Chen Tianpeng, Liu Na, Ren Peifang, Xi Xun, Yang Leyun, Sun Wenjun, Yu Bin, Ying Hanjie, Ouyang Pingkai, Liu Dong, Chen Yong
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.
Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University, Nanjing, China.
Front Microbiol. 2019 Aug 2;10:1773. doi: 10.3389/fmicb.2019.01773. eCollection 2019.
Biofilms provide cells favorable growth conditions, which have been exploited in industrial biotechnological processes. However, industrial application of the biofilm has not yet been reported in , one of the most important platform strains, though the biofilm has been extensively studied for pathogenic reasons. Here, we engineered by overexpressing the gene, which successfully enhanced its biofilm formation under industrial aerobic cultivation conditions. Subsequently, a biofilm-based immobilized fermentation strategy was developed. L-threonine production was increased from 10.5 to 14.1 g/L during batch fermentations and further to 17.5 g/L during continuous (repeated-batch) fermentations with enhanced productivities. Molecular basis for the enhanced biofilm formation and L-threonine biosynthesis was also studied by transcriptome analysis. This study goes beyond the conventional research focusing on pathogenic aspects of biofilm and represents a successful application case of engineered biofilm to industrial processes.
生物膜为细胞提供了有利的生长条件，这已在工业生物技术过程中得到应用。然而，尽管出于致病原因对生物膜进行了广泛研究，但在最重要的平台菌株之一中，生物膜的工业应用尚未见报道。在此，我们通过过表达基因对进行了工程改造，该基因在工业好氧培养条件下成功增强了其生物膜形成能力。随后，开发了一种基于生物膜的固定化发酵策略。在分批发酵过程中，L-苏氨酸产量从10.5克/升提高到14.1克/升，在连续（重复分批）发酵过程中进一步提高到17.5克/升，同时生产率得到提高。还通过转录组分析研究了生物膜形成增强和L-苏氨酸生物合成的分子基础。本研究超越了传统上对生物膜致病方面的研究，代表了工程化生物膜在工业过程中的一个成功应用案例。
