Mechanistic investigations in ultrasound-assisted biodegradation of phenanthrene.
Ultrason Sonochem
; 62: 104890, 2020 Apr.
Article
em En
| MEDLINE
| ID: mdl-31796330
ABSTRACT
This study has addressed the biodegradation of polycyclic aromatic hydrocarbon, phenanthrene using Candida tropicalis. Optimization using central composite statistical design yielded optimum experimental parameters as pH = 6.2, temperature = 33.4 °C, mechanical shaking = 190 rpm and % inoculum = 9.26% v/v. Sonication of biodegradation mixture at 33 kHz and 10% duty cycle in log phase (12 h per day for 4 days) resulted in a 25% enhancement in phenanthrene removal. Profiles of specific growth rate (µ) and specific degradation rate (q) versus initial substrate concentration were fitted to Haldane substrate inhibition model. Both µ and q showed maxima for initial concentration of 100 mg L-1. Kinetic analysis of degradation profiles showed higher biomass yield coefficient and smaller decay coefficient in presence of sonication. Expression of total intracellular proteins in control and test experiments were analyzed using SDS-PAGE. This analysis revealed overexpression of enzyme catechol 2,3-dioxygenase (in meta route metabolism) during sonication which is involved in ring cleavage of phenanthrene. Evaluation of cell viability after sonication by flow cytometry analysis revealed > 80% live cells. These effects are attributed to enhanced cellular transport induced by intense microturbulence generated by sonication.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenantrenos
/
Hidrocarbonetos Policíclicos Aromáticos
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Sonicação
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Biodegradação Ambiental
Idioma:
En
Revista:
Ultrason Sonochem
Assunto da revista:
DIAGNOSTICO POR IMAGEM
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Índia