English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Background  2,3-Butanediol (2,3-BD), a platform and fuel bio-chemical, can be efficiently produced by  Klebsiella pneumonia ,  K. oxytoca , and  Serratia marcescens . However, these strains are opportunistic pathogens and not favorable for industrial application. Although some generally regarded as safe (GRAS) microorganisms have been isolated in recent years, there is still a demand for safe 2,3-BD producing strains with high productivity and yield under thermophilic fermentation.    Results   Bacillus licheniformis  strain 10-1-A was newly isolated for 2,3-BD production. The optimum temperature and medium pH were 50°C and pH 7.0 for 2,3-BD production by strain 10-1-A. The medium composition was optimized through Plackett–Burman design and response surface methodology techniques. With a two-stage agitation speed control strategy, 115.7 g/L of 2,3-BD was obtained from glucose by fed-batch fermentation in a 5-L bioreactor with a high productivity (2.4 g/L·h) and yield (94% of its theoretical value). The 2,3-BD produced by strain 10-1-A comprises (2 R ,3 R )-2,3-BD and  meso -2,3-BD with a ratio of nearly 1:1. The  bdh  and  gdh  genes encoding  meso -2,3-butanediol dehydrogenase ( meso -BDH) and glycerol dehydrogenase (GDH) of strain 10-1-A were expressed in  Escherichia coli  and the proteins were purified.  meso -2,3-BD and (2 R ,3 R )-2,3-BD were transformed from racemic acetoin by  meso -BDH and GDH with NADH, respectively.    Conclusions  Compared with the reported GRAS 2,3-BD producers,  B. licheniformis  10-1-A could thermophilically produce 2,3-BD with a high concentration, productivity and yield. Thus, the newly isolated GRAS strain 10-1-A might be a promising strain for industrial production of 2,3-BD. Two key enzymes for  meso -2,3-BD and (2 R ,3 R )-2,3-BD production were purified and further studied, and this might be helpful to understand the mechanism for 2,3-BD stereoisomers forming in  B. licheniformis .

A newly isolated Bacillus licheniformisstrain thermophilically produces 2,3-butanediol, a platform and fuel bio-chemical