基于工程化盐单胞菌的下一代工业生物技术

Engineering Halomonas spp.for next generation industrial biotechnology(NGIB)

我国是工业生物技术大国,拥有世界上最大的发酵产业,但传统发酵需要灭菌操作,发酵过程高耗能、耗淡水且不能连续,导致生产成本偏高,无法与化学工业竞争。因此,急需开发下一代工业生物技术(NGIB)来克服这些缺点。NGIB利用盐单胞菌等极端微生物作为底盘细胞,具有发酵不需灭菌、节能节水、设备投资少、产物终浓度高、分离过程简单等优点。本文围绕下一代工业生物技术的发展过程,系统介绍了近年来在技术优势强化,生物元件和工具开发如Porin启动子系统、CRISPRi系统、CRISPR-Cas9系统等,新产物合成如聚(3-羟基丁酸-co-3-羟基戊酸)(PHBV)、聚(3-羟基丁酸-co-4-羟基丁酸)(P3HB4HB)、表面活性剂蛋白等,以及PHA分离过程优化、发酵工艺放大、废水循环利用等方面取得的最新进展。随着合成生物学发展和应用,基于工程化盐单胞菌的下一代工业生物技术体系正在不断完善,优势也愈加明显。下一代工业生物技术将为大幅提升绿色生物制造的竞争力提供强力支撑。

China is a country with the largest industrial biotechnology capacity especially fermentation.However,it requires complicated sterilization procedures,high consumption of fresh water and energy,and expensive wastewater treatment processes.Therefore,it is urgent to develop the"Next Generation Industrial Biotechnology(NGIB)".The NGIB based on Halomonas spp.has many advantages,including:(1)energy-saving:no need for sterilization at high temperature and high pressure;(2)water-saving:use seawater instead of fresh water,and water can be recycled;(3)time-saving:production process can be continuous;(4)less investment in equipment:no need to use stainless steel fermentation system,instead,plastic,ceramics or even cement can be used as bioreactors;(5)high concentration of final product,bacteria can produce products at a high concentration;(6)simplification of separation process:increase bacterial volume or surface charge,which is conducive to gravity or self-flocculation precipitation.Based on the newly developed‘Next Generation Industrial Biotechnology',this paper systematically introduces the latest progress in recent years in the fields such as strengthening technical advantages,development of biobricks and control parts including the porin promoter library,CRISPRi,CRISPR/Cas9 gene editing system,production of new products including poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV),Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)(P3HB4HB)and Bio-surfactant Protein PhaP,optimization of separation process,scale up of fermentation processes,and recycling of wastewater.With the application of synthetic biology,the efficiency of NGIB has been continuously improved,and its advantages are obvious.Nevertheless,NGIB also faces some technical challenges,particularly treatment of salt containing wastewater.NGIB will further improve the recycling strategy of high salt wastewater,develop control modules under high cell density fermentation conditions,strengthen the design of low-cost substrate utilization ways,expand the scale and application fields,and achieve the mass production of various chemicals.The continuous improvement of NGIB will provide strong support for the competitiveness of green bio-manufacturing.