7.9 ± 1.0 kg) were used in a feeding experiment with dried oregano. The diets differed in their oregano content: 0 g, 2 g, 4 g and 8 g oregano/kg feed, corresponding to 0, 23.5, 46.9 and 93.9 mg carvacrol/kg DM. After the experimental period of 5 weeks, 20 piglets of both extreme feeding groups were slaughtered: 10 animals of the control group and 10 animals of the group that received 8 g oregano/kg. Ingesta samples of jejunum, caecum and colon were collected and analyzed by FISH and PCR RFLP to compare the diversity of microbiota. The results showed no significant changes in microbiota in response to oregano. The patterns of the PCR-RFLP showed a similarity of 61.8% - 91.8% in both feeding groups. In conclusion, an effect of oregano on the in- testinal microbiota could not be shown under the methods used.
基金the Science Foundation ofJiangsu Province, China (No. BK2005402)the Nation-al Natural Science Foundation of China (No. 30640018)
文摘To characterize the effects of pentachlorophenol (PCP) on the performance and microbial community of aerobic granular sludge in sequencing batch reactor (SBR), the web-based terminal restriction fragment length polymorphism (T-RFLP) and real-time PCR (RT- PCR) techniques were used to explore the bacterial community structure. When PCP increased from 0 to 50 mg/L, the COD removal rate changed little, while the ammonia removal rate dropped from 100% to 64.9%. The results of molecular characterization showed that the quantity of ammonia oxidizing bacteria (AOB) kept constantly, although the number of bacteria species decreased with the increase of PCP concentration. Significant shift in bacterial community structure at different PCP stresses was observed within aerobic granular sludge. When the PCP was absent, there are 69 strains in aerobic granular sludge detected by T-RFLP method. With the increase of PCP, most of bacteria disappeared and only 19 bacteria existed at all five PCP concentrations. These results contributed to comprehensive understanding of the microbial community structure under the PCP stress and its relationship with the performance for wastewater treatment by aerobic granular sludge.
基金the National NaturalScience Foundation of China (No. 39925007)the HiTech Research and Development Program (863) of China(No. 2002AA60l021)the Pilot Project of KnowledgeInnovation Program of Chinese Academy of Sciences (No.KSCX2-SW-102)
文摘The bacterial diversity of activated sludge from submerged membrane bioreactor (SMBR) was investigated. A 16S rDNA clone library was generated, and 150 clones were screened using restriction fragment length polymorphism (RFLP). Of the screened clones, almost full-length 16S rDNA sequences of 64 clones were sequenced. Phylogenetic tree was constructed with a database containing clone sequences from this study and bacterial rDNA sequences from NCBI for identification purposes. The 90.6% of the clones were a?liated with the two phyla Bacteroidetes (50%) and Proteobacteria (40%), and β-, γ-, and δ-Proteobacteria accounted for 7.8%, 28.1%, and 4.7%, respectively. Minor portions were a?liated with the Actinobacteria and Firmicutes (both 3.1%). Only 6 out of 64 16S rDNA sequences exhibited similarities of more than 97% to classified bacterial species, which indicated that a substantial fraction of the clone sequences were derived from unknown taxa. Rarefaction analysis of operational taxonomic units (OTUs) clusters demonstrated that 150 clones screened were still insu?cient to describe the whole bacterial diversity. Measurement of water quality parameter demonstrated that performance of the SMBR maintained high level, and the SMBR system remained stable during this study.
文摘The method to analyze both eukaryotic and prokaryotic microorganisms without preliminary microbial information of sample seemed to be useful not only for research and investigation of microorganisms but also for industry using microorganisms. In the present manuscript, preparation of a new DNA primers, new reference database for 18S rDNA for our newly developed method [1]- [3], and analyses of eukaryotic and prokaryotic microorganisms in fermentation products were presented. In komekouji, Aspergillus spp., was enumerated to be 46.5 × 106 MPN g<sup>-1</sup>, and Penicillium spp., was enumerated to be 1.5 × 106 MPN g<sup>-1</sup>. In dry yeast, Saccharomyces group, were enumerated to be 8600 × 106 MPN g<sup>-1</sup>. In komekouji-miso, no eukaryotic microorganism was detected, while the other Bacillus spp., was numerically dominant (21.5 × 106 MPN g<sup>-1</sup>) as prokaryotic microorganisms, followed by B. subtilis group (4.65 × 106 MPN g<sup>-1</sup>), and the other Firmicutes (3.7 × 106 MPN g<sup>-1</sup>). The komekouji-miso included lower number of Actinobacteria (0.15 × 106 MPN g<sup>-1</sup>), Burkhokderia sp. (1.5 × 106 MPN g<sup>-1</sup>), and the other α,β,γ-proteobacteria (0.12 × 106 MPN g<sup>-1</sup>). In sake-kasu, both prokaryote and eukaryote were not detected by the method. Present results indicated that using both universal primers for eukaryotic and prokaryotic microorganisms, each groups of prokaryotic and eukaryotic microorganisms were enumerated without any preliminary information nor setting up standard curve, which were required for real time PCR.
