ABSTRACT
Exopolysaccaharides (EPS) are carbohydrate polymers secreted by microbial cells, as a protective layer termed sheath or capsule. Their composition is variable. Optimisation of nutrient factors and the effect of some simple stresses on the ability of Cyanothece epiphytica to produce EPS were tested. Of the tested stresses, exposure to ozone for 50 s at 0.06 mg/L resulted in a relatively high EPS yield, without any damage to cell structure. EPS was characterised physicochemically. Chemically, it was found to be composed of pentoses arabinose and xylose; hexoses glucose, galactose and mannose; and the deoxyhexose fucose sugars which were sulphated and with different functional groups. EPS from C. epiphytica was found to be a good hydrophobic dispersant, an excellent emulsifier as well as a flocculant. Its potential as a biolubricant with characteristics better than the conventional lubricant 'grease' was revealed through analysis. This study gave the clue for developing a commercial technology to produce a less expensive and more environment-friendly natural lubricant from the cyanobacterium C. epiphytica for tribological applications.
Subject(s)
Cyanothece/chemistry , Industrial Microbiology , Lubricants/chemistry , Polysaccharides, Bacterial/biosynthesis , Lubricants/standards , Pentoses/chemistry , Polysaccharides, Bacterial/chemistryABSTRACT
Cyanobacterial KnowledgeBase (CKB) is a free access database that contains the genomic and proteomic information of 74 fully sequenced cyanobacterial genomes belonging to seven orders. The database also contains tools for sequence analysis. The Species report and the gene report provide details about each species and gene (including sequence features and gene ontology annotations) respectively. The database also includes cyanoBLAST, an advanced tool that facilitates comparative analysis, among cyanobacterial genomes and genomes of E. coli (prokaryote) and Arabidopsis (eukaryote). The database is developed and maintained by the Sub-Distributed Informatics Centre (sponsored by the Department of Biotechnology, Govt. of India) of the National Facility for Marine Cyanobacteria, a facility dedicated to marine cyanobacterial research. CKB is freely available at http://nfmc.res.in/ckb/index.html.
