Zalila-Kolsi Imen, Kessentini Sameh, Tounsi Slim, Jamoussi Kaïs
Laboratory of Biopesticides, Centre of Biotechnology of Sfax, University of Sfax, P.O. Box 1177, Sfax 3018, Tunisia.
Department of Health and Medical Sciences, Khawarizmi International College, Abu Dhabi P.O. Box 25669, United Arab Emirates.
Microorganisms. 2022 Apr 16;10(4):830. doi: 10.3390/microorganisms10040830.
BLB369 is an important plant growth-promoting bacterium, which produces antifungal compounds. A statistics-based experimental design was used to optimize a liquid culture medium using inexpensive substrates for increasing its antifungal activity. A Plackett-Burman design was first applied to elucidate medium components having significant effects on antifungal production. Then the steepest ascent method was employed to approach the experimental design space, followed by an application of central composite design. Three factors were retained (candy waste, peptone, and sodium chloride), and polynomial and original trigonometric models fitted the antifungal activity. The trigonometric model ensured a better fit. The contour and surface plots showed concentric increasing levels pointing out an optimized activity. Hence, the polynomial and trigonometric models showed a maximal antifungal activity of 251.9 (AU/mL) and 255.5 (AU/mL) for (19.17, 19.88, 3.75) (g/L) and (19.61, 20, 3.7) (g/L) of candy waste, peptone, and NaCl, respectively. This study provides a potential strategy for improving the fermentation of BLB369 in low-cost media for large-scale industrial production.
BLB369是一种重要的促进植物生长的细菌，它能产生抗真菌化合物。采用基于统计学的实验设计，利用廉价底物优化液体培养基，以提高其抗真菌活性。首先应用Plackett-Burman设计来阐明对抗真菌产物有显著影响的培养基成分。然后采用最速上升法逼近实验设计空间，接着应用中心复合设计。保留了三个因素（糖果废料、蛋白胨和氯化钠），多项式模型和原始三角函数模型均能拟合抗真菌活性。三角函数模型拟合效果更好。等高线图和曲面图显示出同心递增水平，表明活性得到了优化。因此，对于糖果废料、蛋白胨和氯化钠，当浓度分别为(19.17, 19.88, 3.75) (g/L)和(19.61, 20, 3.7) (g/L)时，多项式模型和三角函数模型显示的最大抗真菌活性分别为251.9 (AU/mL)和255.5 (AU/mL)。本研究为在低成本培养基中改善BLB369的发酵以实现大规模工业生产提供了一种潜在策略。
