High temperature resistant α amylase

Artichoke waste was obtained as a byproduct of canned artichoke processing from Huimei Agricultural Technology Co., Ltd. (Changde, China). Alkaline protease (enzyme activity ≥ 200 U/mg), high-temperature- resistant α-amylase (enzyme activity ≥ 40 U/mg) and diastatic enzyme (enzyme activity ≥ 10 U/mg) were obtained from Shanghai Yuanye Biotechnology Co., Ltd. (Shanghai, China). All other chemicals were of analytical grade. Basal diet (21% casein, 0% ADF, 7% sunflower oil, 1% cholesterol, 15% sucrose, 51.2% starch, 0.3% methionine, 3.6% minerals, 1% mixed vitamins), ADF special diet (basal diet plus 2% ADF), HPH-ADF special diet (basal diet plus 2% HPH-ADF) and CM-ADF special diet (basal diet plus 2% CM-ADF) were prepared by Jiangsu Medison Biomedical Co. (Jiangsu, China). The kits for measurement of glutathione peroxidase (GSH-PX) were obtained from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). The kits for measurement of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine (CREA-S) and urea were obtained from Shenzhen Mindray Bio-medical Electronics Co. Ltd. (Shenzhen, China). Cadmium chloride (CdCl₂) of analytical grade was supplied by Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China).

Fresh soybean residue was provided by Kangle Tofu Workshop (Changchun, China). Soybean residue should be dried for 24 h at 55 °C before reuse. Saccharomyces cerevisiae strain BNCC337309 was obtained from the BeNa Culture Collection (Beijing, China). The KC205 LAB strain was isolated and screened from homemade pickled cabbage juice by the food microbiology team of the Agro-product Process Institute of the Jilin Academy of Agricultural Sciences, and has the characteristics of strong acid production and acid resistance.
High temperature-resistant α -amylase (2 × 10⁴ U/mL), papain (800 U/mg), and amyloglucosidase (1 × 10⁵ U/mL), were purchased from Shanghai Yuanye Bio-Technology Co., Ltd. (Shanghai, China). Peptone, yeast extract fermentation, glucose, NaCl, beef extract, anhydrous sodium acetate, sodium citrate, K₂HPO₄, MgSO₄, MnSO₄ and Tween 80 were all purchased from Sangon Biotech Co., Ltd. (Shanghai, China). All chemicals were of analytical grade or better.