Kumari Archana, Ghosh Chiranjit, Kannan N, Balaji S
Department of Biotechnology, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
Int Microbiol. 2025 May 7. doi: 10.1007/s10123-025-00671-6.
In the present study, characterization of bacterial isolate from fermented foods based on the morphology, biochemical, and molecular analysis identified Lactiplantibacillus plantarum. The bacterium was tested for its ability to degrade monocrotophos (MCP) at a concentration of 1000 ppm. The dephosphorylation potential of this bacterial enzyme against organophosphate substrates including MCP was analyzed. The Lactiplantibacillus plantarum phosphatase showed optimal activity at 40 °C and 6 pH. The Michaelis-Menten constant was found to be 238.14 µM while Vmax is 357.14 µmol/min.ml for MCP as a substrate. The enzyme activity was enhanced by metal ions such as Mn, Mg, and Ca and inhibited by K, Zn, and Fe ions. Plant growth promotion assays of Lp. plantarum exhibited characteristic traits including phosphate solubilization, cellulase, catalase, and xylanase activities. The degradation of MCP was confirmed based on the presence of acetamide and trimethyl phosphate as intermediate metabolites, confirmed by FTIR and GC-MS analysis. Thus, L. plantarum is a suitable candidate for phosphate solubilization, plant growth promotion, and bio-fertilizer application.
在本研究中，基于形态学、生化分析和分子分析对发酵食品中的细菌分离株进行鉴定，确定为植物乳杆菌。测试了该细菌在1000 ppm浓度下降解久效磷（MCP）的能力。分析了这种细菌酶对包括MCP在内的有机磷底物的去磷酸化潜力。植物乳杆菌磷酸酶在40℃和pH值为6时表现出最佳活性。以MCP为底物时，米氏常数为238.14 μM，最大反应速度为357.14 μmol/min·ml。金属离子如Mn、Mg和Ca可增强酶活性，而K、Zn和Fe离子则抑制酶活性。植物乳杆菌的植物生长促进试验表现出包括解磷、纤维素酶、过氧化氢酶和木聚糖酶活性等特征特性。基于傅里叶变换红外光谱（FTIR）和气相色谱-质谱联用（GC-MS）分析确认的中间代谢产物乙酰胺和磷酸三甲酯的存在，证实了久效磷的降解。因此，植物乳杆菌是解磷、促进植物生长和生物肥料应用的合适候选菌株。
