EngineeringBacillusfor efficient production of heterologous protein: current progress, challenge and prospect

Abstract

Summary Bacillus species are widely recognized as good industrial platform strains, which can produce a variety of valuable products including enzymes and functional proteins. Bacillus expression systems gain various competitive edges over other expression systems, with respect to nontoxicity, convenience for gene modification and high yield of target proteins. Recently, a number of Bacillus expression systems have been developed, and various strategies were conducted to improve the yields of target proteins. In this review, we focused on the strategies of host strain optimization for heterologous protein production, including secretion pathway optimization, RNA and protein stability enhancement, cell growth facilitation, genome streamlining and transcriptional regulator engineering. In addition, Bacillus spore surface display and food‐grade expression systems were developed to expand the application of Bacillus expression system in recent years. Finally, the challenges and prospects of Bacillus expression system were discussed regarding the recent progresses, challenges and trends in this field.

Unraveling the Underlying Heavy Metal Detoxification Mechanisms of Bacillus Species

“…One of the unique characteristics of Bacillus spp. is the formation of spores under extreme environments, which is usually triggered during a deficit of nutrients [ 48 , 49 ]. Owing to their resilient structures, spores are able to endure severe environmental stress such as desiccation, high temperature, humidity, as well as radiation [ 50 ].…”

High-Efficiency Secretion and Directed Evolution of Chitinase BcChiA1 in Bacillus subtilis for the Conversion of Chitinaceous Wastes Into Chitooligosaccharides

“…Heterologous expression is an effective strategy to increase the production of target proteins. As one of the most widely used expression systems, B. subtilis possesses many advantages such as a high growth rate, short fermentation period, easy genetic manipulation, and superior secretion capacity of recombinant proteins (Cui et al, 2018;Gu et al, 2018;Cai et al, 2019). Moreover, as one of the most widespread and powerful strategies for protein design, directed evolution plays a key role in enhancing the activity of target enzymes through the construction of mutant libraries and highthroughput screening (Porter et al, 2016).…”

Food‐Grade Expression and Characterization of a Dextranase from Chaetomium gracile Suitable for Sugarcane Juice Clarification

“…However, the strong autoflocculation and relatively long growth cycle of C. gracile lead to a low fermentation efficiency, and resulted in the high price of dextranase [11] . B. subtilis is one of the most used microbial cell factory for industrial food‐grade production of recombinant proteins, due to its superior capacity of protein secretion and nontoxicity characters [12] . Here, the aim of the present study was to investigate the production of a recombinant food‐grade DEX enzyme from C. gracile expressed in B. subtilis .…”

“…[11] B. subtilis is one of the most used microbial cell factory for industrial food-grade production of recombinant proteins, due to its superior capacity of protein secretion and nontoxicity characters. [12] Here, the aim of the present study was to investigate the production of a recombinant foodgrade DEX enzyme from C. gracile expressed in B. subtilis. The enzyme was purified and characterized, and fermentation conditions were optimized to maximize production in engineered B. subtilis strains.…”