Characterization of Feruloyl Esterase from Bacillus pumilus SK52.001 and Its Application in Ferulic Acid Production from De-Starched Wheat Bran

Abstract

Feruloyl esterase (FAE; EC 3.1.1.73) catalyzes the hydrolysis of the 4-hydroxy-3-methoxycinnamoyl group in an esterified sugar to assist in waste biomass degradation or to release ferulic acid (FA). An FAE-producing strain was isolated from humus soil samples and identified as Bacillus pumilus SK52.001. The BpFAE gene from B. pumilus SK52.001 was speculated and heterogeneously expressed in Bacillus subtilis WB800 for the first time. The enzyme exists as a monomer with 303 amino acids and a molecular mass of 33.6 kDa. Its specific activity was 377.9 ± 10.3 U/ (mg protein), using methyl ferulate as a substrate. It displays an optimal alkaline pH of 9.0, an optimal temperature of 50 °C, and half-lives of 1434, 327, 235, and 68 min at 50, 55, 60, and 65 °C, respectively. Moreover, the purified BpFAE released 4.98% FA of the alkali-acidic extractable FA from de-starched wheat bran (DSWB). When the DSWB was enzymatically degraded by the synergistic effect of the BpFAE and commercial xylanase, the FA amount reached 49.47%. It suggested that the alkaline BpFAE from B. pumilus SK52.001, which was heterologously expressed in B. subtilis WB800, possesses great potential for biomass degradation and achieving high-added value FA production from food by-products.

Comparative Analysis of Bacterial Diversity between the Liquid Phase and Adherent Fraction within the Donkey Caeco-Colic Ecosystem

“…However, the abundance of fibrolytic enzymes including cellulose-1-4-beta-cellobiosidase and feruloyl esterase were increased along the donkey hindgut. Ferulic acid esterases are enzymes that cleave the ester bond between xylans' primary polysaccharide chain and monomeric or dimeric ferulates, which are essential for complete degradation of plant cell wall polysaccharides [29]. Previous studies have noted that feruloyl esterase is a key lignin-degrading enzyme in hydrolyzing the cross-linkages in the plant cell wall through phenolic compounds [30].…”

Effective Biotransformation of Variety of Guaiacyl Lignin Monomers Into Vanillin by Bacillus pumilus

“…B. pumilus is one of the rhizobacteria which shows a good adaption to the environment ( Liu et al, 2021 ). The practical application of the enzymatic systems from B. pumilus generally exhibits good performance in the alkaline environment, such as laccase, feruloyl esterase, and endoxylanase ( Asha Poorna and Prema, 2007 ; Duan et al, 2021 ; Liu et al, 2021 ). In our study, the conversion of isoeugenol to vanillin by monooxygenases in the alkaline environment was more effective than that in the acidic environment, implying that B. pumilus ZB1 and its enzymatic systems could keep biological activity in an extreme environment and improve lignin biotransformation for vanillin production.…”

Enhanced Extracellular Production and Characterization of Sucrose Isomerase in Bacillus subtilis with Optimized Signal Peptides

“…Bacillus subtilis has been utilized extensively in commercial enzyme production. Bacillus subtilis possesses a number of advantages, including nonpathogenicity, suitability for large-scale fermentation, and a diverse toolkit for genetic manipulation [ 16 , 17 , 18 , 19 , 20 ]. In addition, various signal peptides and promoters can be used to achieve effective heterologous protein expression in Bacillus subtilis [ 16 , 21 , 22 ].…”