Assessment of Acidified Fibrous Immobilization Materials for Improving Acetone-Butanol-Ethanol (ABE) Fermentation

Abstract

Acetone-butanol-ethanol (ABE) fermentation using Clostridium acetobutylicum is a process that can be used to produce butanol, which can be utilized as an alternative to petroleum-based fuels. Immobilization of the bacteria using three different fibrous materials was studied in order to see how to improve the ABE fermentation process. The results were compared to those of non-immobilized bacteria. Modal and charcoal fibers had OD levels below one at 72 h with the butanol concentration reaching 11.0 ± 0.5 and 10.7 ± 0.6 g/L, respectively, each of which were close to the free cell concentration at 11.1 ± 0.4 g/L. This suggests that bacteria can be efficiently immobilized in these fibrous materials. Although an extended lag phase was found in the fermentation time course, this can be easily solved by pre-treating fibrous materials with 3.5% HCl for 12 h. From comparisons with previous studies, data in this study suggests that a hydrophilic surface facilitates the adsorption of C. acetobutylicum.

Polycationic Surfaces Promote Whole-Cell Immobilization and Induce Microgranulation of Clostridium saccharoperbutylacetonicum N1-4 for Enhanced Biobutanol Production

“…Specifically, the butanol titer reached the maximum when the cation density of cotton was around 6 nmol(+)/m 2 (Figure 5A) and when the cation density of MCC was around 350 nmol(+)/m 2 (Figure 5B). The big difference in the optimum cation density The CHTPA/cotton molar ratios are 4.500 (1), 2.700 (2), 1.800 (3), 0.900 (4), 0.675 (5), 0.450 (6), and 0.225 (7). CHTPA/MCC molar ratios are 4.500 (8), 2.700 (9), 1.800 (10), 0.900 (11), 0.675 (12), 0.450 (13), and 0.225 (14).…”

“…Cells can be immobilized through various mechanisms including entrapment, adsorption, encapsulation, chemical bonding, and cell aggregation . Different materials have been tested for cell immobilization in clostridial fermentation such as lignocellulosic biomass, natural and synthetic fibers, synthetic polymers, metals, ceramics, clays, and zeolites . Fibrous cellulosic and lignocellulosic materials are often used as immobilization carriers because they are cheap, widely available, and easy to modify.…”

Production of Bio-Derived Fuels and Chemicals

“…These facts were echoed by Li's group whose article focused on the feasibility of using acidified fibrous immobilization materials (cotton balls, modal fiber and charcoal fiber) to improve production [13]. By pre-treating modal fiber materials with 3.5% HCl for 12 h, the structure of modal fibers was etched to decrease mass transfer resistance, increased adsorption of C. acetobutylicum to the material, and ultimately, enhanced the kinetics of acetone butanol ethanol (ABE) fermentation [13].…”