Microbacterium agarici sp. nov., Microbacterium humi sp. nov. and Microbacterium pseudoresistens sp. nov., isolated from the base of the mushroom Agaricus blazei

Abstract

Three Gram-positive, rod-shaped bacteria (strains CC-SBCK-209T, CC-12309T and CC-5209T) were isolated from the stalk of the edible mushroom Agaricus blazei grown in the laboratory. 16S rRNA gene sequence analysis indicated that all three isolates clearly belonged to the genus Microbacterium. Strains CC-SBCK-209T and CC-12309T were most related closely to the type strain of Microbacterium halotolerans (95.9 and 96.1 %16S rRNA gene sequence similarity, respectively). These two novel strains shared 97.9 % 16S rRNA gene sequence similarity. Levels of similarity to the type strains of all other recognized Microbacterium species were lower than 95.5 %. The third strain (CC-5209T) showed the highest 16S rRNA gene sequence similarity to the type strain of Microbacterium resistens (97.6 %); levels of similarity to the type strains of all other recognized Microbacterium species were lower than 96 %. The quinone systems of strains CC-SBCK-209T, CC-12309T and CC-5209T consisted of MK-11/MK-12, MK-11/MK-10 and MK-13 as major compounds, respectively. All three strains contained ornithine in their peptidoglycan. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unknown glycolipid. The polyamine pattern consisted of spermidine and spermine as predominant components. Fatty acid profiles (anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0 as major components) supported the affiliation of all three strains to the genus Microbacterium. The results of physiological and biochemical tests and DNA–DNA hybridization experiments allowed the clear phenotypic and genotypic differentiation of strains CC-SBCK-209T and CC-12309T from M. halotolerans and other closely related Microbacterium species. Strain CC-5209T could be differentiated clearly from M. resistens both genotypically and phenotypically. Based on these data, the novel strains are considered to represent three novel species of the genus Microbacterium. The names proposed for these organisms are Microbacterium agarici sp. nov. [type strain CC-SBCK-209T (=DSM 21798T=CCM 7686T)], Microbacterium humi sp. nov. [type strain CC-12309T (=DSM 21799T=CCM 7687T)] and Microbacterium pseudoresistens sp. nov. [type strain CC-5209T (=DSM 22185T=CCM 7688T)].

Cultivable mushroom growth-promoting bacteria and their impact on Agaricus blazei productivity

“…and Mycobacterium sp. have been described as important non-symbiotic nitrogen-fixers and as being able to exert beneficial effects on plant growth (Tilak et al, 2005). Within the identified firmicute phylum, 82% belong to the genus Bacillus, which is the most abundant genus in the rhizosphere.…”

“…2013 DOI: 10.1590/S0100-204X2013000600009 the plant disease suppressing capabilities of some of these strains have resulted in a broad knowledge of the mechanisms involved (Probanza et al, 2002). The phylum proteobacteria accommodates Enterobacter, Pseudomonas, and Serratia genera, which are known to be associated with the plant rhizosphere and are able to exert growth-promoting effects (Tilak et al, 2005;Zarenejad et al, 2012). In fact, Pseudomonas sp.…”

Molecular identification of different actinomycetes isolated from East Black Sea region plateau soil by 16S rDNA gene sequencing

“…Microbacterium includes a diverse collection of Grampositive, non-spore-forming rods that were isolated from various environmental habitats including water, soil, steep liquor, milk products and also from humans. Members of the genus Microbacterium were charac-terized largely by their marked heat resistance, presence in dairies, and production of small amounts of L(+) lactic acid from glucose (Brennan et al, 2001;Young et al, 2010) Our literature search showed that there was no isolation study of rare actinomycetes of East Black Sea region in Turkey until now. Therefore, the present preliminary study was aimed to identify rare actinomycetes strains isolated from different localities of plateau soil and to place them in phylogeny by 16S rDNA gene sequencing.…”

Microbacterium sediminis sp. nov., a psychrotolerant, thermotolerant, halotolerant and alkalitolerant actinomycete isolated from deep-sea sediment

“…schleiferi IFO 15075 T (Bakir et al, 2008); 9, M. barkeri DSM 20145 T (Young et al, 2010); 10, M. paraoxydans CF36 T (Madhaiyan et al, 2010); 11, M.…”