بررسي فرآيند يكپارچه جهت استخراج تركيبات زيست‌فعال و توليد حلال‌هاي زيستي از ضايعات گياه سنتلاآسياتيكا

Centella asiatica , Bio-based solvents , Acetone–butanol–ethanol(ABE) , Acidic pretreatment , Organosolv pretreatment , Extraction an‎d recovery of bioactive compounds , Saccharomyces cerevisiae , Clostridium acetobutylicum

Integrated extraction of bioactive compounds an‎d microbial synthesis of biosolvents from Centella asiatica biomass

زيست فناوري

Solvents play a fundamental role in the chemical, pharmaceutical, an‎d biotechnology industries, an‎d their appropriate selec‎tion for the extraction of plant bioactive compounds directly influences the yield an‎d quality of the final product. Considering the importance of developing sustainable bio-based solvents an‎d utilizing plant residues, this study investigated the potential of the residue obtained after extraction of bioactive compounds from Centella asiatica for bio-based solvent production. In parallel, various extraction processes were eva‎luated to recover an‎d isolate bioactive compounds. The plant samples, after drying an‎d milling, were subjected to three process routes: Soxhlet extraction, organic solvent pretreatment, an‎d a combination of Soxhlet extraction an‎d acidic pretreatment, to simultaneously assess the extraction of bioactive compounds an‎d the production of bio-based solvents (acetone–butanol–ethanol (ABE) an‎d ethanol). A circular approach was applied to fully exploit Centella asiatica; initially, Soxhlet extraction, as a conventional laboratory method, was performed, followed by acidic pretreatment of the obtained residue. Moreover, organic solvent pretreatment, originally intended to modify an‎d separate the lignocellulosic structure of the plant, was applied in this study with a dual purpose, providing not only structural modification but also facilitating the extraction an‎d recovery of bioactive compounds prior to enzymatic hydrolysis an‎d fermentation. The obtained extracts were eva‎luated for total phenolics, total flavonoids, antioxidant capacity, an‎d antibacterial activity. The results indicated that butanol extracts exhibited the highest total phenolic content an‎d antibacterial effects, while Soxhlet extraction with ethanol provided the highest total flavonoid content an‎d antioxidant capacity. The residues from the Soxhlet–acidic pretreatment route, due to the preliminary removal of phenolic compounds an‎d extractable substances, showed higher accessibility an‎d suitable conditions for enzymatic hydrolysis. This route demonstrated the highest yields in both fermentation processes, where fermentable sugars reached 29.91 g/L during enzymatic hydrolysis. In the acetone–butanol–ethanol (ABE) fermentation, butanol an‎d total ABE production were approximately 7.84 an‎d 14.7 g/L, respectively, whereas in ethanol fermentation with Saccharomyces cerevisiae, the ethanol yield was about 10.9 g/L. The results of this study demonstrated that the combination of Soxhlet extraction an‎d organic solvent pretreatment not only enables the recovery of bioactive compounds with pharmaceutical value but also converts the remaining residues into suitable resources for bio-based solvent production. Therefore, this circular approach represents a sustainable an‎d economical strategy for the full utilization of plant biomass an‎d the development of biorefinery processes.

5

157839