Enzymatic bioremediation of cashew nut shell liquid contamination.
Cashew nut shell liquid (CNSL), a by-product of the cashew kernel industry, is a caustic, viscous, dark liquid. The process is done manually, which leaves stains on the hands of the workers. The aim was to find the utility of enzymes, oxidoreductases and proteases for the bioremediation of CNSL, which contains phenolics, mainly cardanol (60-65%). The results show that peroxidase reduced the color of the CNSL solution by polymerization and precipitation, where as laccase, papain and fungal and bacterial protease degraded the phenolic constituents. The degradation was mainly at the double bonds of the C15 hydrocarbon chain of the cardanol. To improve the enzyme stability, laccase and papain was separately immobilized in alginate-starch beads. Immobilized laccase can degrade 28.6% CNSL within 2 h, where as papain takes longer duration, and at 73 h, the adsorbed phenols on the alginate (45.86%) also got degraded. MALDI-TOF MS revealed that, immobilized laccase-papain beads combination; 1:1 (w/w) degraded 60% of the cardanol and some phenolic compounds having molecular mass of 374, 390 and 407. These beads are active and stable in aqueous media, can be used to prepare a mild, nontoxic, ecofriendly, cost effective hand wash solution for the removal of phenolic stains.
Cheriyan
Soly
S
Chemical Sciences and Technology Division, National Institute for Interdisciplinary Science and Technology (CSIR), Industrial Estate (PO), Trivandrum 695019, India.
Abraham
Emilia T
ET
D031021:Anacardium; D001673:Biodegradation, Environmental; D004800:Enzymes, Immobilized; D005525:Food-Processing Industry; D006235:Hand Disinfection / Q000379:methods*; D007220:Industrial Waste / Q000009:adverse effects*; D010447:Peptide Hydrolases / Q000378:metabolism; D010544:Peroxidases / Q000378:metabolism; D010636:Phenols / Q000378:metabolism; D014865:Waste Disposal, Fluid / Q000379:methods
D004800:Enzymes, Immobilized; D007220:Industrial Waste; D010636:Phenols; C038590:cardanol; D010544:Peroxidases; D010447:Peptide Hydrolases