一株反硝化真菌的分离鉴定及其对生物塔脱氮效率的影响

Isolation and Identification of a Fungi with Denitrification and Its Influence on Nitrogen Removal Efficiency of Biological Tower

国内外对细菌的作用及作用机制研究较多,而对真菌的作用及机制研究较少.为了提高NO,NO_x的脱除效率,本文对脱氮塔生物膜中的反硝化真菌进行了分离、纯化及鉴定,通过摇瓶实验研究了反硝化真菌对NO_3^-的作用特征,最后在脱氮塔中投加了分离的反硝化真菌纯菌株扩大培养液,研究了其对NO_x脱除效率的影响,还对脱氮塔内真菌的群落结构进行了高通量测序分析.实验结果表明:经过真菌形态特征和脱氮(NO_3^-)特性研究及ITS序列测定分析,将3LNB菌株鉴定为镰刀菌的腐皮镰刀菌Fusarium solani.高通量测序分析结果证明了脱氮塔内确实存在镰刀菌属的腐皮镰刀菌Fusarium solani.在NO_3^-—N浓度高达10.01g/L的条件下,实验共10d,细菌反硝化组反硝化率为5.6%,其脱除效率为0.56g/L;真菌3LNB菌株的反硝化率能达到15.1%,其脱除效率为1.51g/L.实验室实验证明3LNB菌株对NO_3^-具有较强的反硝化能力.将3LNB纯菌株扩大培养液400mL(4%)投加到脱氮塔中,NO,NO_x的平均脱除率分别提高了5.12%,5.36%.脱氮塔净化实验证明3LNB培养液能强化微生物对NO,NO_x的脱除效能,这可能主要与腐皮镰刀菌等真菌细胞存在细胞色素P450nor有关.

At home and abroad, many studies of bacterial technology to remove NO and NO.have been performed. However, the effect and mechanism of fungal were poorly studied. To improve the removal effi- ciency of NO and NOx, the fungi isolated and identified from the biofilm of denitrifying tower through sha- king flasks experiment was studied on its nitrogen removal characteristics to nitrate （NO3-）. Expanding culture was put into the denitrify tower to study its effect on the NO and NOx removal efficiency. The fun- gal community structure through high-throughput sequencing analysis was monitored. The results showed that the strain 3LNB through morphological, nitrogen （NO3-） removal characteristics research, and ITS se- quence analysis was identified as Fusarium solani. For up to 10.01 g/L of NO3-N, the denitrifying rate ofbacteria control group was 5.6% with nitrogen removal eltlcmncy , strain 3LNB was 15.1% with nitrogen removal efficiency of 1.51 g/L for 10 days,which proved that the strain 3LNB had strong denitrification function. The nitrogen removal rate of NO and NO2 was increased by 5.12% and 5.36% on average, respectively, after the expanding culture 400 mL （4%） of pure strain 3LNB was put into denitrifying tower, which proved that the strain 3LNB culture can improve removal rate of NO and NO, in denitrifying tower. This may be mainly related to the presence of cytochrome P450nor in fungi such as Fusarium solani.