Efficient production of 5-aminolevulinic acid from low-cost and sustainable bioresources of corn by engineered Corynebacterium glutamicum

Abstract

5-Aminolevulinic acid (5-ALA) has drawn intensive attention owing to its potential applications in agriculture, medicine and other fields, but the high production cost limits its large-scale application. Cheap and renewable bioresources derived from corn was used to lower the cost of culture medium for 5-ALA production by engineered Corynebacterium glutamicum. Pretreated corn steep liquor was an ideal alternative to yeast extract in that the final 5-ALA titer reached 1.46 g/L at a dosage of 15 g/L, which was 22.07 % higher than that of the yeast powder group. Notably, pretreated corn gluten meal was also a good substitute for yeast extract, and the above feedstocks will reduce the nitrogen source cost by 91.95 % and 84.38 %, respectively. Furthermore, C. glutamicum exhibited different growth forms during the fermentation process, which was related to the production of 5-ALA. This may provide basis for studying the regulation mechanism of bacterial growth and fermentative production of 5-ALA.