Recycled Lactobacillus pentosus biomass can regenerate biosurfactants after various fermentative and extractive cycles

Abstract

In this work cells of Lactobacillus pentosus, growing on 20 g/L of glucose for 15 h at 31 degrees C, were subjected to sequential fermentation and extraction processes with phosphate buffered saline (PBS) in order to study the capacity of L. pentosus to regenerate biosurfactants after various fermentative and extractive cycles. After a first extraction cycle, it was observed that, in absence of nutrients, L pentosus, dissolved in PBS, does not have the capacity to induce the formation of new biosurfactants, although the extraction process almost did not affect the cell viability. However, when this biomass was recycled and subjected to three sequential fermentative processes, in presence of fresh fermentative medium, with their respective extraction procedures, L. pentosus cells recovered its capacity to produce more biosurfactants, observing an increase in the biosurfactant/biomass ratio, achieving a total biosurfactant concentration of 2.7 g/L, being the highest reported at the moment in the literature for L pentosus growing on glucose. (C) 2018 Elsevier B.V. All rights reserved.