High-frequency occurrence of surfactin monomethyl isoforms in the ferment broth of a Bacillus subtilis strain revealed by ion trap mass spectrometry - Kecskeméti Anita; Bartal Attila; Bóka Bettina; Kredics László; Manczinger László; Shine Kadaikunnan; Alharby Naiyf S.; Khaled Jamal M.; Varga Mónika; Vágvölgyi Csaba; Szekeres András (2018)