Relationship between lactobacillus species and heavy metal concentration in fish fillet

This study was applied to investigate levels of lead, cadmium, and mercury in commercially sold fish species (Oreochromis niloticus and Lates niloticus) and the effect of addition of lactobacillus species on metals level in fish fillet. A total of 120 fish fillet samples represented by Oreochromis niloticus and Lates niloticus (60 samples of each) obtained from different markets in Qalubiya Governorate, Egypt. The obtained results indicated that Oreochromis niloticus exhibits higher levels of heavy metal contamination, specifically lead, cadmium, and mercury, compared to Lates niloticus. The average level of lead, cadmium, and mercury( mg/ kg )were 1.07 ± 0.01, 0.49 ± 0.01, and 1.53 ± 0.02 in Oreochromis niloticus compared with those of 0.65 ± 0.01, 0.32 ± 0.01, and 0.98 ± 0.01 in Lates niloticus, respectively . A higher percentage of Oreochromis niloticus samples were deemed unfit for consumption due to excessive heavy metal levels compared to Lates niloticus ones according to Egyptian standards. The experimental inoculation of a mixture of L. rhamnosus and L. plantarum probiotic strains to fish fillets were resulted in a higher reduction (83%) in lead levels after 72 hours than reductions seen with L. plantarum (67%) and L. rhamnosus(75% ) separately. So, we recommended the potential application of probiotics to ensure the safety of seafood consumption.