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ACA‐DC 0040 produced an antimicrobial agent, which was named thermophilin T, active against several lactic acid bacteria strains of different species and food spoilage bacteria, such as Clostridium sporogenes C22/10 and Cl. tyrobutyricum NCDO‐1754. The crude antimicrobial compound is sensitive to proteolytic enzymes and α‐amylase, heat‐stable (100 °C for 30 min), resistant to pH exposure at pH 1–12 and demonstrates a bactericidal mode of action against the sensitive strain Lactococcus cremoris CNRZ‐117. The production of bacteriocin was optimized approximately 10‐fold in an aerobic fermenter held at constant pH 5·8 and 6·2. Ultrafiltration experiments with culture supernatant fluids containing the bacteriocin, and further estimation of molecular weight with gel filtration chromatography, revealed that bacteriocin in the native form has a molecular weight in excess of 300 kDa. SDS‐gel electrophoresis of partially purified thermophilin T showed that bacteriocin activity was associated with a protein band of approximately 2·5 kDa molecular mass.

This study presents, the development of a green method to produce rich in thymol natural zeolite (TO@NZ) nanostructures. This material was used to prepare sodium-alginate/glycerol/xTO@NZ (ALG/G/TO@NZ) nanocomposite active films for the packaging of soft cheese to extend its shelf-life. Differential scanning calorimetry (DSC), X-ray analysis (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR) instruments were used for the characterization of such nanostructures and films, to identify the thymol adsorbed amount, to investigate the thermal behaviour, and to confirm the dispersion of nanostructure powder into the polymer matrix. Water vapor transmission rate, oxygen permeation analyzer, tensile measurements, antioxidant measurements, and antimicrobial measurements were used to estimate the film’s water and oxygen barrier, mechanical properties, nanostructure’s nanoreinforcement activity, antioxidant and antimicrobial activity. The findings from the study revealed that ALG/G/TO@NZ nanocomposite film could be used as an active packaging film for foods with enhanced, mechanical properties, oxygen and water barrier, antioxidant and antimicrobial activity, and it is capable of extending food shelf-life.

-Thermophilin ST-1 is produced by Streptococcus thermophilus ACA-DC 0001, a "wild" strain isolated from traditional Greek yogurt products. It exerts an inhibitory effect on lactic acid bacteria, several food spoilage and food-borne pathogenic microorganisms, and some Gramnegative phytopathogen bacteria, including Listeria innocua BL 86/20 , Enterococcus faecalis EF1, Staphylococcus aureus ATCC 29996, Xanthomonas campestris BPIC 1660, Pseudomonas syringae BPIC 1549 and Erwinia rubrifasciens BPIC 1710. The crude antimicrobial compound is heat-labile (60°C for 10 min) and sensitive to the proteolytic enzymes pronase and trypsin and high acidic and alkaline conditions, and shows a bactericidal mode of action against the indicator strain Lactococcus lactis ssp. cremoris CNRZ-117. Production of thermophilin ST-1 starts during the early growth of the producer strain and reaches a maximum titer of 2560 AU·mL -1 at the end of the exponential growth. Thermophilin ST-1 was partially purified by ammonium sulfate precipitation, ionexchange and size-exclusion chromatography. SDS-PAGE electrophoresis of purified thermophilin ST-1 showed a single protein band with a molecular mass of 30 kg·mol -1 , classifying this novel bacteriocin with the large heat-labile proteins. Until now, however, the molecular mass of bacteriocins reported in the species of S. thermophilus was less than 10 kg·mol -1 (small, heat-stable peptides). Curing experiments did not result in the loss of bacteriocin production, suggesting that the genetic determinant is probably located on the chromosome. Streptococcus thermophilus