Fibrinolytic enzymes are important components in the treatment of thrombosis-associated disorders. A new bi-functional fibrinolytic enzyme, versiase, was identified from a marine-derived fungus Aspergillus versicolor ZLH-1. The enzyme was isolated from the fungal culture through precipitation with ammonium sulfate at 90% saturation. Additionally, it was further purified by DEAE-based ion-exchange chromatography, with a recovery of 20.4%. The fibrinolytic enzyme presented as one band on both SDS-PAGE and fibrin-zymogram, with a molecular mass of 37.3 kDa. It was elucidated as a member of metalloprotease in M35 family by proteomic approaches. The homology-modeling analysis revealed that versiase shares significant structural homology wuth the zinc metalloendopeptidase. The enzyme displayed maximum activity at 40 °C and pH 5.0. The activity of versiase was strongly inhibited by the metalloprotease inhibitors EDTA and BGTA. Furthermore, versiase hydrolyzed fibrin directly and indirectly via the activation of plasminogen, and it was able to hydrolyze the three chains (α, β, γ) of fibrin(ogen). Additionally, versiase demonstrated promising thrombolytic and anticoagulant activities, without many side-effects noticed. In conclusion, versiase appears to be a potent fibrinolytic enzyme deserving further investigation.

In this study, isolate Bacillus velezensis1-3 was selected out for its anti- Listeria potency, from which a novel circular bacteriocin, velezin, was purified out of the fermentate, and then characterized. Facilitated with a broad antibacterial spectrum, velezin has demonstrated decent inhibitive activity against of foodborne pathogen L. monocytogenes ATCC 19115. It exerted the antibacterial activity through damaging the membrane integrity of targeted cell and causing leakage of vital elements, including K⁺ ion. It was noteworthy that velezin also inhibited the biofilm formation by L. monocytogenes ATCC 19115. At the challenge of velezin, L. monocytogenes ATCC 19115 up-regulated expression of genes associated with membrane, ion transporters, stressing-related proteins as well as the genes responsible for the synthesis of small molecule. Taken together, velezin may have potential to be a candidate as natural additive used in food/feed in the future.