Mixed culture ofLactococcus lactisandKluyveromyces marxianusisolated from kefir grains for pollutants load removal from Jebel Chakir leachate

The wastewater from the dumping site usually contains high pollutant levels. Biological process and physico-chemical treatments are among several technologies for wastewater treatment. Using microorganisms in the treatment of landfill leachate is an emerging research issue. Furthermore, bioremediation is a feasible approach for pollutants removal from landfill leachate which would provide an efficient way to resolve the issue of landfill leachate. In this study, the performance of yeast and bacteria isolated from kefir grains was assessed for landfill leachate treatment. Kefir grains microbial composition was evaluated by molecular approaches (Rep-PCR and 16S rRNA gene sequencing). The obtained outcomes denoted that high concentrations of lactic acid bacteria and yeast populations (over 10(7) CFU/ml) were found in the kefir grains and were essentially composed ofLactococcus lactis,Lactobaccillus kefirien,bacillussp.,L. lactis, andKluyveromyces marxianus. The co-culture with 1% of inoculum size was demonstrated as the most efficient in the degradation of different contaminants. The overall abatement rate of chemical oxygen demand (COD), ammonium nitrogen (NH4+-N), and salinity were 75.8%, 85.9%, and 75.13%, respectively. The bioremediation process resulted in up of 75% removal efficiency of Ni and Cd, and a 73.45%, 68.53%, and a 58.17% removal rates of Cu, Pb, and Fe, respectively. The research findings indicate the performance ofL. lactisandK. marxianusco-culture isolated from kefir grains for the bioremediation of LFL. Practitioner Points Isolation and identification of microorganisms from kefir grains was carried out. Biological treatment of LFL using monoculture of (Lactoccocus lactis;Kluyveromyces marxianus) and co-culture (5% ofL. lactisand 5%K. marxianus) has been performed. Biological treatment using co-culture strain is an effective approach to remove organic matter,NH4+-Nand heavy metals.