锑氧化菌Pseudomonas sp.AO-1的分离鉴定及其对Sb(III)的氧化性能

Isolation and identification of antimony-oxidizing bacterium Pseudomonas sp.AO-1 and its oxidation properties for Sb(Ⅲ)

采用抗性筛选法从锡矿山筛选出一株锑氧化菌,并利用分子生物学技术对其进行鉴定;考察了其氧化Sb()Ⅲ的性能和氧化次生矿物的特征.结果表明:锑氧化菌属于假单胞菌属(Pseudomonas),将其命名为Pseudomonas sp.AO-1(简称:AO-1);影响AO-1氧化Sb(Ⅲ)的因素主要有溶液pH值、溶解氧和铁锰氧化物(单质铁、FeCl_(3)和MnO_(2))等;AO-1在好氧和缺氧条件下均能氧化Sb(Ⅲ),好氧氧化Sb(Ⅲ)的米门常数Km和最大氧化速率Vmax值分别为393.05µmol/L和0.271µmol/(L·min),体现了较强的锑氧化性;AO-1和铁锰氧化物的耦合作用能促进Sb(Ⅲ)的氧化,且铁锰氧化物促进AO-1氧化Sb(Ⅲ)的速率依次为:FeCl_(3)>MnO_(2)>单质铁;AO-1和铁锰氧化物耦合氧化Sb(Ⅲ)生成含Sb(Ⅴ)的次生矿物,次生矿物会加速Sb(Ⅲ)的氧化以及影响锑在环境中的迁移转化.菌株AO-1的锑氧化性能良好,对于锑的生物化学转化和土壤微生物修复的应用有重要意义.

An antimony-oxidizing bacterium was screened from Xikuangshan by the resistance screening method and identified by molecular biology techniques.And its oxidation properties for Sb(Ⅲ)and the characteristics of oxidized secondary minerals were investigated.The results showed that the antimony-oxidizing bacterium belonged to the genus Pseudomonas sp.,which was named Pseudomonas sp.AO-1(AO-1).The main factors affecting the oxidation of Sb(Ⅲ)by AO-1 were solution pH,dissolved oxygen and iron/manganese oxide(elemental iron,FeCl_(3)and MnO_(2)).In addition,AO-1 could oxidize Sb(Ⅲ)under both aerobic and anoxic conditions,and the Michaelis-Menten constant and maximum oxidation rate of aerobic oxidation of Sb(Ⅲ)were 393.05µmol/L and 0.271µmol/(L·min),respectively,presenting strong oxidizing ability to antimony.The combination of AO-1 and iron/manganese oxides could promote Sb(Ⅲ)oxidation,and the rate of iron/manganese oxides promoting the oxidation of Sb(Ⅲ)by AO-1 was in the following order:FeCl_(3)>MnO_(2)>elemental iron.Furthermore,the coupled oxidation of Sb(Ⅲ)by AO-1 and iron/manganese oxides generated secondary minerals containing Sb(V),which accelerated Sb(Ⅲ)oxidation and affected the migration and transformation of antimony in the environment.AO-1indeed exhibits satisfactory antimony oxidation performance,which is of great significance for the biogeochemical transformation of antimony and the application of soil microbial remediation.