Production conditions of exopolysaccharide from bacillus megaterium identified by 16S rRNA gene sequencing

THE BACILLUS megaterium exopolysaccharide [EPS] producer was isolated from the Egyptian soil and identified by molecular biology technique [16S rRNA]. It was found that the exopoiysaccharide showed a high yield after 72 hr, with an initial pH of 5.0, in 250 ml Erlenmeyer flasks containing 50 ml of culture, medium having 2% sucrose as a sole carbon source. The yeast extract [0.1%] and animonium chloride [0.1%] were the best organic and inorganic nitrogen source, respectively, as they gave the maximum EPS production. Optimum incubation temperature was found to be 35°C. Pretreated molasses from sugarcane and sugarbeet were used as carbon source and they gave a considerable yield [-tow fold] in relation to sucrose. The pretreatment of molasses by sulfuric acid showed high yield of polysaccharide and maximum yield coefficient

Isolation, purification and modification of sulfated polysaccharides from spirulina platensis and its antitumor activity

The water-soluble polysaccharide obtained from a blue-green alga Spirulina platensis by boiling water extraction and ethanol precipitation [118.25g kg[-1] on dry weight basis] was fractionated by DEAE-cellulose column chromatography, and purified by Sephacry-S300 giving two active fractions termed Ca-SPIIa and Ca-SPIIb. These fractions were mainly composed of glucose, galactose, rhamnose, fructose, glucouronic acid, mannose, xylose with the molar ratio [6.5: 3.3: 50.0: 38.5: 9.6: 1.5: 1.0] and [7.2: 3.5: 55.0: 40.2: 8.5: 2.0: 1.0] and sulfate percent [2.25% and 3.47%, respectively]. Calcium ion binding with the anionic part of a molecule was replaced with various metal cation and their inhibitory effects on Ehrlich Ascites Carcinoma Cells [EACC] was determined. The Ca-SPIIb was able to kill 95% of the tumor cells when they were incubated with 200microg. While, replacement of Ca[+2] with Na[+], Ag[+], Cu[+2] and H[+] reduced the activity