The present invention is directed to a composition for decomposing a majority of food waste into water and carbon dioxide comprising an effective combination of at least two species of microorganisms chosen from bacillus, lactobacillus, burkholderia, yeast fungus, eumycetes or any combinations thereof. A preferred embodiment comprises a combination of four different species of microbes having DNA sequences that correspond to SEQ ID Nos. 5-8 and which were deposited with the Korean Collection for Type Cultures (KCTC) on Mar. 8, 2007, and designated KCTC11085BP; KCTC11086BP; KCTC11087BP; KCTC11088BP, respectively. Also, presented by this invention is a device and methods for decomposing a majority of food waste into water and carbon dioxide using the microbial compositions presented herein.