Category Archives: Bacterial Spores

Research – From Germination to Stagnation: Sodium Diacetate’s Impact on Clostridium perfringens Spores

Posted on December 7, 2024 by | Leave a comment

Wiley Online

ABSTRACT

Sodium diacetate is recognized for its high efficiency as a preservative, demonstrating strong antibacterial properties that help extend the shelf life of food products. However, it is still unclear how it influences spores. This research investigated the influence of sodium diacetate on the germination and outgrowth stage in the revival process of Clostridium perfringens (C. perfringens) spores. The germination and outgrowth rate of spores after sodium diacetate treatment were measured. The changes of spore inner membrane were monitored by laser confocal microscope, electron scanning microscope and macromolecular leakage. The interaction between sodium diacetate and DNA was investigated by EB fluorescence probe, and the finding was verified by the outgrowth of spores in ham sausage. An investigation into the effects of sodium diacetate treatment on the biological activity, inner membrane permeability, morphology, and DNA integrity of spores devoid of both the coat and cortex revealed that sodium diacetate significantly hindered the transition of germinated spores into vegetative cells. In the presence of sodium diacetate, C. perfringens spores underwent germination, characterized by the hydrolysis of the spore cortex and the disassembly of the spore coat. As the spores advanced into the outgrowth phase, sodium diacetate penetrated their structure, causing damage to the inner membrane and compromising DNA integrity. Moreover, sodium diacetate was demonstrated to effectively inhibit spore outgrowth in ham sausage. This study provided theoretical guidance and references for the application of sodium diacetate in food to control the germination and outgrowth of spore-forming bacteria.

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Posted in Bacterial Spores, Clostridium, Clostridium perfringens, Food Microbiology Research, Food Technology, Research, Spores, Technology

Research – Microbial food spoilage: impact, causative agents and control strategies

Posted on August 14, 2024 by | Leave a comment

Nature

Abstract

Microbial food spoilage is a major contributor to food waste and, hence, to the negative environmental sustainability impacts of food production and processing. Globally, it is estimated that 15–20% of food is wasted, with waste, by definition, occurring after primary production and harvesting (for example, in households and food service establishments). Although the causative agents of food spoilage are diverse, many microorganisms are major contributors across different types of foods. For example, the genus Pseudomonas causes spoilage in various raw and ready-to-eat foods. Aerobic sporeformers (for example, members of the genera Bacillus, Paenibacillus and Alicyclobacillus) cause spoilage across various foods and beverages, whereas anaerobic sporeformers (for example, Clostridiales) cause spoilage in a range of products that present low-oxygen environments. Fungi are also important spoilage microorganisms, including in products that are not susceptible to bacterial spoilage due to their low water activity or low pH. Strategies that can reduce spoilage include improved control of spoilage microorganisms in raw material and environmental sources as well as application of microbicidal or microbiostatic strategies (for example, to products and packaging). Emerging tools (for example, systems models and improved genomic tools) represent an opportunity for rational design of systems, processes and products that minimize microbial food spoilage.

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Posted in Bacillus, Bacterial Spores, Food Spoilage, Mesophilic Aerobes, Microbial Spoilage, Spores

Research – Inactivation of Bacillus cereus Spores and Vegetative Cells in Inert Matrix and Rice Grains Using Low-Pressure Cold Plasma

Posted on July 21, 2024 by | Leave a comment

MDPI

Abstract

This study investigated the effects of low-pressure cold plasma on the inactivation of Bacillus cereus vegetative cells and spores in an inert matrix (borosilicate glass slide) and in rice grains, using oxygen as ionization gas. Greater reductions in B. cereus counts were observed in vegetative cells rather than spores. The experimental data obtained show that both the power of the plasma treatment and the matrix proved to be determining factors in the inactivation of both the spores and vegetative cells of B. cereus. To characterize the inactivation of B. cereus, experimental data were accurately fitted to the Weibull model. A significant decrease in parameter “a”, representing resistance to treatment, was confirmed with treatment intensification. Furthermore, significant differences in the “a” value were observed between spores in inert and food matrices, suggesting the additional protective role of the food matrix for B. cereus spores. These results demonstrate the importance of considering matrix effects in plasma treatment to ensure the effective inactivation of pathogenic microorganisms, particularly in foods with low water activity, such as rice. This approach contributes to mitigating the impact of foodborne illnesses caused by pathogenic microorganisms.

