NOVELTY - Method for reducing time to initiate methane produced in a methane fermentation system using organic waste involves supplying microorganisms which have 16S ribosomal (r)RNA or 16SrDNA comprising base sequence which is detected with a specific primer set, and performing methane production using glycerol as a raw material in the methane fermentation system.    USE - The method is useful for reducing time to initiate methane produced in a methane fermentation system using organic waste (claimed).    ADVANTAGE - The method is rapid.    DETAILED DESCRIPTION - Method for reducing time to initiate methane produced in a methane fermentation system using organic waste involves supplying microorganisms which have 16S ribosomal (r)RNA or 16SrDNA comprising base sequence which is detected with a specific primer set, and performing methane production using glycerol as a raw material in the methane fermentation system. The primer set includes primer set 1 comprising (a) oligonucleotide which comprises base pair sequence or base pair sequence that is identical to the nucleotide sequence shown in SEQ ID NO: 1, and (b) oligonucleotide which comprises base pair sequence or base pair sequence that is identical to the nucleotide sequence shown in SEQ ID NO: 2, primer set 2 comprising (a) oligonucleotide which comprises base pair sequence or base pair sequence that is identical to the nucleotide sequence shown in SEQ ID NO: 3, and (b) oligonucleotide which comprises base pair sequence or base pair sequence that is identical to the nucleotide sequence shown in SEQ ID NO: 4, and (c) primer set 1 comprising (a) oligonucleotide which comprises base pair sequence or base pair sequence that is identical to the nucleotide sequence shown in SEQ ID NO: 5, and (b) oligonucleotide which comprises base pair sequence or base pair sequence that is identical to the nucleotide sequence shown in SEQ ID NO: 6. ctacgggaggcagcag (SEQ ID NO: 1), cgacttgttcttctctgaca (SEQ ID NO: 2), aaacctccgcaatgcgagca (SEQ ID NO: 3), gcccagctcttattcctgaagct (SEQ ID NO: 4), tttaccatgcgggcaaccgtgat (SEQ ID NO: 5), and ctgaacgcccaccggttaag (SEQ ID NO: 6). An INDEPENDENT CLAIM is included for composition comprising microorganism comprising nucleotide sequence to-be-detected by the above-mentioned primer set.