Maltose

Pseudarthrobacter sp. TBRC 2005 was provided by the Thailand Bioresource Research Center (TBRC) (www.tbrcnetwork.org). The bacterial strain was cultivated at 30 °C in nutrient broth for genomic DNA extraction. Escherichia coli DH5α was used as a host for plasmid propagation and E. coli BL21(DE3) (Invitrogen, Carlsbad, CA, USA) was used for recombinant protein production. The pJET1.2 vector and pET28a vectors (Novagen, Darmstadt, Germany) were used for cloning and protein expression, respectively. Maltose and trehalose used as standardss for analysis were purchased from Megazyme (Wicklow, Ireland). All analytical-grade chemicals and reagents used in this work were purchased from Sigma-Aldrich, Merck and Fluka.

The acidothermophilic Alicyclobacillus sp. A4 (whole genome sequenced) isolated from the hot spring water was stored in our laboratory [1 (link)]. GH3 β-glucosidase Bgl3A derived from Talaromyces leycettanus JCM12802 [376] was used as the reference. Ni²⁺-affinity beads from Suzhou Beaver Biomedical Engineering (China), and glucose oxidation (GOD-POD) kit from Beijing Leadman (China) were purchased. Substrates of p-nitrophenyl β-d-glucopyranoside (pNPG), p-nitrophenyl α-l-arabinofuranoside (pNPAf), p-nitrophenyl β-d-xylopyranoside (pNPX), barley β-glucan, lichenan, Avicel, and standard samples of daidzein, glycitein and genistein from Sigma-Aldrich (USA), cellobiose to cellohexose, laminaritetraose and maltose from Megazyme (Ireland), and daidzin from Tokyo Chemical Industry were obtained. The soybean meal was purchased from local market. All the other reagents were of analytical grade and commercially available.