Activation and immobilization of phenol-degrading bacteria on oil palm residues for enhancing phenols degradation in treated palm oil mill effluent

Abstract

The presence of phenols in treated palm oil mill effluent (POME) is an environmental concern due to their phytotoxicity and antimicrobial activity. In this study, phenol-degrading bacteria, Methylobacterium sp. NP3 and Acinetobacter sp. PK1 were immobilized on oil palm empty fruit bunches (EFBs) for removal of phenols in the treated POME. The bacterial exopolysaccharides (EPS) were responsible for cell adhesion to the EFBs during the immobilization process. These immobilized bacteria could effectively remove up to 5,000 mg/L phenol in a carbon free mineral medium (CFMM) with a greater degradation efficiency and rate than that with suspended bacteria. To increase the efficiency of the immobilized bacteria, three approaches, namely activation, acclimation, and combined activation and acclimation were applied. The most convenient and efficient strategy was found when the immobilized bacteria were activated in a CFMM containing phenol for 24 h before biotreatment of the treated POME. These activated immobilized bacteria were able to remove about 63.4% of 33 mg/L phenols in the treated POME, while non-activated and/or acclimated immobilized bacteria could degrade only 35.0%. The activated immobilized bacteria could be effectively reused for at least ten application cycles and stored for 4 weeks at 4˚C with the similar activities. In addition, the utilization of the abundant EFBs gives value-added to the palm oil mill wastes and is environmentally friendly thus making it is attractive for practical application.

A kinetic study of 4-chlorophenol biodegradation by the novel isolated Bacillus subtilis in batch shake flask

“…The optical densities (OD 600 ) of the broth culture were converted as dry cell weight by plotting a calibration curve amid the dry cell weights versus optical density (OD 600 ). The broth was centrifuged at 10,000 g for a predetermined duration of 10 min to separate cell biomass, and the sediment was washed and re-suspended [19]. It was further filtered via a pre-washed 0.45-mm filter paper and dried at 105°C until steady mass was found.…”

Phenolic compounds removal by grasses and soil bacteria after land application of treated palm oil mill effluent: A pot study

“…NP3 and Acinetobacter sp. PK1 [2,27] or fungi such as Trametes hirsuta AK04 [3] and Pleurotus sajor caju [28] in the grass-soil pots to support the activity of soil bacteria.…”

Synthesis and Characterization of Manganese-Modified Black TiO2 Nanoparticles and Their Performance Evaluation for the Photodegradation of Phenolic Compounds from Wastewater

“…TPOME has been reported to contain various phenolic compounds including ferulic acid (dihydroxycinnamic acid, C 10 H 10 O 4 ), caffeic acid (3,4 dihydroxycinnamic acid, C 9 H 8 O 4 ), gallic acid (3,4,5 trihydroxybenzoic acid, C 7 H 6 O 5 ), phenol (C 6 H 5 OH), 3-methylcatechol (C 7 H 8 O 2 ), catechol (1,2-dihydroxybenzene, C 6 H 6 O 2 ), 4-hydroxybenzoic acid, protocatechuic acid (C 9 H 8 O 3 ), p-coumaric acid, and p-hydroxybenzoic acid [ 1 , 2 ]. The phenolic compounds are liberated from palm fruits during the wet extraction processes used in palm oil mills [ 3 ].…”

“…Chemical pollution from TPOME containing organic and inorganic contaminants could jeopardize aquatic biodiversity, and the presence of hazardous organic components in TPOME could harm aquatic ecology [ 4 ]. Because of their high toxicity, inertness, teratogenic and mutagenic behavior, endocrine-disrupting capability, and bioaccumulation potential, phenolic compounds are regarded as a significant threat to aquatic life and human health [ 2 , 3 ]. More effective and robust technologies to extract refractory phenolic compounds from TPOME before discharge into the environment are required to prevent water pollution and maintain the sustainability of palm oil production.…”