Biotransformation of ferulic acid to vanillin in the packed bed-stirred fermentors

Abstract

We performed the biotransformation of ferulic acid to vanillin using Bacillus subtilis (B. subtilis) in the stirring packed-bed reactors filled with carbon fiber textiles (CFT). Scanning electron microscope (SEM), HPLC, qRT-PCR and ATP assay indicated that vanillin biotransformation is tightly related to cell growth, cellar activity and the extent of biofilm formation. The biotransformation was affected by hydraulic retention time (HRT), temperature, initial pH, stirring speed and ferulic acid concentration, and the maximum vanillin production was obtained at 20 h, 35 °C, 9.0, 200 rpm, 1.5 g/L, respectively. Repeated batch biotransformation performed under this optimized condition showed that the maximum productivity (0.047 g/L/h) and molar yield (60.43%) achieved in immobilized cell system were 1.84 and 3.61 folds higher than those achieved in free cell system. Therefore, the stirring reactor packed with CFT carrier biofilm formed by B. subtilis represented a valid biocatalytic system for the production of vanillin.

Prospecting the Potential of Agroresidues as Substrate for Microbial Flavor Production

“…Food and agricultural wastes are produced in large amounts and are rich in carbohydrates as well as other nutrients and thus can be used efficiently as substrate for the production of bulk chemicals, flavors per se under solid-state fermentation conditions. In addition to the supply of nutrients to the microbial cells, solid substrate also provides an anchorage site for the cells (Yan et al, 2016). The work of various researchers that have used food and agroresidues for microbial production of flavor compounds is summarized in Table 1.…”

Effects of processing on the phenolic contents, antioxidant activity and volatile profile of wheat bran tea

“…Previous study reported that 2methoxy-4-vinylphenol could be formed by thermal decarboxylation of ferulic acid (Di Gioia et al, 2009), which could be further converted into vanillin. The convention of ferulic acid to 2-methoxy-4-vinylphenol and vanillin could relieve the bitterness of ferulic acid, but decrease the antioxidant activity (Yan et al, 2016). The ketones of 3-hydroxy-2-butanone was disappeared in the soaking pretreated samples after the roasting process, possibly because of its low boiling point of 147.8°C (Pubchem.ncbi.nlm.nih.gov, 2019).…”

Comparative Studies of White-Rot Fungal Strains (Trametes hirsuta MTCC-1171 and Phanerochaete chrysosporium NCIM-1106) for Effective Degradation and Bioconversion of Ferulic Acid

“… 12 In another report, Bacillus subtilis could obtain 60.43% molar yield of vanillin in 20–30 h of incubation when initial concentration was 1.5 g L –1 of ferulic acid. 16 The biodegradation of ferulic acid involving bacteria has been widely reported with efficient yield. However, biodegradation of ferulic acid by fungi has been underexplored when compared to the studies related to bacteria.…”