Solid/Gas Synthesis of Isobutyl Propionate Catalyzed by Packed-Bed CalB Cross-Linked Enzyme Aggregates (CLEA)

Sep 29, 2026

This research evaluates the feasibility and performance of cross-linked enzyme aggregates (CLEA) composed of Candida antarctica lipase B (CalB) with bovine serum albumin (BSA) for the green synthesis of isobutyl propionate (isoPro) from propionic acid and isobutyl alcohol. Solid/gas (S/G) biocatalysis is presented as a more sustainable option than chemical synthesis and plant-extraction routes. A formulation with 10 mg mL−1 BSA and 3% glutaraldehyde enabled 91.71% isoPro yield under defined water activity, gas flow, and stoichiometric conditions, demonstrating improved mass-based sustainability versus CalB alternatives for potential industrial scale use.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages14

Reading Time35 min

AccessFree to download

ABSTRACT

INTRODUCTION

This article is licensed under CC-BY 4.0 [http://pubs.acs.org/journal/acsodf](http://pubs.acs.org/journal/acsodf) Article Solid/Gas Synthesis of Isobutyl Propionate Catalyzed by Packed-Bed CalB Cross-Linked Enzyme Aggregates (CLEA) Yahir Alejandro Cruz-Martínez, Carlos O. Castillo-Araiza, Edmundo Castillo-Rosales, Susana Velasco-Lozano,* and Sergio Huerta-Ochoa * Cite This: ACS Omega 2025, 10, 59692−59705 Read Online | | | | | | | | --- | --- | --- | --- | --- | --- | | ACCESS | Metrics & More | | Article Recommendations | | *sı Supporting Information | ABSTRACT: This research examines the viability and effectiveness of cross-linked enzyme aggregates (CLEA) ofCandida antarctica lipase B (CalB)/bovine serum albumin (BSA) for the green synthesis of isobutyl propionate (isoPro) from propionic acid (aciP) and isobutyl alcohol (isoB). Solid/gas (S/G) biocatalysis is proposed as a more sustainable alternative to chemical synthesis, which involves toxic catalysts and harsh conditions, or plant extraction compounds, which are economically unfeasible for bulk production. A formulation containing 10 mg mL−1 BSA and 3% glutaraldehyde (GA) was selected based on CalB-CLEA’s demonstrated catalytic efficiency in nheptane as solvent, along with its thermal and operational stability. Using 600 mg of the selected CalB-CLEA in the S/G bioreactor yielded 91.71% isoPro at a water activity (aw) of 0.52, with a nitrogen flow rate of 62 mL min−1 and a 1:4 acid/alcohol molar ratio, operating at 55 °C and 585 mmHg. Although 1.0 g of commercial CalB ImmoPlus achieved a higher yield (98.9%), its total turnover number (TTN) (mol product mol−1 enzyme) and specific space−time yield (STYspe) (g product L−1 h−1 mg−1 CalB) under steady-state conditions were 6-and 4-fold lower, respectively, than those of CalB-CLEA. Additionally, CalB-CLEA eliminates resin disposal costs, yielding similar outputs with lower enzyme loads while achieving comparable productivity. Ultimately, the S/G system incorporating CalB-CLEA outperforms both CalB ImmoPlus (in S/G) and CalB-CLEA (in n-heptane) in green, mass-based sustainability metrics, underscoring its strong potential for industrial-scale applications. 1. INTRODUCTION Consumer demand tends toward natural products because the quality of the final product obtained by chemical synthesis can be affected by the toxic byproducts generated that are harmful to health. 1−3 Natural volatile organic compounds (VOCs) have focused on human health because of their antioxidant, antiinflammatory, anticancer, and antiobesity activities and their applications in the food, pharmaceutical, cosmetic, and personal care industries. Consumers consider natural flavors therapeutic, sustainable, and eco-friendly, so their demand in the global market is expected to grow on a large scale. The global flavor market was valued at US $5 billion in 2022 and is expected to grow at an annual growth rate of 6% from 2024 to 2032 (Aroma Chemicals Market Report By Source, Product, Application and Forecast, Research and Markets, March 2024). In recent years, there has been increasing interest in producing VOCs through biotechnological processes including de novo synthesis and biotransformation using enzymes or whole cells. This is attributed to the use of mild conditions, meaning that synthesis does not require toxic catalysts, and the resulted waste treatment is considered an environmentally safe solution due to its organic 4 nature. The use of reaction media with organic solvents for synthesis reactions has been shown to be an advantageous approach to expanding the field of biocatalyst applications.5 In addition, ecological alternatives have been reported by using alternative solvents with low toxicity, low vapor pressure, good biodegradability, and easy recycling. Solvents that can fill the gap between volatile organic solvents and water are ionic liquids, deep eutectic solvents, supercritical fluids, and fluorinated sol

FAQs

What is the purpose of using CalB cross-linked enzyme aggregates (CLEA) in this study?

To assess whether CalB/BSA CLEA can effectively catalyze the green synthesis of isobutyl propionate from propionic acid and isobutyl alcohol using solid/gas biocatalysis.

How does the study justify solid/gas (S/G) biocatalysis over chemical synthesis?

S/G biocatalysis is framed as more sustainable because it avoids toxic catalysts and harsh conditions typical of chemical routes, while enabling environmentally safer waste handling.

What comparative performance result is reported between CalB-CLEA in S/G and a commercial CalB catalyst?

The commercial CalB (ImmoPlus) gives a higher yield, but CalB-CLEA shows much higher total turnover number (TTN) and specific space-time yield (STYspe) under steady-state conditions, indicating better productivity efficiency.

Sep 29, 2026

Upload by วิน