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Posted in Bacillus, Bacillus cereus, Bacterial Spores, Cold Atmospheric Plasma, Cold Plasma, Food Microbiology Research, Research, Spores

Research – Inactivation of Alicyclobacillus acidoterrestris in apple juice using pulsed light

Posted on May 21, 2024 by | Leave a comment

Science Direct

We aimed to investigate the effect of pulsed light (PL) on inactivating Alicyclobacillus acidoterrestris in apple juice, the mechanism behind the inactivation, and the resultant effects on the quality of the juice. Our results showed that PL had a good inactivation effect on both spores and vegetative cells of A. acidoterrestris in apple juice, with a reduction of 3.5 ± 0.1 and 2.1 ± 0.1 log CFU/mL, respectively, following 3 s of treatment. This effect was better when lower concentrations of apple juice and lower liquid layer depths were used. Transmission electron microscopy (TEM) showed that the morphology and structure of A. acidoterrestris spores did not change significantly before and after treatment. When we compared the dipicolinic acid (DPA) release rate and death rate of the spores, we hypothesized that PL might have damaged the cortical proteins on A. acidoterrestris that are associated with the resistance of the spores, thus leading to their death. However, TEM revealed that the cell membranes of vegetative cells of A. acidoterrestris were intact and smooth before the treatment, but significantly wrinkled afterward. Raman spectroscopy revealed that the main targets of PL on A. acidoterrestris vegetative cells were: amide I on the proteins, nucleic acids [adenine(A) and guanine (G), in particular] and DNA (O–P–O‾ stretching) structures, and lipids (C–H2 deformation). The PL treatment increased the sugar content significantly, while having little to no effect on the other basic physicochemical parameters of apple juice.

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Posted in Alicyclobacillus, Bacterial Spores, Food Microbiology Research, Food Technology, Pulsed Light, Research, Technology

Research – Inactivation mechanism of phenyllactic acid against Bacillus cereus spores and its application in milk beverage

Posted on May 19, 2024 by | Leave a comment

Science Direct

Phenyllactic acid (PLA) as a natural phenolic acid exhibits antibacterial activity against non-spore-forming bacteria, while the inhibitory effect against bacterial spore remained unknown. Herein, this study investigated the inactivation effect of PLA against Bacillus cereus spores. The results revealed that the minimum inhibitory concentration of PLA was 1.25 mg/mL. PLA inhibited the outgrowth of germinated spores into vegetative cells rather than germination of spores. PLA disrupted the spore coat, and damaged the permeability and integrity of inner membrane. Moreover, PLA disturbed the establishment of membrane potential due to the inhibition of oxidative metabolism. SEM observations further visualized the morphological changes and structural disruption caused by PLA. Besides, PLA caused the degradation of DNA of germinated spores. Finally, PLA was applied in milk beverage, and showed promising inhibitory effect against B. cereus spores. This finding could provide scientific basis for the application of PLA against spore-forming bacteria in food industry.

