title: Spoilage potential of Vagococcus salmoninarum in preservative-free, MAP-stored brown shrimp and differentiation from Brochothrix thermosphacta on streptomycin thallous acetate actidione agar.
abstract: OBJECTIVE
  During a previous study concerning brown shrimp (Crangon crangon), selective streptomycin thallous acetate actidione (STAA) agar was used to determine the growth of Brochothrix thermosphacta. However, the growth of Vagococcus salmoninarum on this medium was also noticed. This study explores the spoilage potential of this organism when inoculated on sterile shrimp.
  
  
  RESULTS
  Isolates growing on STAA were identified using (GTG)5 clustering followed by partial 16S rRNA gene sequence analysis. Their biochemical spoilage potential was analysed for H2 S production and enzymatic activities were tested using an APIZYM test. Headspace solid phase micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used to analyse the volatile organic compounds (VOCs) produced during storage of inoculated shrimp.
  
  
  CONCLUSIONS
  Fifty-five per cent of isolates taken from STAA could be identified as V. salmoninarum, while no apparent morphological difference with B. thermosphacta isolates was identified upon the prescribed incubation conditions. For isolates identified as V. salmoninarum, production of 2-heptanone, 2-nonanone, 2-undecanone was found, as was the possibility to form H2 S.
  
  
  CONCLUSIONS
  When using the STAA medium for detecting B. thermosphacta, one should consider the possible abundant presence of V. salmoninarum as well. Based on this study, V. salmoninarum does not exhibit great spoilage potential, although it can produce H2 S and formed VOCs which are also found in other spoiled seafood products.
authors.affiliation: Technology and Food Science Unit - Food safety, Institute of Agriculture and Fisheries Research, Melle, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Calliauw
authors.affiliation: Departement of Food Safety & Food Quality, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Horemans
authors.affiliation: Technology and Food Science Unit - Food safety, Institute of Agriculture and Fisheries Research, Melle, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Broekaert
authors.affiliation: Centre for Food and Microbial Technology and Leuven Science and Nutrition Research Centre (LFoRCe), KU Leuven, Leuven, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Michiels
authors.affiliation: Technology and Food Science Unit - Food safety, Institute of Agriculture and Fisheries Research, Melle, Belgium.|Department of Pathology, Bacteriology and Poultry Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Heyndrickx
mesh_terms: D000362:Agar; D000818:Animals; D058640:Brochothrix / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D003513:Cycloheximide; D056569:Enterococcaceae / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D005506:Food Contamination / Q000032:analysis; D018857:Food Packaging; D008401:Gas Chromatography-Mass Spectrometry; D007659:Ketones / Q000378:metabolism; D009942:Organometallic Compounds; D033561:Penaeidae / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000737:chemistry; D017747:Seafood / Q000382:microbiology*; D012758:Shellfish; D013307:Streptomycin; D055549:Volatile Organic Compounds / Q000032:analysis / Q000378:metabolism
chemical_list: D007659:Ketones; D009942:Organometallic Compounds; D012336:RNA, Ribosomal, 16S; D055549:Volatile Organic Compounds; C011917:2-heptanone; D000362:Agar; D003513:Cycloheximide; C026995:thallium acetate; D013307:Streptomycin; C526928:undecan-2-one; C026636:2-nonanone
keywords: STAA; Vagococcus salmoninarum; brown shrimp; spoilage potential; volatile organic compounds