Impact of Inoculation with Pseudomonas aestus CMAA 1215T on the Non-target Resident Bacterial Community in a Saline Rhizosphere Soil.

Plant growth reduction caused by osmotic stress, pathogens, and nutrient scarcity can be overcome by inoculation with plant growth-promoting rhizobacteria (PGPR). Knowing the effects of PGPR on the microbial community beyond those on plant growth can bring new options of soil microbiota management. The present study aimed to investigate the effect of inoculation with the newly described Pseudomonas aestus CMAA 1215T [a 1-aminocyclopropane-1-carboxylate (ACC) deaminase and glycine-betaine producer] on the rhizosphere bacterial community of Zea mays in natural (non-salinized) and saline soil. The bacterial community structure was assessed by sequencing the V6-V7 16S ribosomal RNA using the Ion Personal Genome Machine™. The non-metric multidimensional scaling (NMDS) of the OTU profile (ANOSIM P < 0.01) distinguishes all the treatments (with and without inoculation under saline and natural soils). Inoculated samples shared 1234 OTUs with non-inoculated soil. The most abundant classes in all samples were Alphaproteobacteria, Gammaproteobacteria, Actinobacteria, Acidobacteriia, Bacteroidia, Thermoleophilia, Verrucomicrobiae, Ktenodobacteria, and Bacilli. The inoculation, on the other hand, caused an increase in the abundance of the genera Bacillus, Bryobacter, Bradyrhizobium, "Candidatus Xiphinematobacter", and "Candidatus Udaeobacter" independent of soil salinization. "Candidatus Udaeobacter" has the largest Mean Decrease in Gini Values with higher abundance on inoculated salted soil. In addition, Pseudomonas inoculation reduced the abundance of Gammaproteobacteria and Phycisphaerae. Understanding how inoculation modifies the bacterial community is essential to manage the rhizospheric microbiome to create a multi-inoculant approach and to understand its effects on ecological function.

Williamsia aurantiacus sp. nov. a novel actinobacterium producer of antimicrobial compounds isolated from the marine sponge.

An antibiotic-producing actinobacterium, designated isolate B375T, was isolated from marine sponge Glodia corticostylifera collected from Praia Guaecá, São Paulo, Brazil (23°49S; 45°25W), and its taxonomic position established using data from a polyphasic study. The organism showed a combination of morphological, physiological, biochemical and chemotaxonomic characteristics consistent with its classification in the genus Williamsia. Comparative 16S rRNA gene sequence analysis indicated that the strain B375T was most closely related to Williamsia serinedens DSM 45037T and Williamsia spongiae DSM 46676T and having 99.43% and 98.65% similarities, respectively, but was distinguished from these strains by a low level of DNA-DNA relatedness (53.2-63.2%) and discriminatory phenotypic properties. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and N-glycolated muramic acid residues present in the wall cells. The cells contained C16:0 (23.3%), C18:0 10-methyl (23.2%) and C18:1 ω9c (21.6%) as the major cellular fatty acids. The strain B375T inhibited growing of Staphylococcus aureus and Colletotrichum gloeosporioides strains and was considered a producer of antimicrobial compounds. Based on the data obtained, the isolate B375T (= CBMAI 1090T = DSM 46677T) should, therefore, be classified as the type strain of a novel species of the genus Williamsia, for which the name Williamsia aurantiacus sp. nov. is proposed.

Rhodococcus psychrotolerans sp. nov., isolated from rhizosphere of Deschampsia antarctica.

