Efficient whole cell catalysis for 5 aminovalerate production from L lysine by using engineered Escherichia coli with ethanol pretreatment
Microorganisms can utilize biomass to produce valuable chemicals, showing sustainable, renewable and economic advantages compared with traditional chemical synthesis. As a potential five carbon platform polymer monomer, 5 aminovalerate has been widely used in industrial fields such as clothes and disposable goods. Here we establish an efficient whole cell catalysis for 5 aminovalerate production with ethanol pretreatment. In this study, the metabolic pathway from L lysine to 5 aminovalerate was constructed at the cellular level by introducing L lysine a oxidase. The newly produced H2O2 and added ethanol both are toxic to the cells, obviously inhibiting their growth. Here, a promising strategy of whole cell catalysis with ethanol pretreatment is proposed, which greatly improves the yield of 5 aminovalerate. Subsequently, the effects of ethanol pretreatment, substrate concentration, reaction temperature, pH value, metal ion additions and hydrogen peroxide addition on the whole cell biocatalytic efficiency were investigated. Using 100 g/L of L lysine hydrochloride as raw material, 50.62 g/L of 5 aminovalerate could be excellently produced via fed batch bioconversion with the yield of 0.84 mol/mol. The results show that a fast, environmentally friendly and efficient production of 5 aminovalerate was established after introducing the engineered whole cell biocatalysts. This strategy, combined with ethanol pretreatment, can not only greatly enhance the yield of 5 aminovalerate but also be applied to the biosynthesis of other valuable chemicals.
Scientific Reports