Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Thu, 06 Dec 2018 09:46:10 Promicromonospora callitridis sp. nov., an endophytic actinobacterium isolated from the surface-sterilized root of an Australian native pine tree Onuma Kaewkla 1,2 and Christopher M. M. Franco 2, * Abstract A new strain of the genus Promicromonospora, CAP94 T , was isolated from the surface sterilized root of Callitrispreissii (Australian native pine tree). This strain was a Gram-stain-positive, aerobic actinobacterium with hyphae breaking up into fragments which were non-motile, rod-like, coccoid elements. Phylogenetic evaluation based on 16S rRNA gene sequence analysis placed this isolate as a member of the family Promicromonospora ceae, and most closely to Promicromonospora sukumoe NBRC 14650 T (99.4 %), Promicromonospora kroppenstedtii DSM 19349 T (99.2 %) and Promicromonosporaaerolata V54A T (99.1 %). Chemotaxonomic data including cell-wall components, major menaquinone and major fatty acids confirmed the affiliation of strain CAP94 T to the genus Promicromonospora. The results of the phylogenetic analysis, including physiological and biochemical studies in combination with DNA–DNA hybridization, allowed the genotypic and phenotypic differentiation of strain CAP94 T and the closest species with validly published names. The name proposed for the new species is Promicromonospora callitridis sp. nov. The type strain is CAP94 T (=DSM 103339 T =TBRC 6025 T ). The genus Promicromonospora was first described by Krasil’nikov et al. [1] and belongs to the family Promicro- monosporaceae, which includes six other genera: Cellulosi- microbium, Isoptericola, Myceligenerans, Xylanibacterium, Xylanimicrobium and Xylanimonas [2]. The family is defined by peptidoglycan type A4a, MK-9 (H 4 ) as the predominant menaquinone and iso- and anteiso-branched cellular fatty acids [3]. At the time of writ- ing, the genus Promicromonospora contained 12 species. They were isolated from diverse environments. Five species, Promicromonospora citrea [1], Promicromonospora suku- moe [4], Promicromonospora kroppenstedtii [5], Promicro- monospora iranensis [6] and Promicromonospora kermanensis [7] were isolated from soil. Promicromonospora thailandica was isolated from marine sediment [8]. Promi- cromonospora aerolata and Promicromonospora vindobo- nensis were isolated from air [9]. Promicromonospora umidemergens was isolated from indoor wall material [10]. Promicromonospora alba was isolated from the cuticle of Camponotus japonicus Mayr [11]. There are two endo- phytes reported from this genus: Promicromonospora xyla- nilytica [12] and Promicromonospora endophytica [13]. Promicromonospora-like strain CAP94 T was isolated from the surface-sterilized root of a native pine tree (Callitris pre- issii) collected from the grounds of Flinders University, Adelaide, South Australia, and processed within 4 h of col- lection [14]. Crushed surfaced sterilized root tissue was placed onto VL70 medium containing 0.05 % xylan solidi- fied with 0.8 % gellan gum [15]. Strain CAP94 T emerged from the root tissue onto the isolation medium after incuba- tion for 1 week at 27  C. In this paper, we describe the taxo- nomic position of this strain, including its morphological, physiological, chemotaxonomic and phylogenetic character- istics. Polyphasic taxonomy showed that this strain repre- sents a novel species of the genus Promicromonospora, for which the name Promicromonospora callitridis sp. nov. is proposed. Extraction of genomic DNA from strain CAP94 T , amplifica- tion and sequencing of the 16S rRNA gene were carried out as described previously [16]. The resultant 16S rRNA gene sequence of CAP94 T was analysed by using the EzTaxon-e server [17] and subsequently aligned with the 16S rRNA gene sequences of representatives of all Promicromonospora members available from GenBank/EMBL by using CLUSTAL X [18] with Xylanimicrobium pachnodae NBRC 107786 T as Author affiliations: 1 Department of Biology, Faculty of Science, Mahasarakham University, Maha Sarakham Province 44150, Thailand; 2 Department of Medical Biotechnology, School of Medicine, Flinders University, Bedford Park SA 5042, Australia. *Correspondence: Christopher M. M. Franco, chris.franco@flinders.edu.au Keywords: Promicromonospora sp. nov.; endophytic actinobacteria; pine tree. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain CAP94 T is GU434237. Three supplementary figures and two supplementary tables are available with the online Supplementary Material. TAXONOMIC DESCRIPTION Kaewkla and Franco, Int J Syst Evol Microbiol 2017;67:3559–3563 DOI 10.1099/ijsem.0.002165 002165 ã 2017 IUMS 3559