Sa-Uth Chirayu, Rattanasena Paweena, Chandrapatya Angsumarn, Bussaman Prapassorn
Department of Biotechnology, Faculty of Technology, Mahasarakham University, Maha Sarakham 44150, Thailand.
Community Public Health Sub-Department, Department of Applied Sciences, Faculty of Science and Technology, Phranakhon Si Ayutthaya Rajabhat University, Ayutthaya 13000, Thailand.
Int J Microbiol. 2018 Jun 12;2018:3965851. doi: 10.1155/2018/3965851. eCollection 2018.
PB09 bacterium has been shown to exhibit antifungal activity against several plant pathogens. To improve its efficacy, the optimization of the nutritional components in culture media was performed. The medium components that have significant effects on antifungal activity of PB09 were initially identified using a fractional factorial design. Response surface methodology and central composite design were then used to create a model for optimizing the levels of carbon, nitrogen, and mineral sources that maximize antifungal activity of PB09. After that, the suitable carbon, nitrogen, and mineral sources were selected and adjusted by the second-order polynomial regression model, which predicted that 98.62% of antifungal activity could be obtained when the medium contained sucrose, yeast extract, NaCl, and KHPO at 3.24, 23.71, 5.46, and 2.73 g/L, respectively. Laboratory verification of this recipe resulted in the antifungal activity at 97.95% in the shake flask experiment after 48-hour cultivation, which was significantly 27.22% higher than that obtained by using the TSB medium. In addition, PB09 cultured in the verified recipe by using 5 L fermenter could effectively inhibit the mycelial growth of sp., , sp., and . This study demonstrated that the RSM and CCD were shown to be valuable tools for optimizing the culture medium that maximize the antifungal activity of PB09.
PB09细菌已被证明对多种植物病原体具有抗真菌活性。为提高其功效，对培养基中的营养成分进行了优化。首先使用分数析因设计确定了对PB09抗真菌活性有显著影响的培养基成分。然后采用响应面法和中心复合设计创建模型，以优化碳源、氮源和矿物质源的水平，从而使PB09的抗真菌活性最大化。之后，通过二阶多项式回归模型选择并调整了合适的碳源、氮源和矿物质源，该模型预测当培养基分别含有3.24、23.71、5.46和2.73 g/L的蔗糖、酵母提取物、NaCl和KHPO时，可获得98.62%的抗真菌活性。对该配方进行实验室验证，在摇瓶实验中培养48小时后，抗真菌活性为97.95%，比使用TSB培养基时显著高出27.22%。此外，使用5 L发酵罐按照验证后的配方培养PB09，可有效抑制 sp.、 sp.、 sp.和 sp.的菌丝生长。本研究表明，响应面法和中心复合设计是优化培养基以最大化PB09抗真菌活性的有价值工具。
