Efficient 2,3-butanediol production from whey powder using metabolically engineered Klebsiella oxytoca

• DOI: 10.1186/s12934-020-01420-2
• Publication Date: 2020-08-10T18:03:56Z
• Authors: Wensi Meng; Yongjia Zhang; Menghao Cao; Wen Zhang; Chuanjuan Lü; Chunyu Yang; Chao Gao; Ping Xu; Cuiqing Ma
• Keywords: 0106 biological sciences; 2. Zero hunger; Klebsiella oxytoca PDL-0; Research; Klebsiella oxytoca; Lactose; Microbiology; 01 natural sciences; QR1-502; Gene Knockout Techniques; Bioreactors; Metabolic Engineering; Batch Cell Culture Techniques; Whey; Fermentation; 2,3-Butanediol; Powders; Butylene Glycols; Metabolic engineering

Abstract Background Whey is a major pollutant generated by the dairy industry. To decrease environmental pollution caused by the industrial release of whey, new prospects for its utilization need to be urgently explored. Here, we investigated the possibility of using whey powder to produce 2,3-butanediol (BDO), an important platform chemical.

Results Klebsiella oxytoca strain PDL-0 was selected because of its ability to efficiently produce BDO from lactose, the major fermentable sugar in whey. After deleting genes pox, pta, frdA, ldhD, and pflB responding for the production of by-products acetate, succinate, lactate, and formate, a recombinant strain K. oxytoca PDL-K5 was constructed. Fed-batch fermentation using K. oxytoca PDL-K5 produced 74.9 g/L BDO with a productivity of 2.27 g/L/h and a yield of 0.43 g/g from lactose. In addition, when whey powder was used as the substrate, 65.5 g/L BDO was produced within 24 h with a productivity of 2.73 g/L/h and a yield of 0.44 g/g.

Conclusion This study demonstrated the efficiency of K. oxytoca PDL-0 for BDO production from whey. Due to its non-pathogenicity and efficient lactose utilization, K. oxytoca PDL-0 might also be used in the production of other important chemicals using whey as the substrate.