Dynamics of Methanotrophs during in situ Bioremediation

Abstract

Changes in diversity of type I and type II methanotrophs during a biostimulation field experiment were investigated for 73 days after the start of treatment by denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rDNA fragments. DGGE profiles of the type I and type II methanotrophs yielded simple banding patterns. The type I methanotrophs' profile showed a single intense band at day 10 of biostimulation, and sequence analysis showed 99% similarity with Methylobacter psychrophilus. The type II methanotrophs' profile showed a single band appeared at day 31, becoming an intense band after day 40. Sequence analysis of this band pattern showed 99% similarity with Methylocystis parvus. These results suggest a possible shift of numerically dominant methanotrophs from type I to type II during the field experiment.