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1.
Innovative procedures were used to selectively isolate small numbers of Micromonospora strains from extreme hyper-arid and high altitude Atacama Desert soils. Micromonosporae were recognised on isolation plates by their ability to produce filamentous microcolonies that were strongly attached to the agar. Most of the isolates formed characteristic orange colonies that lacked aerial hyphae and turned black on spore formation, whereas those from the high altitude soil were dry, blue-green and covered by white aerial hyphae. The isolates were assigned to seven multi- and eleven single-membered groups based on BOX-PCR profiles. Representatives of the groups were assigned to either multi-membered clades that also contained marker strains or formed distinct phyletic lines in the Micromonospora 16S rRNA gene tree; many of the isolates were considered to be putatively novel species of Micromonospora. Most of the isolates from the high altitude soils showed activity against wild type strains of Bacillus subtilis and Pseudomonas fluorescens while those from the rhizosphere of Parastrephia quadrangulares and from the Lomas Bayas hyper-arid soil showed resistance to UV radiation.  相似文献   

2.
To understand the isolation and classification state of actinobacterial species with valid names for Korean indigenous isolates, isolation source, regional origin, and taxonomic affiliation of the isolates were studied. At the time of this writing, the phylum Actinobacteria consisted of only one class, Actinobacteria, including five subclasses, 10 orders, 56 families, and 330 genera. Moreover, new taxa of this phylum continue to be discovered. Korean actinobacterial species with a valid name has been reported from 1995 as Tsukamurella inchonensis isolated from a clinical specimen. In 1997, Streptomyces seoulensis was validated with the isolate from the natural Korean environment. Until Feb. 2016, 256 actinobacterial species with valid names originated from Korean territory were listed on LPSN. The species were affiliated with three subclasses (Acidimicrobidae, Actinobacteridae, and Rubrobacteridae), four orders (Acidimicrobiales, Actinomycetales, Bifidobacteriales, and Solirubrobacterales), 12 suborders, 36 families, and 93 genera. Most of the species belonged to the subclass Actinobacteridae, and almost of the members of this subclass were affiliated with the order Actinomycetales. A number of novel isolates belonged to the families Nocardioidaceae, Microbacteriaceae, Intrasporangiaceae, and Streptomycetaceae as well as the genera Nocardioides, Streptomyces, and Microbacterium. Twenty-six novel genera and one novel family, Motilibacteraceae, were created first with Korean indigenous isolates. Most of the Korean indigenous actionobacterial species were isolated from natural environments such as soil, seawater, tidal flat sediment, and fresh-water. A considerable number of species were isolated from artificial resources such as fermented foods, wastewater, compost, biofilm, and water-cooling systems or clinical specimens. Korean indigenous actinobacterial species were isolated from whole territory of Korea, and especially a large number of species were from Jeju, Gyeonggi, Jeonnam, Daejeon, and Chungnam. A large number of novel actinobacterial species continue to be discovered since the Korean government is encouraging the search for new bacterial species and researchers are endeavoring to find out novel strains from extreme or untapped environments.  相似文献   

3.
As potential probiotic candidates, plant vertically transmitted actinobacteria are beneficial to growth and health of host plants. New methods to isolate the actinobacterial taxa with low growth rates should be developed. Based on the actinobacterial population information, the probiotic actinobacterial taxa could be directly isolated from healthy banana shoot tips. However, actinobacterial DNAs with high GC contents could bias estimates of actinobacteria by PCR. In the study, two amplicon sequencing strategies were adopted to elucidate the endophytic actinobacterial community of banana plants. More than 92.5% bacterial OTUs were affiliated with actinobacteria by these two strategies, and total 14,289 actinobacterial OTUs with above 97% similarity were detected in banana shoot tips. Although the libraries generated by the two strategies differed in the abundance of some genera, Mycobacterium and Nocardia dominated both libraries and most actinobacterial taxa were overlapped. Higher phylogenetic resolution actinobacteriome of banana plants was successfully established. Based on the endophytic actinobacterial community information, the streptomycetes were isolated from shoot tips. Pot experiments illustrated that the strain could promote banana plantlet growth and elevate resistance to Fusarium oxysporum f. sp. cubense (FOC) under FOC infested soils. The results suggested that the selection for probiotic agents based on actinobacteriome analysis is reliable and feasible compared with present greenhouse selection.  相似文献   

