Department of Biotechnology, Manipal Institute of Technology (MIT), Manipal Academy of Higher Education (MAHE), Manipal, 576104, India.
School of Pharmaceutical Sciences, Universidade Estadual Paulista, Araraquara, Brazil.
Arch Microbiol. 2022 Sep 1;204(9):584. doi: 10.1007/s00203-022-03168-2.
A tannase-positive Bacillus gottheilii M2S2 and Bacillus cereus M1GT were co-cultivated for the production of gallic acid using tannic acid as the sole carbon source through submerged fermentation. Taguchi orthogonal array of design of experimental methodology was used to estimate the influence and significance of tannic acid concentration, glucose concentration, agitation speed, and inoculum size on the gallic acid production in a shake flask. Among all the factors, agitation speed contributed the highest for gallic acid production (28.28%), followed by glucose concentration (21.59%), inoculum size (19.6%), tannic acid concentration (19.54%), and pH (11.09%). Validation experiments were executed at the found optimized conditions which resulted in a 6.36-fold increase in gallic acid yield compared to unoptimized conditions. Further, the kinetics of growth, tannic acid degradation, and gallic acid yield were evaluated at the optimized conditions. The kinetic parameters Y , Y , and Y were determined as 0.292 mg of cells/mg of tannic acid, 22.2 µg of gallic acid/mg of tannic acid, and 70.76 µg of gallic acid/mg of cells with a growth rate of 0.273 h after 24 h of fermentation. Finally, the antimicrobial activity of the product gallic acid was investigated against food-borne pathogenic E. coli, S. aureus, and Serriatia marcescens and showed a zone of inhibition of 2 cm, 1.6 cm, and 1.3 cm, respectively, using the agar disc diffusion technique. Thus, the cost-effective bioproduct gallic acid proved to be potentially effective to control food poisoning diseases and preserve foodstuff.
一株单宁酶阳性的地衣芽孢杆菌 M2S2 和蜡状芽孢杆菌 M1GT 被共同培养，以单宁酸为唯一碳源，通过深层发酵生产没食子酸。采用田口正交试验设计法来评估单宁酸浓度、葡萄糖浓度、搅拌速度和接种量对摇瓶中产没食子酸的影响和重要性。在所有因素中，搅拌速度对产没食子酸的贡献最大（28.28%），其次是葡萄糖浓度（21.59%）、接种量（19.6%）、单宁酸浓度（19.54%）和 pH 值（11.09%）。在找到的最佳条件下进行验证实验，与未优化条件相比，没食子酸产量提高了 6.36 倍。此外，还在最佳条件下评估了生长、单宁酸降解和没食子酸产率的动力学。在 24 小时发酵后，确定了 Yx、Yp 和 Yg 的动力学参数分别为 0.292mg 细胞/mg 单宁酸、22.2µg 没食子酸/mg 单宁酸和 70.76µg 没食子酸/mg 细胞，生长速率为 0.273h-1。最后，使用琼脂平板扩散技术研究了产物没食子酸对食源性致病菌大肠杆菌、金黄色葡萄球菌和粘质沙雷氏菌的抗菌活性，抑菌圈直径分别为 2cm、1.6cm 和 1.3cm。因此，这种具有成本效益的生物制品没食子酸有望有效控制食物中毒疾病并保存食品。
