TABLE 1.

Fermentation production of acetoin by recombinant Bacillus species.

Strain	Engineering strategy	Concentration (g/L)	Yield (g/g)	Productivity (g/[L h])	References
B. subtilis F126-2	Disrupting 2,3-butanediol dehydrogenase gene bdhA and overexpression of alsSD operon based on a uridine producing strain	60.48	/	1.26	Fan et al., 2018
B. subtilis BSA	Over-expression of 2,3-butanediol dehydrogenase in B. subtilis JNA 3-10, applying a two-stage pH control strategy	73.6	0.408	0.77	Zhang et al., 2014a
B. subtilis BMN	Moderate-expression of the water-forming NADH oxidase C in bdhA disrupted B. subtilis JNA 3-10	56.7	0.675	0.639	Zhang et al., 2014b
B. subtilis 168/pMA5-zwf	Over-expression of glucose-6-phosphate dehydrogenase G6PDH in B. subtilis 168	43.3	0.33	0.36	Bao et al., 2015
B. subtilis BS168D	Blocking of 2,3-butanediol dehydrogenase gene bdhA in B. subtilis 168	24.6	0.246	0.342	Zhang et al., 2017
B. subtilis ZB02	Over-expression of xylose transport protein AraE, xylose isomerase XylA, and xylulokinase XylB in B. subtilis 168ARSRCPΔacoAΔbdhA, using glucose, xylose, and arabinose as substrates	62.2	NRa	0.864	Zhang B. et al., 2016
B. subtilis BSK814A4	Deleting araR, bdhA, acoA and inserting a native xyl operon into genome-reduced B. subtilis strain BSK814	23.3	0.46	0.194	Yan et al., 2018
B. subtilis BSUW06	Overexpressing alsSD operon and deleting bdhA, acoA, and pta in B. subtilis 168	19.8	NR	0.566	Wang et al., 2012
B. subtilis PAR	Moderate enhancement of ALsR expression using promoter PbdhA in B. subtilis 168	41.5	0.35	0.43	Zhang X. et al., 2013
B. licheniformis WX-02ΔbudCΔacoR	Deleting budC and acetoin degradation transcriptional activator encoding gene acoR in B. licheniformis WX-02	78.79	0.31	0.58	Li et al., 2017
B. licheniformis MW3 (ΔbudCΔgdh)	Deleting budC and gdh in B. licheniformis MW3	64.4	0.412	2.378	This work

^aNR, not reported.