RESUMO
A novel actinobacterium, designated strain 1AS2cT, was isolated from the wheat rhizosphere collected from the Brazilian Cerrado biome. A polyphasic approach, including phenotypic characterization and phylogenetic multilocus sequence analysis (MLSA), was used to determine the taxonomic position of this strain. Analysis of the 16S rRNA gene sequence indicated that the novel strain is closely related to Streptomyces cavourensis NBRC 13026T, Streptomyces albolongus NBRC 13465T and Streptomyces araujoniae ASBV-1T, sharing a similarity value of 98.2, 98.1 and 97.9â%, respectively. Additionally, MLSA of five housekeeping genes (atpD, gyrB, recA, rpoB and trpB) showed evolutionary distances beyond the 0.007 threshold, as well as low DNA-DNA relatedness between strain 1AS2cT and its closest phylogenetic neighbours (S. cavourensis NBRC 13026T, S. albolongus NBRC 13465T and S. araujoniae ASBV-1T: 56, 62.5 and 63.0â%, respectively), indicating a new phylogenetic lineage. The phylogenetic, chemotaxonomic and phenotypic characteristics support the assignment of strain 1AS2cT to the genus Streptomyces, representing a novel species. It is concluded that strain 1AS2cT (=CMAA 1679T=NRRL B-65479T=DSM 105299T) can be classified as the type strain of a novel species of the genus Streptomyces, for which the name Streptomyces rhizosphaericola sp. nov. is proposed.
Assuntos
Filogenia , Rizosfera , Microbiologia do Solo , Streptomyces/classificação , Triticum/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Brasil , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Tipagem de Sequências Multilocus , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/isolamento & purificaçãoRESUMO
Here, we report the draft genome sequence of radiation-resistant Rhodococcus erythropolis strain P27, isolated from leaves of Deschampsia antarctica Desv. (Poaceae) in the Admiralty Bay area, Antarctica.
RESUMO
With the recent focus on environmental problems, increasing awareness of the harmful effects of industrial and agricultural pollution has created a demand for progressively more sophisticated pollutant and toxicity detection methods. Using Aspergillus nidulans strains this work presents a new short term-test that, most importantly, enables the rapid and inexpensive detection of volatile pollutants that induce genotoxic/carcinogenic effects in animals. The main aim is to contribute to environmental health protection, and special attention is directed to monitoring the hazard posed by benzene (as a carcinogenic agent model) mainly because its ubiquitous presence often leads to severe noxious effects in humans among whom increased rates of human leukemia have been reported. To evaluate even the submutagenic effects of benzene fumes, two Aspergillus nidulans diploid strains, heterozygous for several auxotrophic mutations, were used. The DNA lesions produced stimulate mitotic recombination and homozygotization of auxotrophic recessive mutations. Conidial exposure to a saturated atmosphere of benzene fumes for 20 s was enough to increase the mitotic recombination frequencies significantly. Genetic analyses of treated diploids evidenced alterations related to mitotic recombination frequencies, gene expression, and allelic segregation rates. Altogether they reflect the potential of benzene to induce alterations in the fungal DNA, and albeit indirectly, they also respond for the genotoxic/carcinogenic harmful side effects widely connected to benzene. This is the first description of a sensitive, rapid and inexpensive test able to detect the submutagenic dose effects of volatile environmental compounds. In addition, despite concentrating on benzene the same test can be applied to many other pollutants, volatile or not. Additionally, the test can also be used to detect the antigenotoxic properties of foods and drugs.