Abstract:
This paper belongs to a more complex study, study that has as aim the
emphasize of antibacterial activity of ”isothiocyanates” bioactive
compounds, compounds present in more vegetable sources (Armoracia
rusticana and Brassica nigra). In this case, the biological material studied,
were the Brassica nigra seeds. On the basis of kinetics, thermodynamics
and pH studied, the optimum conditions corresponding to obtaining the
extracts were the following: phosphate buffer pH was 7, reaction time was of
120 ÷ 330 minutes, temperature of 55°C.The emphasize of antibacterial
activity of there compounds was done by taking microbiological tests on the
following microbiological cultures: Escherichia coli, Candida albicans,
Bacillus subtilis, Staphylococcus aureus, Agrobacterium tumefaciens and
Rhizopus nigricans, using the inoculate microbiological technique on culture
medium surface. After 24 hours of incubation, the ITCs exhibit a average
inhibitory action towards to Bacillus subtilis, because the free zones around
the filter paper with extract (that contain sulphur compounds), have the
values in the range 0.2-0.6 cm. Candida albicans exhibit a significant
sensitivity to words ITCs action, from mustard seeds extracts, the free zone
diameters to maximum concentration is 0.7 cm and decreases to the other
concentrations, maintaining themselves unchanged after 48 hours, too
respectively. In the presence of ITCs from mustard seeds extracts,
Escherichia coli exhibits a average negative reaction, with free zone
diameters in the range of 0.2-0.5 cm. The obtained results have shown a
relative antibacterial activity, induced by these compounds, comparing to
results obtained in the case of crushed down mustard extracts (results shown
in a previous paper). On the base of obtained results, we can infer, that, as a
rule, the majority of tested microbial species, present a sensitiveness more or
less increased (with some exceptions), which determine us to recommend the
utilization of these compounds obtained from seeds mustard, in food and
medicine domain.
