Efficient production of l-lactic acid by an engineered Thermoanaerobacterium aotearoense with broad substrate specificity.

摘要: Background: Efficient conversion of lignocellulosic biomass to optically pure lactic acid is a key challenge for the economical production biodegradable poly-lactic acid. A recently isolated strain, Thermoanaerobacterium aotearoense SCUT27, promising as an efficient bacterium from due its broad substrate specificity. Additionally, strictly anaerobic and thermophilic characteristics suppress contamination other microoragnisms. Herein, we report significant improvements concentration yield in various derived sugars, achieved by carbon flux redirection through homologous recombination T. SCUT27. Results: SCUT27 was engineered block acetic formation pathway improve production. The genetic manipulation resulted 1.8 2.1 fold increase using 10 g/L glucose or xylose substrate, respectively. maximum L-lactic 0.93 g/g with optical purity 99.3% obtained designated LA1002, 50 which very close theoretical value (1.0 glucose). In particular, LA1002 produced at unprecedented up 3.20 xylan single without any pretreatment after 48 h fermentation. non-sterilized fermentative also carried out, achieving values 44.89 0.89 mixed sugar yield, Conclusions: Blocking increased dramatically. To our best knowledge, this performance fermentation on sole source, considering final concentration, time. addition, it should be mentioned that simultaneous normal sterilized cultivation. All these results used mutant indicated new candidate effective biomass.