Dataset Information

Actinomadura rubteroloni sp. nov. and Actinomadura macrotermitis sp. nov., isolated from the gut of the fungus growing-termite Macrotermes natalensis.

ABSTRACT: The taxonomic positions of two novel aerobic, Gram-positive actinobacteria, designated strains RB29^T and RB68^T, were determined using a polyphasic approach. Based on 16S rRNA gene sequence analysis, the closest phylogenetic neighbours of RB29^T were identified as Actinomadura rayongensis DSM 102126^T (99.2 % similarity) and Actinomadura atramentaria DSM 43919^T (98.7 %), and for strain RB68^T was Actinomadura hibisca DSM 44148^T (98.3 %). Digital DNA-DNA hybridization (dDDH) between RB29^T and its closest phylogenetic neighbours, A. rayongensis DSM 102126^T and A. atramentaria DSM 43919^T, resulted in similarity values of 53.2 % (50.6-55.9 %) and 26.4 % (24.1-28.9 %), respectively. Additionally, the average nucleotide identity (ANI) was 93.2 % (94.0 %) for A. rayongensis DSM 102126^T and 82.3 % (78.9 %) for A. atramentaria DSM 43919^T. dDDH analysis between strain RB68^T and A. hibisca DSM 44148^T gave a similarity value of 24.5 % (22.2-27.0 %). Both strains, RB29^T and RB68^T, revealed morphological characteristics and chemotaxonomic features typical for the genus Actinomadura, such as the presence of meso-diaminopimelic acid in the cell wall, galactose and glucose as major sugar components within whole-cell hydrolysates and the absence of mycolic acids. The major phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. Predominant menaquinones were MK-9(H₆) and MK-9(H₈) for RB29^T and MK-9(H₄) and MK-9(H₆) for RB68^T. The main fatty acids were identified as 10-methyloctadecanoic acid (10-methyl C_18:0), 14-methylpentadecanoic acid (iso-C_16:0), hexadecanoic acid (C_16:0) and cis-9-octadecanoic acid (C_18 : 1 ω9c). Here, we propose two novel species of the genus Actinomadura: Actinomadura rubteroloni sp. nov. with the type strain RB29^T (=CCUG 72668^T=NRRL B-65537^T) and Actinomadura macrotermitis sp. nov. with the type strain RB68^T (=CCUG 72669^T=NRRL B-65538^T).

SUBMITTER: Benndorf R

PROVIDER: S-EPMC7660899 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Two morphologically distinct, H2- and CO2-utilizing methanogens were isolated from gut homogenates of the subterranean termite, Reticulitermes-flavipes (Kollar) (Rhinotermitidae). Strain RFM-1 was a short straight rod (0.4 by 1.2 micron), whereas strain RFM-2 was a slightly curved rod (0.34 by 1.6 microns) that possessed polar fibers. Their morphology, gram-positive staining reaction, resistance to cell lysis by chemical agents, and narrow range of utilizable substracts were typical of species belonging to the family Methanobacteriaceae. Analysis of the nearly complete sequences of the small-subunit rRNA-encoding genes confirmed this affiliation and supported their recognition as new species of Methanobrevibacter: M. cuticularis (RFM-1) and M. curvatus (RFM-2). The per cell rates of methanogenesis by strains RFM-1 and RFM-2 in vitro, taken together with their in situ population densities (ca. 10(6) cells.gut-1; equivalent to 10(9) cells . ml of gut fluid-1), could fully account for the rate of methane emission by the live termites. UV epifluorescence and electron microscopy confirmed that RFM-1- and RFM-2-type cells were the dominant methanogens in R.flavipes collected in Michigan (but were not the only methanogens associated with this species) and that they colonized the peripheral, microoxic region of the hindgut, i.e., residing on or near the hindgut epithelium and also attached to filamentous prokaryotes associated with the gut wall. An examination of their oxygen tolerance revealed that both strains possessed catalase-like activity. Moreover, when dispersed in tubes or agar medium under H2-CO2-O2 (75: 18.8:6.2, vol/vol/vol), both strains grew to form a thin plate about 6 mm below the meniscus, just beneath the oxic-anoxic interface. Such growth plates were capable of mediating a net consumption of O2 that otherwise penetrated much deeper into uninoculated control tubes. Similar results were obtained with an authentic strain of Methanobrevibacter arboriphilicus. This is the first detailed description of an important and often cited but poorly understood component of the termite gut microbiota.

Dataset Information

Actinomadura rubteroloni sp. nov. and Actinomadura macrotermitis sp. nov., isolated from the gut of the fungus growing-termite Macrotermes natalensis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets