不同泥藻接种比的光生物反应器中细菌种群

Bacterial Population of Photobioreactor with Different Sludge/Algae Inoculation Ratios

光生物反应器(PBR)在处理实际废水时,形成的微藻-细菌群落仅依靠光合充氧就能高效去除废水污染物。然而,目前对不同接种比下的微藻-细菌群落组成仍知之甚少。为了研究不同接种比下的PBR中稳定的细菌种群结构,将污水处理厂的活性污泥和藻类按不同比值接种至PBR中,以实际生活污水为营养来源,进行菌藻共培养,利用高通量测序技术分析PBR中微生物群落组成和相对丰度。结果发现∶泥藻接种比会影响PBR中的细菌多样性和种群结构,变形菌门、蓝细菌门和厚壁菌门为各PBR中的优势菌门。光合细菌、产氧蓝细菌和化能异养菌能共生于PBR中,使其获得较优的营养物质去除率,不同接种比的PBR对NH_(3)-N的去除率均在90%以上,同时在泥藻接种比为0.3∶1和0.76∶1(泥/g∶藻/g)的PBR中,光合细菌、蓝细菌和微藻光合作用导致的pH上升会引起一些功能性细菌,如硝化螺旋菌Nitrospira的缺失,从而导致NO_(2)^(-)-N积累。初始泥藻接种比为1.3∶1的PBR中,微生物种群结构最丰富,尤其是γ-变形菌纲、异球菌纲、硝化螺旋菌纲等微生物的丰度增加。

When a photobioreactor(PBR)is used to treat domestic sewage,the microalga-bacteria community formed can efficiently remove pollutants only by photosynthetic oxygenation.However,the composition of the microalgal-bacterial community is still poorly understood.In order to study the population structure of microorganisms in PBR,the activated sludge and algae from a sewage treatment plant were inoculated into PBRs at different ratios,and the bacteria and algae were co-cultured with the actual domestic sewage as the source of nutrient.High-throughput sequencing technology was used to analyze the composition and relative abundance of microbial community in PBR.The results showed that different inoculation ratios of sludge and algae would affect the bacterial population diversity and structure in PBR,photosynthetic bacteria,Cyanobacteria and heterotrophic bacteria co-exsited in PBR,causing a good nutrients removal rate,and the removal rates of NH_(3)-N were all above 90%for PBRS with different inoculation ratios.Proteobacteria,Cyanobacteria and Firmicutes were the dominant phyla in each PBR.In the PBRs inoculated with 0.3∶1 and 0.76∶1(sludge/g∶algae/g),rising in pH due to photosynthesis by photosynthetic bacteria,Cyanobacteria,and microalgae caused the lack of some functional bacteria,such as nitrifying bacteria Nitrospira,thus resulting in the accumulation of NO_(2)^(-)-N in PBR.In PBR with addition of sludge in the midway or the initial inoculation of 1.3∶1,the microbial population was the richest,with increased abundance of classesγ-Proteobacteria,Deinococcota and Nitrospira.