Characterization of sericin protein recovered from silk wastewaters

ÇAPAR G., Aygün S. S.

Turk Hijyen ve Deneysel Biyoloji Dergisi, cilt.72, sa.3, ss.219-234, 2015 (Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 72 Sayı: 3
  • Basım Tarihi: 2015
  • Doi Numarası: 10.5505/turkhijyen.2015.47113
  • Dergi Adı: Turk Hijyen ve Deneysel Biyoloji Dergisi
  • Derginin Tarandığı İndeksler: Scopus, TR DİZİN (ULAKBİM)
  • Sayfa Sayıları: ss.219-234
  • Anahtar Kelimeler: Amino acid, Molecular weight, Recovery, Sericin, Silk
  • Ankara Üniversitesi Adresli: Evet

Özet

Objective: This study aims to determine the characteristics of sericin protein recovered from silk wastewaters. Method: Sericin protein was recovered from silk wastewaters by membrane technology in Engineering Sciences Department of the Middle East Technical University between 2007 and 2008. The protein characterization study was completed in Ankara University Water Management Institute in 2012. The recovered protein was characterized in terms of molecular weight, moisture and ash contents, elemental and amino acid compositions. Dialysis was adopted to purify the protein. Sericin was extracted from native cocoons via hydrothermal processing. The solubility of recovered sericin samples at various pH values was determined. 2-D gel electrophoresis and MALDI-TOF analyses were used for protein identification. Results: The molecular weight range of recovered sericin was found as 40-176 kDa, with 86-96 kDa at the highest fraction of 79-97%. The recovered sericin was classifed as high-molecular weight sericin, which is suitable for making biomaterials and membranes. Moisture and ash contents were found as; 2.8-3.9% and 11.3-14.4%. In terms of elemental composition, C, H, N contents of recovered sericin were determined as; 36.7-45.3%, 5.4-8.8% and 10.2-16.8%, respectively. Properties of recovered sericin were quite similar to the reference sericin used in this study and those reported in literature. Solution pH significantly influenced the solubility of recovered sericin, so ethanol was observed to be a better precipitation agent than the acids used. Although some amino acids were lost during processing, the amino acid composition was acceptable. Sericin recovered from silk wastewater, with a serine content of 28.9%, had the potential of high moisture absorption. Conclusion: Sericin recovered from silk wastewaters is a promising raw material for potential applications in biomedical, cosmetics and pharmaceutical industries.