Spoilage potential of Vagococcus salmoninarum in preservative-free, MAP-stored brown shrimp and differentiation from Brochothrix thermosphacta on streptomycin thallous acetate actidione agar
Calliauw, F.; Horemans, B.; Broekaert, K.; Michiels, C.; Heyndrickx, M. (2016). Spoilage potential of Vagococcus salmoninarum in preservative-free, MAP-stored brown shrimp and differentiation from Brochothrix thermosphacta on streptomycin thallous acetate actidione agar. J. Appl. Microbiol. 120(5): 1302-1312. https://dx.doi.org/10.1111/jam.13107 In: Journal of Applied Microbiology. Blackwell Science: Oxford. ISSN 1364-5072; e-ISSN 1365-2672, more | |
Keywords | Crangon crangon (Linnaeus, 1758) [WoRMS] Marine/Coastal | Author keywords | brown shrimp; spoilage potential; STAA; Vagococcus salmoninarum;volatile organic compounds |
Authors | | Top | - Calliauw, F.
- Horemans, B., more
- Broekaert, K., more
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Abstract | AimsDuring 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.Methods and ResultsIsolates growing on STAA were identified using (GTG)5 clustering followed by partial 16S rRNA gene sequence analysis. Their biochemical spoilage potential was analysed for H2S 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.ConclusionFifty-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 H2S.Significance and impact of the StudyWhen 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 H2S and formed VOCs which are also found in other spoiled seafood products. |
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