为有效防范惠州市水产养殖中细菌病害的发生,对惠州市水产养殖致病菌的耐药情况进行分析。首先,在28℃和37℃下,经6种抗生素平板筛选惠州市水产养殖采集水样中的耐药菌株;然后,随机选取分离得到的70株菌,对其16S rDNA进行测序,并获得46...为有效防范惠州市水产养殖中细菌病害的发生,对惠州市水产养殖致病菌的耐药情况进行分析。首先,在28℃和37℃下,经6种抗生素平板筛选惠州市水产养殖采集水样中的耐药菌株;然后,随机选取分离得到的70株菌,对其16S rDNA进行测序,并获得46株阳性扩增产物的测序结果;最后对16S r DNA测序结果进行分析,得出分离菌株中耐药菌的种属。研究发现,从养殖水样中分离得到的菌株分别属于产气单胞菌属、丛毛单胞菌属等8个属,养殖水体中的细菌主要对氨苄西林和诺氟沙星耐药,对四环素耐药率较低。因此,在水产养殖过程中,应尽量避免使用氨苄西林和诺氟沙星类抗生素,首选耐药率低的四环素作为水产养殖的药物。展开更多
PCR-based DNA fingerprinting, REP-PCR(repetitive element PCR), RAPD(randomly amplified polymorphic DNA) and16 S r DNA sequence analyses were used to characterize 23 Acidithiobacillus ferrooxidans strains isolated from...PCR-based DNA fingerprinting, REP-PCR(repetitive element PCR), RAPD(randomly amplified polymorphic DNA) and16 S r DNA sequence analyses were used to characterize 23 Acidithiobacillus ferrooxidans strains isolated from different environments.(GTG)5 and BOXA1 R primer were selected for REP-PCR. Twenty arbitrary primers were used for RAPD to acquire DNA profiles from A. ferrooxidans. Both RAPD and REP-PCR produce complex banding patterns and show good discriminatory ability in differentiating closely related strains of A. ferrooxidans. The strains are clustered into 4 or 5 major groups and reveal genomic diversity using(GTG)5-PCR, BOX-PCR and RAPD analysis. Phylogenetic tree based on 16 S r DNA sequences of 23 strains and related strains shows that they are clustered into two distinct groups. Twelve strains are highly related to a new Acidithiobacillus named Acidithiobacillus ferrivorans. The results indicate that PCR-based methods are effective in revealing genetic diversity among A. ferrooxidans.展开更多
The microbial community structures in an integrated two-phase anaerobic reactor（ITPAR）were investigated by 16 S r DNA clone library technology. The 75 L reactor was designed with a 25 L rotating acidogenic unit at t...The microbial community structures in an integrated two-phase anaerobic reactor（ITPAR）were investigated by 16 S r DNA clone library technology. The 75 L reactor was designed with a 25 L rotating acidogenic unit at the top and a 50 L conventional upflow methanogenic unit at the bottom, with a recirculation connected to the two units. The reactor had been operated for 21 stages to co-digest fruit/vegetable wastes and wheat straw, which showed a very good biogas production and decomposition of cellulosic materials. The results showed that many kinds of cellulose and glycan decomposition bacteria related with Bacteroidales,Clostridiales and Syntrophobacterales were dominated in the reactor, with more bacteria community diversities in the acidogenic unit. The methanogens were mostly related with Methanosaeta, Methanosarcina, Methanoculleus, Methanospirillum and Methanobacterium; the predominating genus Methanosaeta, accounting for 40.5%, 54.2%, 73.6% and 78.7% in four samples from top to bottom, indicated a major methanogenesis pathway by acetoclastic methanogenesis in the methanogenic unit. The beta diversity indexes illustrated a more similar distribution of bacterial communities than that of methanogens between acidogenic unit and methanogenic unit. The differentiation of methanogenic community composition in two phases, as well as pH values and volatile fatty acid（VFA） concentrations confirmed the phase separation of the ITPAR. Overall, the results of this study demonstrated that the special designing of ITPAR maintained a sufficient number of methanogens, more diverse communities and stronger syntrophic associations among microorganisms, which made two phase anaerobic digestion of cellulosic materials more efficient.展开更多
