Metabolic Engineering of Bacillus licheniformis for Production of Acetoin

Abstract

Acetoin is a potential platform compound for a variety of chemicals. Bacillus licheniformis MW3, a thermophilic and generally regarded as safe (GRAS) microorganism, can produce 2,3-butanediol with a high concentration, yield, and productivity. In this study, B. licheniformis MW3 was metabolic engineered for acetoin production. After deleting two 2,3-butanediol dehydrogenases encoding genes budC and gdh, an engineered strain B. licheniformis MW3 (budC gdh) was constructed. Using fedbatch fermentation of B. licheniformis MW3 (budC gdh), 64.2 g/L acetoin was produced at a productivity of 2.378 g/[L h] and a yield of 0.412 g/g from 156 g/L glucose in 27 h. The fermentation process exhibited rather high productivity and yield of acetoin, indicating that B. licheniformis MW3 (budC gdh) might be a promising acetoin producer.

Development of a Conjugation-Based Genome Editing System in an Undomesticated Bacillus subtilis Strain for Poly-γ-glutamic Acid Production with Diverse Molecular Masses

“…subtilis KH2 using commonly used methods, a genetic engineering system based on conjugation was first developed in B. licheniformis MW3, a laboratory strain in which two REases in the type I restriction-modification system have been knocked out . pKVM1 is a temperature-sensitive knockout plasmid, which has been successfully transferred to B.…”

“…18 Considering it is difficult to genetically modify B. subtilis KH2 using commonly used methods, a genetic engineering system based on conjugation was first developed in B. licheniformis MW3, a laboratory strain in which two REases in the type I restriction-modification system have been knocked out. 27 pKVM1 is a temperature-sensitive knockout plasmid, which has been successfully transferred to B. licheniformis MW3 through conjugation (Figure S1a). Antibiotic-resistance cassettes in pKVM1 (Amp r and Em r ) were replaced by Km r , generating plasmid pKVMK3 (Figure S1b).…”

Metabolic engineering enables Bacillus licheniformis to grow on the marine polysaccharide ulvan

“…Consequently, in-depth characterization of the selected microbial production species is a prerequisite for strain optimization. The well-established biotechnological work horse Bacillus licheniformis is an attractive target to be investigated for the utilization of alternative algal derived biomasses: It produces a variety of enzymes to degrade plant materials, it is a generally recognized as safe (GRAS) strain, has a fast growth rate and is already of high industrial importance [ 22 ]. This bacterial cell factory naturally produces the extracellular protease subtilisin [ 23 ], which has been developed into industrial production due to its widespread use in detergents [ 24 ].…”

“…In addition, first processes that use B. licheniformis to convert plant biomass into valuable products have already been established. This includes metabolic engineering approaches which enabled the production of acetoin, 2,3-butanediol or lactic acid from kitchen waste or corncob molasses [ 22 , 25 – 27 ]. Furthermore, the production of extracellular proteins from algal feedstock [ 28 ] was already studied to broaden up the possible use of this bacterium in fermentation processes.…”

Identification and Validation of Four Novel Promoters for Gene Engineering with Broad Suitability across Species

“…P. denitrificans PD1222, a soil-denitrifying bacterium, is considered as one of the best sources for polyhydroxyalkanoate (PHA) production because the strain can accumulate high yield in the cells [18], and can use a wide variety of industrial wastes as carbon sources to produce target products [19,20]. B. licheniformis, as a generally regarded as a safe (GRAS) strain with the qualified characteristics of fast growth rate and strong sugar consumption, is usually used to produce 2,3-butanediol (BDO) [21], and is also a good chassis strain for the production of acetoin, a common additive in the food industry and a building block for chemical materials [22]. R. ornithinolytica can be used to produce 2,5-furandicarboxylic acid (FDCA), an important renewable biotechnological building block.…”