Screening and Separation of Industrially Useful Hydrolases from the Wasteful Skim Latex Serum of Hevea Brasiliensis

Abstract

Hydrolases extracted from Hevea brasiliensis are a source of very useful industrial enzymes. They play an important role in industries related to detergent, food, oil processing, fine chemicals, and agrochemicals. Rubber tree can be a source of phytochemicals which have the potential for use in making various nutraceutical and pharmaceutical products. Malaysia is one of the biggest producers of natural rubber in the world. However, Malaysia is still striving with the problems related to waste management and environmental pollution despite the high income from natural rubber production. Skim latex is a by-product and the most polluting waste in the rubber-processing industry. Therefore, it is very important to find new uses for this rubber waste. Protein constitutes about 2 % of dry mass of the total latex and has been reported to contain useful enzymes such as hydrolases. Compared to other enzymes, hydrolases are more frequently used in industrial applications. Over half of all detergents presently available contain hydrolases and their subclasses, including proteases, cellulases, amylases, and lipases. Malaysia has vast sources of hydrolases because it is one of the largest producers of natural rubber. Thus, it is unfortunate that the Hevea brasiliensis skim latex is as yet not fully utilized. This work proposes to systematically identify these potentially useful enzymes from the waste skim latex of Hevea brasiliensis. The work involved the identification of the hydrolases by screening for their presence using known in vitro enzymatic assays. This was followed by extraction and separation of the most active hydrolases identified via bioactivity-guided column chromatography techniques. From this study, lipid acyl hydrolase (LAH), a subtype of lipase, was considered as the potential protein that can be recovered from the skim latex serum of Hevea brasiliensis. This is because its activity was found to be the highest (1.561 U/ml). Further separation by gel-filtration chromatography on Sephacryl™ S-200 gave the results for LAH activity (1.304 U/ml) and total activity (97.782 U). 10 ml of skim latex serum was successfully granted a purified LAH with specific activity of 0.593 μmol min⁻¹mg⁻¹. A running buffer solution of 100 mM Tris HCl (pH 7.0) was used in all the steps. The significances of this work are contribution toward the utilization of latex serum to produce value-added product, generation of additional income for the manufacturers, and development of environment-friendly techniques in latex processing.