摘要：The aim of this work was to ascertain the efficacy of immobilised yeast for the remediation of caffeine in soilunder laboratory condition. Biostimulation with inorganic nutrients and bioaugmentation with caffeine utilizingsingle and mixed yeast cultures viz., Mixed culture 1, Mixed culture 2, Mixed culture 3 and Mixed culture 4were employed as remedial options for the removal of caffeine from contaminated soil. To promote caffeineremoval, biowaste materials (wheat bran, sawdust, peanut hull powder) were used as biocarriers forimmobilization of caffeine degrading yeast species following the method of physical adsorption. Weconstructed laboratory biopiles to compare the treatment bioaugmentation with bioaugmentation combinedbiostimulation using single and mixed cultures of immobilized yeast. Maximum removal of caffeine wasfound to be 98.3 % after 24 days in the biostimulated soil which was bioaugmented with sawdust immobilizedyeast mixed culture No. 4 consisting of three yeast species viz., Trichosporon asahii, Candida tropicalis andCandida inconspicua. Dehydrogenase activity in the soil was remarkably enhanced to 639 µg TPF g -1 soiland microbial numbers were also increased for the soil treated under the same conditions described above.Phytotoxicity assay confirmed the reduction of caffeine toxicity in the contaminated soil after treatment.Thus, sawdust immobilized mixed yeast culture No. 4 could serve as potential tool for the remediation ofcaffeine from contaminated soil.
