硫自养反硝化颗粒表面与间隙微生物群落特征和基因分布

研究了单质硫颗粒自养反硝化柱中表面和间隙生物膜的微生物群落结构、功能基因和代谢途径等生物信息学特征.结果表明，硫颗粒表面生物膜的微生物菌群多样性低于间隙生物膜.氮代谢功能基因丰度差异较为显著,间隙生物膜中硝酸盐和亚硝酸盐的胞外转运蛋白基因丰度远高于表面生物膜,分别为0.0792%、0.109%与0.0157%、0.0314%.对于还原性反硝化代谢,表面生物膜的总基因丰度却明显低于间隙生物膜,分别为0.367%、0.406%.此外,参与反硝化过程的基因丰度明显不同,特别是将NO₃^-还原成NO₂^-以及将N₂O还原成N₂过程中的基因.对于硫代谢,没有观察到明显的差异.APS (硫酸腺苷)氧化是将SO₃^2-氧化为SO₄^2-的主要途径,其基因丰度远远高于直接氧化途径,分别为0.137%与0.0005%(表面)、0.138%与0.0007%(间隙).结果表明,在单质硫自养反硝化过程中,间隙生物膜与表面生物膜中的微生物存在合作关系,协同促进硫自养反硝化脱氮过程.

Community structure and gene distribution of the surface and interstitial biofilm in the particle sulfur autotrophic denitrification

Bioinformation including microbial community structure, functional genes and metabolic pathways of surface and interstitial biofilms in the particle elemental sulfur autotrophic denitrification column were investigated in the present study. Bacterial diversity of microorganisms in the surface biofilm of sulfur particles was lower than that of interstitial biofilm. Differences in the abundance of functional genes for nitrogen metabolism were significant. Abundance of extracellular nitrate and nitrite transportation genes in the interstitial biofilm was much higher than that in the surface biofilm, with the abundance of 0.0792%, 0.109% and 0.0157%, 0.0314%. For reductive denitrification metabolism, the total gene abundance in surface biofilm was significantly lower than that in interstitial biofilm, with their abundance of 0.367%、0.406% respectively. Moreover, abundances of genes participated in denitrification process were remarkably different, especially the genes in the process of reducing nitrate to nitrite and nitrous oxide to nitrogen gas. Regarding sulfur metabolism, no obvious difference was observed. APS (adenosyl phosphosulfate) oxidation was the major pathway for oxidation of sulfite to sulfate, with its gene abundance was much higher than the direct oxidation pathway, and their abundances were 0.137% and 0.0005% (surface), 0.138% and 0.0007% (interstitial). Results indicated that microorganisms in interstitial biofilms cooperated with that in the surface biofilms, contributing to sulfur autotrophic denitrification synergistically.