Study On Purification And Partial Biological Activities Of The Polysaccharides And Proteins From Two Microalgae

Lectin antibiotic protein and polysaccharide were isolated and purified from two microalgae, Porphyridium cruentum and Chlorella pacifica, and were investigate their partial characterizations. The conclusions were as follows:1. Porphyridium cruentum lectin (PCL) was a glycoprotein with a relative molecular weight of 32.5kD~39.6kD, containing 28.4% neutral succharide. In its amino acid composition, Val has the highteat content, followed by Glu and Gly, but there were lack of Met His,. Arg and Pro. PCL could agglutinated erythrocytes from rabbit and pig .Further more, PCL could agglutinated four species of unicellular algae and some bacteria or fungia such as Rhizopus chinensis Saito Fasarium oxyssporam, Bacillus subtilis Cohn and Saccharomyces carlsbergengensis Hansen treated by heating. The agglutinating activity was sensitive to temperature change and stable over a wide pH range, but inhibited by the presence of some mono or bisaccharides and mucin. Inhibition of EDTA-Na2 was activated adding of Ca2+ Mn2+ and Zn2+2. Chlorella pacifica lectin (CPL) was a glycoprotein with a relative molecular weight of 63.9kD~70.kD, containing 10.8% neutral succharide. In its amino acid composition, Gly has the highteat content, followed by Glu and Asp, but there were lack of Pro. CPL could agglutinated erythrocytes from rabbit goat chicken and pig. Further more, CPL could agglutinated five species of unicellular algae and some bacteria or fungia such as Escherichia coli Castellani et Chalmers, Fasarium oxyssporam Piricularia oryzae Cav and Proteas valgaris Hauser treated by heating. The agglutinating activity was insensitive to temperature change and stable over a wide pH range, but inhibited by the presence of some mono or bisaccharides. Inhibition of EDTA-Na2 was activated adding of Ca2+ Mn2+andZn2+3. A antibiotic protein was isolated and purified from Porphyridium cruentum. In SDS-PAGE the protein appears two bands and their molecular weight were 21kD and 30kD, respectively. Analysis of amino acid composition suggests this protein contains of 17 amino acid, especially with high content of Glu> Gly and Asp. The protein was strongly activity against two fungi, Penicillium chrysogenum Thom and Ustilagu Scitaminea Sydow, and exhibited a moderate activity against Bacillus subtilis Cohn and Sarcinalutea Schroeter. This antibiotic protein was sensitive to temperature change.4. A antibiotic protein was isolated and purified from Chlorella pacifica, In SDS-PAGE the protein appears two bands and their molecular weight was 61kD and 70kD, respectively. Analysis of amino acid composition suggests this protein contains of 17 amino acid, especially with high content of Glu> Gly and Asp. The protein was strongly activity against two fungi, Penicillium chrysogenum Thom and Rhizopus chinensis Saito, the protein also exhibited a moderate antibacterial action against Staphylococcus aureus Roenbach and Ameromonas punctata. The protein was insensitive to temperature change. Ingeneral, antibiotic proteins from the two microalgae inhibited antifungal activities more strongly than antibacterial activity.5. Crude polysaccharides from Chlorella pacifica and Porphyridium cruentum were extracted by hot water .followed by deproteinizining(Sevag) and purified by DEAE-cellulose. Extracts obtained were tested the antibiotic activities using the agar disc diffusion method. The result showed that there were few differences between antibacterial activities and antifungal activities of polysaccharide extracts from Porphyridium cruentum, but it has strong activities against Pseudomonas fluorecens and Piricularia oryzae Cav. The minimum inhibitionconcentration (MICs) of polysaccharides against Piricularia oryzae Cav was 6.25 mg/ mL. The polysaccharide extract from Chlorella pacifica had more strong activity fugia than against bacteria. It showed strong activities aainst Rhizopus chinensis Saito Sarcina lutea Schroeter Aspergillus niger V.Tiegh Helminthos porium turcicum Pass and Piricularia oryzae Cav . The minimum inhibition concentration (MICs) of polysaccharides against Piricularia oryzae Cav and Rhizopus chinensis Saito was 6.25 mg/ mL.In a word, Porphyridium cruentum and Chlorella pacifica have richbiologically active compounds, so they have great value of development andutilization.