Nutritional requirements for Lactobacillus vini growth in sugarcane derivative substrate of ethanol fermentation

Abstract

Lactobacillus vini is a bacterial contaminant found in industrial environments of winemaking and fuel-ethanol fermentation. However, there has been no standard analysis of its physiology that can pinpoint its adaptive traits to these kinds of environments. In view of this lack of information, the aim of this study is to determine the nutritional factors that lead to the growth of L. vini in the industrial plants of fuel-ethanol. First of all, the limited growth of this bacterium was studied in the industrial substrate, which was improved by nutritional supplementation with amino acids, and its homofermentative status was confirmed. Metabolite analysis showed that citrate is a growth factor of paramount importance for this bacterium in industrial processes through pyruvate metabolization, and increases ATP production and biomass formation. Furthermore,e acetate uptake, either from the medium or generated from citrate metabolism, was assimilated for biomass production. Hence, a metabolic model was designed to describe the role of citrate and acetate in the growth of L. vini that could be tested on other lactobacilli.

Journey of the Probiotic Bacteria: Survival of the Fittest

“…In this case, hexoses would serve more as a generator of ATP at the substrate level in the oxidative phase of glycolysis since much of the carbon would be dissimilated as lactic acid that is extrude from the cell. In this case, the highest industrial biomass yield would depend on the presence of other carbon sources, such as peptides and amino acids, citrate and acetate that can provide intermediates for biosynthetic reaction rather than energy for ATP synthesis [ 102 , 111 ]. Thus, the production of a homofermentative probiotic from sugarcane juice or corn syrup, the cheapest sugar-containing industrial substrates on the planet, would most certainly require supplementation with these carbon-supplying molecules.…”

“…Some species can use the PK reaction without the oxidative phase of PPP sole to metabolize pentoses and composes the third group of classification called facultative heterofermentative ( Figure 3 c), which is homofermentive for hexoses and heterofermentive for pentoses [ 110 ]. There is also the very peculiar and, so far, exclusive case of the Lactobacillus vini species, which is homofermentive for both hexoses and pentoses [ 111 , 114 ]. Some LAB species were recently classified as fructophilic (BALF) [ 115 , 116 ].…”

Beyond the stress response: absence of RelA protein hampers the cell wall structuring and cell size in Liquorilactobacillus vini

“…Genetic and metabolic studies have been conducted on Liquorilactobacillus vini, formerly known as Lactobacillus vini, since its identi cation as quantitatively relevant bacterial species in the composition of the microbial population with in bioethanol industrial processes in Sweden and Brazil (Passoth et al 2007; Lucena et al 2010; de Lucena et al 2012; Mendonça et al 2016Mendonça et al , 2020da Silva et al 2019). Since then, research has focused on understanding the biological mechanisms responsible for the adaptation of this bacterium to the industrial environment.…”