title: Bacterial composition and succession during storage of North-Atlantic cod (Gadus morhua) at superchilled temperatures.
abstract: BACKGROUND
  The bacteriology during storage of the North-Atlantic cod has been investigated for the past decades using conventional cultivation strategies which have generated large amount of information. This paper presents a study where both conventional cultivation and cultivation independent approaches were used to investigate the bacterial succession during storage of cod loins at chilled and superchilled temperatures.
  
  
  RESULTS
  Unbrined (0.4% NaCl) and brined (2.5% NaCl) cod loins were stored at chilled (0 degrees C) and superchilled (-2 and -3.6 degrees C) temperatures in air or modified atmosphere (MA, % CO2/O2/N2: 49.0 +/- 0.6/7.4 +/- 0.2/43.7 +/- 0.4). Discrepancy was observed between cultivation enumeration and culture independent methods where the former showed a general dominance of Pseudomonas spp. (up to 59%) while the latter showed a dominance of Photobacterium phosphoreum (up to 100%).Gas chromatography-mass spectrophotometry (GC-MC) showed that trimethylamine was the most abundant volatile in mid- and late storage periods. Terminal restriction polymorphism (t-RFLP) analysis showed that the relative abundance of P. phosphoreum increased with storage time.
  
  
  CONCLUSIONS
  The present study shows the bacteriological developments on lightly salted or non-salted cod loins during storage at superchilled temperatures. It furthermore confirms the importance of P. phosphoreum as a spoilage organism during storage of cod loins at low temperatures using molecular techniques. The methods used compensate each other, giving more detailed data on bacterial population developments during spoilage.
authors: Food Safety & Environment, Matis-Icelandic Food Research (Vínlandsleieth 12), Reykjavík, Iceland. eyjolfur.reynisson@matis.is
authors: Eyjólfur
authors: E
authors: Reynisson
authors: Hélène L
authors: HL
authors: Lauzon
authors: Hannes
authors: H
authors: Magnússon
authors: Rósa
authors: R
authors: Jónsdóttir
authors: Gudrún
authors: G
authors: Olafsdóttir
authors: Viggó
authors: V
authors: Marteinsson
authors: Gudmundur Oli
authors: GO
authors: Hreggvidsson
mesh_terms: D000818:Animals; D003080:Cold Temperature; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000235:genetics; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D048389:Gadus morhua / Q000382:microbiology*; D008401:Gas Chromatography-Mass Spectrometry; D010776:Photobacterium / Q000235:genetics / Q000302:isolation & purification; D012150:Polymorphism, Restriction Fragment Length; D011549:Pseudomonas / Q000235:genetics / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017747:Seafood / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S