4.
The taxonomic position of a novel Amycolatopsis strain isolated from a high altitude Atacama Desert subsurface soil was established using a polyphasic approach. The strain, isolate H5T, was shown to have chemical properties typical of members of the genus Amycolatopsis such as meso-diaminopimelic acid as the diamino acid in the cell wall peptidoglycan, arabinose and galactose as diagnostic sugars and MK-9(H4) as the predominant isoprenologue. It also has cultural and morphological properties consistent with its classification in the genus, notably the formation of branching substrate hyphae which fragment into rod-like elements. 16S rRNA gene sequence analyses showed that the strain is closely related to the type strain of Amycolatopsis mediterranei but could be distinguished from this and other related Amycolatopsis strains using a broad range of phenotypic properties. It was separated readily from the type strain of Amycolatopsis balhymycina, its near phylogenetic neighbour, based on multi-locus sequence data, by low average nucleotide identity (92.9%) and in silico DNA/DNA relatedness values (51.3%) calculated from draft genome assemblies. Consequently, the strain is considered to represent a novel species of Amycolatopsis for which the name Amycolatopsis vastitatis sp. nov. is proposed. The type strain is H5T (= NCIMB 14970T = NRRL B-65279T).  相似文献   

5.
Eccopsis razowskii Vargas (Lepidoptera: Tortricidae: Olethreutini) is a Neotropical micromoth native to the Atacama Desert with leaf-tying larvae that feed on Acacia macracantha Willd. (Fabaceae). The external morphology of its last instar and that of its pupa are described and illustrated for the first time with the aid of light and scanning electron microscopy. The morphology of each of these life stages is highly similar to that of the only sympatric congeneric, the pest species E. galapagana Razowski & Landry, the larvae of which feed on Prosopis spp. (Fabaceae). The pupae of the two species cannot be separated based on morphology; they can only be accurately separated based on the form of the mandible. The findings are discussed in terms of their significance for the taxonomy and systematics of Eccopsis. In addition, a comparison with the two other Tortricidae associated with A. macracantha in the Atacama Desert is provided.  相似文献   

6.
Given the impact of climate change on the availability of water resources, it becomes necessary the use of plant species well suited to planting on dryland sites. Eucalyptus cladocalyx, a native tree of South Australia, is capable of growing under relatively dry environments and saline soils. Two hundred twenty simple sequence repeat (microsatellites) markers, from a consensus linkage map of Eucalyptus, were selected to examine genetic diversity and population structure in a collection of E. cladocalyx introduced to southern Atacama Desert, Chile. A total of 130 microsatellites were successfully amplified, some of which are associated with quantitative traits of interest in Eucalyptus. Genetic analysis revealed a total of 457 alleles, ranging from 2 to 8 alleles per locus. A moderate level of genetic diversity (He = 0.492) and differentiation (FST = 0.086) was found among the populations. Mount Remarkable and Marble Range showed the highest and lowest level of genetic diversity, respectively. The Bayesian clustering analysis revealed three homogeneous genetic groups confirming that the individuals of E. cladocalyx from natural forest are highly and significantly structured. These results provide a novel information for the development of breeding strategies in E. cladocalyx by using marker-assisted selection in regions with low rainfall patterns.  相似文献   

7.
8.
The Atacama Desert presents one of the most extreme environments on Earth and we report here the first extensive isolations of actinomycetes from soils at various locations within the Desert. The use of selective isolation procedures enabled actinomycetes to be recovered from arid, hyper-arid and even extreme hyper-arid environments in significant numbers and diversity. In some cases actinomycetes were the only culturable bacteria to be isolated under the conditions of this study. Phylogenetic analysis and some phenotypic characterisation revealed that the majority of isolates belonged to members of the genera Amycolatopsis, Lechevalieria and Streptomyces, a high proportion of which represent novel centres of taxonomic variation. The results of this study support the view that arid desert soils constitute a largely unexplored repository of novel bacteria, while the high incidence of non-ribosomal peptide synthase genes in our isolates recommend them as promising material in screening for new bioactive natural products.  相似文献   

9.
Marine sediments from Newfoundland, Canada were explored for biotechnologically promising Actinobacteria using culture-independent and culture-dependent approaches. Culture-independent pyrosequencing analyses uncovered significant actinobacterial diversity (H′—2.45 to 3.76), although the taxonomic diversity of biotechnologically important actinomycetes could not be fully elucidated due to limited sampling depth. Assessment of culturable actinomycete diversity resulted in the isolation of 360 actinomycetes representing 59 operational taxonomic units, the majority of which (94 %) were Streptomyces. The biotechnological potential of actinomycetes from NL sediments was assessed by bioactivity and metabolomics-based screening of 32 representative isolates. Bioactivity was exhibited by 41 % of isolates, while 11 % exhibited unique chemical signatures in metabolomics screening. Chemical analysis of two isolates resulted in the isolation of the cytotoxic metabolite 1-isopentadecanoyl-3β-d-glucopyranosyl-X-glycerol from Actinoalloteichus sp. 2L868 and sungsanpin from Streptomyces sp. 8LB7. These results demonstrate the potential for the discovery of novel bioactive metabolites from actinomycetes isolated from Atlantic Canadian marine sediments.  相似文献   

