Growth culture conditions and recovery method impact the yield of hyaluronic acid produced by genetically modified Escherichia coli strains

Abstract

Hyaluronic acid is a biopolymer present in a wide variety of biological structures and it is implied in multiple biochemical processes, this is why it has been suggested its artificial use to treat several illnesses and, also in cosmetology. Nowadays, recombinant bacteria seem to be the key for the biotechnological production of this molecule since non-pathogenic strains can be used and, in some cases, it could be expected to increase the production yields. Given that culture conditions have an impact on the generation of any microbial metabolite, in this work, we looked for the best culture conditions in the bioreactor. Then, we present the bioengineering analysis of hyaluronic acid production by two genetically modified strains of E. coli. We tested two plasmids and three physicochemical parameters in flasks. In this work, we demonstrated that the media composition, aeration, and the relation between agitation and volume, but the extra plasmid, impact the production of the biopolymer. Besides, it was determined the modified E. coli with genes PmHAS and kfiD is viable to produce up to 105 mg/L of hyaluronic acid in a culture media with a carbohydrate source, such as glycerol, and keeping an aeration ratio of 1.5 vvm. This last was corroborated using the carbazole method with modifications in the purification procedure of the produced acid.