The underlying mechanism of bacterial spore germination: An update review

Abstract

Bacterial spores are highly resilient and universally present on earth and can irreversibly enter the food chain to cause food spoilage or foodborne illness once revived to resume vegetative growth. Traditionally, extensive thermal processing has been employed to efficiently kill spores; however, the relatively high thermal load adversely affects food quality attributes. In recent years, the germination-inactivation strategy has been developed to mildly kill spores based on the circumstance that germination can decrease spore-resilient properties.However, the failure to induce all spores to geminate, mainly owing to the heterogeneous germination behavior of spores, hampers the success of applying this strategy in the food industry. Undoubtedly, elucidating the detailed germination pathway and underlying mechanism can fill the gap in our understanding of germination heterogeneity, thereby facilitating the development of full-scale germination regimes to mildly kill spores. In this review, we comprehensively discuss the mechanisms of spore germination of Bacillus and Clostridium species, and update the molecular basis of the early germination events, for example, the activation of germination receptors, ion release, Ca-DPA release, and molecular events, combined with the latest research evidence. Moreover, high hydrostatic pressure (HHP), an advanced non-thermal food processing technology, can also trigger spore germination, providing a basis for the application of a germinationinactivation strategy in HHP processing. Here, we also summarize the diverse germination behaviors and mechanisms of spores of Bacillus and Clostridium species under HHP, with the aim of facilitating HHP as a mild processing technology with possible applications in food sterilization.

Microfluidic platform for microbial spore germination studies in multiple growth conditions

“…The next set of experiments consisted of investigating germination at various concentrations of L-alanine in more detail. The pathways involved in endospore germination have been extensively studied in the past few years and summarised in detail by Lyu et al (Lyu et al 2023). Briefly, receptors located in the inner membrane or cortex receive signals from germinants, eventually triggering germination.…”

“…The 4CMC device was then used to study the germination of B. subtilis spores in more detail upon exposure to a concentration gradient (1 μM, 100 μM, 10 mM and 1 M) of L-alanine (Video 2). L-alanine has been studied extensively, but not using methods that give direct single spore level information about germination events (Lyu et al 2023). The relative frequency distributions of the spore germination time, showing what fraction of the analysed spores germinated within each 5-minute interval, are displayed in Figure 3A-D.…”

Multi-Omics Insights into the Impact of Increased Litter Size on Sow Gut Microbiota: Unveiling the Role of Serotonin-Associated Microbiota in Fertility Enhancement

“…To our knowledge, base excision repair is a major pathway for the removal of endogenous and exogenous DNA damage caused by environmental stress [41][42][43]. Additionally, the upregulation spore formation suggests that the gut microbiota is adapting to environmental stress [44,45]. The metabolic burden of HRP sows, particularly in amino acid and energy metabolism (as illustrated in Fig.…”

Inactivation Effect of Germination Combined with Cold Plasma Treatment on Bacillus licheniformis Spores

“…Several studies in the scientific literature have reported the enhanced susceptibility of germinating spores to inactivation [8][9][10][11]. Spore germination can be triggered by exposure to various molecules such as amino acids, sugars, and cell wall muropeptides, which can bind to receptors on the inner spore membrane [12,13].…”