Artisanal tanneries: Potential application of inoculants formulated with lactic acid bacteria

Abstract

In artisanal tanneries, the skins are immersed in cereals fermented by natural microbial flora in order to reduce the pH of the skin, an essential condition for carrying out the final step. The environmental thermal variation alters the fermentation process and affects the quality of the final product. The aim of this work was to isolate lactic acid bacteria from cereals mixture fermented in an artisanal tannery and to evaluate in vitro the acidifying activity of the strains as a first step for the formulation of a starter culture. In most samples, a prevalence of cocci (95%) was observed with respect to bacilli. The best acidifying strains were identified by phenotypic and genotypic techniques as Enterococcus faecium CRL 1943 (rapid acidification at 37 °C) and Leuconostoc citreum CRL 1945 (high acidifying activity at 18 °C). In addition, the biomass production of the selected strains was analyzed at free and controlled pH (bioreactors 1.5 L). The production of biomass was optimal at controlled pH, with a higher growth (0.5-1.1 log units). Both strains were compatible, allowing their inclusion in a mixed culture. These lactic strains could contribute to the systematization of the tanning process.

Effect of culture parameters on the heat tolerance and inorganic polyphosphate accumulation by Lacticaseibacillus rhamnosus CRL1505, a multifunctional bacterium

“…This result may have been due to the final pH (4.0) reached at this point, the effect of which could have been detrimental to cell viability. Similar outcomes were reported by Polak-Berecka et al ( 2011 ) for L. rhamnosus E/N and other genera belonging to LAB such as Enterococcus faecium CRL1943 and Leuconostoc citreum CRL1945 (Correa Deza et al 2018 ). In contrast, different results were obtained for L. bulgaricus Q7 where the average growth rate and the final biomass were higher under free pH conditions (Ai et al 2017 ).…”