The role of resistance and para-probiotics in nickel biosorption by probiotic lactobacilli

Background: Nickel is a major pollutant of water and food, playing a destructive role in the health disorders of humans. Recently, probiotic bacteria have been recognized as a highly secure and eco-friendly approach to nickel biodetoxification. Methods: Four lactobacillus strains, namely L. brevis 205, L. mucosae 226, L. plantarum 78, and L. casei 303 were investigated to assess their nickel resistance through disk diffusion and MIC methods. Strains with the highest and lowest resistance were selected for Bioremediation assays including Biosorption, Desorption, and Bioaccumulation. Results: L. brevis 205 and L. casei 303 exhibited the highest and lowest sensitivity to nickel, respectively. Both of them exhibited a plentiful performance in Biosorption assays, with 82.22% for L. brevis 205, and 72% for L. casei 303. The bioremoval assay with the para-probiotic (dead) biomass of the two strains exhibited a Biosorption yield of about 69% for L. brevis 205 and 75% for L. casei 303. Conclusion: both probiotic and para-probiotic biomass demonstrated excellent nickel Biosorption capability and L. casei 303 para-probiotic biomass outperformed L. brevis 205. Thus, probiotic Lactobacillus strains of this study could be brilliant candidates for nickel bioremoval in water, food, and pharmaceutical industries, regardless of bacterial resistance or viability. /p