Rational reformation of Corynebacterium glutamicum for producing L-lysine by one-step fermentation from raw corn starch

Abstract

This article focuses on engineering Corynebacterium glutamicum to produce L-lysine efficiently from starch using combined method of "classical breeding" and "genome breeding." Firstly, a thermo-tolerable L-lysine-producing C. glutamicum strain KT 45-6 was obtained after multi-round of acclimatization at high temperature. Then, amylolytic enzymes were introduced into strain KT 45-6 , and the resultant strains could use starch for cell growth and L-lysine production except the strain with expression of isoamylase. In addition, co-expression of amylolytic enzymes showed a good performance in starch degradation, cell growth and L-lysine production, especially co-expression of α-amylase (AA) and glucoamylase (GA). Moreover, L-lysine yield was increased by introducing AA-GA fusion protein (i.e., strain KT 45-6 S-5), and finally reached to 23.9 ± 2.3 g/L in CgXII IP M-medium. It is the first report of an engineered L-lysine-producing strain with maximum starch utilization that may be used as workhorse for producing amino acid using starch as the main feedstock. Key points• Thermo-tolerable C. glutamicum was obtained by temperature-induced adaptive evolution.• The fusion order between AA and GA affects the utilization efficiency of starch. • C. glutamicum with starch utilization was constructed by optimizing amylases expression.

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Microbial synthesis of bacitracin: Recent progress, challenges, and prospects

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Prospective bacterial and fungal sources of hyaluronic acid: A review

“…Corynebacterium glutamicum is a non-pathogenic and non-sporulating bacteria classified as GRAS. It is widely used for large-scale production of various organic compounds, such as organic acids [262] , [263] , alcohols [264] , [265] , [266] and pyrazine [267] , [268] , [269] , and has a special significance in the industrial production of amino acids [270] , [271] , [272] , [273] , [274] . In a detailed survey, the variety of applications of this organism in industry was analyzed by Becker [275] .…”