Akossi Moya Joëlle Carole

Lipases are essential in many industrial processes. Although microbial lipases are widely used, plant lipases remain more accessible and abundant, particularly in germinated kernels. This study aims to evaluate the catalytic potential of lipase extract powder of germinated rubber kernels in transesterification reaction. Germinated rubber kernels, lipase extract powder of germinated rubber kernels, and crude oils of palm (PKO), Jatropha curcas (JCO), and rubber (RSO) were characterized. The presence of lipase in the plant extract powder was evidenced by FT-IR and SEM-EDX analyses and hydrolysis reaction. Biodiesel was produced from crude rubber oil. The results showed that germinated rubber kernels have high moisture (33.48%), protein (15.75%), and fat (50.11%) contents. The optimum hydrolytic activities of lipase on PKO, JCO, and RSO were 25.67 U/mL, 26.67 U/mL, and 31 U/mL, respectively, at pH 5. Lipase extract concentration, temperature, and storage time influenced the lipase hydrolytic activity. The optimum biodiesel yield (29.63%) was obtained at 30 °C. The addition of co-solvents (water and n-hexane) to the reaction mixture increased yields from 20.47% (without co-solvent) to 31.06% and 21.85%, respectively. These insights show that germinated rubber seeds are rich in oil and contain lipase with good hydrolytic and catalytic activity.

The goal of biodiesel production is to obtain a clean, biodegradable, and renewable fuel. Industrial-scale processes use homogeneous and heterogeneous chemical catalysts. These are efficient but require the use of very pure reagents and complex product purification steps or processing conditions under high temperature and pressure. Enzymatic catalysis, in contrast, using lipases as biocatalysts, is an alternative that produces a better-quality product under less extreme conditions. Since free lipases are not reusable, it is necessary to immobilize them to stabilize them and allow their reuse over several reaction cycles. This informative review presents various methods of lipase immobilization (physical adsorption, ionic bonding, covalent bonding, entrapment, encapsulation, and cross-linking) as well as their advantages and disadvantages, followed by a comparative study. Articles from 2010 to 2022 were used for bibliometry to show that the topic is still relevant. The immobilization methods are classified into two main groups, physical and chemical, according to the enzyme-support interaction. Among these methods, ionic bonding is recommended, because in addition to this process being easily achievable, lipases immobilized this way are more stable and reusable. In summary, the production of biodiesel from immobilized lipases is in line with sustainable development and respect for the environment.