This review explores the fundamental mechanisms behind sporulation, germination, and outgrowth of spore-forming bacteria, with a focus on how environmental conditions affect these processes. By detailing factors such as temperature, pH, and water activity, it examines how these elements influence transitions between vegetative growth, sporulation, and germination, as well as the quality of the spores produced, particularly their resistance and germination ability. The review also addresses the heterogeneity observed in the spore-forming bacteria life cycle, particularly variation in germination and outgrowth responses, as well as phenomena such as cannibalism, competence, and biofilm formation. It highlights the significance of these factors for understanding the persistence and dispersal of spores across different environments. The implications of these mechanisms are particularly relevant for the food industry, where effective management of contamination by spores is critical for controlling food spoilage and safety. It also has important implications for biotechnology. A better understanding of how environmental conditions influence spore properties can help optimize the production of spores with specific resistance or germination traits suited to their intended applications.

View full abstract

Aquaculture disease management, historically reliant on antibiotics and synthetic chemicals, requires sustainable and effective alternatives for microbial control. One of the strategies is by utilizing bioactive compound from natural product. However, the current method of extraction requires a huge amount of solvent and cause detrimental to the end product. Thus, this lead to extraction strategy using supercritical carbon dioxide (SC-CO₂). This minireview explores the application of SC-CO₂ extraction as a green technology for disease management in aquaculture. SC-CO₂ operates as a clean, selective solvent, efficiently isolating high-purity bioactive compounds from plant, algal, and fishery by-products without toxic solvent residues. Unlike conventional extraction methods, SC-CO₂ preserves thermolabile antimicrobial compounds, yielding extracts with enhanced bioactivity against aquatic pathogens. By providing effective, natural alternatives to antibiotics, SC-CO₂ technology directly contributes to disease control in aquaculture. The integration of SC-CO₂-derived natural products represents a transformative strategy for sustainable microbial control while aligning with the principles of environmental safety and food security.

View full abstract

House dust was simultaneously collected from bedding and bedroom floors in 40 homes between 2021 and 2022, and the fungal flora was examined using a culture-based method. Although there was no significant difference in the total fungal count between bedding and floors, several fungi taxa were found to be significantly more abundant in bedding. In particular, Alternaria spp. and Aspergillus section Versicolores were disproportionately more prevalent in bedding samples. Furthermore, compared to previous studies, an increase in wood flooring was observed in the sampled homes, suggesting a potential suppression of xerophilic house dust fungi such as Aspergillus section Restricti.

View full abstract

Establishing a technique that can inactivate highly heat-resistant bacterial spores under milder conditions would be of great benefit in terms of ensuring food safety and extending shelf life. In this study, we investigated the combined effect of hydrostatic pressure processing (HPP) and the addition of a food emulsifier (sucrose fatty acid ester; SE) on two bacterial spores (Bacillus spizizeni and Alicyclobacillus acidoterrestris）. The results demonstrated that supplementing HPP at 50 MPa with SE significantly reduced the heat resistance of both spores. In particular, A. acidoterrestris spores were more sensitive to treatment than the B. spizizenii spores. HPP combined with SE resulted in a 4 log reduction in A. acidoterrestris spores, whereas a 2 log reduction was observed for B. spizizenii spores. Additionally, heat treatment following HPP combined with SE further inactivated B. spizizenii spores by 0.5 log. To evaluate practical applications in the food industry, the effect of the SE-HPP combination in the presence of glucose, a representative nutrient component, was also assessed. The findings indicated that the heat resistance of A. acidoterrestris spores was reduced, with viable spore counts falling below the detection limit (less than 10 CFU/mL）. These results suggest that this approach may enhance the efficiency of HPP in bacterial spore control for food processing applications.

View full abstract