Optimising nutrient additives to improve delignification and biolipid production from oil palm empty fruit bunches (OPEFB)

Abstract

Fungi obtain nutrients by decomposing dead and living organic materials into useable substances, playing a crucial role in nutrient recycling. This decomposition process is essential for biolipid production, as it allows fungi to effectively break down lignocellulosic biomass into fatty acids and oils. This study aimed to optimise the growth conditions of Serpula lacrymans in oil palm empty fruit bunches (OPEFB) by incorporating sucrose, yeast extract and magnesium (Mg²⁺) to facilitate the breakdown of lignocellulosic components and enhance lipid generation. The experimental design employed Response Surface Methodology (RSM) based on a Central Composite Design (CCD), encompassing three factors and three response variables. The observed response variables included total reducing sugars (TRS), lignin content, and lipid yield. Under optimal conditions, characterised by the addition of 30 g L⁻¹ sucrose, 0.029 g L⁻¹ yeast extract, and 0.025 g L⁻¹ Mg²⁺, the results yielded 9.634 mg g⁻¹ TRS, 20.73% lignin, and a lipid yield of 5.35%. The predominant fatty acid produced was palmitic acid (C16:0) (15.34%), followed by oleic acid (C18:1) and linoleic acid (C18:2). This research highlights the potential of OPEFB as a substrate for microbial lipid production, contributing to the development of sustainable biofuels.