Colony mass spectrometry analysis of L. lactis CSK2775, L. lactis CSK3281 (nisin transconjugant, Nis+), L. lactis CSK3594 (lacticin transconjugant, Ltn+), and L. lactis CSK3533 (nisin and lacticin double producer, Nis+, Ltn+). Masses corresponding to the bacteriocins are indicated. Inset photos show inhibition zones produced by each strain against the indicator strain L. lactis HP.