A novel actinobacterium, designated strain CMAA 1533T, was isolated from the rhizosphere of Deschampsia antarctica collected at King George Island, Antarctic Peninsula. Strain CMAA 1533T was found to grow over a wide range of temperatures (4-28 °C) and pH (4-10). Macroscopically, the colonies were observed to be circular shaped, smooth, brittle and opaque-cream on most of the culture media tested. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CMAA 1533T belongs to the family Nocardiaceae and forms a distinct phyletic line within the genus Rhodococcus. Sequence similarity calculations indicated that the novel strain is closely related to Rhodococcus degradans CCM 4446T, Rhodococcus erythropolis NBRC 15567T and Rhodococcus triatomae DSM 44892T (≤ 96.9%). The organism was found to contain meso-diaminopimelic acid, galactose and arabinose in whole cell hydrolysates. Its predominant isoprenologue was identified as MK-8(H2) and the polar lipids as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. The major fatty acids were identified as Summed feature (C16:1 ω6c and/or C16:1 ω7c), C16:0, C18:1 ω9c and 10-methyl C18:0. The G+C content of genomic DNA was determined to be 65.5 mol%. Unlike the closely related type strains, CMAA 1533T can grow at 4 °C but not at 37 °C and was able to utilise adonitol and galactose as sole carbon sources. Based on phylogenetic, chemotaxonomic and physiological data, it is concluded that strain CMAA 1533T (= NRRL B-65465T = DSM 104532T) represents a new species of the genus Rhodococcus, for which the name Rhodococcus psychrotolerans sp. nov. is proposed.

Pseudomonas aestus sp. nov., a plant growth-promoting bacterium isolated from mangrove sediments.

Strain CMAA 1215T, a Gram-reaction-negative, aerobic, catalase positive, polarly flagellated, motile, rod-shaped (0.5-0.8 × 1.3-1.9 µm) bacterium, was isolated from mangrove sediments, Cananéia Island, Brazil. Analysis of the 16S rRNA gene sequences showed that strain CMAA 1215T forms a distinct phyletic line within the Pseudomonas putida subclade, being closely related to P. plecoglossicida ATCC 700383T, P. monteilii NBRC 103158T, and P. taiwanensis BCRC 17751T of sequence similarity of 98.86, 98.73, and 98.71%, respectively. Genomic comparisons of the strain CMAA 1215T with its closest phylogenetic type strains using average nucleotide index (ANI) and DNA:DNA relatedness approaches revealed 84.3-85.3% and 56.0-63.0%, respectively. A multilocus sequence analysis (MLSA) performed concatenating 16S rRNA, gyrB and rpoB gene sequences from the novel species was related with Pseudomonas putida subcluster and formed a new phylogenetic lineage. The phenotypic, physiological, biochemical, and genetic characteristics support the assignment of CMAA 1215T to the genus Pseudomonas, representing a novel species. The name Pseudomonas aestus sp.nov. is proposed, with CMAA 1215T (=NRRL B-653100T = CBMAI 1962T) as the type strain.

Saccharopolyspora spongiae sp. nov., a novel actinomycete isolated from the marine sponge Scopalina ruetzleri (Wiedenmayer, 1977).

A novel marine actinomycete, designated strain CMAA 1452T, was isolated from the sponge Scopalina ruetzleri collected from Saint Peter and Saint Paul Archipelago, in Brazil, and subjected to a polyphasic taxonomic investigation. The organism formed a distinct phyletic line in the Saccharopolyspora 16S rRNA gene tree and had chemotaxonomic and morphological properties consistent with its classification in this genus. It was found to be closely related to Saccharopolyspora dendranthemae KLBMP 1305T (99.5% 16S rRNA gene sequence similarity) and shared similarities of 99.3, 99.2 and 99.0 % with 'Saccharopolyspora endophytica' YIM 61095, Saccharopolyspora tripterygii YIM 65359T and 'Saccharopolyspora pathumthaniensis' S582, respectively. DNA-DNA relatedness values between the isolate and its closest phylogenetic neighbours, namely S. dendranthemae KLBMP 1305T, 'S. endophytica' YIM 61095 and S. tripterygii YIM 65359T, were 53.5, 25.8 and 53.2 %, respectively. Strain CMAA 1452T was also distinguished from the type strains of these species using a range of phenotypic features. On the basis of these results, it is proposed that strain CMAA 1452T (=DSM 103218T=NRRL B-65384T) merits recognition as the type strain of a novel Saccharopolyspora species, Saccharopolyspora spongiae sp. nov.

Williamsia spongiae sp. nov., an actinomycete isolated from the marine sponge Amphimedon viridis.

