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1.
Sci Rep ; 14(1): 9716, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38678060

RESUMO

High-precision and high-efficiency Semantic segmentation of high-resolution remote sensing images is a challenge. Existing models typically require a significant amount of training data to achieve good classification results and have numerous training parameters. A novel model called MST-DeepLabv3+ was suggested in this paper for remote sensing image classification. It's based on the DeepLabv3+ and can produce better results with fewer train parameters. MST-DeepLabv3+ made three improvements: (1) Reducing the number of model parameters by substituting MobileNetV2 for the Xception in the DeepLabv3+'s backbone network. (2) Adding the attention mechanism module SENet to increase the precision of semantic segmentation. (3) Increasing Transfer Learning to enhance the model's capacity to recognize features, and raise the segmentation accuracy. MST-DeepLabv3+ was tested on international society for photogrammetry and remote sensing (ISPRS) dataset, Gaofen image dataset (GID), and practically applied to the Taikang cultivated land dataset. On the ISPRS dataset, the mean intersection over union (MIoU), overall accuracy (OA), Precision, Recall, and F1-score are 82.47%, 92.13%, 90.34%, 90.12%, and 90.23%, respectively. On the GID dataset, these values are 73.44%, 85.58%, 84.10%, 84.86%, and 84.48%, respectively. The results were as high as 90.77%, 95.47%, 95.28%, 95.02%, and 95.15% on the Taikang cultivated land dataset. The experimental results indicate that MST-DeepLabv3+ effectively improves the accuracy of semantic segmentation of remote sensing images, recognizes the edge information with more completeness, and significantly reduces the parameter size.

2.
Artigo em Inglês | MEDLINE | ID: mdl-38536076

RESUMO

Three yeast strains belonging to the ascomycetous yeast genus Pichia were isolated from two soil samples from Yunnan and Guizhou provinces and a marine water sample from Liaoning province, PR China. Phylogenetic analyses based on the sequences of the D1/D2 domains of the large subunit(LSU) rRNA gene and the internal transcribed spacer (ITS) region indicate that these three strains, together with 12 additional strains isolated from various substrates collected in different regions or countries of the world, represent a novel species of the genus Pichia, for which the name Pichia kurtzmaniana sp. nov. (holotype: strain CGMCC 2.7213) is proposed. The novel species differs from its close relatives Candida californica by eight (1.5 %) and 26 (11.1 %) mismatches in the D1/D2 domains and the ITS region, respectively; and from Pichia chibodasensis by 11 (2.1 %) and 20 (8.7 %) mismatches in the D1/D2 domains and the ITS region, respectively. In addition, eight Candida species which belong to the Pichia clade are transferred to the genus Pichia, resulting in the proposal of the following new combinations: Pichia cabralensis comb. nov., Pichia californica comb. nov., Pichia ethanolica comb. nov., Pichia inconspicua comb. nov., Pichia phayaonensis comb. nov., Pichia pseudolambica comb. nov., Pichia rugopelliculosa comb. nov., and Pichia thaimueangensis comb. nov.


Assuntos
Candida , Pichia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
3.
Int J Syst Evol Microbiol ; 73(10)2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37847534

RESUMO

Three strains belonging to the basidiomycetous yeast genus Vishniacozyma were isolated from marine water samples collected from intertidal zones in Liaoning province, northeast China. Phylogenetic analyses based on the sequences of the small subunit (SSU) ribosomal DNA (rDNA), the D1/D2 domain of the large subunit (LSU) ribosomal DNA (rDNA), the internal transcribed spacer region (ITS), the two subunits of DNA polymerase II (RPB1 and RPB2), the translation elongation factor 1-α (TEF1), and the mitochondrial gene cytochrome b (CYTB) showed that these strains together with 20 strains from various geographic and ecological origins from other regions of the world represent a novel species in the genus Vishniacozyma. We propose the name Vishniacozyma pseudocarnescens sp. nov. (holotype CGMCC 2.6457) for the new species, which differs phenotypically from its close relatives V. carnescens, V. tephrensis, and V. victoriae by its ability to grow at 30 °C and on 50 % (w/v) glucose-yeast extract agar.


