FIG. 3.

Distance dendrogram constructed for partial mmoX sequences based on 286 derived amino acid sites. The dendrogram shows environmental mmoX sequences retrieved from roots of submerged rice plants (M84, M90) in relation to mmoX sequences of representative type I and type II methanotrophs. The environmental mmoX sequence designated peat bog clone 24 (AF004555) was retrieved from an acidic Sphagnum peat bog (12). The numbers at the nodes indicate the percentage of recovery in 500 bootstrap resamplings. Only bootstrap values ≥50 are shown. Scale bar, 0.1 substitution per amino acid site. Database accession numbers of reference organisms are as follows: Methylocystis sp. strain LR1, Y18440; Methylocystis sp. strain M, U81594; Methylosinus trichosporium, X55394; Methylocella palustris, AF004554; Methylococcus capsulatus, M90050; and Methylomonas sp. strain KSWIII, AB025022.