水体细菌碱性磷酸酶及其编码基因研究进展

水体溶解性反应磷是浮游植物可直接利用的主要磷营养形式,细菌碱性磷酸酶催化的有机磷矿化过程则是维持溶解性反应磷供给的重要途径.通过总结细菌碱性磷酸酶的种类与分布特征,发现主要包括Pho A、Pho X和Pho D 3种类型细菌碱性磷酸酶,其中超过50%的Pho X分布于细菌细胞的外部环境,对溶解性反应磷的循环再生尤为重要.综述水体产碱性磷酸酶细菌群落组成的研究进展,以及影响编码基因表达的环境因素,对比分析产碱性磷酸酶细菌群落鉴定方法的特点及发展趋势.细菌碱性磷酸酶编码基因的研究多关注寡营养海洋生态系统,对于同样存在磷限制问题的富营养化湖泊生态系统鲜有涉及,而构建针对典型富营养化湖泊生态系统的细菌宏基因组数据库,则可为建立淡水生态系统细菌碱性磷酸酶及其编码基因的研究方法奠定基础,有助于认识湖泊水华频发的微生物学驱动机制.

Bacterial alkaline phosphatases and affiliated encoding genes in natural waters: A review

Soluble reactive phosphorus is the main form of phosphorus directly available for phytoplankton in natural waters, and the organophosphate mineralization catalyzed by bacterial alkaline phosphatases maintains the supply of soluble reactive phosphorus. We summarized the species and subcellular location of bacterial alkaline phosphatases and found that PhoA, PhoX and PhoD were the main phosphatase species. Over 50% of PhoX were distributed outside of bacterial cells, which is particularly important for the regeneration of soluble reactive phosphorus in natural waters. The research progress in communities of alkaline phosphatase encoding bacteria and the environmental factors influencing the expression of alkaline phosphatase encoding genes were also reviewed. We compared and analyzed the characteristics and developing trend of identification methods towards bacterial communities generating alkaline phosphatases. Most of studies about bacterial alkaline phosphatase-encoding genes were focused on oligotrophic marine ecosystems, and little was on the lake ecosystems which are also facing the phosphorus-limiting problem. Further researches should construct the bacterial metagenomic databases for certain eutrophic lakes to provide basis for build the methodology for bacterial alkaline phosphatases and affiliated encoding genes in freshwater ecosystems, which are beneficial to understand the microbial mechanisms driving frequent cyanobacterial blooms in lakes.