RT Journal Article SR Electronic(1) A1 Kittiwongwattana, Chokchai A1 Thawai, ChittiYR 2013 T1 Rhizobiumpaknamense sp. nov., isolated from lesser duckweeds (Lemna aequinoctialis) JF International Journal of Systematic and Evolutionary Microbiology, VO 63 IS Pt_10 SP 3823 OP 3828 DO https://doi.org/10.1099/ijs.0.051888-0 PB Microbiology Society, SN 1466-5034, AB A Gram-stain-negative, rod-shaped bacterium was isolated and designated strain L6-8T during a study of endophytic bacterial communities in lesser duckweed (Lemna aequinoctialis). Cells of strain L6-8T were motile with peritrichous flagella. The analysis of the nearly complete 16S rRNA gene sequence indicated that strain L6-8T was phylogenetically related to species of the genus Rhizobium . Its closest relatives were Rhizobium borbori DN316T (97.6 %), Rhizobium oryzae Alt 505T (97.3 %) and Rhizobium pseudoryzae J3-A127T (97.0 %). The sequence similarity analysis of housekeeping genes recA, glnII, atpD and gyrB showed low levels of sequence similarity (<91.5 %) between strain L6-8T and other species of the genus Rhizobium with validly published names. The pH range for growth was 4.0–9.0 (optimum 6.0–7.0), and the temperature range for growth was 20–45 °C (optimum 30 °C). Strain L6-8T tolerated NaCl up to 2 % (w/v) (optimum 1 % NaCl). The predominant components of cellular fatty acids were C19 : 0 cyclo ω8c (31.32 %), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 25.39 %) and C16 : 0 (12.03 %). The DNA G+C content of strain L6-8T was 60.4 mol% (T m). nodC and nifH were not amplified in strain L6-8T. DNA–DNA relatedness between strain L6-8T and R. borbori DN316T, R. oryzae Alt505T and R. pseudoryzae J3-A127T was between 11.2 and 18.3 %. Based on the sequence similarity analyses, phenotypic, biochemical and physiological characteristics and DNA–DNA hybridization, strain L6-8T could be readily distinguished from its closest relatives and represents a novel species of the genus Rhizobium , for which the name Rhizobium paknamense sp. nov. is proposed. The type strain is L6-8T ( = NBRC 109338T = BCC 55142T)., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.051888-0