English

T T,Okogbenin E A,Obibuzor J U

doi:10.5897/ajbr2015.0818

Abstract

Lipases hydrolyze lipids to yield fatty acids and glycerol which are used as raw materials in industries. The lipase from raphia mesocarp was extracted, purified and characterized. Assay was carried out using p- nitrophenyl palmitate as substrate. The lipase was subjected to 80% ammonium sulphate precipitation, purified on ion exchange and gel filtration chromatography. Native and subunit molecular weights were determined on a gel filtration column and 10% sodium dodecyl sulphate polyacrylamide gel electrophoresis respectively. Kinetic parameters (Km and Vmax), effect of temperature, pH, sensitivity to metal ions and substrate specificities of the lipase enzyme were studied. Specific activity of 17.40µmol/min/mg and purification fold of 2.68% were obtained.Native and subunitmolecular weightwas 35 kDa. The Km and Vmax values were0.01mM and 20.5µmol/min/ml respectively. The lipase enzyme was inhibited by all metallic salts used and enhanced by CaCl2. Optimal pH was 7.0 and temperature for maximal activity was 40C. The lipase hydrolyzed coconut oil at about twice the rate of palm kernel oil and palm oil, and at a higher rate than olive oil and Raphia oil. The study reveals that raphia mesocarp isa possible source of lipase which can be of industrial use. Key words: Lipase, raphia palm fruit, mesocarp

Highlights

Lipases are a group of enzymes that catalyses the hydrolysis and synthesis of various forms of lipids (Svendsen, 2000)
In this study we report the isolation, purification and characterization of lipase from raphia palm mesocarp to hydrolyze vegetable oils for production of fatty acid and glycerol
The enzyme was not bound to the DEAE-Sephadex A-50 as it came out in the flow through fractions.No lipase activity was recovered in the fractions obtained by gradient elution

Summary

Introduction

Lipases are a group of enzymes that catalyses the hydrolysis (cleavage) and synthesis of various forms of lipids (Svendsen, 2000). They belong to a subclass of the esterases and have been reported to be active at the oil water interface (Ibrahim, 1996). Oilseed lipases have great potential for commercial exploitation as industrial enzymes. The demand of lipolytic enzymes has been increased due to its potentiall use in the various manufacturing processes of industrial goods such as food and pharmaceuticals (Boland et al, 1991; Gandhi, 1997), in the production of biodiesel and industrial detergent (Freire and Castilho, 2008) as well as in the analysis of triacylglycerols (Forgia et al, 1995), raw materials in food, cosmetics and pharmaceutical industries (Hermansyah et al, 2006). With lipase as a catalyst, is advantageous compared to conventional process due to low energy consumption, low cost, high product quality, ease of purification and safer process.

Methods

Results

Conclusion