A novel actinobacterium, designated isolate B138T, was isolated from the marine sponge, Amphimedon viridis, which was collected from Praia Guaecá (São Paulo, Brazil), and its taxonomic position was established using data from a polyphasic study. The organism showed a combination of chemotaxonomic and morphological characteristics consistent with its classification in the genus Williamsia and it formed a distinct phyletic line in the Williamsia 16S rRNA gene tree. It was most closely related to Williamsia serinedens DSM 45037T and Williamsia deligens DSM 44902T (99.0 % 16S rRNA gene sequence similarity) and Williamsia maris DSM 44693T (97.5 % 16S rRNA gene sequence similarity), but was distinguished readily from these strains by the low DNA-DNA relatedness values (62.3-64.4 %) and by the discriminatory phenotypic properties. Based on the data obtained, the isolate B138T (=CBMAI 1094T=DSM 46676T) should be classified as the type strain of a novel species of the genus Williamsia, for which the name Williamsia spongiae sp. nov. is proposed.

Gordonia didemni sp. nov. an actinomycete isolated from the marine ascidium Didemnum sp.

A novel actinobacterium, designated isolate B204(T), was isolated from a marine ascidian Didemnum sp., collected from São Paulo, Brazil, and its taxonomic position established using data from a polyphasic study. The organism showed a combination of chemotaxonomic and morphological characteristics consistent with its classification in the genus Gordonia and formed a distinct phyletic line in the Gordonia 16S rRNA gene tree. It was closely related to Gordonia terrae DSM 43249(T) (99.9 % 16S rRNA gene sequence similarity) and Gordonia lacunae DSM 45085(T) (99.3 % 16S rRNA gene sequence similarity) but was distinguished from these strains by a moderate level of DNA-DNA relatedness (63.0 and 54.7 %) and discriminatory phenotypic properties. Based on the data obtained, the isolate B204(T) (=CBMAI 1069(T) = DSM 46679(T)) should therefore be classified as the type strain of a novel species of the genus Gordonia, for which the name Gordonia didemni sp. nov. is proposed.

Streptomyces atlanticus sp. nov., a novel actinomycete isolated from marine sponge Aplysina fulva (Pallas, 1766).

The taxonomic position of a novel marine actinomycete isolated from a marine sponge, Aplysina fulva, which had been collected in the Archipelago of Saint Peter and Saint Paul (Equatorial Atlantic Ocean), was determined by using a polyphasic approach. The organism showed a combination of morphological and chemotaxonomic characteristics consistent with its classification in the genus Streptomyces and forms a distinct branch within the Streptomyces somaliensis 16S rRNA gene tree subclade. It is closely related to Streptomyces violascens ISP 5183T (97.27 % 16S rRNA gene sequence similarity) and Streptomyces hydrogenans NBRC 13475T (97.15 % 16S rRNA gene sequence similarity). The 16S rRNA gene similarities between the isolate and the remaining members of the subclade are lower than 96.77 %. The organism can be distinguished readily from other members of the S. violacens subclade using a combination of phenotypic properties. On the basis of these results, it is proposed that isolate 103T (=NRRL B-65309T = CMAA 1378T) merits recognition as the type strain of a new Streptomyces species, namely Streptomyces atlanticus sp. nov.

Amycolatopsis rhabdoformis sp. nov., an actinomycete isolated from a tropical forest soil.

Strain SB026T was isolated from Brazilian rainforest soil and its taxonomic position established using data from a polyphasic study. The organism showed a combination of chemotaxonomic and morphological features consistent with its classification in the genus Amycolatopsis and formed a branch in the Amycolatopsis 16S rRNA gene tree together with Amycolatopsis bullii NRRL B-24847T, Amycolatopsis plumensis NRRL B-24324T, Amycolatopsis tolypomycina DSM 44544T and Amycolatopsis vancoresmycina NRRL B-24208T. It was related most closely to A. bullii NRRL B-24847T (99.0 % 16S rRNA gene sequence similarity), but was distinguished from this strain by a low level of DNA-DNA relatedness (~46 %) and discriminatory phenotypic properties. Based on the combined genotypic and phenotypic data, it is proposed that the isolate should be classified in the genus Amycolatopsis as representing a novel species, Amycolatopsis rhabdoformis sp. nov. The type strain is SB026T ( = CBMAI 1694T = CMAA 1285T = NCIMB 14900T).

