Characteristics of a new fibrinolytic enzyme produced from Rhizopus chinensis 12# / 生物工程学报

As a therapeutic agent in thrombosis the fibrinolytic enzymes are of interest and the search for a new enzyme continues. A novel fibrinolytic enzyme was produced from Rhizopus chinensis 120, which was screened from the starter for brewing rice wine in the South of China, by solid fermentation, and purified through ammonium sulfate precipitation, hydrophobic interaction, ionic exchange and gel filtration chromatographies. The purified enzyme hydrolyzed fibrin, it cleaved the alpha-, beta- and gamma-chains of fibrinogen simultaneously, and it also activated plasminogen to plasmin. The enzyme hydrolyzed N-Succinyl-Ala-Ala- Pro-Phe-pNA, and Km was 0.23 mmol/L and Kcat 16.36 s(-1). The optimal temperature of the enzyme for hydrolying fibrin was 45 degrees C, and the optimal pH range of 6.8 - 8.8. The isoelectric point of the enzyme estimated by isoelectric focusing electrophoresis was 8.5 +/- 0.1. The enzyme was a glycoprotein. EDTA, PCMB, PMSF inhibited the activety of the enzyme, and SBTI, Lys, TPCK, Aprotinine had none obvious inhibition, which suggested that the activity centre of the enzyme had hydrosulfuryl, metal and serine. The first 12 amino acids of the N-termimal sequence of the enzyme were NH2-Ser-Val-Ser-Glu-Ile-Gln-Leu-Met-His-Asn-Leu-Gly, and had none homology with that of other fibrinolytic enzyme from other microbes. The novel fibrinolytic enzyme from Rhizopus chinensis 12# has potential to become a therapeutic agent in thrombosis.

A STUDY ON BIOTECHNOLOGY OF GLYCOLIPID PRODUCED BY A BACILLUS COAGULANS / 微生物学通报

The biotechnology of glycolipid fermented b y a bacillus coagulans was studied and the fermentation pro cess in 10L bioreactor was conducted.Suitable medium contained 6% bean oil as ca rbon source,3 5g/L NaNO 3 as nitrogen source,0 75g/L yeast extract and some i no rganic salts.The fermentation temperature of 30℃,initial pH of 8 5,strring rev olution of 150～240r/min and fermentation period of 96h proved to be optimal.The yield of glycolipid in 10L bioreactor was 7 073g/L.