Frontiers of Environmental Science & Engineering ( IF 6.4 ) Pub Date : 2020-10-10 , DOI: 10.1007/s11783-020-1349-3 Yuxin Li , Jiayin Ling , Pengcheng Chen , Jinliang Chen , Ruizhi Dai , Jinsong Liao , Jiejing Yu , Yanbin Xu
The problem of nitrate accumulation in aerobic tank and total nitrogen excessive discharge in effluent was very common in traditional livestock and poultry farming wastewater treatment systems owing to the lengthy process flow and low process control level. A strain LYX of aerobic bacterium was isolated from the activated sludge of a wastewater treatment system in a pig farm, which could remove nitrate effectively in aerobic tank and was identified Pseudomonas mendocina by 16S rRNA sequencing. Under the condition of nitrate as the sole nitrogen source, this strain removed over 90% of NO3−-N with an initial concentration of 110 mg/L under aerobic conditions within 48 hours. Among them, 37.9% of NO3− -N was assimilated into Bio-N, about 51.9% was reduced to gaseous nitrogen and less than 0.5% of nitrogen was replaced by NO3−-N and NH4+-N, 9.7% NO3−-N remained in the effluent at the end. At the same time, four key genes (napA, nirK, norB and nosZ) related to nitrate nitrogen removal were expressed during the denitrification process of P. mendocina LYX, in which the transcription level of the indicator genes of this aerobic denitrifying bacterium (napA) was the highest. In addition, it was found with the 15N tracer technique that inoculation of this strain on sludge increased the amount of nitrogen loss from 9.26 nmol N/(g·h) to 23.835 nmol N/(g·h). Therefore, P. medocina LYX is a potential bioagent for advanced nitrogen removal by assimilating and reducing nitrate simultaneously in aerobic tanks.
中文翻译:
Mendocina假单胞菌LYX:一种新型需氧细菌,具有通过同化和异化同时高效去除硝酸盐的优势
在传统的畜禽养殖废水处理系统中,好氧池中的硝酸盐积累和废水中总氮过量排放的问题由于过程流程长且过程控制水平低而非常普遍。从养猪场废水处理系统的活性污泥中分离出一种需氧细菌LYX菌株,该菌株可有效去除需氧罐中的硝酸盐,并通过16S rRNA测序鉴定为门氏假单胞菌。在硝酸盐作为唯一氮源的条件下,该菌株在有氧条件下在48小时内去除了90%以上的NO 3 -- N(初始浓度为110 mg / L)。其中,NO的37.9%,3 --N被同化为生物氮,约51.9%的氮还原为气态氮,少于0.5%的氮被NO 3 -- N和NH 4 + -N替代,废水中残留有9.7%NO 3 -- N在最后。同时,四个关键基因(绒毛A,NIR K,也不B和号有关硝酸盐氮的去除Z)期间的反硝化过程中表达门多萨假单胞菌LYX,其中该需氧的指示基因的转录水平反硝化细菌(小睡A)最高。另外,发现与15将此示踪剂接种到污泥上的N示踪技术使氮的损失量从9.26 nmol N /(g·h)增加到23.835 nmol N /(g·h)。因此,P。medocina LYX是通过在需氧罐中同时吸收和还原硝酸盐而用于高级脱氮的潜在生物制剂。