亚硝化/电化学生物反硝化全自养脱氮工艺细菌形态及多样性研究

采用电镜观察和分子生物学手段16S rDNA克隆文库方法对亚硝化/电化学生物反硝化全自养脱氮工艺中的细菌进行了形态和多样性研究,从16S rDNA克隆文库中随机挑选60(61)个克隆子进行序列测定(约500bp),对测序结果进行BLAST比对和系统发育分析.结果表明,亚硝化段内的细菌主要为球状和椭球状的氨氧化细菌,以亚硝酸氮作为进水基质时,电化学反硝化生物段内细菌主要为短杆状和椭球状的脱氮菌.亚硝化/电化学生物反硝化脱氮系统中蕴藏着特有的微生物新资源.亚硝化段细菌类群的优势顺序为β-Proteobacteria类群(60.00%)、Bacteroidetes类群(28.33%)和Chloroflexi类群(11.67%).当电化学生物反硝化段进水氮基质为亚硝氮(429～543mg.L-1)和氨氮(412～525mg.L-1)时,细菌优势类群顺序为β-Proteobacteria(78.33%)类群和ε-Proteobacteria类群(21.67%);当电化学生物反硝化段进水氮基质为亚硝氮(519～578mg.L-1)时,细菌优势类群顺序为β-Proteobacteria类群(81.97%)、ε-Proteobacteria(16.39%)类群和γ-Proteobacteria类群(1.64%);优势类群变化不大,但每种类群中细菌的种类和数量变化较大,这主要是由进水基质变化导致.

Morphology and diversity of the bacteria in the complete autotrophic nitrite-nitrification and electrochemical bio-denitrification combined process

The morphology and diversity of the bacteria in the complete autotrophic nitrlte-nitrification and electrochemical bio-denitrification combined process were studied by scanning electron microscopy (SEM) and molecular biological methods, I.e. Partial 16S rDNA cloning and sequencing. Sixty (61) clones were randomly selected, and their partial 16S rDNA gene (ca. 5006p) was sequenced and searched in the BLAST database. A representative clone of each phylotype was also phylogenetically analyzed. The dominant bacteria in the nitrite-nitrification phase were ammonium oxidizing bacteria in spherical and elliptical form, while the short-bacilliform and elliptical nitrogen removing bacteria were the dominant bacteria in the electrochemical denitrification phase when nitrite-nitrogen was the influent nitrogen substrate. Some unknown bacteria with new characteristics were found in the combined process. The dominant bacterial communities in the nitrite-nitrification phase were fl-Proteobacteria (60. 00%), Bacteroidetes (28.33 %) and Chloroflexi (11.67 %). The dominant communities in the electrochemical bio-denitrificution phase were ~-Proteobacteria (78.33 %) and ε-Proteobacteria (21. 67 %) when the influent ammonia and nitrite-nitrogen concentrations were 429 ～543 mg· L~(-1) and 412～525 rag·L~(-1). When 519～578 rag·L~(-1) nitrite was the only nitrogen substrute in the influent, the dominant communities of the electrochemical bio-denitrification phase, which changed slightly, were β-Proteobacteria (81.97 %) ,ε-Proteobacteria (16.39%) andγ-Proteubacteria (1.64%). However, the species and amount of the bacteria in each community changed relatively greatly as a result of the change of influent substrute.