Jin Hu, Zhang Xinran, Li Kunpeng, Niu Yanxing, Guo Mian, Hu Chuanjiong, Wan Xia, Gong Yangmin, Huang Fenghong
Oil Crops Research Institute, Chinese Academy of Agriculture Sciences, Wuhan, China; Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, China.
Oil Crops Research Institute, Chinese Academy of Agriculture Sciences, Wuhan, China; College of Life Science, Hubei University, Wuhan, China.
PLoS One. 2014 Oct 31;9(10):e111171. doi: 10.1371/journal.pone.0111171. eCollection 2014.
The feasibility of using untreated rapeseed meal as a nitrogen source for iturin A production by Bacillus subtilis 3-10 in submerged fermentation was first evaluated by comparison with two different commercial nitrogen sources of peptone and ammonium nitrate. A significant promoting effect of rapeseed meal on iturin A production was observed and the maximum iturin A concentration of 0.60 g/L was reached at 70 h, which was 20% and 8.0 fold higher than that produced from peptone and ammonium nitrate media, respectively. It was shown that rapeseed meal had a positive induction effect on protease secretion, contributing to the release of soluble protein from low water solubility solid rapeseed meal for an effective supply of available nitrogen during fermentation. Moreover, compared to raw rapeseed meal, the remaining residue following fermentation could be used as a more suitable supplementary protein source for animal feed because of the great decrease of major anti-nutritional components including sinapine, glucosinolate and its degradation products of isothiocyanate and oxazolidine thione. The results obtained from this study demonstrate the potential of direct utilization of low cost rapeseed meal as a nitrogen source for commercial production of iturin A and other secondary metabolites by Bacillus subtilis.
通过与蛋白胨和硝酸铵这两种不同的商业氮源进行比较，首次评估了在深层发酵中使用未处理的菜籽粕作为枯草芽孢杆菌3-10生产伊枯草菌素A的氮源的可行性。观察到菜籽粕对伊枯草菌素A的生产有显著的促进作用，在70小时时达到了0.60 g/L的最大伊枯草菌素A浓度，分别比蛋白胨和硝酸铵培养基产生的浓度高20%和8.0倍。结果表明，菜籽粕对蛋白酶分泌有积极的诱导作用，有助于从低水溶性固体菜籽粕中释放可溶性蛋白质，以便在发酵过程中有效供应可用氮。此外，与未发酵的菜籽粕相比，发酵后的剩余残渣可作为更合适的动物饲料补充蛋白质来源，因为主要抗营养成分包括芥子碱、硫代葡萄糖苷及其降解产物异硫氰酸盐和恶唑烷硫酮的含量大幅降低。本研究所得结果证明了直接利用低成本菜籽粕作为氮源，通过枯草芽孢杆菌商业生产伊枯草菌素A和其他次级代谢产物的潜力。
