Pulsed light (PL) inactivates microorganisms by UV-rich, high-irradiance and short time pulses (250 μs) of white light with wavelengths from 200 nm to 1100 nm. PL is applied for disinfection of food packaging material and food-contact equipment. Spores of seven Bacillus ssp. strains and one Geobacillus stearothermophilus strain and conidia of filamentous fungi (One strain of Aspergillus brasiliensis, A. carbonarius and Penicillium rubens) were submitted to PL (fluence from 0.23 J/cm to 4.0 J/cm) and UVC (at λ = 254 nm; fluence from 0.01 J/cm to 3.0 J/cm). One PL flash at 3 J/cm allowed at least 3 log-reduction of all tested microorganisms. The emetic B. cereus strain F4810/72 was the most resistant of the tested spore-forming bacteria. The PL fluence to 3 log-reduction (F) of its spores suspended in water was 2.9 J/cm and F was 0.21 J/cm, higher than F and F of spores of B. pumilus SAFR-032 2.0 J/cm and 0.15 J/cm, respectively), yet reported as a highly UV-resistant spore-forming bacterium. PL and UVC sensitivity of bacterial spores was correlated. Aspergillus spp. conidia suspended in water were poorly sensitive to PL. In contrast, PL inactivated Aspergillus spp. conidia spread on a dry surface more efficiently than UVC. The F of A. brasiliensis DSM1988 was 0.39 J/cm and F was 0.83 J/cm. The resistance of spore-forming bacteria to PL could be reasonably predicted from the knowledge of their UVC resistance. In contrast, the sensitivity of fungal conidia to PL must be specifically explored.
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http://dx.doi.org/10.1016/j.fm.2024.104518 | DOI Listing |
J Bacteriol
January 2025
College of Food Science and Nutritional Engineering, National Engineering Research Center for Fruit and Vegetable Processing, Key Laboratory of Fruit and Vegetable Processing of Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory for Food Non-Thermal Processing, China Agricultural University, Beijing, China.
Bacterial spores can remain dormant for years, but they maintain the ability to recommence life through a process termed germination. Although spore germination has been reviewed many times, recent work has provided novel conceptual and molecular understandings of this important process. By using as a model organism, here we thoroughly describe the signal transduction pathway and events that lead to spore germination, incorporating the latest findings on transcription and translation that are likely detected during germination.
View Article and Find Full Text PDFPlants (Basel)
December 2024
Department of Life Science, Health, and Health Professions, University of Rome "Link Campus", 00165 Rome, Italy.
Mandarin, one of the winter fruits commonly used in the preparation of foods and juices, is a fruit native to China and Southeast Asia. In this work, essential oils (EOs) obtained from by-products of the Blanco flavedo of five cultivars present and cultivated within the Botanical Garden of Palermo were chemically and biologically studied: 'Avana' (), 'Tardivo di Ciaculli' (), 'Bombajensis' (), 'Aurantifolia' (), and 'Padre Bernardino' (). The GC and GC-MS analysis performed on all the extracted samples clearly highlighted the notable presence of limonene, a characteristic hydrocarbon monoterpene of EOs of the genus.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun 130062, China.
Microbial attack, particularly fungal degradation of cellulose, is a leading cause of paper damage. To address fungal spores and the rising concern of microbial drug resistance, a nano-Germanium dioxide (GeO)/cetyltrimethylammonium bromide (CTAB) complex (nano-GeO/CTAB complex) with potent antibacterial properties was synthesized. Its inhibitory effects were evaluated against bacteria, including Gram-positive and Gram-negative , as well as fungi isolated from paper ( spp.
View Article and Find Full Text PDFFoods
December 2024
College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai 201306, China.
Spore-forming bacterial species pose a serious threat to food plants and healthcare facilities that use high-temperature processing and sterilizing techniques to sanitize medical equipment and food items. These severe processing conditions trigger sporulation, which is the process by which spore-forming bacteria, such as those of the and species, begin to produce spores, which are extremely resilient entities capable of withstanding adverse environmental circumstances. Additionally, these spores are resistant to a wide range of disinfectants and antibacterial therapies, such as hydrolytic enzymes, radiation, chemicals, and antibiotics.
View Article and Find Full Text PDFNat Commun
January 2025
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland.
In the spore-forming bacterium Bacillus subtilis transcription and translation are uncoupled and the translational machinery is located at the cell poles. During sporulation, the cell undergoes morphological changes including asymmetric division and chromosome translocation into the forespore. However, the fate of translational machinery during sporulation has not been described.
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