A novel biocatalyst, Enterobacter aerogenes LU2, for efficient production of succinic acid using whey permeate as a cost-effective carbon source

Hubert Szczerba,Adam Waśko,Elwira Komoń-Janczara,Zdzisław Targoński,Karolina Dudziak

doi:10.1186/s13068-020-01739-3

Abstract

BackgroundSuccinic acid (SA), a valuable chemical compound with a broad range of industrial uses, has become a subject of global interest in recent years. The bio-based production of SA by highly efficient microbial producers from renewable feedstock is significantly important, regarding the current trend of sustainable development.ResultsIn this study, a novel bacterial strain, LU2, was isolated from cow rumen and recognized as an efficient producer of SA from lactose. Proteomic and genetic identifications as well as phylogenetic analysis were performed, and strain LU2 was classified as an Enterobacter aerogenes species. The optimal conditions for SA production were 100 g/L lactose, 10 g/L yeast extract, and 20% inoculum at pH 7.0 and 34 °C. Under these conditions, approximately 51.35 g/L SA with a yield of 53% was produced when batch fermentation was conducted in a 3-L stirred bioreactor. When lactose was replaced with whey permeate, the highest SA concentration of 57.7 g/L was achieved with a yield and total productivity of 62% and 0.34 g/(L*h), respectively. The highest productivity of 0.67 g/(L*h) was observed from 48 to 72 h of batch fermentation, when E. aerogenes LU2 produced 16.23 g/L SA.ConclusionsThis study shows that the newly isolated strain E. aerogenes LU2 has great potential as a new biocatalyst for producing SA from whey permeate.

Highlights

Succinic acid (SA), a valuable chemical compound with a broad range of industrial uses, has become a subject of global interest in recent years
Succinate was commercially produced from n-butane through maleic anhydrate by a chemical process requiring the use of costly catalysts, and this process contributed to environmental problems [7, 8]
Identification of SA‐producing microorganisms from lactose To screen the succinate-producing microorganisms from lactose under anaerobic conditions, 50 bacterial isolates obtained from rumen samples were tested in bottle cultivation

Summary

Introduction

Succinic acid (SA), a valuable chemical compound with a broad range of industrial uses, has become a subject of global interest in recent years. The bio-based production of SA by highly efficient microbial producers from renewable feedstock is significantly important, regarding the current trend of sustainable development. Several renewable feedstocks are attractive for use as substrates in the microbial production of valuable bioproducts. Due to the high lactose content (> 80%) of whey permeate, which is recovered from cheese whey during the production of whey protein concentrate, this by-product can be an attractive, easy-to-use and low-cost substrate for succinate production [5, 15]. Whey permeate is an economically attractive feedstock, and it contains approximately 80% lactose as well as a high amount of micro- and macro-elements that lead to better cell growth [5, 15]. There is still little research on the effective use of this substrate as a sole carbon source for SA production

Methods

Results

Conclusion