Abstract
Morphology and sulfate polysaccharide relationship were compared among
the three species in the Caulerpa collected from different habitats
in Thailand. Plants of Caulerpa sp. (CR), and C. racemosa
var. macrophysa (CMR) were collected from Rayong province, the C.
racemosa var. corynephora (CCT) from Trang and C. lentillifera
(CLC and CLP) from Chachoengsao, and Phetchaburi provinces, respectively.
Based on six morphological characters, the samples were divided into group 1
(CR, CLC and CLP) and group 2 (CMR and CCT). Crude polysaccharides of each
species were isolated in distilled water at 25-26 C to determine the
carbohydrate, sulfate and sugar contents. The extracts were analyzed using
chemical methods, IR spectroscopy, and thin-layer chromatography (TLC). The
highest yield of total carbohydrate was obtained from CLP (86.99%), while
the lowest value (25.83%) obtained from CMR. The extracts of CLC and CLP had
a higher sulfate content (14.67-15.78%) than CR (7.40%), CMR (5.54%) and CCT
(5.57%). The extracts showed a high substitution of sulfate ester groups,
with galactose and glucose as the major sugar component. Difference in
sulfate content was because of the individual algal species but not on
variety and location. The sulfate was high in the pyrenoid-absent algae (CR,
CLC and CLP) while low in the pyrenoid-containing species (CMR and CCT). The
presence of pyrenoid showed a negative correlation to the sulfate content (r
= -0.866, p<0.05) but not to the carbohydrate content.
