Assessment of enhanced p-cresol biodegradation by encapsulating pre-immobilised Serratia marcescens strain HL 1 on tea waste biochar into polyvinyl alcohol/sodium alginate matrix

• Published in: Biochemical engineering journal 2023-10, Vol.199, p.109046, Article 109046
• Main Authors: Jaiswal, Vivek Kumar, Sonwani, Ravi Kumar, Singh, Ram Sharan
• Format: Article
• Language: English
• Subjects: Andrew-Haldane model; Biodegradation; Biokinetic study; Immobilisation; p-cresol; PI(1%)biochar@PVA/SA matrix
• ISSN: 1369-703X; 1873-295X
• DOI: 10.1016/j.bej.2023.109046

In this study, the potential microorganism was isolated from activated sludge to degrade the p-cresol from wastewater. The isolated species (i.e., Serratia marcescens strain ΗL 1) was identified using a 16 S rRNA gene sequencing technique. Microorganism was immobilized into 1% (w/v) tea waste biochar and encapsulated into polyvinyl alcohol (PVA)/sodium alginate (SA) matrix to save the pure species from contaminant and able to sustain under high loading concentration. The maximum biodegradation efficiency was found to be 86.1 ± 2.0% of p-cresol by using PVA/SA (pre-immobilized (PI) (1%) biochar into PVA/SA) matrix which is much higher than the free cell (42.4 ± 0.7%) and immobilized system (73.8 ± 1.0). The % biodegradation of p-cresol was reduced from 86.1 ± 2.0–80.2 ± 1.4% after the fourth cycle. The matrix's surface morphology and the functional group were analysed by SEМ and FTIR, respectively. Monod and Andrew-Haldane model was used to identify biokinetic parameters. This research work revealed that an innovative PI(1%)biochar@PVA/SA matrix would be useful for the bioremediation of p-cresol. The main metabolic by-product obtained were 4-hydroxybenzoylalcohal (m/z = 124), 4-hydroxybenzoic acid (m/z = 138), maleic acid (m/z = 116) and acetaldehyde (m/z = 29) [Display omitted] ●Optimal amount of PVA, SA, and CaCl2 were found to be 8.0%, 1.5% and 1.5%, respectively.●Maximum biodegradation of 86.1 ± 2.0% was found using PI(1%)biochar@PVA/SA matrix.●The Andrew-Haldane model successfully predicted the growth kinetics.●Biokinetic paramters µmax,Ks and KI, were obtained as 0.182 h−1, 60.2 mg.L−1, and 120 mg.L−1 respectively.●4-hydroxybenzoylalcohal, 4-hydroxybenzoic acid, maleic acid and acetaldehyde were by-product.