Marmoricola aquaticus sp. nov., an actinomycete isolated from a marine sponge.

A novel marine actinomycete, designated B374(T), was isolated from a marine sponge, Glodia corticostylifera, which was collected from São Paulo, Brasil. The taxonomic position of B374(T) was established by using data derived from a polyphasic approach. The organism showed a combination of chemotaxonomic and morphological characteristics consistent with its classification in the genus Marmoricola and it formed a distinct phyletic line in the clade of the genus Marmoricola, based on 16S rRNA gene sequences. Strain B374(T) was most closely related to Marmoricola aequoreus SST-45(T) (98.5% 16S rRNA gene sequence similarity), but was distinguished from this strain and from the other type strains of species of the genus Marmoricola on the basis of a combination of phenotypic properties. The data obtained, therefore, indicates that isolate B374(T) ( = CBMAI 1089(T) = DSM 28169(T)) should be classified as a novel species of the genus Marmoricola, for which the name Marmoricola aquaticus sp. nov. is proposed.

Genomic and chemical insights into biosurfactant production by the mangrove-derived strain Bacillus safensis CCMA-560.

Many Bacillus species can produce biosurfactant, although most of the studies on lipopeptide production by this genus have been focused on Bacillus subtilis. Surfactants are broadly used in pharmaceutical, food and petroleum industry, and biological surfactant shows some advantages over the chemical surfactants, such as less toxicity, production from renewable, cheaper feedstocks and development of novel recombinant hyperproducer strains. This study is aimed to unveil the biosurfactant metabolic pathway and chemical composition in Bacillus safensis strain CCMA-560. The whole genome of the CCMA-560 strain was previously sequenced, and with the aid of bioinformatics tools, its biosurfactant metabolic pathway was compared to other pathways of closely related species. Fourier transform infrared (FTIR) and high-resolution TOF mass spectrometry (MS) were used to characterize the biosurfactant molecule. B. safensis CCMA-560 metabolic pathway is similar to other Bacillus species; however, some differences in amino acid incorporation were observed, and chemical analyses corroborated the genetic results. The strain CCMA-560 harbours two genes flanked by srfAC and srfAD not present in other Bacillus spp., which can be involved in the production of the analogue gramicidin. FTIR and MS showed that B. safensis CCMA-560 produces a mixture of at least four lipopeptides with seven amino acids incorporated and a fatty acid chain with 14 carbons, which makes this molecule similar to the biosurfactant of Bacillus pumilus, namely, pumilacidin. This is the first report on the biosurfactant production by B. safensis, encompassing the investigation of the metabolic pathway and chemical characterization of the biosurfactant molecule.

Actinospica durhamensis sp. nov., isolated from a spruce forest soil.

Seven acidophilic actinobacteria isolated from humus and mineral layers of a spruce forest soil were examined using a polyphasic approach. Chemotaxonomic properties of the isolates were found to be consistent with their classification in the genus Actinospica. The strains formed a distinct phyletic line in the Actinospica 16S rRNA gene tree being most closely related to Actinospica robiniae DSM 44927(T) (98.7-99.3 % similarity). DNA:DNA relatedness between isolate CSCA57(T) and the type strain of A. robiniae was found to be low at 40.8 (±6.6) %. The isolates were shown to have many phenotypic properties in common and were distinguished readily from the type strains of Actinospica acidiphila and A. robiniae using a range of phenotypic features. On the basis of these data the seven isolates were considered to represent a new species for which the name Actinospica durhamensis sp. nov. is proposed. The type strain of the species is CSCA 57(T) (=DSM 46820(T) = NCIMB 14953(T)).

Chromobacterium amazonense sp. nov. isolated from water samples from the Rio Negro, Amazon, Brazil.

