The growing cells of Bacillus cereus M${}_{16}^1$, depending on the growth phase of culture was found to bioaccumulate Ni(II) from its aqueous solution to the extent of 80% wherein surface binding ($\sim$60%) dominated over intracellular accumulation ($\sim$20%). No growth was observed in the metal ion concentration beyond 50 mg L${}^{-1}$. The hydroxyl, amine, carboxylate and phosphate groups of cell surface were the most important moieties in chemical interactions with Ni(II) ions as measured by FTIR. The surface characteristics of cells were investigated meticulously by FE-SEM equipped with EDXA indicating conspicuous changes due to metal accumulation. The potential effects of the process variables [initial pH (A), temperature (B), inoculum volume (C) and medium volume (D)] were optimized using Response Surface Methodology (RSM) followed by Box–Behnken design to study the bioaccumulation phenomenon. The maximum Ni(II) accumulation was noted at 6.5, 32.5 °C, 2.5% and 50 mL corresponding to pH, temperature, inoculum volume and medium volume, respectively. The most significant factors including one independent variable (D) and two quadratic effects (B² and D²) were identified by ANOVA. The experimental response under these optimum conditions was found to be 78.76% which closely matched the yield (78.52%) predicted by the statistical model with R${}^2=0.8790$.

蜡状芽孢杆菌M的生长细胞${}_{16}^{\mathrm{1个}}$，取决于培养物的生长期，发现其水溶液中的Ni（II）会生物累积至80％的程度，其中表面结合（$〜$60％）超过细胞内积累（$〜$20％）。超过50 mg L的金属离子浓度未观察到生长${}^{-\mathrm{1个}}$。FTIR测得，细胞表面的羟基，胺基，羧酸根和磷酸根基团是与Ni（II）离子化学相互作用中最重要的部分。通过配备EDXA的FE-SEM仔细研究了细胞的表面特性，表明由于金属积累而引起的明显变化。过程变量的潜在影响[初始pH（A），温度（B），接种量（C）和中等体积（D）]使用响应表面方法（RSM）和Box–Behnken设计进行了优化，以研究生物累积现象。分别在6.5、32.5°C，2.5％和50 mL处观察到最大的Ni（II）积累，分别对应于pH，温度，接种量和培养基体积。最重要的因素包括一个自变量（D）和两个二次效应（B ²和D ²）通过ANOVA鉴定。在这些最佳条件下的实验响应被发现为78.76％，与统计模型预测的R紧密匹配（78.52％）${}^2=0。8790$。