Mechanistic insights into co-culture inhibition of pellicle formation in fermented chili peppers by Pediococcus ethanolidurans M1117.

Abstract

Pellicle formation in pickles is detrimental, yet current inhibition methods are limited, necessitating the exploration of novel strategies and underlying mechanisms. This study identified Pichia kudriavzevii M420 as the primary microorganism responsible for pellicle formation in fermented chili peppers, which significantly reduced the levels of organic acids, free amino acids, and aroma compounds. Consequently, this altered the sensory profile of pickles by diminishing sourness and sweetness, increasing bitterness, and introducing a wine-like flavor along with other undesirable odors, thereby compromising overall quality. Co-culturing with Pediococcus ethanolidurans M1117 effectively inhibited pellicle formation through microbial interactions with P. kudriavzevii M420. Transcriptome analysis revealed substantial downregulation of genes in P. kudriavzevii M420, particularly those involved in energy metabolism, genetic information processing, and cellular functions. Notably, inhibition of protein synthesis was identified as a crucial mechanism in preventing pellicle formation. These findings provide deep insights into the molecular mechanisms underlying pellicle formation and highlight the potential of P. ethanolidurans M1117 as an innovative biocontrol strategy to enhance the quality and safety of fermented chili peppers.