NISCAIR Online Periodicals Repository Collection: IJMS Vol.30(2) [June 2001]

Effect of shelf life of brown algae Sargassum wightii (Fucales/Phaeophyta) and Turbinaria conoides (Fucales/Phaeophyta) on alginic acid yield

Title: Effect of shelf life of brown algae Sargassum wightii (Fucales/Phaeophyta) and Turbinaria conoides (Fucales/Phaeophyta) on alginic acid yield

Authors: Ganesan, M; Mairh, O P; Rao, P V Subba

Abstract: Two brown algae Sargassum wightii and Turbinaria conoides were collected from the shores of Mandapam, (south east coast of India) then dried in air under sun and shade separately and stored at room temperature (30±2°C) for a period of 120 days. Their alginic acid yield was determined at regular intervals of 15 days period. In sun dried Sargassum wightii, (moisture content 84.81±2.31%),slight increase in alginic acid was observed from 30 days to 105 days whereas in shade dried alga (moisture 81.17±2.19%), slight decrease in alginic acid yield was obtained on 120^th day. In the case of Turbinaria conoides, depletion of alginic acid yield was more in shade dried alga (moisture 81.82±1.68%) and lesser in sun dried alga (moisture 83.96±2.5%). Therefore algae dried under direct sunlight and then stored in polythene bags increases the shelf life of above algae with respect to alginic acid content.

Page(s): 108-110

Impact of ultraviolet-B radiation on a marine red alga Kappaphycus alvarezii (Solieriaceae, Rhodophyta)

Title: Impact of ultraviolet-B radiation on a marine red alga Kappaphycus alvarezii (Solieriaceae, Rhodophyta)

Authors: Eswaran, K; Rao, P V Subba; Mairh, O P

Abstract: Kappaphykus alvarezii (Doty) Doty, an exotic alga to Indian waters is one of the best sources of kappa carrageenan. It was cultured and 60 days old algal fragments were subjected to UV-B radiation (280-320 nm) for 30 to 180 minutes, in the laboratory and analysed for pigments and carrageenam content. A gradual decrease in pigment levels, soluble protein content, carrageenan yield, and in the properties of carrageenan was observed as compared to control. More than 150 min exposure to UV-B radiation strongly inhibited pigment accumulation (63.90 to 92.20%), carrageenan yield (21.68 to 33.82%), gel strength (81.17 to 82.90%) and protein (48.42 to 58.20%).

Page(s): 105-107

Effect of temperature, salinity and light intensity on the growth of Gracilaria spp. (Gracilariales, Rhodophyta) from Japan, Malaysia and India

Title: Effect of temperature, salinity and light intensity on the growth of Gracilaria spp. (Gracilariales, Rhodophyta) from Japan, Malaysia and India

Authors: Raikar, S V; Iima, M; Fujita, Y

Abstract: Species of Gracilaria Greville were collected from Japan, India and Malaysia. Growth rate experiments were conducted at different temperatures, salinities and light intensities. Gracilaria vermiculophylla was found to be the fastest growing species with a growth rate of 22.32%. The growth rates of all species varied with salinities, but most of them attained their optimum growth rates at a normal seawater salinity 35‰. During the temperature tolerance experiments, it was observed that only G. vermiculophylla had a high temperature tolerance limit of up to 35°C. The temperate and the tropical species of Gracilaria were divided into three groups depending upon their optimum growth rates at the optimum temperatures. Group I consisting of G. arcuata and G. textorii from Japan with optimum growth rates at 20°C. Group II consisting of G. vermiculophylla, G. incurvata from Japan and G. foliifera, G. corticata from India with optimum growth rates at 25°C, while group III consisting of G. edulis from India and G. lichenoides from Malaysia with optimum growth rates at 30°C.

Page(s): 98-104

In vitro sperm agglutination and spermicidal activity of protein isolated from a marine mollusc Telescopium telescopium(Gastropoda)

Title: In vitro sperm agglutination and spermicidal activity of protein isolated from a marine mollusc Telescopium telescopium(Gastropoda)

Authors: Pakrashi, A; Datta, U

Abstract: The crude extract of spermatheca gland and its 50% ammonium sulphate fractionated protein (SF-50) were found to have sperm agglutinating and immobilizing effect on murine, ovine and human spermatozoa in vitro. The effects were dose-dependent. Human unwashed and washed sperm cells were found dead within 20 sec after application of 6 mg/ml and 5 mg /ml of SF-50 respectively. Hemolymph of the mollusc, however, showed much less agglutinating effect than that of SF-50. SF-50 caused coiling of spermatozoan tail, swelling of acrosome and neck region and extrusion of the sperm tail membrane. The protein is highly soluble in water and contains sialic acid binding lectin.

Page(s): 93-97