Probiotic Lactic acid bacteria: A Promising alternative approach to control human threats

Document Type : Original Article

Authors

Al-Azhar University, Faculty of Science, Botany and Microbiology Department, Cairo, Egypt

10.21608/ajar.2024.246914.1291

Abstract

The valuable effects of viable probiotic bacteria as dietetic supplements have gained massive research note, Lactobacillus spp. with probiotic properties are extensively used to prepare dairy products such as yoghurts, Cheese etc. The target of the present study is to assess LAB species with prospective activities, 22 samples of fermented food samples were collected from local markets of Giza for isolation of probiotic microbes. From the samples, 10 LAB strains were isolated, promising isolates were selected by primary screening as potential probiotics with antimicrobial activity against bacterial pathogens. Selected LAB isolates were in vitro characterized for their probiotic pattern and antimicrobial activities against pathogens. Isolates were found to be resistant to NaCl% (6%), bile salt% (0.5%) and exhibited respectable growth in the acidic condition, while highest growth was noted at pH around 6.0. The most potent LAB isolate was exhibited antimicrobial activity against 4 different test pathogens with inhibition zone diameter (24-32) mm. Additionally, the MIC of the same isolate was (1.5-3 mg/ml) which is considerable result when compared to studies of the same field. Organic acids production with quantity of 0.76% are found to be responsible for antimicrobial activity. Also, the isolates showed remarkable aggregation and hydrophobicity properties. According to the results, selected LAB isolates (Y2c) were believed to be potential probiotic bacteria. Subsequently, identification of the Y2c isolate conventionally and genetically revealed that it is found to be Limosilactobacillus fermentum and has been registered in GenBank under Limosilactobacillus fermentum strain HwOs.

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