The effect of some food additives in the microbial growth of some starter cultures used in the manufacturing of fermented meat

The research aimed to study the contrast between three commercial starter cultures used in the manufacturing of fermented meat and different concentrations of nitrite, salt, lactic acid and black pepper all alone on the impact of inhibition of the microbial growth. The first starter culture contained a mixture of Staphylococcus carnosus and Staphylococcus vitulinus, and the second one contained Lactococcus lactis and Lactobacillus sakei while the third one contained Lactococcus lactis, Lactobacillus sakei, Staphylococcus carnosus and Staphylococcus xylosus. Four concentrations of each additive were individually prepared and the inhibition activity on the microbial growth was estimated by comparing the total microbial counts with and without the addition of the same additive. Analysis of variance and least significant difference (LSD) test at P<0.05 showed that the lactic acid was the most influential on the microbial growth of starter cultures, and significant differences were also detected between the used concentrations of lactic acid, while no significant effect was observed when 100 ppm of nitrite, 1-3% of salt and 0.1-0.4% for black pepper were used. Consequently, the previously mentioned concentrations could be applied in the manufacturing of fermented meats.

Bioeffect of some Syrian Myrtus communis L. leaves extracts in the growth of some pathogenic microorganisms

Bioeffect of some Syrian Myrtus communis L. leaves extracts in growth of some pathogenic microorganisms, which were isolated from Al-Assad hospital laboratory in Lattakia, was tested by disc diffusion method. Results showed that cold and hot water extracts have antibacterial activity against all Gram positive and negative bacteria, and pathogenic Candida albicans except Klebsiella pneumoniae. All organic extracts have antibacterial activity against Proteus vulgaris, Entrococcus faecium, Staphylococcus aureus and Staphylococcus albus. Pseudomonas aeruginosa and Pseudomonas fluorescens were affected by most of the organic extracts, and the most bioactivity was by methanol extract, and all inhibition zones of extracts were bigger than inhibition zones by control antibiotics. Serratia marcescens and Acinetobacter calcoaceticus were affected by methanol (with highest inhibition zone 37.33 and 27.33 mm respectively), ethanol, acetone and ethyl acetate extracts, but resistant to the others. Klebsiella pneumoniae affected by ethanol extract only with inhibition zone 20.33 mm. Results of bioactivity according to a various solvents used in this study demonstrate that Syrian Myrtus communis L. leaves extracts have antimicrobial activity, so expected to be potential sources of natural antibacterial and antifungal products against some pathogenic bacteria and fungi in the future.