NOVELTY - A microorganism (I) belonging to the genus Geobacillus and capable of producing a solubilization enzyme that solubilizes organic solid matters such as organic sludge or biological sludge, is new.    USE - (I) Is useful for treating organic solid matters such as organic sludge or biological sludge, which involves solubilizing the organic solid matters using (I) (claimed), where the biological sludge includes fresh sludge and excessive sludge discharged from a production process or a waste treatment process of a food plant, a chemical plant, etc.    ADVANTAGE - (I) Has an excellent ability to solubilize various organic solid matters.    DETAILED DESCRIPTION - A new microorganism (I) belonging to the genus Geobacillus, is capable of producing a solubilization enzyme that solubilizes organic solid matters such as organic sludge or biological sludge, has a 16S rRNA gene comprising a fully defined 1495 (SEQ ID No: 1, derived from Geobacillus species SPT4), 1498 (SEQ ID No: 2, derived from Geobacillus species SPT5), 1495 (SEQ ID No: 3, derived from Geobacillus species SPT6) or 1498 (SEQ ID No: 4, derived from Geobacillus species SPT7) base pair sequence, given in the specification, and has the following properties:    (A) morphological property:    (1) form and size of a cell: width 0.7-0.8 microm, and length 2.0-4.0 microm;    (2) motility: positive; and    (3) formation of spore: positive;    (B) culture characteristics (ordinary agar (Nutrient agar) plate culture):    (1) form of colony: circular, smooth edged, and convex shaped;    (2) color: cream;    (3) glossiness: positive; and    (C) physiological characteristics:    (1) Gram's stain property: positive;    (2) reduction of nitrate: negative;    (3) production of indole: negative;    (4) production of a hydrogen sulfide: negative;    (5) use of citric acid: negative;    (6) urease: negative;    (7) oxidase: positive;    (8) catalase: positive;    (9) attitude with respect to oxygen: aerotropism;    (10) O-F test (glucose): negative /negative;    (11) production of the acid from saccharides, and gas: D-glucose acid (positive)/gas(negative);    (12) properties in fermentation test:    (a) D-glucose: positive;    (b) D-fructose: positive;    (c) D-mannose: positive;    (d) D-sorbitol: negative;    (e) inositol: negative;    (f) maltose: positive;    (g) trehalose: positive; and    (h)    (13) other physiological character:    (a) beta-galactosidase activity: negative;    (b) arginine dihydrase activity: negative;    (c) lysine decarboxylase activity: negative;    (d) tryptophan deaminase activity: negative;    (e) acetoin production: negative;    (f) gelatinase activity: positive; and    (g) ornithine decarboxylase activity: negative.    DESCRIPTION OF DRAWING(S) - The figure shows schematic representation the apparatus for treating organic waste using the novel Geobacillus microorganisms.    biological treatment tank (2)    precipitation tank (4)    solubilization tank (7)