文摘Analyses of microbial properties in soil and manure had always included the problem that there was no available standard method to evaluate microbial property. The one of the major problems was the vast diversity and the enormous population of soil microorganisms [1], the other was an existence of numerically dominant unculturable microorganisms which comprise 99% of soil habitat [2]. We evaluated whether our newly developed method, by which taxonomies and their number of each bacterial groups were estimated, could be used as evaluation method of microbial properties of soils and manures. In the forest soil, β-Proteobacteria, which included Burkholderia sp., Ralstonia sp., and Alcaligenes sp., was numerically dominant bacteria (3.64 × 10<sup>6</sup> MPN g<sup>-1</sup> dry soil), followed by γ-Proteobacteria (1.32 × 10<sup>6</sup> MPN), δ-Proteobacteria (0.006 × 10<sup>6</sup> MPN), and the other gram negative bacteria (0.006 × 10<sup>6</sup> MPN). In the commercial manure, Actinobacteria, which included Streptoverticillium salmonis, Mycrococcus sp., Streptomyces bikiniensis, and Microbacterium ulmi, was numerically dominant bacterial group (30.8 × 10<sup>6</sup> MPN), followed by α-Proteobacteria (26.0 × 10<sup>6</sup> MPN), β-Proteobacteria (17.1 × 10<sup>6</sup> MPN), δ-Proteobacteria (11.2 × 10<sup>6</sup> MPN), the other Firmicutes (1.71 × 10<sup>6</sup> MPN), γ-Proteobacteria (0.5 × 10<sup>6</sup> MPN), and the other gram negative bacteria (0.05 × 10<sup>6</sup> MPN). In the upland field, the other Firmicutes, which included Paenibacillus sp., was numerically dominant bacteria (4.41 × 10<sup>6</sup> MPN), followed by Actinobacteria (2.14 × 10<sup>6</sup> MPN), Bacillus sp. (2.14 × 10<sup>6</sup> MPN), and γ-Proteobacteria (0.35 × 10<sup>6</sup> MPN). Although the precision of the affiliations became lower because of higher diversity of samples and the number of some Antinobacteria and Firmicutes might be underestimated by the used PCR condition, the method was found suitable as a candidate of a new evaluation system of soil and manure.
文摘In the present manuscript it was presented whether spreading of antibiotic resistant bacterial groups in environment could be monitored by our newly developed method by enumerating antibiotic resistant bacterial groups in various biological wastes and composts. Although the numbers were not so high, diverse kinds of colistin resistant bacteria (25 mg·L<sup>-1</sup><sup></sup>) were included in row cattle feces (1.78 × 10<sup>4</sup> MPN g<sup>-1</sup>) and cattle feces manure (>3.84 × 10<sup>4</sup> MPN g<sup>-1</sup>). Compost originated from leftover food (>44.8 × 10<sup>4</sup> MPN g<sup>-1</sup>) and shochu lee (>320 × 10<sup>4</sup> MPN g<sup>-1</sup>) included higher numbers of chlortetracycline resistant Pseudomonas sp., (25 mg·L<sup>-1</sup><sup></sup>), and row cattle feces included higher numbers of chlortetracycline resistant Enterobacteriacea (15.7 × 10<sup>4</sup> MPN g<sup>-1</sup>), which mostly consisted from Pantoea sp. or Xenorhobdus doucetiae. Numbers of multi drug resistant bacteria, resistant to 25 mg·L<sup>-1 </sup>of<sup> </sup>ciprofloxacin, streptomycin, chloramphenicol, and ampicillin, were the highest in row cattle feces (>143.6 × 10<sup>4</sup> MPN g<sup>-1</sup>), followed by cattle feces manure (4.19 × 10<sup>4</sup> MPN g<sup>-1</sup>), and shochu lee (0.36 × 10<sup>4</sup> MPN g<sup>-1</sup>), which included diverse kinds of bacterial group. The present results indicated that higher numbers of multi drug resistant bacteria were typically found in row cattle feces, and the method was found suitable to enumerate and identify them. These results suggested that the method might become their environmental risk evaluation method.
基金This research was supported by the 908 Special Program from State Oceanic Administration—Investigation and Evaluation on Marine Medicinal Organism Sources(No.908-01-ST12).
文摘Four typical coastal sites(rocky shore,sandy shore,mud flat shore,and artificial harbor)at the Yellow Sea were chosen to investigate the spatial and seasonal variations in bacterial communities.This was accomplished by using terminal restriction fragment length polymorphism(T-RFLP)analysis of PCR amplified 16S rDNA fragments.Two kinds of tetrameric restriction enzymes,HhaI and MspI,were used in the experiment to depict the bacterial community diversity in different marine environments.It was found that the community compositions digested by the two enzymes separately were different.However,the results of bacterial community diversity derived from them were similar.The MDA analysis results of T-RFLP profiles coming from HhaI and MspI both exhibited a significant seasonal community shift for bacteria and a relatively low spatial variation among the four locations.With HhaI as the sample,the pair wise Ttests also revealed that variations were minor between each pair of marine environments,with R ranging from 0.198 to 0.349.However,the bacterial community structure in the mud flat site depicted a larger difference than each of the other three sites(R ranging from 0.282 to 0.349).
基金This study was supported by the National Natural Science Foundation of China(Grant No.51078207)Mega-projects of Science Research for Water(No.2008ZX07313-3)the Program of Research on Key Technology of Environmental Pollution Control and Quality Improvement(No.2007DFC90170),and Research Fund for the Doctoral Program of Higher Education of China(No.20090002770003).
文摘To determine whether the functional stability of nitrification was correlated to a stable community structure of ammonia oxidizing bacteria(AOB)in a fullscale wastewater treatment plant,the AOB community dynamics in a wastewater treatment system was monitored over one year.The community dynamics were investigated using specific PCR followed by terminal restriction fragment length polymorphism(T-RFLP)analysis of the amoA gene.The T-RFLP results indicated that during the period of nitrification stability,the AOB community structure in the full-scale wastewater treatment system was relatively stable,and the average change rate every 15 d of the system was 6.6%±5.8%.The phylogenetic analysis of the cloned amoA gene showed clearly that the dominant AOB in the system was Nitrosomonas spp.The results of this study indicated that throughout the study period,the AOB community structure was relatively stable in the full-scale wastewater treatment system with functional stability of nitrification.