Micromonospora zeae sp. nov., a novel endophytic actinomycete isolated from corn root (Zea mays L.)

Abstract

A novel actinomycete, designated strain NEAU-gq9(T), was isolated from corn root (Zea mays L.) and characterized using a polyphasic approach. The organism was found to have morphological and chemotaxonomic characteristics typical of the genus Micromonospora. On the basis of 16S rRNA gene sequence similarity studies, strain NEAU-gq9(T) was most closely related to Micromonospora zamorensis CR38(T) (99.3%), Micromonospora jinlongensis NEAU-GRX11(T) (99.2%), Micromonospora saelicesensis Lupac 09(T) (99.2%), Micromonospora chokoriensis 2-19(6)(T) (98.9%), Micromonospora coxensis 2-30-b(28)(T) (98.6%) and Micromonospora lupini Lupac 14N(T) (98.5%). Phylogenetic analysis based on the 16S rRNA gene and gyrB gene demonstrated that strain NEAU-gq9(T) is a member of the genus Micromonospora and supported the closest phylogenetic relationship to M. zamorensis CR38(T), M. jinlongensis NEAU-GRX11(T), M. saelicesensis Lupac 09(T), M. chokoriensis 2-19(6)(T) and M. lupini Lupac 14N(T). A combination of DNA-DNA hybridization, morphological and physiological characteristics indicated that the novel strain could be readily distinguished from the closest phylogenetic relatives. Therefore, it is proposed that strain NEAU-gq9(T) represents a novel species of the genus Micromonospora, for which the name Micromonospora zeae sp. nov. is proposed. The type strain is NEAU-gq9(T) (=CGMCC 4.7092(T)=DSM 45882(T)).

Hunting for cultivable Micromonospora strains in soils of the Atacama Desert

“…Isolation procedures designed to recover specific actinobacterial genera from environmental samples are many and varied but tend to reflect the biological properties of the target organisms (Goodfellow 2010), as was the case in the present study. It is, for instance, known that Micromonospora spores are activated by heat pretreatment regimes, are resistant to phenol and germinate on nutrient rich media such as humic acid-vitamin agar (Hoskisson et al 2000;Shen et al 2014;Carro et al 2018b). It is, therefore, encouraging that over half of the Micromonospora strains were isolated from the soil samples using the phenol-heat procedure, albeit on several isolation media (Table 2).…”

“…Micromonosporae have been isolated from diverse natural habitats (Genilloud 2012), notably from rhizosphere soil (Carro et al 2013b;Thawai et al 2016) from desert locations in China (Ding et al .2013) and from tissues of a broad range of plants, such as Triticum aestivum (Coombs and Franco 2003), Zea mays (Shen et al 2014), and Parathelypteris beddomei (Zhao et al 2017); as well as from nitrogen-fixing root nodules of actinorhizal plants (Trujillo et al 2006;Carro et al 2013a) and legumes (Trujillo et al 2007;Garcia et al 2010;Trujillo et al 2010;Carro et al 2018b).…”

Micromonospora ureilytica sp. nov., Micromonospora noduli sp. nov. and Micromonospora vinacea sp. nov., isolated from Pisum sativum nodules

“…The growth temperature range is between 20 and 37 C, with an optimum at 28 C. Growth in the presence of 1 % NaCl is observed. Shen et al (2014). All strains are positive for esterase (C4), lipase (C18), leucine arylamidase, valine arylamidase, cystine arylamidase, trypsin, a-chymotrypsin, b-galactosidase, N-acetyl-b-galactosidase and oxidase, and utilization of fructose, melibiose, arbutin and gelatin.…”

Recent progress on the development of antibiotics from the genus Micromonospora

“…This remained the only known strain among the actinomycetes bearing the generic name Micromonospora until Jensen in 1930 described a large number of soil micro-organisms which corresponded with Ørskov's description [19]. At the time of writing, the genus consisted of 61 validly named species (http://www.bacterio.net) [20], in addition to the recently described species, like: M. spongicola [21], M. jinlongensis [22], M. zeae [23], M. maoerensis [24], M. endophytica [25], M. palomenae [26], M. harpali [26], M. oryzae [27], M. vulcania [28], M. fluostatini [29], M. nickelidurans [30], M.…”