|
KMID : 1094720140190010058
|
|
Biotechnology and Bioprocess Engineering
2014 Volume.19 No. 1 p.58 ~ p.69
|
|
|
New chitin, chitosan, and O-carboxymethyl chitosan sources from resting eggs of Daphnia longispina (Crustacea); with physicochemical characterization, and antimicrobial and antioxidant activities
|
|
Kaya Murat
Cakmak Yavuz Selim
Baran Talat
Asan-Ozusaglam Meltem
Mentes Ayfer
Tozak Kabil Ozcan
|
|
|
Abstract
|
|
|
|
The paper describes the isolation and characterization of chitin and chitosan from Daphnia longispina resting eggs harvested from a reservoir. Resting eggs are fertilized eggs that are encased in chitinous shells called ‘ephippia’ and which ensure the survival of the Daphnia population in adverse conditions. The chitin-content of D. longispina resting eggs was found to be 23 ∼ 25% and the chitosan (having a 70 ∼ 75% deacetylation degree) yield of the chitin was 76 ∼ 77%. This high chitin-content indicates that D. longispina resting eggs can be exploited as a chitin source. The structure and thermal properties of chitin, extracted from D. longispina resting eggs, were characterized by employing Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction and scanning electron microscopy. The crystallinity of the chitin was found to be very low (48%). Physicochemicallycharacterized chitosan and the produced O-carboxymethyl chitosan were tested for their antimicrobial and antioxidant activity. It has been observed that chitosan displays antimicrobial activity against all pathogenic bacteria, whereas O-carboxymethyl chitosan only exhibits inhibition activity against L. garvieae, L. Monocytogenes ATCC 7644, Y. enterocolitica NCTC 11175 and S. aureus ATCC 25923. In a free radical scavenging activity assay, the IC50 values of chitosan, O-carboxymethyl chitosan and butylated hydroxytoluene were found to be 23.01, 56.43 and 0.05, respectively. The ferric-reducing power of O-carboxymethyl chitosan (EC50 = 8.30) indicated higher activity than chitosan (EC50 = 10.12).
|
|
|
KEYWORD
|
|
|
chitin, chitosan, O-carboxymethyl, physicochemical characterization, biological activity
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
 
|
|