Maari is a spontaneously alkaline fermented food condiment made from baobab tree seeds. Due to the spontaneous nature of maari fermentations growth of the opportunistic human pathogen Bacillus cereus is occasionally observed. Bacillus subtilis strains are important for alkaline seed fermentations because of their enzymatic activities contributing to desirable texture, flavor and pH development....

The effect of nisin or citric acid or combinations of these two inhibitors on the inactivation of a cocktail of three Listeria innocua strains was investigated in a model brain heart infusion (BHI) broth and hummus (chickpea dip). In BHI broth, citric acid had a limited ability to inhibit L. innocua growth. Nisin initially reduced L. innocua concentrations by about 3 log cycles; however, L. inn...

Outbreaks of food-borne pathogens, such as Escherichia coli O157:H7 and Salmonella, continue to draw public attention to food safety. Several reports have demonstrated the efficacy of using natural ingredients to control the growth of food-borne pathogens. The objective of this study was to investigate antimicrobial effects of lactic acid and copper, alone and in combination, on the survival an...

This study evaluated the effects of growth medium, temperature, and incubation time on biofilm formation by Enterobacter cloacae strains. The ability to adhere to a surface was demonstrated using a microtiter plate adherence assay whereas the role of cell surface properties in biofilm formation was assessed using the coaggregation and autoaggregation assays. The architecture of the biofilms was...

The gram-negative bacterium Francisella tularensis (Ft) is both a potential biological weapon and a naturally occurring microbe that survives in arthropods, fresh water amoeba, and mammals with distinct phenotypes in various environments. Previously, we used a number of measurements to characterize Ft grown in Brain-Heart Infusion (BHI) broth as (1) more similar to infection-derived bacteria, a...

An extruded composite food packaging film containing pectin, polylactic acids (PLAs) and nisin was developed to inhibit Listeria monocytogenes. The mechanical properties and surface structure of the film were also examined. Cells of L. monocytogenes were reduced by 2.1, 4.5 and 3.7 log units mL by the pectin plus PLA (pectin ⁄PLA) film containing nisin (1000 IU mL of tested liquid) in Brain Hea...

Ultrafine bubbles (UFB) are a novel concept that has the potential to enhance potency of antimicrobials eliminate biofilms. This study investigated impact incorporating gas (air, CO2, and N2) UFB on chlorine (Cl2; 50, 100, 200 ppm) peracetic acid (PAA; 20, 40, 80 antimicrobial (AM) solutions against fresh (3 days) aged (30 Listeria monocytogenes biofilms polypropylene, silicone, stainless steel...

Conjugation experiments with Bacillus thuringiensis and transfer kinetics demonstrated that salt stress has a positive impact on plasmid transfer efficiency. Compared to standard osmotic conditions (0.5% NaCl), plasmid transfer occurred more rapidly, and at higher frequencies (>100-fold), when bacteria were exposed to a high-salt stress (5% NaCl) in liquid brain heart infusion (BHI). Under mild...

Tests of 25 strains of Neisseria meningitidis for sensitivity to sodium polyanethol sulfonate (SPS) showed that the sensitivity of strains varied with both inoculum size and SPS concentration. In Trypticase soy broth (TSB), 2 out of 13 strains were sensitive to 0.05% SPS, whereas 8 out of 13 strains were sensitive to the same concentration of SPS in brain heart infusion (BHI). In artificial blo...