Lisintta E S, George Annie, Gafoor Sona, Vishnupriya S, Yousuf Jesmi, Kachiprath Bhavya, Valsa A K, Antony Ally C, Aneesa P A, Hatha A A Mohamed
Department of Biochemistry, Sree Sankara College, Kalady, Kerala, 683574, India.
Department of Marine Biology, Microbiology, and Biochemistry, Cochin University of Science and Technology (CUSAT), Kochi, Kerala, 683016, India.
World J Microbiol Biotechnol. 2025 Feb 14;41(2):72. doi: 10.1007/s11274-025-04252-7.
This study reports the identification of a phosphatase-producing psychrotolerant bacterium, Bacillus cereus KR_O9, isolated from Arctic Krossfjorden sediments. The extracellular KR_O9 phosphatase was purified to homogeneity through acetone precipitation and ion exchange chromatography, achieving a specific activity of 12.51 U mg⁻ min⁻, a 17.3-fold purification, and a 64.94% yield. The molecular mass of the enzyme was estimated as 37 kDa by SDS-PAGE. K, and V for KR_O9 phosphatase towards substrate p-NPP were determined as 0.033 M L, 1.67 mg min. The enzyme exhibited optimal activity at 40 °C and pH 6.0, with stability up to ≤ 40 °C and at pH levels ≤ 7.0, highlighting its thermolability and sensitivity to alkaline pH. At 10 mM level, Cu, Hg, Co, Pb, urea, EDTA, and GSH significantly stimulated the enzyme, and Ca, Zn, Mn, SDS, and CTAB were, strong inhibitors. The kinetic efficiency, resilience to low to neutral pH, and tolerance to various metal ions, including heavy metals, underscore the potential of B. cereus KR_O9 phosphatase for bioremediation and biofertilizer applications, paving the way for industrial exploration.
本研究报告了从北极克罗斯峡湾沉积物中分离出的一种产磷酸酶的耐冷细菌——蜡样芽孢杆菌KR_O9的鉴定。通过丙酮沉淀和离子交换色谱法将细胞外KR_O9磷酸酶纯化至同质，比活性达到12.51 U mg⁻¹ min⁻¹，纯化倍数为17.3倍，产率为64.94%。通过SDS-PAGE估计该酶的分子量为37 kDa。KR_O9磷酸酶对底物对硝基苯磷酸酯（p-NPP）的Km和Vmax分别确定为0.033 M和1.67 mg min⁻¹。该酶在40°C和pH 6.0时表现出最佳活性，在≤40°C和pH≤7.0时具有稳定性，突出了其热不稳定性和对碱性pH的敏感性。在10 mM浓度下，铜、汞、钴、铅、尿素、乙二胺四乙酸（EDTA）和谷胱甘肽（GSH）显著刺激该酶，而钙、锌、锰、十二烷基硫酸钠（SDS）和十六烷基三甲基溴化铵（CTAB）是强抑制剂。动力学效率、对低至中性pH的耐受性以及对包括重金属在内的各种金属离子的耐受性，突显了蜡样芽孢杆菌KR_O9磷酸酶在生物修复和生物肥料应用方面的潜力，为工业开发铺平了道路。
