Abstract
Brochothrix thermosphacta is one of the main spoilers in food, responsible for meat and seafood spoilage through the production of malodorous volatile organic compounds. The molecules produced by this bacterium depend on the substrate (meat or seafood) and the storage conditions such as gas mixtures used in the packaging. It seems also that the spoilage potential is strain dependent as production of diacetyl and acetoin, two molecules responsible for seafood spoilage, varies with strains. Therefore, this suggests the involvement of different metabolic functions depending on both food substrate and strain capacities. In this study, we selected two strains with different abilities to produce diacetyl and acetoin and compared their behavior after grown in beef or cooked peeled shrimp juices. We determined the genes upregulated by both strains depending on the growth substrate and those that were specifically upregulated in only one strain. The genes upregulated by both strains in meat or in shrimp juice revealed the importance of the substrate for inducing specific metabolic pathways. The examination of genes that were specifically upregulated in only one of the two strains revealed strain features associated to specific substrates and also strain-specific regulations of metabolic pathways putatively leading to different levels of spoilage molecule production. This shows that the spoilage potential of B. thermosphacta depends on nutrients provided by food substrate and on metabolic activity potential that each strain possesses.
Highlights
Brochothrix thermosphacta is commonly reported as belonging to the microbiota of a wide range of food matrices including various raw and processed meat and seafood products (Chaillou et al, 2015; Remenant et al, 2015; Illikoud et al, 2018a)
This study provided insights into the relative difference in gene expression and volatile organic compounds (VOCs) production by B. thermosphacta, during growth in meat or shrimp juice
The catabolism of meat or shrimp specific substrates may lead to different metabolisms depending on the food matrix
Summary
Brochothrix thermosphacta is commonly reported as belonging to the microbiota of a wide range of food matrices including various raw and processed meat and seafood products (Chaillou et al, 2015; Remenant et al, 2015; Illikoud et al, 2018a) This results from its ubiquitous nature and its ability to grow at the refrigerated temperatures in various atmosphere packaging used for. Different base substitutions in or upstream from genes encoding enzymes required for the production of spoilage molecules were noticed when comparing several B. thermosphacta genomes (Illikoud et al, 2018b) This suggests that different spoilage abilities among strains may rely on differences in gene expression or enzyme activity levels. We attempted to identify metabolic pathways involved in the spoilage potential of B. thermosphacta in meat and in shrimp
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
