Indonesia is one of the biggest cocoa producers in the world with total production 240,000 tons by 2019. Meanwhile, we have about 400,000 tons cocoa pod husk (CPH). CPH biomass is a serious problem in Indonesia, but at the same time, it is also an important, challenging, and environmental renewable source for bioproduction. Therefore, it becomes a focus of interest in this research aiming to utilize of CPH as renewable substrate for citric acid production. The solid-state fermentation (SSF) approach was applied to CPH using Aspergillus niger Tiegh F359 for produce citric acid. Response surface methodology (RSM) was used to optimize the citric acid production with water concentration, nitrogen concentration, and fermentation time as variable factors. Around 7530 ppm citric acid was produced from 1 g CPH as a carbon source. Entirely, this study has succeeded in optimizing citric acid production by using SSF using A. niger Tiegh F359 and providing a fundamental study for CPH as low-cost renewable substrate for bioproduct production and future endeavors.

印度尼西亚是世界上最大的可可生产国之一，到 2019 年总产量为 240,000 吨。同时，我们拥有约 400,000 吨可可豆壳 (CPH)。CPH 生物质在印度尼西亚是一个严重的问题，但同时，它也是一种重要的、具有挑战性的、环境可再生的生物生产来源。因此，利用CPH作为柠檬酸生产的可再生底物成为本研究的一个重点。将固态发酵 (SSF) 方法应用于使用黑曲霉的CPHTiegh F359 用于生产柠檬酸。响应面法 (RSM) 用于以水浓度、氮浓度和发酵时间为可变因素优化柠檬酸生产。大约 7530 ppm 的柠檬酸由 1 克 CPH 作为碳源产生。总的来说，这项研究通过使用A. niger Tiegh F359 的SSF 成功地优化了柠檬酸生产，并为 CPH 作为生物产品生产和未来努力的低成本可再生基质提供了基础研究。