Low cell surface hydrophobicity is one of the key factors for high butanol tolerance of Lactic acid bacteria

Abstract

Highly butanol‐tolerant strains have always been attractive because of their potential as microbial hosts for butanol production. However, due to the amphiphilic nature of 1‐butanol as a solvent, the relationship between the cell surface hydrophobicity and butanol resistance remained ambiguous to date. In this work, the quantitatively estimated cell surface hydrophobicity of 74 Lactic acid bacteria strains were juxtaposed to their tolerance to various butanol concentrations. The obtained results revealed that the strains’ hydrophobicity was inversely proportional to their butanol tolerance. All highly butanol‐resistant strains were hydrophilic (cell surface hydrophobicity<1%), whereas the more hydrophobic the strains were, the more sensitive to butanol they were. Furthermore, cultivation at increasing butanol concentrations showed a clear tendency to decrease the level of hydrophobicity in all tested organisms, thus suggesting possible adaptation mechanisms. Purposeful reduction of cell surface hydrophobicity (by removal of S‐layer proteins from the cell envelope) also led to an increase of butanol resistance. Since the results covered 23 different Lactic acid bacteria species of seven genera, it could be concluded that regardless of the species, the lower degree of cells’ hydrophobicity clearly correlates with the higher level of butanol tolerance.

Isolation and characterization of lactic acid bacteria from sugarcane waste

“…As a result, this shows that all three isolates in this study possessed the hydrophilic nature of the cell surface. This is supported by several studies where L. lactis, L. paracasei, L. plantarum, L. fermentum, L. casei, and L. rhamnosus were found to have hydrophilic surfaces (Bhanwar et al, 2014;Sadrani et al, 2014;Petrova et al, 2019).…”

Butanol Tolerance of Lactiplantibacillus plantarum: A Transcriptome Study

“…Butanol stress alters first of all the content and structure of the cell envelope. The results from the differential gene expression showed that L. plantarum most probably increases the production of exopolysaccharides (EPS) to build up a physical barrier between the solvent and the cell wall, as well as to increase the cell envelope hydrophilicity, which has been shown to enhance butanol resistance [ 34 ]. Six DEGs with FC between +2.0 and +3.4 responsible for EPS synthesis are overexpressed only in Ym1: wzx gene encoding oligosaccharide flippase (lp_2099), wzy for polysaccharide polymerase (lp_2101), and three genes encoding different ‘polysaccharide biosynthesis’ proteins (lp_2108, lp_1221, and lp_1225), well-characterized as part of the cps gene clusters in L. plantarum WCFS1 [ 39 ].…”

“…L. plantarum is a species that participates in lactic acid fermentation of numerous beverages and foods, including wine, yoghurt, boza, sourdough, sauerkraut, and sausages [ 32 , 33 , 34 ], and is typically resistant to environmental stress caused by acidic pH, extremes in temperature, osmotic pressure, oxygen, starvation, and high alcohol concentrations [ 35 , 36 ]. Selected strains of L. plantarum can grow at butanol concentrations up to 3–4% ( v / v ) [ 34 , 37 ]. Despite these promising data, the reasons for the butanol resistance of L. plantarum have been studied very little on a genetic level and remain elusive [ 38 ].…”

Physicochemical and Functional Characterization of Newly Designed Biopolymeric-Based Encapsulates with Probiotic Culture and Charantin

“…The resulting intestinal chyme was incubated (37 • C, pH 7) for 2 h. At the end of each stage, aliquots of each sample (1 mL) were diluted in 9 mL of sterile peptone water (0.2%, w/v) and placed in a stomacher for 30 s. The bacterial count was obtained by serially diluting the Foods 2021, 10, 2677 5 of 20 suspensions, followed by incubation in MRS agar plates at 37 • C for 48 h. CT content was determined via UV-Vis spectrophotometry at wavelength 281 nm following the method described in Section 2.5.2. The surface hydrophobicity of the free and encapsulated bacteria cells was determined using the microbial adhesion to hydrocarbons method according to Petrova et al [28], with some modifications. The microparticles were mixed with a sodium phosphate buffer (0.4 M) solution and stirred to allow the release of bacteria cells.…”