The taxonomic position of a bacterium isolated from water samples from the Rio Negro, in Amazon, Brazil, was determined by using a polyphasic approach. The organism formed a distinct phyletic line in the Chromobacterium 16S rRNA gene tree and had chemotaxonomic and morphological properties consistent with its classification in this genus. It was found to be closely related to Chromobacterium vaccinii DSM 25150(T) (98.6 % 16S rRNA gene similarity) and shared 98.5 % 16S rRNA gene similarity with Chromobacterium piscinae LGM 3947(T). DNA-DNA relatedness studies showed that isolate CBMAI 310(T) belongs to distinct genomic species. The isolate was readily distinguished from the type strain of these species using a combination of phenotypic and chemotaxonomic properties. Thus, based on genotypic and phenotypic data, it is proposed that isolate CBMAI 310(T) (=DSM 26508(T)) be classified in the genus Chromobacterium as the type strain of a novel species, namely, Chromobacterium amazonense sp. nov.

Oligonucleotide primers for specific detection of actinobacterial laccases from superfamilies I and K.

Although many putative laccase-like genes have been assigned to members of the phylum Actinobacteria, few of the related enzymes have been characterized so far. It is noteworthy, however, that this small number of enzymes has presented properties with industrial relevance. This observation, combined with the recognized biotechnological potential and the capability of this phylum to degrade recalcitrant soil polymers, has attracted attention for bioprospective approaches. In the present work, we have designed and tested primers that were specific for detection of sub-groups of laccase-like genes within actinomycetes, which corresponded to the superfamilies I and K from the classification presented by the laccase and multicopper oxidase engineering database. The designed primers have amplified laccase-like gene fragments from actinomycete isolates that were undetectable by primers available from the literature. Furthermore, phylogenetic alignments suggest that some of these fragments may belong to new laccases-like proteins, and thus emphasize the benefits of designing subgroup-specific primers.

Streptomyces araujoniae Produces a Multiantibiotic Complex with Ionophoric Properties to Control Botrytis cinerea.

A recently described actinomycete species (Streptomyces araujoniae ASBV-1(T)) is effective against many phytopathogenic fungi. In this study, we evaluated the capacity of this species to inhibit Botrytis cinerea development in strawberry pseudofruit, and we identified the chemical structures of its bioactive compounds. An ethyl acetate crude extract (0.1 mg ml(-1)) of ASBV-1(T) fermentation broth completely inhibited fungus growth in strawberry pseudofruit under storage conditions. The crude extract was fractionated by preparative high-performance liquid chromatography; the active fraction was further evaluated by tandem mass spectrometry. ASBV-1(T) produced a multiantibiotic complex with ionophoric properties. This complex contained members of the macrotetralides class (including monactin, dinactin, trinactin, and tetranactin) and the cyclodepsipeptide valinomycin, all of which were active against B. cinerea. Furthermore, the addition of 2 mM MgSO4 and 1 mM ZnSO4 enhanced macrotetralide and valinomycin production, respectively, in the culture broth. These compounds are considered to be the main active molecules that S. araujoniae produces to control B. cinerea. Their low to moderate toxicity to humans and the environment justifies the application of ASBV-1(T) in biological control programs that aim to mitigate the damage caused by this phytopathogen.

Actinomadura xylanilytica sp. nov., an actinomycete isolated from soil.

The taxonomic position of a soil isolate, strain BK147(T), was established using data from a polyphasic study. The organism showed a combination of chemotaxonomic and morphological characteristics consistent with its classification in the genus Actinomadura. It formed a distinct phyletic line in the phylogenetic tree based on 16S rRNA gene sequences of members of the genus Actinomadura and was most closely, albeit loosely, related to Actinomadura bangladeshensis DSM 45347(T), Actinomadura meyerae DSM 44715(T) and Actinomadura napierensis NRRL B-24319(T) but was readily distinguished from these strains using a range of phenotypic properties. Based on the combined genotypic and phenotypic data it is proposed that isolate BK147(T) ( = KACC 20919(T) = NCIMB 14771(T) = NRRL B-24852(T)) be classified as the type strain of a novel species of the genus Actinomadura, for which the name Actinomadura xylanilytica sp. nov. is proposed.

