Chandrika Kumari, Sachan Ashish
Department of Life Sciences, Central University of Jharkhand, Ranchi, Jharkhand 835 222 India.
3 Biotech. 2024 Feb;14(2):37. doi: 10.1007/s13205-023-03883-7. Epub 2024 Jan 12.
Bacteriocin-producing strains were isolated from the soil of the rice field, screened out using an agar-well diffusion assay against six indicator bacterial strains, and the highest among them was selected for further investigation. The study focuses on how different growing conditions affect bacteriocin production. One-parameter-at-a-time (OPAT) and a central composite design of response surface methodology (RSM) were used to perform the optimization in two steps. In the OPAT trials, bacteriocin synthesis was elevated by 29%, 45%, and 34%, by employing sucrose as a carbon source and changing the NaCl concentration and pH at 7, respectively. To determine the linear, squared, and interaction correlations among the process variables to predict the ideal conditions for production, a four-factor central composite design (CCD) of RSM was used. It was determined that the analysis of variance (ANOVA), which produces a recognized model using RSM, is sufficient to describe bacteriocin production regarding activity (R = 0.9606). The ideal conditions for increased production were 1.51% sucrose concentration, 1.59% NaCl concentration, pH 6.35, and 28.66 (about 29) hours of incubation. The value predicted by RSM (4051.55 AU/mL) was approximately two times greater than the value of a non-optimized medium. The experimental value of 4403.85 AU/mL was closer to the expected value. According to the data, increasing bacteriocin activity required employing the ideal sucrose concentration, NaCl concentration, and incubation time. The partially purified bacteriocin was found stable at temperatures between 24 and 50 °C and at pH 5-8. The molecular weight purified bacteriocin was determined to be between 13 and 35 kDa.
从稻田土壤中分离出产细菌素的菌株,通过琼脂孔扩散法对六种指示菌株进行筛选,选出其中抑菌活性最高的菌株进行进一步研究。该研究聚焦于不同生长条件如何影响细菌素的产生。采用单因素法(OPAT)和响应面法(RSM)的中心复合设计分两步进行优化。在OPAT试验中,分别采用蔗糖作为碳源、将NaCl浓度调至7以及改变pH值,使细菌素合成分别提高了29%、45%和34%。为了确定工艺变量之间的线性、平方和交互相关性以预测理想的生产条件,采用了RSM的四因素中心复合设计(CCD)。经测定,使用RSM生成公认模型的方差分析(ANOVA)足以描述细菌素产量与活性的关系(R = 0.9606)。提高产量的理想条件为蔗糖浓度1.51%、NaCl浓度1.59%、pH 6.35以及培养28.66(约29)小时。RSM预测值(4051.55 AU/mL)约为未优化培养基值的两倍。4403.85 AU/mL的实验值更接近预期值。根据数据,提高细菌素活性需要采用理想的蔗糖浓度、NaCl浓度和培养时间。发现部分纯化的细菌素在24至50°C的温度和pH 5 - 8范围内稳定。纯化细菌素的分子量测定为13至35 kDa。