Diversity and abundance of free-living surface water microbial communities were evaluated over a year in three locations across the San Pedro Channel: the Los Angeles port, the San Pedro Ocean Time Series (SPOT) and Two Harbors, Santa Catalina Island (CAT). Microbial community composition was analyzed using DNA and RNA 16S tag sequencing and metagenomic and metatranscriptomic high-throughput sequencing. RNA tags reveal >200 OTUs that were unique to the highly impacted port of LA, e.g. SAR116, OM182, OM60, KI89A, Paraferrimonas, Cycloclasticus, Arcobacter and Propionigenium. SPOT harbored about 70 unique OTUs, and CAT only 40. The core microbiome appearing in all samples contained ~100 OTUs. Potentially highly active OTUs (RNA/DNA ratio>5) almost never overlap across the three sites. The most abundant OTUs in the DNA pool are not always the most abundant in the RNA pool of the same sample. Trends from tag sequencing follow environmental measurements such as ammonium and nitrite availability, bacterial production and bacteria/ml and viruses/ml counts, all of which are generally higher in POLA. Metatranscriptomic comparison of the three sites is consistent with human impact at POLA


Sieradzki, E., University of Southern California, USA, sieradzk@usc.edu

Sachdeva, R., University of Southern California, USA, rsachdev@usc.edu

Fichot, E., University of Southern California, USA, fichot@usc.edu

Fuhrman, J., University of Southern California, USA, fuhrman@usc.edu


Poster presentation

Session #:075
Date: 2/26/2015
Time: 18:30 - 20:00
Location: Poster/Exhibit Hall

Presentation is given by student: Yes

PosterID: 319