Molecular and Biochemical Characterization of a Novel Xylanase from Massilia sp. RBM26 Isolated from the Feces of Rhinopithecus bieti

Abstract

Xylanases sourced from different bacteria have significantly different enzymatic properties. Therefore, studying xylanases from different bacteria is important to their applications in different fields. A potential xylanase degradation gene in Massilia was recently discovered through genomic sequencing. However, its xylanase activity remains unexplored. This paper is the first to report a xylanase (XynRBM26) belonging to the glycosyl hydrolase family (GH10) from the genus Massilia. The gene encodes a 383-residue polypeptide (XynRBM26) with the highest identity of 62% with the endoxylanase from uncultured bacterium BLR13. The XynRBM26 expressed in Escherichia coli BL21 is a monomer with a molecular mass of 45.0 kDa. According to enzymatic characteristic analysis, pH 5.5 is the most appropriate for XynRBM26, which could maintain more than 90% activity between pH 5.0 and 8.0. Moreover, XynRBM26 is stable at 37°C and could maintain at least 96% activity after being placed at 37°C for 1 h. This paper is the first to report that GH10 xylanase in an animal gastrointestinal tract (GIT) has salt tolerance, which could maintain 86% activity in 5 M NaCl. Under the optimum conditions, Km, Vmax, and kcat of XynRBM26 to beechwood xylan are 9.49 mg/ml, 65.79 μmol/min/mg, and 47.34 /sec, respectively. Considering that XynRBM26 comes from an animal GIT, this xylanase has potential application in feedstuff. Moreover, XynRBM26 is applicable to high-salt food and seafood processing, as well as other high-salt environmental biotechnological fields, because of its high catalytic activity in high-concentration NaCl.

Gene Expression and Molecular Characterization of a Xylanase from Chicken Cecum Metagenome

“…XynA MG1 has two conserved motifs, DVVNE and TEXD, of the GH10 family xylanase which contained the two glutamate residues (E157 and E 262) predicted to be the catalytic sites, and an invariant asparagine (N156) preceding the glutamate in the first motif serving as an acid/base catalyst (Figure 1) [24–26]. …”

“…Furthermore, food materials washing, food processing, and fermentation under high salt condition could reduce cost because sterilization is not required [26]. In bakery industry, salt-tolerant XynA MG1 xylanase has potential applications in increasing the strength of the dough and adding flavor to baked goods [52].…”

Neotropical termite microbiomes as sources of novel plant cell wall degrading enzymes

“…This value is 3-and 22-fold higher than the experimental values for endo-xylanases from Paenibacillus sp., rGH10XynA (~100 IU/mg) and HC1 (~13 IU/mg), respectively 55,63 and 5-and 15-fold higher than that of Cohnella laevirobosi HY-21 (~58 IU/mg) 58 and Massilia sp. XynRBM26 (~20 IU/mg) 64 , respectively. Conversely, the specific activity of Xyl10E was of the same order as several xylanases recovered from functional metagenomics analyses, Xyn10N18 derived from bovine rumen (~242 IU/mg) 56 and SCXyl extracted from sugarcane soil www.nature.com/scientificreports www.nature.com/scientificreports/ bacteria (~200 IU/mg) 54 and Xyl-ORF19, from the gut microbiome of termite Globitermes brachycerastes exhibited a specific activity of (~114 IU/mg) 57 .…”

“…As previously noted, GH families 3, 5, 10, and 43 were the most abundant in both termite gut metagenomes. Members of GH family 10 have been extensively studied in terms of their capacity for hemicellulose deconstruction [54][55][56][57][58][59][60][61][62][63][64] . Accordingly, from the 26 modelled GHs, we selected the sequence KBCPBGKF 45352, a GH family 10 enzyme henceforth termed Xyl10E, for further structural analysis and biochemical characterization.…”

Presence of cellulolytic and xylanolytic activities in the gut fluid of grasshopper Oxya velox

“…Therefore, finding a novel source of xylanases is crucial. Although bacteria, fungi, terrestrial plant tissues, and digestive juices of animals are extensive sources of xylanases (Xu et al, 2016), the digestive extracts of many insects, for example, wood-feeding termites (Ali et al, 2017;Arakawa et al, 2009), red palm weevils (Mohamed et al, 2018), coffee berry borers (Padilla-Hurtado et al, 2012), larvae of scarab beetles (Holotrichia parallela ) (Sheng et al, 2015), also contain xylanases. Here, we report for the first time the presence of xylanase activity in the gut extract of O. velox.…”