Prevalence and risk factors of Avian Influenza Viruses among household ducks in Chattogram,Bangladesh     

Rahman  Md. Ashiqur  Belgrad  Joseph P.  Sayeed  Md. Abu  Abdullah  Md. Sadeque  Barua  Shanta  Chisty  Nurun Nahar  Mohsin  Md. Abu Shoieb  Foysal  Mohammad  Hossain  Mohammad Enayet  Islam  Ariful  Akwar  Holy  Hoque  Md Ahasanul 《Veterinary research communications》2022,46(2):471-480

Veterinary Research Communications - Avian influenza viruses (AIV) increase commercial and backyard poultry mortality and morbidity, reduces egg production, and elevates public health risk....  相似文献   

Identification and partial characterization of selected proteolytic enzymes in the digestive system of giant freshwater Prawn Macrobrachium rosenbergii (De Man) Postlarvae     

Mohamed Ayaz Hasan Chisty  Roshada Hashim  & Alexander Shu -Chien Chong 《Aquaculture Research》2009,40(5):519-525

Biochemical assays and substrate SDS-PAGE were conducted to partially characterize and identify various types of proteases present in the digestive tract of PL₁₅ giant freshwater prawn ( Macrobrachium rosenbergii ). Casein hydrolytic assay of the enzyme extracts showed major proteolytic activities at pH 3.0, 6.0 and 9.0, while assay of preincubated enzyme extracts with phenylmethylsulphonyl fluoride (PMSF), a serine protease inhibitor produced a 33.17% reduction in alkaline protease activity. When specific inhibitors tosyl-lysine chloromethyl ketone and tosyl-phenylalanine chloromethyl ketone were used, they resulted in a reduction in activity of proteases in the enzyme extracts by 82.41% and 55.03%, respectively, confirming the presence of trypsin and chymotrypsin, while ethylenediamine tetraacetic acid produced protease activity reduction in 33.92% showing the presence of metalloproteases in the digestive tract of the prawn. Further characterization of the alkaline proteases using SDS-PAGE technique, after incubating the extract in the presence or absence of specific inhibitors, produced six bands corresponding to molecular masses of between 13.48 and 136.1 kDa; two trypsin bands of 13.48 and 36.4 kDa, three chymotrypsin bands in the range of 23.0–73.4 kDa and one for metalloprotease of 136.1 kDa, all of which were identified from a zymogram. This study suggests that protein digestion in M. rosenbergii is initiated by an acid protease followed by a combination of action of alkaline proteases: trypsin, chymotrypsin and metalloproteases.  相似文献