Conversion of Waste Cooking Oil to Glycerol by Halal Microbial Lipase

Abstract

Environmental concern over discharge of waste cooking oil (WCO) has been on the rise. This is particularly alarming since the chain of fast food restaurants in Malaysia is thriving and therefore escalate the usage of cooking oil. Therefore, there is a challenge to manage the abundance of WCO generated by this industry. Interestingly, WCO presents as economical and readily available substrate for the conversion to biodiesel and surplus of crude glycerol which has numerous applications particularly in the food industry to manufacture artificial sweetener. However, concern arises among the Muslim populations on the source of enzyme lipase which is applied for the conversion of WCO to glycerol since the commercially available lipase for this purpose often originates from porcine. Therefore, the present study embarks on the concept of sustainability by converting waste cooking oil by halal microbial lipase to glycerol. Lipase from Rhodococcus sp. strain NAM81 demonstrated high affinity towards the substrate (Km = 1.9349 % (v/v)) and accelerated the rate of olive oil conversion (Vmax = 0.602 mU/mg/hour). The findings of WCO conversion by lipase was comparable to positive control using chemical oxidation indicating the applicability of the enzyme in industry. Therefore, production of high titre of rhodococci lipase will be attempted for future study.