Utilization of Banana Peel Extract for Biomass, Lipid and Carbohydrate Production in Chlorococcum humicola (Nägeli)

Abstract

The high cost of synthetic culture media remains a major limitation for large-scale microalgal cultivation. Therefore, this study investigated the potential use of banana peel extract (BPE) as a low-cost alternative culture medium for the cultivation of the green microalga Chlorococcum humicola. The alga was grown in BPE at concentrations of 10, 25, and 50 mg.L⁻¹ and compared with Chu13 medium as a control. Cultures were maintained for 21 days at 25 ± 2 °C under a light intensity of 3000 lux and a photoperiod of 8:16 h (light). Biomass production, total lipids, fatty acid composition, total carbohydrates, and carbohydrate profiles were evaluated. The results showed that the highest biomass production (459 mg.L⁻¹), total carbohydrate content (587.2 mg.g⁻¹), and α-linolenic acid content (6.31 mg.g⁻¹) were obtained at 10 mg.L⁻¹ BPE. In contrast, the maximum lipid accumulation (288 mg.g⁻¹) was recorded at 25 mg.L⁻¹ BPE. Fatty acid analysis revealed that α-linolenic acid was the predominant fatty acid in algal biomass grown in the alternative medium. Furthermore, BPE supported the production of several carbohydrates, including glucose, fructose, sucrose, galactose, mannose, and xylose. These findings demonstrate that banana peel extract can be utilized as an economical and sustainable alternative culture medium for Chlorococcum humicola cultivation, enhancing biomass production and valuable biochemical compounds while contributing to the valorization of agricultural waste.