Exploring the interactions between Shewanella putrefaciens and Pseudomonas fluorescen on protein degradation of refrigerated large yellow croaker (Pseudosciaena crocea)

Abstract

Exploring the roles of dominant bacteria to spoilage is important in inhibiting spoilage. This study investigated related quality, protein degradation, and muscle microstructure in refrigerated large yellow croaker inoculated with Shewanella putrefaciens (S) and Pseudomonas fluorescens (P) as mono- or co-culture (SP). P. fluorescens had the most robust spoilage ability. P. fluorescens and the co-culture degraded major myofibrillar proteins and the links to disrupt muscle fibers, induced significant free water loss in muscle and formed amounts of trichloroacetic acid (TCA)-soluble peptides and total volatile basic nitrogen (TVB-N). S. putrefaciens caused severe mutual separation in myofibers. The competitive interactions between the two spoilage bacteria inhibited spoilage in the co-culture, while the numbers of differentially abundant peptides in the co-culture were enriched. Therefore, this study revealed competitive interactions of the co-culture of S. putrefaciens and P. fluorescens, which offered a thorough understanding of bacterial spoilage behavior in large yellow croaker.