Description of Azotobacter chroococcum subsp. isscasi subsp. nov. isolated from paddy soil and establishment of Azotobacter chroococcum subsp. chroococcum subsp. nov. Issue 3 (29th January 2020)

• Record Type: Journal Article
• Authors: Jin, Haiyang; Wang, Hui; Zhang, Yanhui; Hu, Tianlong; Lin, Zhibin; Liu, Benjuan; Ma, Jing; Wang, Xiaojie; Liu, Qi; Lin, Xingwu; Xie, Zubin
• Is Part Of: International journal of systematic and evolutionary microbiology. Volume 70:Issue 3(2020)
• Page Start: 2124
• Page End: 2131
• Publication Date: 2020-01-29
• Subjects: Azotobacter chroococcum -- taxonomy -- average nucleotide identity (ANI) -- digital DNA–DNA hybridization (dDDH) -- biological nitrogen fixation; Microbiology -- Periodicals; Microbiology -- Classification -- Periodicals; 579
• DOI: 10.1099/ijsem.0.004026
• Languages: English
• ISSNs: 1466-5026

Abstract

Abstract : Three aerobic, asymbiotic, N2 -fixing bacterial strains, designated P205 T, P204 and P207, were isolated from a paddy soil in Yanting County, China. Based on 16S rRNA gene sequences, the three strains were closely related to Azotobacter chroococcum IAM 12666 T (=ATCC 9043 T ) (99.00–99.79 % similarities). Strain P205 T formed an individual branch distinct from the other two newly isolated strains and other related type strains in phylogenetic analyses based on 16S rRNA gene and 92 core genes. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA–DNA hybridization (dDDH) values based on genome sequences of strain P205 T and A. chroococcum ATCC 9043 T, P204, P207 were near or slightly higher than the thresholds for species circumscription (95–96, 95–96 and 70 %, respectively), and the dDDH values were significantly lower than the threshold for delineating subspecies (79–80 %), which strongly supported that strain P205 T belonged to A. chroococcum but was a novel subspecies distinct from the type strain of A. chroococcum . This finding was further corroborated by distinct phenotypic characteristics such as growth in Luria–Bertani (LB) medium, carbon source utilization and chemical sensitivity to vancomycin. Therefore, strain P205 T represents a novel subspecies of Azotobacter chroococcum, for which the name Azotobacter chroococcum subsp. isscasi subsp. nov. is proposed with the type strain P205 T (=KCTC 72233 T =CGMCC 1.16846 T =CCTCC AB 2019080 T ). The subspecies Azotobacter chroococcum subsp. chroococcum subsp. nov. is created automatically with the type strain ATCC 9043 T (=DSM 2286 T =JCM 20725 T =JCM 21503 T =LMG 8756 T =NBRC 102613 T =NCAIM B.01391 T =NRRL B-14346 T =VKM B-1616 T ).