FIG. 1.

merA genes and transcripts in microbial biomass. (Top) Gel shows 291-bp merA PCR products obtained with sea ice (SI) and lagoon (LG) DNA extracts as templates. SI1 and LG, DNA obtained by extracting biomass with its associated microbes; SI2, extract of a fraction obtained by washing alga with site water; (+) pPB20, positive control consisting of merA from Pseudomonas stutzeri OX (50); PCR blank lane (−) and DNA size markers (in bp). (Bottom) Gel shows merA PCR products following reverse transcriptase reactions (+RT) of RNA extracted from sea ice and lagoon biomass. (−RT), no RT controls; (−) PCR blank lane; a 291-bp PCR fragment is shown.