摘要
异养硝化细菌(heterotrophic nitrifying bacteria)是重要的硝化微生物类群之一,在生长过程中可以通过硝化作用快速去除污水中多余的氮,因而成为生物脱氮领域的研究热点.近10年来异养硝化细菌的研究获得了较大进展,本文系统总结异养硝化细菌类群的硝化酶系及其编码基因特点,梳理异养硝化代谢途径;同时总结其他氮转化功能酶及其编码基因在整个类群中的分布,探讨异养硝化细菌的脱氮机理.迄今为止,已发现的异养硝化功能酶比自养硝化酶的多样性更高,具有更多硝化途径;且异养硝化细菌普遍具有氮转化功能多样性,硝化、反硝化、氨同化作用对脱氮作用贡献很大.目前还有部分异养硝化细菌的氮转化功能相关的基因信息仍然缺乏,生物脱氮过程的分子机制尚不明确.从分子水平对异养硝化细菌的氮转化功能活性进行验证,进一步阐明异养硝化细菌进行脱氮作用的生理机制是今后的重要研究方向.(图2表1参96)
Heterotrophic nitrifying bacteria are an important group of nitrifying microbes and have been a hotspot in nitrogen bio-removal because of their high efficiency in removing sewage nitrogen.Research on heterotrophic nitrifying bacteria has made considerable progress during the last decade.This review summarizes the key enzymes that catalyze nitrification and other nitrogen-transforming processes in heterotrophic nitrifying bacteria,organized heterotrophic nitrification pathways,and underlying molecular and biochemical mechanisms of nitrogen bio-removal.The diversity of nitrifying functional genes is higher in heterotrophic nitrifying bacteria than in autotrophic nitrifiers.Heterotrophic nitrifying enzyme cluster includes ammonia monooxygenase(AMO),hydroxylamine dehydrogenase(HAO),pyruvic oxime dioxygenase(POD),and nitric oxide dioxygenase(NOD).Heterotrophic nitrifying bacteria possess different nitrifying genes and produce nitrate via different nitrification pathways.Moreover,heterotrophic nitrifying bacteria have multiple nitrogen metabolic functions and thus play a key role in sewage nitrogen turnover.Ammonia assimilation and nitrification-denitrification are important ammonia removal pathways.Nonetheless,the genetic information on the nitrogen transformation and nitrogen removal pathways of some heterotrophic nitrifying bacteria remains unclear.In future,more molecular investigations of nitrogen metabolism are required to reveal the nitrogen metabolic pathways of heterotrophic nitrifying bacterial strains and explore bacterial nitrogen removal mechanisms.
作者
亢宗静
胡露星
蔡凯
张岚
李致同
熊旭梅
蒋先军
KANG Zongjing;HU Luxing;CAI Kai;ZHANG Lan;LI Zhitong;XIONG Xumei;JIANG Xianjun(College of Resources and Environmental,Southwest University,Chongqing 400719,China;Guizhou Academy of Tobacco Science,Guiyang 550081,China)
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2023年第4期811-820,共10页
Chinese Journal of Applied and Environmental Biology
基金
国家自然科学基金项目(42077035,41671232)资助
关键词
异养硝化细菌
硝化酶系
异养硝化途径
氮转化基因
生物脱氮机制
heterotrophic nitrifying bacteria
nitrifying enzymes
heterotrophic nitrification pathway
nitrogen-transforming gene
nitrogen bio-removal mechanism
作者简介
通信作者:蒋先军,E-mail:jiangxj@swu.edu.cn
