Xyn10D-Fae1A：Bifunctional xylanase/ferulic acid esterase
Xyn10D-fae1A is a bifunctional enzyme, which has the activity of ferulic esterase and xylanase. Feruloyl esterase can hydrolyze ferulic acid ester groups, which are responsible for attaching in complex cellular cell wall structures. Xylanase can hydrolyze plant cell wall component xylan. This part is responsible for pretreatment of straw.
Sequence and Features
- 10COMPATIBLE WITH RFC
- 12COMPATIBLE WITH RFC
- 21COMPATIBLE WITH RFC
- 23COMPATIBLE WITH RFC
- 25Illegal NgoMIV site found at 534
Illegal AgeI site found at 381
Illegal AgeI site found at 628
- 1000Illegal SapI.rc site found at 1236
This gene codes for a protein of 726 amino acids with a molecular mass of 82.3 kDa.
Detection of ferulic acid
To detect the expression of Xyn10D-Fae1A gene(piGEM2018-Module001), we converted carrying Xyn10D-Fae1A gene to co-culture with straw culture medium. Gas chromatography was used to detect ferulic acid . The ferulic acid production was monitored by periodically taking samples from the fermentation liquid of E. coli BL21(DE3) carrying Xyn10D-Fae1A gene. GC results showed that the peak of ferulic acid was appeared after fermentation for 24h with the strain carrying Xyn10D-Fae1A gene, while no ferulic acid was detected in the sample of E. coli BL21(DE3) without vector (Fig. 1).
The ferulic acid peak was further analyzed by using GC-MS (Fig. 2).
Enzyme activity of xylanase
Xylanase can decompose xylan to xylose. Comparing with wild type,our E. coli carrying Xyn10D-Fae1A gene take effect  (Fig. 3).
Enzyme activity of ferulic acid esterase
Ferulic acid esterase can decompose 4-nitrophenyl trans-ferulate to produce p-nitrophenol and ferulic acid. We used crude extract fraction of strain to detect enzyme activity .
The results (Fig. 4) showed that the ferulic acid enzyme activity of our strain was much higher than that of the wild type.
 Qiu-Yi, L. I., Gan, G. P., Wang, G. Z., & Liu, Y. W. (2007). Determination of ferulic acid in ligusticum chuanxiong hort. oil by gc. Lishizhen Medicine & Materia Medica Research.
 Shen C, Li R, Hu T & Yan K. 2011. Determination of xylanase activity with DNS method. Dyeing & Finishing, 2: 35-39.
 Zhang S, Pei X & Wu Z. 2009. Cloning and expression of feruloyl esterase A from Aspergillus niger, and establishment of fast activity detection methods. Chinese Journal of Applied & Environmental Biology, 2: 276-279.