长期不同施肥量对全程氨氧化细菌丰度的影响  

Long-term Fertilization Effects on the Abundance of Complete Ammonia Oxidizing Bacteria(Comammox Nitrospira) in a Neutral Paddy Soil

作　　者：王梅[1] 王智慧[1] 石孝均 蒋先军[1] WANG Mei;WANG Zhi-hui;SHI Xiao-jun;JIANG Xian-jun(College of Resources and Environment,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学资源环境学院,重庆400715

出　　处：《环境科学》2018年第10期4727-4734,共8页Environmental Science

基　　金：国家自然科学基金项目(41671232);国家重点研发计划项目(2016YFD0300901)

摘　　要：全程氨氧化细菌(Comammox Nitrospira)的发现彻底改变了对传统硝化作用的认知,其在生物地球化学氮循环中可能具有很重要的作用,并为硝化作用研究提供了新的思路,故需要有更多的工作去评估Comammox Nitrospira在不同生态系统中的分布,本试验选取西南大学长期定位试验田的3种不同施肥量的水稻土,分别为对照组(blank control)、常规施肥量(NPK)、高量施肥(1.5NPKS)处理土壤,进行硝化势及硝化微生物尤其是全程氨氧化细菌的测定.结果表明:(1)3种施肥量处理土壤中均检测出较高数量级的Comammox,分支A(Clade A)丰度(以干土计,下同)分别为9.0×107、1.7×108、7.2×108copies·g^(-1),而分支B(Clade B)丰度分别为1.5×107、1.2×107、1.7×107copies·g^(-1).(2)3种施肥土壤中AOA丰度为1.5×107~1.2×108copies·g^(-1),AOB丰度分别为2.0×105~9.3×107copies·g^(-1),均低于Comammox丰度,而不施肥条件下Comammox丰度与AOA、AOB的比值最大,分别为7.2、524.4.(3)Comammox Clade A丰度与Comammox Clade B的比值随施肥量增加而增加,且比值依次为6.1、14.4、43.1.(4)NPK、1.5NPKS两种N肥施用量下全程氨氧化细菌分支A丰度分别为对照组的1.9、8.0倍,氨氧化古菌(AOA)分别是对照组的3.2、7.2倍,氨氧化细菌(AOB)均比对照组显著增加2个数量级;硝化势也随施肥量增加而增大;但不同施肥量对分支B丰度却无显著影响.本试验结果表明Comammox广泛分布于中性紫色水稻土中,在水稻土中丰度均比AOA、AOB高,因此Comammox很有可能在中性紫色水稻土的硝化作用中有一定贡献;水稻土中Comammox以Comammox Clade A为主.The discovery of the complete ammonia-oxidizing microbes, Comammox Nitrospira, had fundamentally changed our perspective on traditional nitrification. The microbe also played a potentially under-appreciated role in the biogeochemical N cycle and provided a new dimension for the research of nitrification. To investigate the abundance of Comammox in different ecosystems was urgently needed. In the present study,three treatments with different quantities of fertilization in a paddy soil（ blank control,NPK and1. 5 NPKS） to investigate the nitrification and amo A gene abundance for nitrifying microorganisms,especially for the complete ammonia oxidizing bacteria（ Comammox Nitrospira）. The results showed that：（1） Both Comammox Clade A and Comammox Clade B were detected in all three treatments,and the abundance of Comammox Clade A were 9. 0 ×10^7,1. 7 ×10^8,7. 2 ×10^8 copies·g^-1（ dry soil）,respectively,and for Comammox Clade B were 1. 5 ×10^7,1. 2 ×10^7,1. 7 ×10^7 copies·g^-1（ dry soil）,respectively.（2） The abundances of both ammonia-oxidizing archaea（ AOA） in the three fertilizers was 1. 5 ×10^7-1. 2 ×10^8 copies·g^-1（ dry soil）,and the ammonia-oxidizing bacteria（ AOB） in the three fertilizers was 2. 0 ×10^5-9. 3 ×10^7 copies·g^-1（ dry soil）,lower than the abundance of the Comammox. The ratio of Comammox to AOA was 7. 2,and the ratio for Comammox to AOB was 524. 4 for blank control,were greater than NPK and 1. 5 NPKS treatments.（3） The ratio of Comammox Clade A to Comammox Clade B showed an increasing trend with the increase in fertilizer application,at 6. 1,14. 4 and 43. 1,respectively.（4） For NPK and 1. 5 NPKS treatments,Comammox Clade A amo A gene copies were 1. 9 and 8. 0 times higher than that of the blank control treatment respectively,and the numbers for AOA significantly increased to 3. 2 and 7. 2 times that of the blank control. The AOB gene copy numbers increased by two orders of magnitude compared with the blank control. In addition, the nitrifi

关 键 词：氮循环 硝化作用 水稻土 氨氧化微生物 亚硝酸盐氧化细菌 全程氨氧化细菌(Comammox Nitrospira) 

分 类 号：X172[环境科学与工程—环境科学]