Development of a chemically defined medium for succinic acid production of mannheimia succiniciproducens MBEL55E

Abstract

The succinic acid bacteria, Mannheimia succiniciproducens MBEL55E are important industrial microorganisms because of their role in food, ion chelator and health-related agent markets. They require both carbohydrates as carbon sources and yeast extract or polypeptone as nitrogen sources. But the heterogeneities of nitrogen sources in a complex medium make difficult to understand cell physiology and control metabolism of Mannheimia sp. MBEL55E. To overcome these problems, the chemically defined mediums (CDM) of M. succiniciproducens MBEL55E were completed by single-omission technique and Plackett-Burman design. The CDM made by single-omission technique for M succiniciproducens MBEL55E growth were composed of 12 L-amino acids, 7 vitamins and 2 nucleic acid bases to replace the yeast extract and polypeptone. Among the 21 nutritional requirements, L-met, L-cys, biotin, nicotinic acid, Ca-pantothenate and thiamine?HCI were the essential nutrients to grow Mannheimia sp. MBEL55E. The CDM made by Plackett-Burman design for M. succiniciproducens MBEL55E growth contains 8 L-amino acids, 7 vitamins and 3 nucleic acids as the nitrogen sources. Among the 18 nutritional requirements, essential L-amino acids and vitamins were same those of the CDM made by single-omission technique. But some components worked as the growth stimulators were a little different comparing to growth stimulators in CDM completed by single-omission technique. And growth rate and succinic acid production of M. succiniciproducens MBEL55E in the CDM made by single-omission technique were higher than those of M. succiniciproducens MBEL55E in CDM made by Plackett-Burman design. Consequently these well defined media showed the possibilities not only to produce succinic acid economically and eco-friendly but also to overcome the metabolic limitation of M. succiniciproducens MBEL55E.