A newly isolated Enterobacter sp. strain produces 2,3-butanediol during its cultivation on low-cost carbohydrate-based substrates

Abstract

2,3-Butanediol (BDO) is an important platform chemical with wide range of applications in various industries. In the present study, a newly isolated wild Enterobacter sp. strain (FMCC-208) was evaluated towards its ability to produce BDO on media composed of sugars derived from sucrose refinery plant. Optimum values of temperature and pH as well as substrate inhibition were determined through batch experiments. The ability of the strain to convert various monosaccharides was also investigated. Maximum BDO concentration of 90.3 g l⁻¹ and 10 g l⁻¹ of acetoin were obtained during a fed-batch bioreactor experiment in with cane molasses and sucrose were employed as substrates. A high volumetric productivity was noted in a fed-batch experiment using molasses and sucrose as carbon source at T = 37°C, in which 73.0 g l⁻¹ of BDO together with 12.4 g l⁻¹ of acetoin were produced where 1.15 g l⁻¹ h⁻¹ of diol/acetoin were produced. In previously pasteurized media, 70.0 g l⁻¹ of BDO and 5.0 g l⁻¹ of acetoin were produced (yield = 0.39 g g⁻¹). Finally, besides BDO production, growth on molasses was accompanied by non-negligible decolorization (25–35%) of the residue. Therefore the strain is a promising candidate for the conversion of sucrose-based materials into BDO.

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