Production of Butyrate from Lactate by a Newly Isolated Clostridium sp. BPY5

Abstract

Lactate-utilizing bacteria play important roles in the production of Chinese strongflavored liquor (CSFL). However, the identity of these bacteria and their lactate-utilizing properties are largely unknown. Here, a lactate-utilizing, butyrate-producing bacterium BPY5 was isolated from an old fermentation pit for CSFL production. The isolate represented a novel species belonging to Clostridium cluster XIVa of family Lachnospiraceae based on phylogenetic analysis using 16S rRNA gene sequences. Strain BPY5 could ferment lactate into butyrate as the major metabolic product. Butyrate was significantly formed at initial lactate concentration from 66 to 104 mM, but substantially declined when initial lactate exceeded 133 mM. At initial lactate concentration of 66 mM, lactate conversion was independent on initial pH from 5.5 to 7.0, but the conversion was completely inhibited when pH dropped below 4.8. Nevertheless, the inhibition on lactate conversion was largely relieved by the addition of acetate, suggesting that exogenous acetate could enhance lactate conversion at low pH condition. Additionally, lactate in CSFL-brewing wastewater was dramatically removed when inoculated with strain BPY5. These results implicate that the isolate may be applied for the industrial production of butyrate or the recovery of butyrate from lactatecontaining wastewater.

Improvement of n-caproic acid production with Ruminococcaceae bacterium CPB6: selection of electron acceptors and carbon sources and optimization of the culture medium

“…Lactate has also been described to generate the acetyl-CoA to provide the two carbon atoms for the acetate to n -butyrate elongation via reverse β-oxidation, in which the oxidation of lactate to pyruvate produces NADH and the conversion of pyruvate to acetyl-CoA with ATP generation. However formerly, propionate and butyrate are the major products, and few caproate is produced from lactate [ 4 , 15 ]. Recently, a series of studies showed that lactate (as ED) can be efficiently converted into CA with reactor microbiomes [ 16 , 17 ].…”

Complete genome sequence of Ruminococcaceae bacterium CPB6: A newly isolated culture for efficient n -caproic acid production from lactate

“…Ethanol has been proved to be the efficient reducing substrate for CA synthesis (Agler et al, 2012;Barker and Taha, 1942;Grootscholten et al, 2013). Lactate, as an energy-rich reducing compound, has generally been reported to be used to produce butyrate (Prabhu et al, 2012;Tao et al, 2016;Weimer and Moen, 2013). Only trace amount of CA production (0.26-0.48 g/L) from lactate have been reported for the fermentation with M. elsdenii (Marounek et al, 1989).…”

A Novel “Microbial Bait” Technique for Capturing Fe(III)-Reducing Bacteria

“…As for the deployed uncoated pumice slurries, lactate metabolism was observed in the absence of an electron acceptor (Fe(III); Figure 4B), suggesting the presence of other electron acceptors, such as insoluble manganese or sulfate minerals (Sousa et al, 2017;Novotnik et al, 2019), sorbed or precipitated from the spring water. Alternatively, fermentation of lactate could also occur in the absence of an electron acceptor (Oude-Elferink et al, 2001;Tao et al, 2016). This indicates that the source of the sulfate in the deployed Fe(III)-coated pumice slurries is most likely from the spring water well.…”