Gonen, CagdasOnal, Nagehan AkterDeveci, Ece Ummu2024-11-072024-11-0720232190-68152190-6823https://doi.org/10.1007/s13399-021-02182-6https://hdl.handle.net/11480/14305Biofuels, derived from sustainable biomass feedstock, are promising alternatives for fossil derivative fuels to mitigate climate change and air pollution. The molecular structure of lignocellulosic biomass, which creates the limitation of utilization by microorganisms, can be degraded to fermentable sugar via a pre-treatment process. In this study, citric acid as a weak acid and sulfuric acid as a strong acid were used for the pre-treatment of sugar beet pulp under pressure and non-pressure conditions. Fermentable sugar amount was determined for total sugar and reduced sugar formation. Acid ratio, solid ratio and reaction time variables were optimized for the highest fermentable sugar concentration via Box-Behnken statistical methods. Finally, pressure is significantly increasing the strong acid effect, where the total sugar can reach up to 33 g/L at 4% acid ratio, 27.5-min reaction time, and 5% solid ratio. A 27.5-min reaction time gives 11 g/L total sugar concentration under pressure conditions at 5% citric acid ratio. The highest reduced sugar concentration is 1170 mg/L for sulfuric acid under pressure with only 3% solid ratio. SEM-EDX and FT-IR analysis show reliable degradation of molecular structure. SEM analysis showed that under the same conditions at 100 degrees C and 1 atm, sulfuric acid produced a much more intense deformation than citric acid, with more fragmentation occurring on the surface parallel to the TS. In addition, protein analysis obtained using Aspergillus niger in microbial cultivation experiments supports that pre-treatment products may be suitable for biofuel production and microbial use. The highest protein value obtained by sulfuric acid pre-treatment is 120 mg/L. Pre-treatment is necessary for the development of microbial activity in the production of biofuels from agricultural wastes. The total protein content is an important parameter in determining total enzyme production in monitoring microbial growth.eninfo:eu-repo/semantics/closedAccessSugar beet pulpPre-treatmentSulfuric acidCitric acidBox-BehnkenBiofuel feedstockMicrobial activityArticle13109213922610.1007/s13399-021-02182-62-s2.0-85123069600Q3WOS:000742297000003Q2