Methanolic peel extracts showed strong broad-spectrum activity against Gram-positive and Gram-negative bacteria, with the minimum inhibitory concentrations (MIC) ranging from 0.2 to 0.78 mg/ml.
Among the resultant Pt5-derived peptides, Pt5-1c showed the strongest antimicrobial activity against both Gram-negative and Gram-positive bacteria, including MDR bacteia, with the minimum inhibitory concentrations (MICs) ranging from 1.2 μM to 4.8 μM.
Group I (proteolytic) C. botulinum is a mesophilic bacterium with a minimum growth temperature of 10-12°C 10-12°Cimum of 37°C and maximum groptimummperature of around 48°C.
It is highly proteolytic, forms very heat resistant spores and strains form one, or occasionally two, neurotoxins of types A, B or F. Group II (non-proteolytic, saccharolytic) C. botulinum is a psychrotrophic bacterium with a minimum growth temperature of 2.5-3.0°C 2.5-3.0°Ctimum of 30°C.
To measure multiple periods in a single bacterium we used short exposures of 50 ms to 100 ms together with the minimum number of images needed for period determination.
The maximum activity against this bacterium occurred with the branched side-chain analogue, 6-(4′,8′-dimethylnonyl)salicylic acid, and the alicyclic side-chain analogue, 6-cyclododecylmethyl salicylic acid, with the minimum inhibitory concentration (MIC) of 0.39 μg/mL, respectively.
However, in population levels of ampicillin resistant bacteria, the minimum difference between sample means to be significant with a likelihood of 80% was 8.9%.
The situation is particularly challenging when bacteria with a minimum inhibitory concentration (MIC) close to the resistance breakpoint are involved [4].
Due to the potentially detrimental effect of bacterial contaminations on yeast fermentations it was decided to assess whether it was possible to choose process conditions that would selectively inhibit bacteria with minimum effects on the yeast.