Assuntos
Basidiomycota , Ácidos Graxos , Filogenia , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , DNA Fúngico/genética , Análise de Sequência de DNA , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Ácidos Graxos/química , DNA Ribossômico
4.
Plants (Basel) ; 12(17)2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37687418

RESUMO

Biotic and abiotic factors influence the formation of fungal-algal pairings in lichen symbiosis. However, the specific determinants of these associations, particularly when distantly related fungi are involved, remain poorly understood. In this study, we investigated the impact of different drivers on the association patterns between taxonomically diverse lichenized fungi and their trebouxioid symbiotic partners. We collected 200 samples from four biomes and identified 41 species of lichenized fungi, associating them with 16 species of trebouxioid green algae, of which 62% were previously unreported. The species identity of both the fungal and algal partners had the most significant effect on the outcome of the symbiosis, compared to abiotic factors like climatic variables and geographic distance. Some obviously specific associations were observed in the temperate zone; however, the nestedness value was lower in arid regions than in cold, polar, and temperate regions according to interaction network analysis. Cophylogenetic analyses revealed congruent phylogenies between trebouxioid algae and associated fungi, indicating a tendency to reject random associations. The main evolutionary mechanisms contributing to the observed phylogenetic patterns were "loss" and "failure to diverge" of the algal partners. This study broadens our knowledge of fungal-algal symbiotic patterns in view of Trebouxia-associated fungi.

5.
Artigo em Inglês | MEDLINE | ID: mdl-37191980

RESUMO

A yeast strain belonging to the basidiomycetous yeast genus Cystofilobasidium was isolated from a marine sediment sample collected in an intertidal zone in Shandong province, PR China. The results of phylogenetic analyses based on sequences of the D1/D2 domain of the 26S ribosomal RNA gene and the internal transcribed spacer (ITS) region indicate that this strain, together with three other strains isolated from basal ice collected in Norway, the gut of an insect and an alga collected in Russia, represent a novel species of the genus, for which the name Cystofilobasidium josepaulonis sp. nov. (holotype strain CGMCC 2.6672T) is proposed. The novel species differs from the known species of the genus Cystofilobasidium by 1.7 %-4.1 and 11.3 %-17.1 % mismatches in the D1/D2 domain and the ITS region, respectively. This species forms teliospores on potato dextrose agar (PDA) and 10 % V8 juice agar, but teliospore germination with basidia was not observed.


Assuntos
Basidiomycota , Ácidos Graxos , DNA Fúngico/genética , Filogenia , Ágar , DNA Espaçador Ribossômico/genética , Análise de Sequência de DNA , Técnicas de Tipagem Micológica , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Ácidos Graxos/química , RNA Ribossômico/genética
6.
Mol Ecol ; 32(23): 6330-6344, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35593386

RESUMO

High-throughput sequencing has substantially improved our understanding of fungal diversity. However, the short read (<500 bp) length of current second-generation sequencing approaches provides limited taxonomic and phylogenetic resolution for species discrimination. Longer sequences containing more information are highly desired to provide greater taxonomic resolution. Here, we amplified full-length rRNA operons (~5.5 kb) and established a corresponding fungal rRNA operon database for ONT sequences (FRODO), which contains ONT sequences representing eight phyla, 41 classes, 109 orders, 256 families, 524 genera and 1116 species. We also benchmarked the optimal method for sequence classification and determined that the RDP classifier based on our FRODO database was capable of improving the classification of ONT reads, with an average of 98%-99% reads correctly classified at the genus or species level. We investigated the applicability of our approach in three representative mycobiomes, namely, the soil, marine and human gut mycobiomes, and found that the gut contains the largest number of unknown species (over 90%), followed by the marine (42%) and soil (33.8%) mycobiomes. We also observed a distinct difference in the composition of the marine and soil mycobiomes, with the highest richness and diversity detected in soils. Overall, our study provides a systematic approach for mycobiome studies and revealed that the previous methods might have underestimated the diversity of mycobiome species. Future application of this method will lead to a better understanding of the taxonomic and functional diversity of fungi in environmental and health-related mycobiomes.


