Genome Sequence of a Food Spoilage Lactic Acid Bacterium, Leuconostoc gasicomitatum LMG 18811 ^T , in Association with Specific Spoilage Reactions

Abstract

Leuconostoc gasicomitatum is a psychrotrophic lactic acid bacterium causing spoilage of cold-stored, modified-atmosphere-packaged (MAP), nutrient-rich foods. Its role has been verified by challenge tests in gas and slime formation, development of pungent acidic and buttery off odors, and greening of beef. MAP meats have especially been prone to L. gasicomitatum spoilage. In addition, spoilage of vacuum-packaged vegetable sausages and marinated herring has been reported. The genomic sequencing project of L. gasicomitatum LMG 18811T was prompted by a need to understand the growth and spoilage potentials of L. gasicomitatum, to study its phylogeny, and to be able to knock out and overexpress the genes. Comparative genomic analysis was done within L. gasicomitatum LMG 18811T and the three fully assembled Leuconostoc genomes (those of Leuconostoc mesenteroides, Leuconostoc citreum, and Leuconostoc kimchii) available. The genome of L. gasicomitatum LMG 18811 T is plasmid-free and contains a 1,954,080-bp circular chromosome with an average GC content of 36.7%. It includes genes for the phosphoketolase pathway and alternative pathways for pyruvate utilization. As interesting features associated with the growth and spoilage potential, LMG 18811 T possesses utilization strategies for ribose, external nucleotides, nucleosides, and nucleobases and it has a functional electron transport chain requiring only externally supplied heme for respiration. In respect of the documented specific spoilage reactions, the pathways/genes associated with a buttery off odor, meat greening, and slime formation were recognized. Unexpectedly, genes associated with platelet binding and collagen adhesion were detected, but their functionality and role in food spoilage and processing environment contamination need further study.

Multilocus Sequence Typing of Leuconostoc gelidum subsp. gasicomitatum, a Psychrotrophic Lactic Acid Bacterium Causing Spoilage of Packaged Perishable Foods

“…T (11), based on their locations in the genome and their putative roles as housekeeping genes under neutral selection. Three of the 10 genes (atpA, dnaA, and rpoA) were rejected because they either contributed with too little variation or were located too close to another gene on the chromosome.…”

“…gasicomitatum strains. Johansson et al (11) showed that the type strain, LMG 18811 T , isolated in spoiled MAP broiler meat and belonging to this group, has genes associated with adhesion, e.g., an ortholog for the putative collagen adhesion protein enabling biofilm formation in staphylococci. However, L. gelidum subsp.…”

“…gasicomitatum has been associated with spoilage of MAP poultry products in Finland (2). The vegetable strains in this study were isolated from spoiled carrots, lettuce, and cooked vegetable sausages during our spoilage investigations for the food industry (6,11). L. gelidum subsp.…”

“…T and annotated the spoilage-associated pathways (11). The aim of the present study was to utilize the genomic sequence to establish a multilocus sequence-typing (MLST) approach for the subspecies.…”

Metagenomic insights into the dynamics of microbial communities in food

“…This concept of SSO was introduced by Dalgaard (2000) and is defined as the part of the total microbiota responsible for spoilage. The inhibition of these SSO could extend the shelf life of marinated products but, on the other hand, the glucose and the acetic acid contained in this marinade selected the spoilageassociated Leuconostoc gasicomitatum and its close relative L. gelidum, two other SSOs (Johansson et al, 2011). Marination also caused changes in the OTU richness.…”