College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China.
College of Resources and Environment, Northeast Agricultural University, Harbin 150030, China.
Waste Manag. 2020 Mar 15;105:190-197. doi: 10.1016/j.wasman.2020.02.010. Epub 2020 Feb 17.
Analyzing diazotrophic community may help to understand nitrogen transformation in composting and improves the final compost quality. In this study, diazotrophic community dynamics were investigated in terms of nifH gene during dairy manure and corn straw composting with biochar addition using high-throughput sequencing. Biochar decreased the diversity of diazotrophic community and altered diazotroph community structure during composting. At phylum level, Proteobacteria, Actinobacteria and Firmicutes were dominant diazotrophic communities throughout composting process. Biochar addition registered higher correlation coefficient (R) between physicochemical factors (temperature, ammonium (NH-N) and nitrate (NO-N)) and diazotroph community composition. Rhodopseudomonas and Pseudoxanthomonas was the key diazotrophic communities influencing NH-N transformation in control (CK) and biochar compost (BC), respectively, while for NO-N transformation Clostridium and Bradyrhizobium in CK, Azospira and Methylocystis in BC served as predominant factors. These results indicated that addition of biochar altered the key diazotroph communities influencing nitrogen transformation. Furthermore, some diazotrophs (e.g. Rhodopseudomonas, Bradyrhizobium and Azospira) affecting NH-N and NO-N transformation were also observed to be mediating total nitrogen (TN). Interestingly, interactions between diazotrophic communities were observed and these interactions could also influence nitrogen transformation.
分析固氮微生物群落有助于了解堆肥过程中的氮转化，并提高最终堆肥质量。本研究采用高通量测序技术，研究了添加生物炭对奶牛粪便和玉米秸秆堆肥过程中固氮微生物群落 nifH 基因的动态变化。生物炭降低了固氮微生物群落的多样性，并改变了堆肥过程中的固氮微生物群落结构。在门水平上，变形菌门、放线菌门和厚壁菌门是整个堆肥过程中的主要固氮微生物群落。添加生物炭后，理化因子（温度、铵（NH-N）和硝酸盐（NO-N））与固氮微生物群落组成之间的相关性系数（R）更高。在对照（CK）和生物炭堆肥（BC）中，假单胞菌属和假单胞菌属是影响 NH-N 转化的关键固氮微生物群落，而在 CK 中影响 NO-N 转化的主要因素是梭菌属和慢生根瘤菌属，在 BC 中则是固氮螺菌属和甲基孢囊菌属。这些结果表明，生物炭的添加改变了影响氮转化的关键固氮微生物群落。此外，还观察到一些影响 NH-N 和 NO-N 转化的固氮微生物（如假单胞菌属、慢生根瘤菌属和固氮螺菌属）也参与了总氮（TN）的转化。有趣的是，还观察到了固氮微生物群落之间的相互作用，这些相互作用也可能影响氮转化。
