A mixture, comprising as active components at least one Paenibacillus strain, selected from the group consisting of: a) Paenibacillus strain Lu16774 deposited with DSMZ under Accession No. DSM 26969; b) Paenibacillus strain Lu17007 deposited with DSMZ under Accession No. DSM 26970; c) Paenibacillus strain Lu17015 deposited with DSMZ under Accession No. DSM 26971; and d) a bacterial strain which comprises a DNA sequence exhibiting d1) at least 99.6 % nucleotide sequence identity to the DNA sequences SEQ ID NO:4 or SEQ ID NO:9; or d2) at least 99.8 % nucleotide sequence identity to the DNA sequence SEQ ID NO:14; or d3) at least 99.9 % nucleotide sequence identity to the DNA sequences SEQ ID NO:5 or SEQ ID NO:10; or d4) at least 99.2 % nucleotide sequence identity to the DNA sequence SEQ ID NO:15; or d5) at least 99.2 % nucleotide sequence identity to the DNA sequences SEQ ID NO:6 or SEQ ID NO:11; or d6) at least 99.8 % nucleotide sequence identity to the DNA sequence SEQ ID NO:16; or d7) at least 99.8 % nucleotide sequence identity to the DNA sequences SEQ ID NO:7 or SEQ ID NO:12; or d8) at least 99.3 % nucleotide sequence identity to the DNA sequence SEQ ID NO:17; or d9) 100.0 % nucleotide sequence identity to the DNA sequences SEQ ID NO:8 or SEQ ID NO:13; or d10) at least 99.9 % nucleotide sequence identity to the DNA sequence SEQ ID NO:18. and wherein said at least one Paenibacillus strain is capable of producing the following compound: in a growth medium comprising at least one source of carbon and one source of nitrogen and B. amyloliquefaciens ssp. plantarum MBI600 in a synergistically effective amount. at least one Paenibacillus strain, selected from the group consisting of: a) Paenibacillus strain Lu16774 deposited with DSMZ under Accession No. DSM 26969; b) Paenibacillus strain Lu17007 deposited with DSMZ under Accession No. DSM 26970; c) Paenibacillus strain Lu17015 deposited with DSMZ under Accession No. DSM 26971; and d) a bacterial strain which comprises a DNA sequence exhibiting d1) at least 99.6 % nucleotide sequence identity to the DNA sequences SEQ ID NO:4 or SEQ ID NO:9; or d2) at least 99.8 % nucleotide sequence identity to the DNA sequence SEQ ID NO:14; or d3) at least 99.9 % nucleotide sequence identity to the DNA sequences SEQ ID NO:5 or SEQ ID NO:10; or d4) at least 99.2 % nucleotide sequence identity to the DNA sequence SEQ ID NO:15; or d5) at least 99.2 % nucleotide sequence identity to the DNA sequences SEQ ID NO:6 or SEQ ID NO:11; or d6) at least 99.8 % nucleotide sequence identity to the DNA sequence SEQ ID NO:16; or d7) at least 99.8 % nucleotide sequence identity to the DNA sequences SEQ ID NO:7 or SEQ ID NO:12; or d8) at least 99.3 % nucleotide sequence identity to the DNA sequence SEQ ID NO:17; or d9) 100.0 % nucleotide sequence identity to the DNA sequences SEQ ID NO:8 or SEQ ID NO:13; or d10) at least 99.9 % nucleotide sequence identity to the DNA sequence SEQ ID NO:18. a) Paenibacillus strain Lu16774 deposited with DSMZ under Accession No. DSM 26969; b) Paenibacillus strain Lu17007 deposited with DSMZ under Accession No. DSM 26970; c) Paenibacillus strain Lu17015 deposited with DSMZ under Accession No. DSM 26971; and d) a bacterial strain which comprises a DNA sequence exhibiting d1) at least 99.6 % nucleotide sequence identity to the DNA sequences SEQ ID NO:4 or SEQ ID NO:9; or d2) at least 99.8 % nucleotide sequence identity to the DNA sequence SEQ ID NO:14; or d3) at least 99.9 % nucleotide sequence identity to the DNA sequences SEQ ID NO:5 or SEQ ID NO:10; or d4) at least 99.2 % nucleotide sequence identity to the DNA sequence SEQ ID NO:15; or d5) at least 99.2 % nucleotide sequence identity to the DNA sequences SEQ ID NO:6 or SEQ ID NO:11; or d6) at least 99.8 % nucleotide sequence identity to the DNA sequence SEQ ID NO:16; or d7) at least 99.8 % nucleotide sequence identity to the DNA sequences SEQ ID NO:7 or SEQ ID NO:12; or d8) at least 99.3 % nucleotide sequence identity to the DNA sequence SEQ ID NO:17; or d9) 100.0 % nucleotide sequence identity to the DNA sequences SEQ ID NO:8 or SEQ ID NO:13; or d10) at least 99.9 % nucleotide sequence identity to the DNA sequence SEQ ID NO:18. d1) at least 99.6 % nucleotide sequence identity to the DNA sequences SEQ ID NO:4 or SEQ ID NO:9; or d2) at least 99.8 % nucleotide sequence identity to the DNA sequence SEQ ID NO:14; or d3) at least 99.9 % nucleotide sequence identity to the DNA sequences SEQ ID NO:5 or SEQ ID NO:10; or d4) at least 99.2 % nucleotide sequence identity to the DNA sequence SEQ ID NO:15; or d5) at least 99.2 % nucleotide sequence identity to the DNA sequences SEQ ID NO:6 or SEQ ID NO:11; or d6) at least 99.8 % nucleotide sequence identity to the DNA sequence SEQ ID NO:16; or d7) at least 99.8 % nucleotide sequence identity to the DNA sequences SEQ ID NO:7 or SEQ ID NO:12; or d8) at least 99.3 % nucleotide sequence identity to the DNA sequence SEQ ID NO:17; or d9) 100.0 % nucleotide sequence identity to the DNA sequences SEQ ID NO:8 or SEQ ID NO:13; or d10) at least 99.9 % nucleotide sequence identity to the DNA sequence SEQ ID NO:18. and wherein said at least one Paenibacillus strain is capable of producing the following compound: in a growth medium comprising at least one source of carbon and one source of nitrogen and B. amyloliquefaciens ssp. plantarum MBI600 in a synergistically effective amount.