摘要
从太湖底泥中筛选出一株能够利用亚磷酸盐（＋3价）的细菌P1.通过生理生化实验及16S rDNA基因序列分析鉴定,P1菌与所有已知菌的同源性都很低,属于未知的新菌株.P1菌的最适培养条件为：pH6.5~7.0、温度30℃.P1菌能以亚磷酸盐为唯一磷源生长,在60~100mg P/L的初始亚磷酸盐培养条件下,100mgP/L的亚磷酸盐培养基中亚磷酸盐减少量最大（11%）,培养基中生成正磷酸盐的比例最高1.6%.初始亚磷酸盐浓度越低,碱性磷酸酶（BAP）活性越高,60mgP/L的亚磷酸盐培养基中BAP的最高活性为1.86mol PNP/（L菌液.h）.P1菌可能通过BAP将亚磷酸盐转化成生物体内所需的磷源.
It is nearly always assumed that phosphorus（P） occurs exclusively as phosphate（with an oxidation state of ＋5） in the environment.Little is known about the redox cycle of P in the environment.However,recent evidence suggested that other less oxidized forms of P（namely reduced P,with an oxidation state lower than ＋5） that were more soluble and active play a critical role in P bioavailability.A bacterial strain（which was named P1） capable of utilizing phosphite（＋3） as the sole P source was isolated and screened firstly from sediment of Lake Taihu.It was identified preliminarily as an unknown bacterium according to its physiological-biochemical analysis and the similarity analysis of its 16S rDNA gene sequence.The optimum conditions of pH and temperature for P1 growth were 6.8~7.0 and 30 oC,respectively.The concentrations of 60 mg P/L,80 mg P/L and 100 mg P/L were set to obtain the optimum phosphite concentration for P1 growth.100 mg P/L phosphite was the optimum P concentration for P1 growth,the rates of the decrease of phosphite and the increase of phosphate in the medium were 11% and 1.6%,respectively.The lower the phosphite concentration,the higher the activity of bacterial alkaline phosphatase（BAP） in the medium.The highest activity of BAP of 1.86 mol PNP/（L？h） was obtained under 60 mg P/L phosphite was added.Phosphite might be changed into the bioavailable P source for P1through the oxidation process of BAP.This study just simply found that phosphite can be utilized as a P source by a kind of bacteria.Further research should be carried out to investigate the role of phosphite in the lake P biogeochemical cycle.
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2012年第2期311-317,共7页
China Environmental Science
基金
国家自然科学基金资助项目(21077051)
江苏省自然科学基金项目(BK2011057)
