Characterization of the mineral phosphate solubilizing activity of Serratia marcescens CTM 50650 isolated from the phosphate mine of Gafsa
Characterization of the mineral phosphate solubilizing activity of Serratia marcescens CTM 50650 isolated from the phosphate mine of Gafsa
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DOI：
10.1007/s00203-009-0513-8
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发表时间：
2009-11-01
影响因子：
2.8
通讯作者：
Chouayekh, Hichem
中科院分区：
文献类型：
--
作者：
Ben Farhat, Mounira;Farhat, Ameny;Chouayekh, Hichem
从Gafsa磷矿中分离的粘质沙雷氏菌菌株CTM 50650在化学成分确定的培养基（NBRIP肉汤）上表现出溶解无机磷的能力。测试了各种不溶性无机磷酸盐，包括磷酸岩（RP）、磷酸钙（CaHPO 4）、磷酸三钙（Ca-3（PO 4）（2））和羟基磷灰石作为细菌生长的唯一磷酸盐来源。S. marcescens CTM 50650是非常有效的。事实上，在最佳条件下，它产生的可溶性磷（P）浓度分别达到967，500，595和326毫克/升，从CaHPO 4，Ca-3（PO 4）（2），羟基磷灰石和RP。对CTM 50650的MPS活性机制的研究表明，磷酸盐溶解伴随着pH值的显著下降。培养上清液的HPLC分析显示，当CTM 50650细胞在含有葡萄糖作为唯一碳源的NBRIP上生长时，葡萄糖的直接氧化途径导致葡萄糖酸（GA）的分泌。这与首次用PCR方法同时检测S.产生GA的粘质杆菌菌株，编码负责GA产生的葡萄糖脱氢酶的基因，以及参与其PQQ辅因子生物合成的基因pqqA、B、C和E。该研究有望在充分考虑S. marcescens CTM 50650，以实现从Gafsa RP中提取高达75%的P的产率。
The mineral phosphate solubilizing (MPS) ability of a Serratia marcescens strain, namely CTM 50650, isolated from the phosphate mine of Gafsa, was characterized on a chemically defined medium (NBRIP broth). Various insoluble inorganic phosphates, including rock phosphate (RP), calcium phosphate (CaHPO4), tri-calcium phosphate (Ca-3(PO4)(2)) and hydroxyapatite were tested as sole sources of phosphate for bacterial growth. Solubilization of these phosphates by S. marcescens CTM 50650 was very efficient. Indeed, under optimal conditions, the soluble phosphorus (P) concentration it produced reached 967, 500, 595 and 326 mg/l from CaHPO4, Ca-3(PO4)(2), hydroxyapatite and RP, respectively. Study of the mechanisms involved in the MPS activity of CTM 50650, showed that phosphate solubilization was concomitant with significant drop in pH. HPLC-analysis of culture supernatants revealed the secretion of gluconic acid (GA) resulting from direct oxidation pathway of glucose when the CTM 50650 cells were grown on NBRIP containing glucose as unique carbon source. This was correlated with the simultaneous detection by PCR for the first time in a S. marcescens strain producing GA, of a gene encoding glucose dehydrogenase responsible for GA production, as well as the genes pqqA, B, C and E involved in biosynthesis of its PQQ cofactor. This study is expected to lead to the development of an environmental-friendly process for fertilizer production considering the capacity of S. marcescens CTM 50650 to achieve yields of P extraction up to 75% from the Gafsa RP.