Department of Chemical Engineering, National Institute of Technology Calicut, Kerala-673601, India.
Department of Biotechnology, Kamaraj College of Engineering and Technology, Virudhunagar, Tamilnadu-626001, India.
Carbohydr Polym. 2017 Oct 15;174:103-110. doi: 10.1016/j.carbpol.2017.06.021. Epub 2017 Jun 21.
The most influencing factor on dextran production by Weissella cibaria NITCSK4 were screened using Plackett Burman design at 95% confidence limit with higher value of co-efficient of determination (R) 99.58%. The combined effects of significant factors, namely, sucrose, temperature, dipotassium hydrogen phosphate (KHPO) and yeast extract were studied and optimized using Response Surface Methodology (RSM). The input parameters of non-linear models predicted by RSM were subsequently optimized using the genetic algorithm (GA) for obtaining a maximum dextran yield. The maximum yield was obtained with sucrose concentration of 15.78%, yeast extract 1.27%, KHPO 1.25%, and at 26°C. The predicted conditions were experimentally validated and 43.79mg/ml of dextran was produced. The dextran yield was 51% higher as compared to unoptimized medium. The molecular weight of resulting dextran produced at 26°C is >2000kDa. The NMR spectroscopic analysis demonstrated that the NITCSK4 produced linear dextran with predominant α (1-6) linkage.
采用 Plackett-Burman 设计，在 95%置信限下，以更高的确定系数 (R) 值 99.58%筛选出影响 Weissella cibaria NITCSK4 生产右旋糖酐的最主要因素。采用响应面法 (RSM) 研究并优化了显著因素（即蔗糖、温度、磷酸二氢钾 (KHPO) 和酵母提取物）的综合效应。通过遗传算法 (GA) 对 RSM 预测的非线性模型的输入参数进行优化，以获得最大的右旋糖酐产量。最大产量在蔗糖浓度为 15.78%、酵母提取物 1.27%、KHPO 1.25%和 26°C 时获得。预测条件经实验验证，可生产 43.79mg/ml 的右旋糖酐。与未优化的培养基相比，右旋糖酐的产量提高了 51%。在 26°C 下生产的右旋糖酐的分子量>2000kDa。NMR 光谱分析表明，NITCSK4 产生的主要为具有α（1-6）键的线性右旋糖酐。