10.
The taxonomic provenance of a filamentous actinobacterial strain isolated from a desert soil was established using a polyphasic approach. The strain has chemotaxonomic and morphological properties consistent with its classification in the genus Saccharothrix. It forms a distinct branch in the Saccharothrix 16S rRNA gene tree, related to the type strain of Saccharothrix saharensis (96.7%) but was distinguished readily from it using a combination of phenotypic properties. The genotypic and phenotypic data show that the strain represents a novel species in the genus Saccharothrix, for which the name Saccharothrix tharensis sp. nov. is proposed with the type strain TD-093T (=?KCTC 39724T?=?MCC 2832T).  相似文献   

11.
The study of how climatic niches change over evolutionary time has recently attracted the interest of many researchers. Different methodologies have been employed principally to analyze the temporal dynamics of the niche and specially to test for the presence of phylogenetic niche conservatism. Menonvillea, a genus of Brassicaceae including 24 species, is distributed primarily along the Andes of Argentina and Chile, with some taxa growing in southern Patagonia and others in the Atacama Desert and the Chilean Matorral. The genus is highly diversified morphologically but also presents a remarkably wide ecological range, growing from the high Andean elevations, to the dry coastal deserts in Chile, or the Patagonia Steppe in Argentina. In this study, we used molecular phylogenies together with climatic data to study climatic niche evolution in the genus. The results show that the main climatic niche shifts in Menonvillea occurred between the sections Cuneata-Scapigera and sect. Menonvillea throughout the Mid-Late Miocene, and associated with the two main geographical distribution centers of the genus: the highlands of the central-southern Andes and the Atacama Desert-Chilean Matorral, respectively. Climatic niches in these lineages were mainly differentiated by the aridity and potential evapotranspiration, the minimum temperatures of the coldest month, and the temperature annual range and seasonality. Niche evolution in Menonvillea deviated from a Brownian motion process, with most of the climatic dimension best-fitting to an Ornstein-Uhlenbeck model of multiple adaptive peaks. Our results also indicated that higher aridity levels and lower annual temperature ranges were associated with the evolution of the annual habit, as exemplified by the distribution of sect. Menonvillea. Finally, the results suggested that climatic niche evolution in Menonvillea exhibited some degree of phylogenetic niche conservatism, fundamentally within the two main lineages (sect. Menonvillea and sects. Cuneata-Scapigera).  相似文献   

12.
The Eurasian bumble bee Bombus terrestris Linnaeus has been used commercially for pollination of a large number of crop species worldwide. This species has become invasive in several countries where it has escaped into natural environments. This species has become naturalized in many zones of Chile and southern Argentina, and may potentially invade other regions and countries in South America. These naturalized populations of B. terrestris have been associated with rapid population declines of the native bee B. dahlbomii Guérin-Méneville. We report new records of the exotic bee B. terrestris in the Region de Arica y Parinacota in the far north of Chile, which includes portions of the Atacama Desert. We used species distribution models (SDMs) and multivariate analyses to evaluate whether these occurrences represent new escapes from managed colonies or natural dispersal of the species from its southern invaded range. These reports of B. terrestris indicate a northward expansion of this bee. In our analyses, these new areas of occurrences have environmental conditions similar to those observed in the species’ southern invaded range, and our SDMs predict that B. terrestris dispersal through the Atacama is possible, although not likely given the occasional flower blooming in that region of Chile. These new occurrences in northern Chile reflect a potential for future invasion into other regions of South America by B. terrestris. Future surveys in the area should be intensified to evaluate if viable populations of this invasive species may become established.  相似文献   

13.
Selection for probiotic candidates by in vivo experimental trials is time and labor consuming; more informed strategy is needed to select successful probiotic candidates. The aim of the study was to elucidate the microbial taxa transmitted from maize seeds to seedlings during the germination process of maize and their probiotic effects. The bacterial and fungal taxa in kernel germs and sprouts were analyzed by Illumina-based sequencing. The sprouts contained more diverse fungi than those in germs. The bacterial species (OTUs) declined with the germination from germs to the sprouts. However, the endophytic fungal diversity increased during the germination process. Seed-borne dominant bacterial genera Bacillus, Halomonas, and Shewanella and dominant fungal genera Aspergillus were also detected in sprouts. The spore-forming bacteria BS3 isolated directly from sprouts could promote growth of maize seedling and resistance to F. verticillioides under F. verticillioides-infested soils. The results suggested that maize contained core bacterial and fungal taxa during the development from seeds to sprouts, and the core endophytes showed more intimate correlation with host plants than did other microbial taxa. Illumina-based sequence analysis is feasible to guide probiotic candidate selection and isolation.  相似文献   

