Isolation of acid soluble collagen from daggertooth pike conger (Muraenesox cinereus) and evaluation of its antimicrobial activity

The study was conducted to isolate acid soluble collagen (ASC) from daggertooth pike conger eel and to evaluate the antimicrobial activity of the isolated protein. Conger eels were collected from Kochi harbour. The proximate composition of eel skin consisted of 68.73 per cent of moisture on a wet basis with a crude protein, crude fat and total ash of 30.24 per cent, 12.17 per cent and 2.16 per cent respectively on a dry matter basis. Conger eel skin collagen was isolated by treating with 0.5 M acetic acid after pretreatment with 0.1 N NaOH and 10 per cent butanol. Salting out and precipitation of ASC was carried out by adding NaCl to a final concentration of 2.3 M. Precipitated ASC was then dialysed against 0.1 M acetic acid for 24h and then in distilled water until neutral pH was obtained. The yield of ASC was 12.78 per cent on a wet basis and 31.95 per cent on a dry basis. The antimicrobial activity of ASC was determined by the agar diffusion method. ASC showed antimicrobial activity against both E. coli and S. aureus.