The Phenotypic Analysis of Lactobacillus plantarum shsp Mutants Reveals a Potential Role for hsp1 in Cryotolerance

In this study, a reverse genetics approach was undertaken to characterize the role of two small heat shock proteins in the stress response of L. plantarum, a versatile probiotic with remarkable relevance for both biomedical and industrial applications. sHSP have been found in almost all organisms, from prokaryotes to eukaryotes. This ubiquity points to fundamental biological roles. Several organisms possess more than one sHSP. Yet, the number of sHSP-encoding genes is quite variable, being influenced by factors including lifestyle and genome size (Han et al., 2008; Guzzo, 2012). In eukaryotes, multiple sHSPs are common in many groups. Among microbes, those species living in more adverse and changeable environments tend to have larger repertoires of sHSPs. This hints to the crucial role of sHSPs in bacterial survival, facilitating the colonization of diverse and adverse niches. Lactobacilli typically have a single sHSP and L. plantarum is probably the only probiotic LAB that possesses such a large sHSP family (Han et al., 2008; Capozzi et al., 2011a). The presence of three different shsp genes might reflect its genome size (which is larger than the average for this group), as well as its ecological flexibility, thus allowing for an effective response to diverse environmental conditions. In order to characterize the contribute of the single sHSPs to stress tolerance, we compared the growth of WT and KO strains under different types of abiotic stress conditions, focusing on th...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research