Insoluble type 1 collagen fiber bovine achilles tendon

Anoxybacillus caldiproteolyticus 1A02591 (MCCC1A02591) was obtained from Marine Culture Collection of China (MCCC), which was isolated from the deep-sea sediment collected from the hydrothermal vent in the east of the Pacific Ocean (12.71°N, 103.91°W). Casein and elastin were purchased from Sigma (United States). Insoluble type I collagen fiber (bovine achilles tendon) was purchased from Worthington Biochemical Co. (United States), gelatin from Boston Biomedical Inc. (United States), and casamino acids from Sangon Biotech Co., Ltd. (Shanghai, China).

Skin of codfish (Gadous macrocephaius) was provided by Chinese Dayudao Group (Yantai, China) and was stored at −20 °C in polyethylene bags before hydrolysis. Strain SM9913, previously isolated from 1,855 m deep-sea sediment^{23 (link)}, was routinely cultured at 20 °C for 24 h in a sea water liquid medium (pH 8.0) containing 10 g/L peptone (Oxoid, England) and 5 g/L yeast extract (Oxoid, England), and then stored at 4 °C for short-term use. Dimethyl sulphoxide (DMSO), 1,1-diphenyl-2-picryl-hydrazylradical (DPPH•) and 3-(4,5-dimethylththiazoyl-2-yl)−2,5-diphenylte-2-H-trazoliumbromide (MTT) were purchased from Sigma (USA). DMEM and fetal bovine serum (FBS) were purchased from Gibco (USA). Human dermal fibroblasts, Japan white rabbits and KM mice were purchased from Shandong Academy of Medical Sciences, China. Insoluble type I collagen fiber (bovine Achilles tendon) was purchased from Worthington Biochemical Corporation (USA). All chemicals used in this study were of analytical reagent grade. Wheat bran, corn powder and bean powder were bought from a local farmer market.