14.
A taxonomic revision of Upper Miocene Neoaves from Polgárdi locality is summarized. Rallicrex polgardiensis is transferred to the genus Rallus. The taxonomic position of R. kolozsvarensis is discussed. Porzana estramosi veterior and P. kretzoii are transferred to the genus Zapornia former is ranked as species. It is shown that the material referred to Egretta polgardiensis, Surnia robusta, and Otis kalmani actually belong to the fossil barn owl Tyto campiterrae. The genera Cuculus and Tetrao are identified incorrectly and several other taxa cannot be identified to genus. A fragmentary carpometacarpus originally referred to as Gallinago veterior actually belongs to Glareolidae. A complete list of revised non-passeriform taxa from Polgárdi is provided and the composition of the avifauna is discussed. The absence of taxa shared with approximately contemporaneous avian assemblage from the Hyargas-Nuur 2 locality in eastern Mongolia is evidence that at least two separate zoogeographical units of temperate avifaunas existed in the Late Miocene of Eurasia.  相似文献   

15.
16.
Morphological revision of Fulvifomes robiniae, as well as phylogenetic inferences based on nITS and nLSU markers, indicated that the species has a narrower concept in its morphology and distribution. Other morphologically related taxa arise from this taxonomic approach. Fulvifomes cedrelae is not accepted as a synonym of F. robiniae, and Fulvifomes squamosus sp. nov. is described as new based on Peruvian specimens. Based on morphology, phylogenetic relationships and host distributions, the taxonomic implication for the genus and other related taxa are discussed.  相似文献   

17.
The Agave angustifolia complex, distributed from Mexico to Costa Rica, comprises four species and five varieties, including three species used for mescal production. The complex is represented in the Mexican state of Oaxaca by two wild taxa, A. angustifolia var. angustifolia and A. angustifolia var. rubescens, the cultivated form A. angustifolia “Espadín” and the partially cultivated species A. rodacantha. The aims of this study were to investigate the morphological and genetic variation of the A. angustifolia complex in the state of Oaxaca and to identify traits useful for taxonomic delimitation. Four wild and three cultivated populations of A. angustifolia from Oaxaca, one population of A. tequilana from Guanajuato and one population of A. angustifolia from Sonora were sampled for morphological, genetic and cytometric analyses. We showed that cultivated populations of A. angustifolia “Espadin,” A. rhodacantha and A. tequilana could be clearly differentiated from wild populations. Furthermore, the domesticated populations of A. angustifolia, known locally as “Espadin,” had a higher ploidy level and lower genetic variation than their related wild populations. The population of A. angustifolia from Sonora could be recognized as a different entity. Populations of A. rhodacantha need to be studied throughout their entire distribution area to further evaluate their taxonomic delimitation.  相似文献   

18.
19.
The geological, hydrological and microbiological features of the Salar de Atacama, the most extensive evaporitic sedimentary basin in the Atacama Desert of northern Chile, have been extensively studied. In contrast, relatively little attention has been paid to the composition and roles of microbial communities in hypersaline lakes which are a unique feature in the Salar. In the present study biochemical, chemical and molecular biological tools were used to determine the composition and roles of microbial communities in water, microbial mats and sediments along a marked salinity gradient in Laguna Puilar which is located in the “Los Flamencos” National Reserve. The bacterial communities at the sampling sites were dominated by members of the phyla Bacteroidetes, Chloroflexi, Cyanobacteria and Proteobacteria. Stable isotope and fatty acid analyses revealed marked variability in the composition of microbial mats at different sampling sites both horizontally (at different sites) and vertically (in the different layers). The Laguna Puilar was shown to be a microbially dominated ecosystem in which more than 60% of the fatty acids at particular sites are of bacterial origin. Our pioneering studies also suggest that the energy budgets of avian consumers (three flamingo species) and dominant invertebrates (amphipods and gastropods) use minerals as a source of energy and nutrients. Overall, the results of this study support the view that the Salar de Atacama is a heterogeneous and fragile ecosystem where small changes in environmental conditions may alter the balance of microbial communities with possible consequences at different trophic levels.  相似文献   

20.
Two novel species of Diatrypaceae, Diatrypella tectonae and Peroneutypa mackenziei, were collected from dead wood in northern Thailand. The new species are introduced in this paper, with evidence from morphology and phylogenetic analyses. The new taxa are described, illustrated and compared with related taxa. Phylogenetic analyses of combined ITS and partial β-tubulin (β-tub) sequence data support their natural placements in the genera Diatrypella and Peroneutypa as new species.  相似文献   

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