Lactobacillus , Bifidobacterium and Lactococcus response to environmental stress: Mechanisms and application of cross‐protection to improve resistance against freeze‐drying

Abstract

The review deals with lactic acid bacteria in characterizing the stress adaptation with cross-protection effects, mainly associated with Lactobacillus, Bifidobacterium, and Lactococcus.It focuses on adaptation and cross-protection in Lactobacillus, Bifidobacterium, and Lactococcus, including heat shocking, cold stress, acid stress, osmotic stress, starvation effect, etc. Web of Science, Google Scholar, Science Direct, and Pubmed databases were used for the systematic search of literature up to the year 2020. The literature suggests that a lower survival rate during freeze-drying is linked to environmental stress. Protective pretreatment under various mild stresses can be applied to LAB which may enhance resistance in a strain-dependent manner. We investigate the mechanism of damage and adaptation under various stresses including heat, cold, acidic, osmotic, starvation, oxidative, and bile stress. Adaptive mechanisms include synthesis of stress-induced proteins, adjusting the composition of cell membrane fatty acids, accumulating compatible substances, etc. Next, we reveal the cross-protective effect of specific stress on the other environmental stresses. Freeze-drying is discussed from three perspectives including the regulation of membrane, accumulation of compatible solutes, and the production of chaperones and stress-responsive proteases. The resistance of lactic acid bacteria against technological stress can be enhanced via cross-protection, which improves industrial efficiency concerning the survival of probiotics. However, the adaptive responses and cross-protection are strain-dependent and should be optimized case-by-case.

Oral nanozyme-engineered probiotics for the treatment of ulcerative colitis

“…The animal experiments were approved by the Animal Care and Use Committee of Zhengzhou University (No. ZZU-LAC20211112 16 ).…”

“…15 Furthermore, the beneficial properties of probiotics are strain-dependent and often unique, and are inadequate to treat complex diseases. 16 Some strategies have been used to enhance the delivery capacity and efficacy of probiotics. Although genetic modification can endow probiotics with enhanced survival rates and special therapeutic functionalities, the potential risks of gene transfer to other intestinal bacteria cannot be ignored.…”

Protective effects of whey protein hydrolysate on Bifidobacterium animalis ssp. lactis Probio-M8 during freeze-drying and storage

“…The addition of exogenous osmoprotectants was particularly important during freezedrying and storage when the cell metabolism stops. In these situations, osmoprotectants act as intracellular components that reduce the effect of osmotic stress on the natural conformations of proteins by reducing the cytosol osmotic potential (Gao et al, 2022). Probiotic counts of selected microorganisms in nutrient agar media were a key metric for assessing product viability, stability, and quality.…”

Pre‐incubation conditions determine the fermentation pattern and microbial community structure in fermenters at mild hydrostatic pressure

“…Cross‐resistance refers to the microbial capacity to resist negative impacts of environmental stress potentially resulting from (a) pre‐incubation under other environmental stress conditions, for example, low to high temperature variation, non‐neutral pH, water activity, and salinity extremes; (b) differences in the growth stage of microbial cells and (c) starvation effects (Abe, 2007; Gao et al, 2022; Lanciotti et al, 1996; Scheyhing et al, 2004). In natural habitats, cross‐resistance develops from the exposure to local‐scale environmental gradients occurring due to tidal, seasonal, and depth variations (Johnson et al, 2009; Tholosan et al, 1999).…”

“…The stress-response associated with cross-resistance effects comprises adaptations at the cellular level such as accumulation of compatible solutes and salts, protein synthesis, and reorganization of cell membrane lipids (Kish et al, 2012). As well, it includes the modulation of metabolic pathways and growth rates (Gao et al, 2022) and ultimately the modification of microbial community functionality and composition due to differences in stress tolerance, energy investment, and exacerbated competition between microbial species (Rillig et al, 2015).…”