The synthesis of n-caproate from lactate: a new efficient process for medium-chain carboxylates production

Sci Rep. 2015 Sep 25:5:14360. doi: 10.1038/srep14360.

Abstract

A unique microbiome that metabolizes lactate rather than ethanol for n-caproate production was obtained from a fermentation pit used for the production of Chinese strong-flavour liquor (CSFL). The microbiome was able to produce n-caproate at concentrations as high as 23.41 g/L at a maximum rate of 2.97 g/L/d in batch trials without in-line extraction. Compared with previous work using ethanol as the electron donor, the n-caproate concentration increased by 82.89%. High-throughput sequencing analysis showed that the microbiome was dominated by a Clostridium cluster IV, which accounted for 79.07% of total reads. A new process for n-caproate production was proposed, lactate oxidation coupled to chain elongation, which revealed new insight into the well-studied lactate conversion and carbon chain elongation. In addition, these findings indicated a new synthesis mechanism of n-caproate in CSFL. We believe that this efficient process will provide a promising opportunity for the innovation of waste recovery as well as for n-caproate biosynthesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bioreactors
  • Caproates / metabolism*
  • Ethanol / metabolism
  • Fermentation
  • Lactic Acid / metabolism*
  • Microbiota

Substances

  • Caproates
  • Lactic Acid
  • Ethanol