title: Enzymatic extraction and characterisation of a thermostable collagen from swim bladder of rohu (Labeo rohita).
abstract: BACKGROUND
  The fish swim bladder is considered as a potential source of realistic collagen. Currently, processing of the Indian major carp rohu (Labeo rohita) generates an enormous quantity of non-edible by-products, including swim bladders, which are discarded as waste with no commercial value. In the present study, collagen was prepared from rohu swim bladder and its physicochemical and fibril-forming capacities were assessed.
  
  
  RESULTS
  The collagen isolated from rohu swim bladder was characterised as type I, containing α1 and α2 chains with triple helical structure by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, fourier transform infrared spectroscopy and amino acid analysis. The extracted collagen denaturation temperature was found to be 42.16 °C by differential scanning calorimetry analysis and also exhibited a high solubility in the presence of low NaCl concentrations (0-0.6 mol L-1). The extracted collagen exhibited a high fibril-formation capacity at a NaCl concentration of 1.5 mol L-1. Examination of the microstructure of collagen by scanning electron microscopy (SEM) showed a porous, sheet-like film and a multilayered structure. The fibril formation capacity of collagen was also confirmed using SEM analysis.
  
  
  CONCLUSIONS
  The rohu swim bladder type I collagen was successfully extracted using an enzymatic method with a yield of 465.2 g kg-1(dry weight basis) and was characterised as a well maintained triple helical structure. The extracted collagen exhibited a high fibril-forming ability. The results of the present study confirm that utilisation of rohu swim bladder will open up a new avenue for the better disposal of by-products and also help to minimise environmental pollution issues. © 2016 Society of Chemical Industry.
authors.affiliation: Academy of Scientific and Innovative Research, CSIR-Central Food Technological Research Institute, Mysuru, 570020, India.|Meat and Marine Sciences Department, CSIR-Central Food Technological Research Institute, Mysuru, 570020, India.
authors.forename: Pal
authors.initials: P
authors.lastname: Gaurav Kumar
authors.affiliation: Academy of Scientific and Innovative Research, CSIR-Central Food Technological Research Institute, Mysuru, 570020, India.|Meat and Marine Sciences Department, CSIR-Central Food Technological Research Institute, Mysuru, 570020, India.
authors.forename: Thadathil
authors.initials: T
authors.lastname: Nidheesh
authors.affiliation: Protein Chemistry and Technology Department, CSIR-Central Food Technological Research Institute, Mysuru, 570020, India.
authors.forename: Karadka
authors.initials: K
authors.lastname: Govindaraju
authors.affiliation: Meat and Marine Sciences Department, CSIR-Central Food Technological Research Institute, Mysuru, 570020, India.
authors.lastname: Jyoti
authors.affiliation: Academy of Scientific and Innovative Research, CSIR-Central Food Technological Research Institute, Mysuru, 570020, India.|Meat and Marine Sciences Department, CSIR-Central Food Technological Research Institute, Mysuru, 570020, India.
authors.forename: Puthanveetil Velappan
authors.initials: PV
authors.lastname: Suresh
mesh_terms: D000400:Air Sacs / Q000737:chemistry*; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002347:Carps; D024042:Collagen Type I / Q000737:chemistry* / Q000302:isolation & purification / Q000648:ultrastructure; D004591:Electrophoresis, Polyacrylamide Gel; D029941:Fish Proteins / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000596:Amino Acids; D024042:Collagen Type I; D029941:Fish Proteins
keywords: Labeo rohita; by-product valorisation; characterisation; fibril formation; pepsin soluble collagen; swim bladder