Downloaded from www.microbiologyresearch.org by IP: 54.198.146.117 On: Fri, 08 Jul 2016 13:20:47 Micromonospora tulbaghiae sp. nov., isolated from the leaves of wild garlic, Tulbaghia violacea Bronwyn M. Kirby3 and Paul R. Meyers Correspondence Paul R. Meyers paul.meyers@uct.ac.za Department of Molecular and Cell Biology, University of Cape Town, Private Bag X3, Rondebosch 7701, Cape Town, South Africa A novel actinomycete, strain TVU1 T , was isolated from leaves of the indigenous South African plant Tulbaghia violacea. Applying a polyphasic approach, the isolate was identified as a member of the genus Micromonospora. Phylogenetic analysis of the 16S rRNA gene sequence showed that strain TVU1 T was most closely related to Micromonospora echinospora DSM 43816 T . However, phylogenetic analysis based on gyrB gene sequences showed that strain TVU1 T was most closely related to the type strains of Micromonospora aurantiaca and Micromonospora chalcea. DNA–DNA relatedness values between strain TVU1 T and the type strains of M. echinospora, M. aurantiaca and M. chalcea were 7.6±4.5, 45.9±2.0 and 60.9±4.5 %, respectively. Strain TVU1 T could be distinguished from the type strains of all three of these species by several physiological characteristics, such as colony colour, NaCl tolerance, growth temperature range and sole carbon source utilization pattern. Strain TVU1 T (5DSM 45142 T 5NRRL B-24576 T ) therefore represents a novel species for which the name Micromonospora tulbaghiae sp. nov. is proposed. The genus Micromonospora was proposed by Ørskov (1923) and is the type genus of the family Micromonosporaceae Krasil’nikov 1938 emend. Stackebrandt et al. 1997 (Kawamoto, 1989). Distinguishing features of members of the genus Micromonospora include the formation of single, non-motile spores on the vegetative mycelium, which does not fragment, and the absence of aerial mycelium (Kawamoto, 1989). Although the first antibacterial activity by a member of this genus was reported in 1942, it was the isolation of the aminoglycoside gentamicin from Micromonospora purpurea (reclassified as Micromonospora echinospora by Kasai et al., 2000) in 1963 that sparked the widespread screening of this genus for antibiotics (Wagman & Weinstein, 1980). After Streptomyces, the genus Micromonospora is probably the second most prolific producer of antibiotics (Wagman & Weinstein, 1980). Micromonosporae appear to be widely distributed in nature and have been isolated from a number of diverse sources, including a Thai peat swamp forest (Thawai et al. , 2005), water samples (Trujillo et al. , 2005) and Antarctic sandstone (Hirsch et al., 2004). Four recently described species are plant endophytes: Micromonospora coriariae was isolated from root nodules of the Mediterranean shrub Coriaria myrtifolia (Trujillo et al. , 2006); Micromonospora lupini and Micromonospora saelicesensis were isolated from root nodules of the Mediterranean shrub Lupinus angustifolius (Trujillo et al. , 2007); and Micromonospora pisi was isolated from root nodules of a pea plant, Pisum sativum (Garcia et al., 2010). The Cape Floral Kingdom hosts more than 9000 plant species. Even though over 3000 of these indigenous plant species have ethnobotanical applications (Van Wyk et al., 1997), indigenous South African plants have not been systematically screened for novel endophytic micro-organ- isms. A novel actinomycete, TVU1 T , was isolated from leaves of the bulbous plant Tulbaghia violacea, which is a member of the onion family, Alliaceae (Manning, 2003), during a screening programme of indigenous plants. Leaves from T. violacea (wild garlic) were collected from an indigenous suburban garden in Wellington, approximately 60 km from Cape Town. The leaves were placed in sterile plastic bags, stored at 4 uC and processed within 24 h of collection. The identity of the plant species was confirmed from Joffe (1993). Leaves were initially surface-sterilized by placing them in 70 % ethanol for 1 min, then soaking them in 1 % (v/v) NaOCl for 3 min, followed by rinsing twice in sterile distilled water. The surface-sterilized leaves were cut into 1 cm segments with sterile flamed scissors (Okazaki, 2003) and placed in a test tube containing 20 ml quarter- strength sterile phosphate buffer [full-strength phosphate 3Present address: Institute for Microbial Biotechnology and Meta- genomics, University of the Western Cape, Private Bag X17, Bellville 7535, Cape Town, South Africa. The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA and gyrB gene sequences of Micromonospora tulbaghiae sp. nov. TVU1 T are EU196562 and EU434806, respectively. Unrooted phylogenetic trees based on 16S rRNA gene sequences of TVU1 T and all species in the genus Micromonospora and the gyrB gene sequences of selected species in the genus Micromonospora are available as supplementary figures with the online version of this paper. International Journal of Systematic and Evolutionary Microbiology (2010), 60, 1328–1333 DOI 10.1099/ijs.0.013243-0 1328 013243 G 2010 IUMS Printed in Great Britain