ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 8, pp. 1341!1346. + Pleiades Publishing, Inc., 2006.
Original Russian Text + E.M. Tretenichenko, V.M. Datsun, L.N. Ignatyuk, L.A. Nud’ga, 2006, published in Zhurnal Prikladnoi Khimii, 2006, Vol. 79,
No. 8, pp. 1353!1358.
AND POLYMERIC MATERIALS
Preparation and Properties of Chitin and Chitosan
from a Hydroid Polyp
E. M. Tretenichenko, V. M. Datsun, L. N. Ignatyuk, and L. A. Nud’ga
Far-Eastern State Technical Fishery University (Dal’rybvtuz), Vladivostok, Russia
Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg, Russia
Received March 30, 2006
Abstract-The chemical composition of Obelia longissima hydroid polyp from mariculture system fouling
community was examined. Conditions for chitin recovery and chitosan preparation thereof were developed.
The initial raw material, chitin, and chitosan were characterized by electron microscopy, infrared spectroscopy,
and X-ray diffraction analysis. Also, certain qualitative characteristics of these materials were determined.
Various marine organisms are responsible for foul-
ing of hydrobiotechnical systems for mariculture cul-
tivation. Among them a significant proportion (123
32.2%) belongs to Obelia longissima (Hydrozoa) hy-
droid polyp. The skeleton of the hydroid polyp is
formed by a chitinoid substance. Large volumes of
the fouling organisms, as well as the possibility of
cultivation of the polyp, make reasonable an elucida-
tion of its suitability as a source of chitin [1, 2].
In this study we identified the chemical composi-
tion of the polyp skeleton, elucidated the possibility
of recovery of chitin thereof, developed a method for
preparation of a chitin derivative, chitosan, and com-
prehensively characterized the resulting products.
We examined marine biological fouling organisms,
uncrushed O. longissima and its processing products,
chitin and chitosan.
Chitin was recovered by successive extraction of
the concomitant substances from the chitin-containing
raw material. Extraction of protein substances (de-
proteinization) was carried out in 4% aqueous sodium
hydroxide at the raw material : alkali fluid ratio M =
1 : 4 and temperature of 95397oC for 60 min. De-
mineralization was carried out with 4% hydrochloric
acid at room temperature for 30 min at M = 1 : 4.
The deproteinization and demineralization stages were
twice repeated in succession.
Chitosan was obtained by base deacetylation with
50% aqueous sodium hydroxide at M = 1 : 5 and
temperatures of 80, 100, and 120oC for 10, 30, and
The moisture and ash contents, as well as the con-
tent of protein substances (by the Kjeldahl method)
in the initial raw material were determined in accor-
dance with GOST (State Standard) 7636385. The
amount of lipids was determined by extraction with
petroleum ether according to GOST 13893368.
The content of protein substances in chitin was
determined on a Biochrom-30 (Cambridge) amino
acid analyzer after sample preparation by acid hydro-
lysis [3, 4].
The kinematic viscosity of the chitosan solutions
was determined according to the appropriate TU
(Technical Specifications) .
The changes of the microsctructure of the initial
raw material during treatment with acid and base
agents, as well as those of the microstructure of chitin
and chitosan, were monitored with an SEM LEO-430
scanning electron microscope at the 0400 magnifi-
cation. The electrically conducting coating was ap-
plied by vacuum thermal sputtering of carbon .
The IR absorption spectra of chitin in KBr pellets
were measured on a Spectrum BX-II (Perkin Elmer)
spectrometer, and the IR spectra of the chitosan films
on calcium fluoride supports, on a Vector-22 (Bruker)
IR Fourier spectrometer.