秸秆类型及配比变化对污泥厌氧消化中微生物群落的影响

Effects of straw type and ratio change on microbial community in anaerobic digestion of sludge

为探讨秸秆类型及配比变化对污泥厌氧消化体系中微生物群落结构的影响,采用16SrRNA高通量测序技术,对污泥-秸秆联合厌氧消化体系中微生物群落进行分析。结果表明:玉米秸秆的添加对体系中pH和挥发性脂肪酸(V FAs)的影响较大,尤其是乙酸。而小麦和水稻秸秆的添加对碱度的影响较大,但当配比增加时体系中的VFAs和乙酸浓度也会增加,特别是1∶1.5(挥发性固体质量比)。通过对微生物群落结构分析发现,秸秆类型及配比的变化能显著提高厌氧体系中水解菌和酸化菌的相对丰度(p<0.001),如深古菌门Bathyarchaeota、未识别的_c_深古菌门(norank_p_Bathyarchaeota)、拟杆菌门(Bacteroidetes)、阴沟单胞菌门(Cloacimonetes)、同力菌门(Synergistetes)、未分类的_p_阴沟单胞菌门(unclassified_p_Cloacimonetes)、未识别的_c_拟杆菌门_vadinHA17(norank_c_Bacteroidetes_vadinHA17)、(Chris tensenellaceae_R-7_group)、未识别的_f_紫单胞菌科(norank_f_Porphyromonadaceae)、未分类的_f_瘤胃菌科(unclassified_f_Ruminococcaceae)、拟杆菌属(Bacteroides)、丙酸杆菌属(Prolixibacter)、长绳菌属(Longilinea)、纤绳菌属(Leptolinea)等菌群;但对体系中乙酸型产甲烷菌(Methanosaeta)和氢型产甲烷菌(甲烷螺菌属Methanospirillum、甲烷杆菌属Methanobacterium和甲烷短杆菌属Methanobrevibacter)的生长产生抑制作用。同时也发现秸秆的添加对甲基型产甲烷菌(Methanomassiliicoccus)的生长具有显著的促进作用(p<0.001),从而影响厌氧体系的产甲烷特性。

In order to investigate the effects of straw type and ratio change on microbial community structure in sludge anaerobic digestion system,16S rRNA high-throughput sequencing technology was used to analyze the microbial community in sludge-straw anaerobic co-digestion system.The results showed that addition of corn straw had a great influence on the pH and volatile fatty acids(VFAs)in the system,especially on acetic acid.Addition of wheat and rice straw had a greater effect on alkalinity,but the VFAs and acetic acid concentrations in the system increased when the ratio increased,especially 1∶1.5(mass ratio of volatile solids).Through the analysis of microbial community structure,it was found that the change of straw ratio and types could significantly increase the relative abundance of hydrolysis bacteria and acidification bacteria(p<0.001)in anaerobic systems,for instance,Bathyarchaeota,norank_p_Bathyarchaeota(archaea),Bacteroidetes,Cloacimonetes,Synergistetes,unclassified_p_Cloacimonetes,norank_c_Bacteroidetes_vadinHA17,Christensenellaceae_R-7_group,norank_f_Porphyromonadaceae,unclassified_f_Ruminococcaceae,Bacteroides,Prolixibacter,Longilinea and Leptolinea(bacteria),but the growth of methanogens(Methanosaeta)and hydrogen methanogenic bacteria(Methanospirillum,Methanobacterium and Methanobrevibacter)could be inhibited.It was also found that the addition of straw significantly promoted the growth of methylotrophic methanogens(Methanomassiliicoccus)(p<0.001),which affected the methanogenic properties of anaerobic systems.