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Posted in Bacillus, Bacillus cereus, Bacterial Spores, Food Microbiology Research, Food Technology, Phenyllactic Acid, Research, Technology

RASFF Alert -Streptomyces soil-based spores and bacteriophage blend

Posted on January 26, 2024 by | Leave a comment

RASFF

Unauthorised novel food ingredients Streptomyces soil-based spores and bacteriophage blend in a food supplement from the United States in Slovenia

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Posted in Bacterial Spores, Bacteriophage, food contamination, food handler, Food Hazard, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, food recall, Food Safety, Food Safety Alert, Food Safety Management, Food Safety Regulations, Food Testing, Phage, RASFF, Spores, Streptomyces

RASFF Alert – Spore Forming Bacteria – Duck Confit

Posted on November 3, 2023 by | Leave a comment

RASFF

Possible presence of spore-forming bacteria (possibly bacillus spp.) in Confit de Canad from Bulgaria in Denmark

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Posted in Bacillus, Bacterial Spores, food contamination, food handler, Food Hazard, Food Hygiene, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Food Pathogen, Food Quality, food recall, Food Safety, Food Safety Alert, Food Safety Management, Food Safety Regulations, Food Testing, RASFF, Spores

Research – Post-Cooking Growth and Survival of Bacillus cereus Spores in Rice and Their Enzymatic Activities Leading to Food Spoilage Potential

Posted on February 2, 2023 by | Leave a comment

MDPI

Abstract

Bacillus cereus strains vary in their heat resistance, post-processing survival and growth capacity in foods. Hence, this study was carried out to determine the effect of cooking on the survival and growth of eight B. cereus spores in rice at different temperatures in terms of their toxigenic profiles and extracellular enzyme activity. Samples of rice inoculated with different B. cereus spores were cooked and stored at 4 °C, 25 °C and 30 °C for up to 7 days, 48 h and 24 h, respectively. Out of eight B. cereus strains, four and three spore strains were able to grow at 30 °C and 25 °C post-cooking, respectively. Rapid growth was observed after a minimum of 6 h of incubation at 30 °C. All strains possessed proteolytic activity, whereas lipolytic and amylolytic activities were exhibited by 50% and 12.5% of the strains, respectively. The post-cooking survival and growth capacity of the B. cereus strains appeared to be independent of their toxigenic profiles, whereas extracellular enzymatic activities were required for their vegetative growth. Due to the B. cereus spores’ abilities to survive cooking and return to their active cellular form, great care should be taken when handling ready-to-eat foods.

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Posted in Bacillus, Bacillus cereus, Bacterial Spores, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Research, Food Microbiology Testing, microbial contamination, Microbial growth, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Spores

RASFF Alert – Clostridium perfringens – Dried Natural Casings

Posted on December 30, 2022 by | Leave a comment

RASFF

Detection of Salmonella and Clostridium perfringens in dried natural casings from Portugal in France

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Posted in Bacterial Spores, Clostridium, Clostridium perfringens, food contamination, food handler, Food Hazard, Food Hygiene, Food Illness, Food Inspections, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Food Pathogen, food recall, Food Safety, Food Safety Alert, Food Safety Management, Food Safety Regulations, Food Testing, RASFF, Spores

What Are Common Food Poisoning Pathogen Incubation Periods?

Posted on September 21, 2022 by | Leave a comment

Food Safety Gov

Check out the fact sheets at the link above.

Bacteria and Viruses

Bacteria and viruses are the most common cause of food poisoning. The symptoms and severity of food poisoning vary, depending on which bacteria or virus has contaminated the food.

To prevent illness, always follow the food safety steps: clean, separate, cook, and chill. Other prevention tips for specific bacteria and viruses are included below.

The bacteria and viruses that cause the most illnesses, hospitalizations, or deaths in the United States are described below and include:

Other important bacteria and viruses that cause foodborne illness include:

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Posted in Bacillus, Bacillus cereus, Bacteria, bacterial contamination, Bacterial Spores, Campylobacter, Clostridium, Clostridium botulinum, Decontamination Microbial, E.coli, Food Micro Blog, Food Microbiology, Food Microbiology Blog, Food Microbiology Testing, Hepatitis A, Listeria, Listeria monocytogenes, microbial contamination, Microbiological Risk Assessment, Microbiology, Microbiology Investigations, Microbiology Risk, Norovirus, Salmonella, Shigella, Staphylococcus aureus, Vibrio