Probiotic Properties of Lactic Acid Bacteria Isolated From Egyptian Salted Food

Abstract

A total of 12 autochthonous lactic acid bacteria (LAB) were isolated from a traditional homemade salted foods (n=14) in Egypt. The salted fish (n=2), mixed pickles (n=3) and mish (n=9) at one to 48 months of fermentation were collected from Sharkia Governorate (Zagazig, Menya-Elkmh, Belbeas, Fakous and Kafr-Suqr districts), North Sinai Governorate (El-Areesh and Rafah cities), Sohag, Luxor and Aswan cities. Identification process to species and strain level was accomplished by biochemical, morphological characteristics and 16S rDNA gene analysis. The isolates were evaluated according to safety, antibacterial and antibiotic susceptibility criteria. The most frequently observed genus identified by 16S rDNA sequencing analysis was Enterococcus faecium (SHM7, ELM33 and ELM38). The most predominant genus identified by biochemical were Lactobacillus rhamnosus < Lb. frumenti < Enterococcus faecium < Lb. plantarum. The highest percentages of antibiotic resistance were to cefotaxime and cefaclor (91.67%), and ampicillin, kanamycin and levofloxacin (83.33%). All the selected isolates were sensitive to tetracycline and penicillin (25 and 50%, respectively).The results also revealed that 33.33% of the isolates were haemolytic, while 66.67% were non-haemolytic and only one isolate (SHM4) was induced βhaemolytic activity. All the selected isolates showed important levels of antibacterial activity against tested food-borne pathogens (Salmonella enterica, Listeria monocytogenes and Escherichia coli). The results suggest the potential of the obtained isolates to improve the quality of these traditional fermented food products in Egypt.