Streptomyces araujoniae sp. nov.: an actinomycete isolated from a potato tubercle.

The taxonomic position of a streptomycete isolated from a potato tubercle was determined by using a polyphasic approach. The organism had chemotaxonomic and morphological properties consistent with its classification in the genus Streptomyces and formed a distinct phyletic line in the Streptomyces 16S rRNA gene tree. It was found to be closely related to Streptomyces celluloflavus NRRL B-2493(T) (99.4 % 16S rRNA gene similarity) and shared a 99.0 % 16S rRNA gene similarity value with Streptomyces albolongus NRRL B-3604(T) and Streptomyces cavourensis subsp. cavourensis NBRC 13026(T); low levels of DNA-DNA relatedness with these organisms showed that the isolate belonged to a distinct genomic species. The isolate was distinguished readily from the type strains of these species using a combination of morphological and other phenotypic properties. On the basis of these results, it is proposed that isolate ASBV-1(T) (= CBMAI 1465(T) = CCMA 894(T) = NRRL B-24922(T)) be classified as the type strain of Streptomyces araujoniae sp. nov.

Verrucosispora fiedleri sp. nov., an actinomycete isolated from a fjord sediment which synthesizes proximicins.

A novel filamentous actinobacterial organism, designated strain MG-37(T), was isolated from a Norwegian fjord sediment and examined using a polyphasic taxonomic approach. The organism was determined to have chemotaxonomic and morphological properties consistent with its classification in the genus Verrucosispora and formed a distinct phyletic line in the Verrucosispora 16S rRNA gene tree. It was most closely related to Verrucosispora maris DSM 45365(T) (99.5 % 16S rRNA gene similarity) and Verrucosispora gifhornensis DSM 44337(T) (99.4 % 16S rRNA gene similarity) but was distinguished from these strains based on low levels of DNA:DNA relatedness (~56 and ~50 %, respectively). It was readily delineated from all of the type strains of Verrucosispora species based on a combination of phenotypic properties. Isolate MG-37(T) (=NCIMB 14794(T) = NRRL-B-24892(T)) should therefore be classified as the type strain of a novel species of Verrucosispora for which the name Verrucosispora fiedleri is proposed.

Amycolatopsis thermophila sp. nov. and Amycolatopsis viridis sp. nov., thermophilic actinomycetes isolated from arid soil.

The taxonomic positions of two thermophilic actinomycetes isolated from an arid Australian soil sample were established based on an investigation using a polyphasic taxonomic approach. The organisms had chemical and morphological properties typical of members of the genus Amycolatopsis and formed distinct phyletic lines in the Amycolatopsis methanolica 16S rRNA subclade. The two organisms were distinguished from one another and from the type strains of related species of the genus Amycolatopsis using a range of phenotypic properties. Based on the combined genotypic and phenotypic data, it is proposed that the two isolates be classified in the genus Amycolatopsis as Amycolatopsis thermophila sp. nov. (type strain GY088(T)=NCIMB 14699(T)=NRRL B-24836(T)) and Amycolatopsis viridis sp. nov. (type strain GY115(T)=NCIMB 14700(T)=NRRL B-24837(T)).

Streptomyces staurosporininus sp. nov., a staurosporine-producing actinomycete.

The taxonomic position of a staurosporine-producing actinomycete isolated from a hay meadow soil was determined using a polyphasic approach. The organism had chemical and morphological characteristics consistent with its classification in the genus Streptomyces and formed a distinct branch between the Streptomyces lydicus and Streptomyces noursei clades in the 16S rRNA Streptomyces gene tree. DNA-DNA relatedness values between the isolate and its nearest phylogenetic neighbours, namely Streptomyces lydicus NBRC 13058T and Streptomyces chattanoogensis NBRC 12754T, were 53 % and 40 %, respectively. The isolate was also readily distinguished from the type strains of these species using a combination of morphological and other phenotypic properties. On the basis of these results, it is proposed that isolate BK179T (=KACC 20912T=NRRL B-24850T) be classified as the type strain of Streptomyces staurosporininus sp. nov.