SKPI (shrimp Kunitz-type protease inhibitor) from Marsupenaeus japonicus is a member of serine protease inhibitors which play an important role in the arthropod immunity. To fully understand its function in the innate immunity of shrimp, the skpi gene was cloned into a modified pPIC9K vector with a 6-His tag and expressed by Pichia pastoris GS115. The secretory SKPI was purified from the medium with high purity by using Ni Sepharose High Performance. This results also indicated that the purified SKPI could inhibit the activity of trypsin specifically.
Animals ; Aprotinin ; biosynthesis ; genetics ; isolation & purification ; Pandalidae ; chemistry ; Pichia ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; Serine Proteinase Inhibitors ; biosynthesis ; genetics ; Trypsin Inhibitors

We analyzed the microbial diversity and quantity of nitrifying bacteria in the enrichment reactor by Terminal Restriction Fragment Length Polymorphism (T_RFLP), a cultured-independent molecular technique. The result indicated that nitrobacteria enriched the best, and the diversity index decreased 62.80% compared with the initial data. Nitrobacteria were predominant in the reactor. Meanwhile, we studied the microbial diversity before and after adding Nitrobacteria into shrimp ponds, and analyzed several major bacterial species that existed stably in the pond. According to the analysis by T_RFLP program, species including Brevibacillus brevis, Microbacterium lactium, Azoarcus indigens and Bordetella holmesii were the dominant bacteria in the ponds.
Animals ; Azoarcus ; genetics ; growth & development ; Bacteria ; classification ; genetics ; Biodiversity ; Bordetella ; genetics ; growth & development ; Brevibacillus ; genetics ; growth & development ; Nitrobacter ; classification ; genetics ; Pandalidae ; Polymorphism, Restriction Fragment Length ; Water Microbiology