Roy A, Dubey P, Srivastava A, Kaur I, Shrivastava A, Vajpayee P, Srivastava S, Srivastava PK. Exploring the potential of Meyerozyma caribbica and its combined application with bacteria for lindane bioremediation.
CHEMOSPHERE 2024;
361:142413. [PMID:
38795920 DOI:
10.1016/j.chemosphere.2024.142413]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 05/28/2024]
Abstract
This study explored the degradation potential of a yeast strain, Meyerozyma caribbica, alone and in combination with Bacillus velezensis and Priestia megaterium, found novel for lindane biodegradation. Isolated from hexachlorocyclohexane (HCH)-contaminated sites, M. caribbica, B. velezensis, and P. megaterium demonstrated lindane reduction efficiencies of 86.5%, 78.6%, and 77.5%, respectively, at 750 mg L⁻1 within 10-day incubation period. Kinetic analysis revealed that M. caribbica followed the first-order degradation (r2 = 0.991; T₁/₂ = 4.3 days). Notably, M. caribbica exhibited the highest dechlorinase activity (9.27 U mL⁻1) in the cell supernatant. Co-cultivation as the mixed culture of M. caribbica and P. megaterium achieved maximum lindane reduction (90%) and dechlorinase activity (9.93 U mL⁻1). Whereas the mixed culture of M. caribbica and B. velezensis resulted in 80.9% reduction at 500 mg L⁻1 lindane with dechlorinase activity of 6.77 U mL⁻1. Growth kinetics, modelled using the Monod equation, showed a maximum specific growth rate of 0.416 h⁻1 for the mixed culture of M. caribbica and P. megaterium at 750 mg L⁻1 lindane. GC-MS analysis confirmed the presence of intermediate metabolites, viz., γ-pentachlorocyclohexane, 1,2,4-trichlorobenzene, 1,4-dichlorobenzene and maleyl acetate, validated successive dechlorination and oxidative-reduction processes during lindane biodegradation. The findings of the study highlighted the potential of these novel microbial strains and their mixed cultures for effective bioremediation of lindane-contamination.
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