Organic acids production from low-cost cellulosic substrates by fermentation

Lignocellulosics have potential to be used as raw materials in the production of a wide range of chemicals. It is important to develop a sustainable bioprocess for organic acids derived from these sources. The present study aimed to produce organic acids from wheat straw and cotton linter biomass materials by fermentation. As an initial step, the fermentation conditions (sugar, yeast concentration, and time) were optimized for the production of organic acids in a higher yield using cellulose as a feed material. Organic acids were quantified with different liquid chromatography techniques. Many organic acids were identified in biomass hydrolysates after fermentation, lactic and butyric acid were the main acids found to be in 122.6-478.9 and 121.0-482.2 mg/g biomass range, respectively. The elution profiles of organic acids were performed with an LC-TOF/MS system by using three different columns for a comparison of the results obtained with HPLC-RID. Furthermore, the use of various methods and perspectives on difficulties and opportunities in organic acid analysis was discussed.