NOVELTY - An isolated cyanobacterium capable of producing extracellular glucose, comprising portion of exogenous bacterial cellulose operon sufficient to express bacterial cellulose, is new.    USE - The cyanobacterium is useful for producing extracellular monosaccharides, disaccharides, oligosaccharides or polysaccharides comprising glucose which is used as renewable feedstock for animals and biofuel production, and for fixing carbon dioxide and reducing atmospheric carbon dioxide. The cyanobacterium is chosen from Synechococcus sp. PCC 7002, Synechococcus sp. ATCC 27264, S.leopoliensis UTCC 100, Agmenellum quadruplicatum UTEX B2268, Nostoc sp., Anabaena sp., Cyanothece sp. and Trichodesmium sp. (all claimed).    ADVANTAGE - The cyanobacterium enables production of extracellular monosaccharides, disaccharides, oligosaccharides or polysaccharide economically, and without polluting the environment and without producing any toxic byproducts.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) method of producing monosaccharides, disaccharides, oligosaccharides or polysaccharides comprising glucose, involves modifying cyanobacterium with portion of exogenous bacterial cellulose operon sufficient to express and produce extracellular glucose, growing the cyanobacteria under conditions that promote extracellular glucose production, and exposing the cyanobacteria to acidic condition, where the acid increases extracellular glucose production and optionally the viable cells are returned to the growth medium after glucose harvest for continued production of cells, biomass, cellulose or glucose; and    (2) method of fixing carbon into a photo biomass, involves growing the cyanobacterium to produce extracellular glucose in carbon dioxide containing growth medium, generating glucose with the cyanobacterium, and calculating amount of carbon dioxide fixed in the glucose to equate to one or more carbon credit units, where carbon dioxide is fixed into glucose at a level higher than unmodified cyanobacterium.