Konjac glucomannan (KGM) aerogel immobilized microalgae: A new way for marine oil spills remediation

This study investigated the oil pollution remediation ability of konjac glucomannan (KGM) aerogel immobilized Chlorella vulgaris LH-1 (C. vulgaris). The KGM aerogel exhibited a high porosity of 86.83 %, and with the change of crude oil concentration (1-10 g/L), the crude oil adsorption efficiency of KGM aerogel was up to 18.75 %. The KGM aerogel carrier enhanced the crude oil biodegradation efficiency of C. vulgaris by 13.86 %. The concentration of residual n-alkanes of the immobilized C. vulgaris group was only 36.83 % of that of the free C. vulgaris group after 14 days of cultivation. In the crude oil metabolites of immobilized C. vulgaris, the concentrations of benzoic acid, phthalic acid, and benzophenone were 1.35, 21.18 and 3.43 times higher than those of the free C. vulgaris, respectively. Compared with free C. vulgaris group, 9 monooxygenase genes, 11 dioxygenase genes and 2 cytochrome P450 genes of immobilized C. vulgaris group were up-regulation and the "hydrocarbon metabolism process" was significantly enriched (enrichment factor is 0.85) in the gene ontology (GO) analysis of the transcriptome of C. vulgaris. These results showed that the ability of C. vulgaris to degrade crude oil was improved due to the existence of the KGM aerogel immobilized carrier.