18D-4

M. AVALLONE and L. A. McLandsborough. Dept. of Food Science, Univ. of Massachusetts, Amherst, Chenoweth Lab., Box 31410, Amherst, MA 01003-1410

It is well documented in literature that microflora possess the ability to affect the quality and safety of food products. However, very little is known about the diversity of microflora in a food processing environment and change over time. Our objective was to evaluate the diversity of microflora in a food processing environment over time using molecular techniques. A floor drain used for runoff from a shrimp brine bath was analyzed. The molecular techniques used were Denaturant Gradient Gel Electrophoresis (DGGE) and cloning of an amplified section of the 16S rDNA. In order to monitor diversity using DGGE and cloning, DNA was extracted using Instagene™ Matrix (BioRad). For DGGE a 233-bp fragment of the 16S rDNA was amplified using PCR with universal primers, one of the primers containing a 5' GC clamp. The optimal range of denaturant was determined experimentally using Perpendicular DGGE and diversity analysis was performed using parallel DGGE. Cloning was performed using a TOPO TA Cloning® Kit for Sequencing (Invitrogen). DNA for cloning was amplified using PCR with R1n and U2 primers which correspond to conserved regions of the 16S rRNA gene. Our results from DGGE showed that gel profiles over time were different and bands that were constant over time varied in intensity. Twenty six clones were sequenced and results were compared using ClustalX. A phylogenic tree was created using TreeView. Of the 26 clones 11 were identified to the Genus and 15 to the Species level. Using the BLAST search program, we identified 14 different bacteria. These results suggest that the types and levels of microflora in the processing environment change over time. Because of this fact it is very important for the quality and safety of our foods that we be aware of the microflora present and how they change with time.

Session 18D, Food Microbiology: General
2:00 PM - 5:30 PM, Sunday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana