Ultrasound technology has emerged as a promising tool for enhancing enzymatic biodiesel production, yet the cavitation effect induced can compromise enzyme stability. This study explored the efficiency of polyols in enhancing lipase stability under ultrasound conditions to further improve biodiesel yield. The incorporation of sorbitol resulted in the highest fatty acid methyl ester (FAME) content in the ultrasound-assisted biodiesel production catalyzed by Eversa® Transform 2.0 among the investigated polyols. Furthermore, sorbitol enhanced the stability of the lipase, allowing it to tolerate up to 100 % ultrasound amplitude, compared to 60 % amplitude in its absence. Enzyme activity assays revealed that sorbitol preserved 99 % of the lipase activity, in contrast to 84 % retention observed without sorbitol under an 80 % ultrasound amplitude. Circular dichroism (CD) and fluorescence spectroscopy analyses confirmed that sorbitol enhanced lipase rigidity and preserved its conformational structure under ultrasound exposure. Furthermore, employing a stepwise methanol addition strategy in ultrasound-assisted reactions with sorbitol achieved an 81.2 wt% FAME content in 8 h with only 0.2 wt% enzyme concentration. This promising result highlights the potential of sorbitol as a stabilizing agent in ultrasound-assisted enzymatic biodiesel production, offering a viable approach for enhancing biodiesel yield and enzyme stability in industrial applications.
The development of sustainable aviation fuel (SAF) presents a promising alternative to conventional jet fuel, with biofuels offering net-zero CO2 emissions. However, the conventional SAF production process typically involves expensive metal catalysts and extreme operating conditions. In contrast, the enzymatic approach offers a milder alternative; however, it is hindered by several limitations, including prolonged reaction times, reliance on cosolvents and low productivity. This study investigates the impact of CO2-based alkyl carbamate ionic liquids (ILs) on the enzymatic photodecarboxylation reaction catalyzed by Chlorella variabilis algal fatty acid photodecarboxylase (CvFAP). Notably, the study examines four ILs: N,N-dimethylammonium N',N'-dimethylcarbamate (DIMCARB), N,N-dipropylammonium N',N'-dipropylcarbamate (DPCARB), N,N-diallylammonium N',N'-diallylcarbamate (DACARB), and bis(2-ethylhexyl)-ammonium bis(2-ethylhexyl)carbamate (DBCARB). The results demonstrated that DACARB was the most optimal IL as it enhanced hydrocarbon conversion by 40 % and was able to reduce DMSO usage up to 86.7 % as compared to the absence of DACARB. This enhancement is attributed to DACARB's optimal balance of hydrophobic and hydrophilic properties, which increased enzyme activity while serving as a viable DMSO replacement, as well as acting as an allosteric modulator, as shown by Michaelis-Menten model fitting. Overall, this study highlights the potential of DACARB to facilitate process intensification in enzymatic SAF production, contributing to sustainable aviation practices.
The enzymatic production of fatty acids from vegetable oils is becoming a preferred method due to its mild conditions, simplicity, and scalability. This review analyzes studies on enzymatic hydrolysis, exploring various feedstocks, lipases, reaction conditions, and conversion yields. However, a key limitation is the longer reaction time compared to conventional methods. This limitation is primarily due to the immiscibility of triacylglycerols (TAGs) with water at low temperatures and pressures, as well as the lower activity of enzymes compared to chemical catalysts. To overcome these issues, chemical additives are identified as the most effective process intensification strategy. They are easy to implement, cause less damage to lipases, and are more efficient than mechanical methods. The impact of various chemical additives was thoroughly examined for potential improvements in the enzymatic hydrolysis of vegetable oils. A synergistic combination of chemical additives comprising ionic liquids (ILs) and polyols, along with ultrasound, as well as the consideration of immobilization techniques were explored. Overall, this review highlights the potential of chemical additives and their synergistic feasibility in enhancing the enzymatic performance of lipase-catalyzed hydrolysis reactions.
Microalgae are a sustainable source of bioactive proteins for personal care and cosmetic applications. Conventional alkaline extraction can achieve high protein recovery but relies on harsh chemical conditions that often compromise protein integrity, reduce bioactivity, and raise environmental concerns. Moreover, the extracted proteins often require additional enzymatic hydrolysis to enhance their functionality, thus increasing process complexity. This study proposes a dual-function Savinase-assisted in situ extraction strategy for the simultaneous extraction and functionalization of protein from Nannochloropsis oculata (N. oculata). Process optimization using improvement in protein extraction yield (IPEY) as the performance indicator identified optimal conditions of pH 7, 50 °C, 0.5 wt% Savinase and 2 h hydrolysis, under which a maximum IPEY of 85.1% was achieved. Fluorescence spectroscopy and zeta potential measurements confirmed that Savinase remained structurally stable under the optimized conditions while promoting protein solubilization. The resulting protein hydrolysates exhibited enhanced functional properties, with ABTS•+ radical scavenging activity reaching 83.3% at 5 mg/mL, representing a 56.9% increase compared with the non-enzymatic control. In addition, UV absorption analysis revealed a critical wavelength (λc) of 383.6 nm, indicating broad-spectrum photoprotective potential. Overall, the proposed one-step Savinase-assisted process provides a mild, sustainable, and effective strategy for producing bioactive microalgal protein hydrolysates with strong potential as natural ingredients in skin-protective cosmetic formulations.