The objectives of this study were to compare the biochemical profiles with biogroups for the identification of Cronobacter spp. (formally known as Enterobacter sakazakii) isolates using biochemical identification kits. A total of 38 Cronobacter spp. contained 5 clinical, 31 food, and 2 environmental isolates were used. All isolates were identified as Cronobacter spp. with the Vitek II system and ID 32E kit. The API 20E kit identified all isolates as Cronobacter spp. but the percentage identification was 51.1% for 16 of 38 isolates. These strains were contained to Biogroup 2, 9, 10, and 11. The utilization of inositol is a factor determining the percentage identification of Cronobacter spp. with the API 20E kit.

To investigate characteristics of biogeochemical environment of the Korea Deep Ocean Study(KODOS) area in the northeast Pacific Ocean, we preferentially measured inorganic nutrients and fluorescent organic matters. Typically, the permanent thermocline was well developed at the depth of 200∼1000m in the study area. Nitrate, phosphate and silicate were low in the surface mixed layer and increased with depth. N/P and N/Si showed 15 and 0.2 respectively in the deeper layer. Two fluorophores, biomacromolecule(protein-like) and geomacromolecule (humic-like), were observed by three dimensional fluorescence excitation/emission spectra matrix. Biomacromolecule(maximum fluorescence at Ex_280nm/Em_330nm) ranged from 41.9 to 147.0 TU with its maximum in the surface mixed layer and minimum in deeper water. This is a same trend that has been reported for DOC in the equatorial Pacific. This suggests that biomacromolecule might be labile and converted to refractory humic substance after bacterial degradation in the deeper layer. On the contrary, geomacromolecule(maximum fluorescence at Ex_330nm/Em_430), ranged from 7.6 to 46.5 QSU, showed minimum in the surface mixed layer(euphotic zone) implying photodegradation and then increased with depth at all stations. In the characteristics of vertical profiles, the relationship between biomacromolecule and geomacromolecule showed negative correlation. Such trend can be attributed to biochemical regeneration or formation of fluorescent materials accompanying oxidation and remineralization of settling organic matter.