文摘为有效防范惠州市水产养殖中细菌病害的发生,对惠州市水产养殖致病菌的耐药情况进行分析。首先,在28℃和37℃下,经6种抗生素平板筛选惠州市水产养殖采集水样中的耐药菌株;然后,随机选取分离得到的70株菌,对其16S rDNA进行测序,并获得46株阳性扩增产物的测序结果;最后对16S r DNA测序结果进行分析,得出分离菌株中耐药菌的种属。研究发现,从养殖水样中分离得到的菌株分别属于产气单胞菌属、丛毛单胞菌属等8个属,养殖水体中的细菌主要对氨苄西林和诺氟沙星耐药,对四环素耐药率较低。因此,在水产养殖过程中,应尽量避免使用氨苄西林和诺氟沙星类抗生素,首选耐药率低的四环素作为水产养殖的药物。
基金Project(2010CB630901)supported by the National Basic Research Program of China
文摘PCR-based DNA fingerprinting, REP-PCR(repetitive element PCR), RAPD(randomly amplified polymorphic DNA) and16 S r DNA sequence analyses were used to characterize 23 Acidithiobacillus ferrooxidans strains isolated from different environments.(GTG)5 and BOXA1 R primer were selected for REP-PCR. Twenty arbitrary primers were used for RAPD to acquire DNA profiles from A. ferrooxidans. Both RAPD and REP-PCR produce complex banding patterns and show good discriminatory ability in differentiating closely related strains of A. ferrooxidans. The strains are clustered into 4 or 5 major groups and reveal genomic diversity using(GTG)5-PCR, BOX-PCR and RAPD analysis. Phylogenetic tree based on 16 S r DNA sequences of 23 strains and related strains shows that they are clustered into two distinct groups. Twelve strains are highly related to a new Acidithiobacillus named Acidithiobacillus ferrivorans. The results indicate that PCR-based methods are effective in revealing genetic diversity among A. ferrooxidans.
基金supported by the Major Science and Technology Programs for Water Pollution Control and Management of China(No.2012ZX07205-001)the National Science and Technology Support Program(No.2008BADC4B18)
文摘The microbial community structures in an integrated two-phase anaerobic reactor（ITPAR）were investigated by 16 S r DNA clone library technology. The 75 L reactor was designed with a 25 L rotating acidogenic unit at the top and a 50 L conventional upflow methanogenic unit at the bottom, with a recirculation connected to the two units. The reactor had been operated for 21 stages to co-digest fruit/vegetable wastes and wheat straw, which showed a very good biogas production and decomposition of cellulosic materials. The results showed that many kinds of cellulose and glycan decomposition bacteria related with Bacteroidales,Clostridiales and Syntrophobacterales were dominated in the reactor, with more bacteria community diversities in the acidogenic unit. The methanogens were mostly related with Methanosaeta, Methanosarcina, Methanoculleus, Methanospirillum and Methanobacterium; the predominating genus Methanosaeta, accounting for 40.5%, 54.2%, 73.6% and 78.7% in four samples from top to bottom, indicated a major methanogenesis pathway by acetoclastic methanogenesis in the methanogenic unit. The beta diversity indexes illustrated a more similar distribution of bacterial communities than that of methanogens between acidogenic unit and methanogenic unit. The differentiation of methanogenic community composition in two phases, as well as pH values and volatile fatty acid（VFA） concentrations confirmed the phase separation of the ITPAR. Overall, the results of this study demonstrated that the special designing of ITPAR maintained a sufficient number of methanogens, more diverse communities and stronger syntrophic associations among microorganisms, which made two phase anaerobic digestion of cellulosic materials more efficient.