Assuntos
Micobioma , Sequenciamento por Nanoporos , Humanos , Micobioma/genética , Óperon de RNAr , Filogenia , Solo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Fungos/genética
7.
Toxics ; 12(1)2023 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-38250979

RESUMO

Fireworks burning significantly degrades air quality over a short duration. The prohibition of fireworks burning (POFB) policy of 2016 and the restricted-hours fireworks burning (RHFB) policy of 2023 in Zhengzhou City provide an ideal opportunity to investigate the effects of such policies and of fireworks burning on air quality during the Spring Festival period. Based on air quality ground-based monitoring data and meteorological data for Zhengzhou City, the article analyzes the impact of the POFB policy and the RHFB policy on air quality. The results show that: (1) The ban on fireworks burning significantly affects Spring Festival air quality, with a decrease of 16.0% in the Air Quality Index (AQI) value in 2016 compared to 2015 and a 74.9% increase in 2023 compared to 2022. (2) From 2016 to 2022, the Spring Festival period witnessed a substantial decrease in average concentration of main pollutants, along with a delayed occurrence of peak concentrations, indicating a noticeable "peak-shaving" effect. However, in 2023, there was an increase in pollutant concentrations, volatility, and a significant surge in hourly concentration. (3) The POFB policy and RHFB policy notably impacted PM2.5 and PM10, with a decrease of 16.1% and 23.6% in PM2.5 and PM10 concentrations, respectively, in 2016 compared to 2015, but an increase of 74.5% and 79.2%, respectively, in 2023 compared to 2022. (4) The contribution of fireworks burning to PM2.5 concentrations significantly decreased during the fireworks burning period (FBP) in 2016 after the POFB policy and increased significantly in 2023 during FBP after the implementation of the RHFB policy. Unfavorable meteorological conditions will undoubtedly exacerbate air quality pollution caused by fireworks burning.

8.
J Fungi (Basel) ; 8(8)2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-36012846

RESUMO

The Qaidam Basin is the highest and one of the largest and driest deserts on Earth. It is considered a mars analog area in China. In contrast to numerous studies concerning its geology, geophysical, and chemistry, relatively few studies have reported microbial diversity and distribution in this area. Here, we investigated culturable yeast diversity in the northeast Qaidam Basin. A total of 194 yeast strains were isolated, and 12 genera and 21 species were identified, among which 19 were basidiomycetous yeasts. Naganishia albida, N. adeliensis, and Filobasidium magnum were the three most dominant species and were distributed in thirteen samples from eight locations. Five new species (Filobasidium chaidanensis, Kondoa globosum, Symmetrospora salmoneus, Teunia nitrariae, and Vishniacozyma pseudodimennae) were found and described based on ITS and D1D2 gene loci together with phenotypic characteristics and physiochemical analysis. Representative strains from each species were chosen for the salt-tolerant test, in which species showed different responses to different levels of NaCl concentrations. Further, the strain from soil can adapt well to the higher salt stress compared to those from plants or lichens. Our study represents the first report of the yeast diversity in the Qaidam Basin, including five new species, and also provides further information on the halotolerance of yeasts from the saline environment in mars analog.

9.
J Fungi (Basel) ; 8(2)2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35205887

RESUMO

The genus Peltula is an important cyanobacterial lichen group. We performed a taxonomic study on the Peltula from China using phylogenetic analysis based on three gene loci (ITS, nuSSU, nuLSU) together with additional species delimitation analyses by ABGD, bPTP and GMYC approaches and the phenotypic characteristics. Five new species (Peltula lobulata, P. polycarpa, P. polyphylla, P. pseudoboletiformis and P. submarginata) were found and described. Peltula lobulata is diagnostic in its small thallus with plenty of lobules, rolled down and irregularly lobed margins, and uneven cracked surfaces. Peltula polycarpa has convex and rolled down lobes and numerous apothecia with a thalloid rim covering the whole lobe, and it can be distinguished from fertile P. farinosa (southern Switzerland) by a bright olive-green and epruinose surface, and the absence of isidia. Peltula polyphylla is differentiated from any other known Peltula species by a very small polyphyllous thallus composed of abundant olive-brown to olive-black small lobes growing tightly and sometimes anastomosing and attaching to the substrate by a large and strong umbilical cluster. Peltula submarginata is similar to P. marginata but differs in the presence of encircled epinecral and algae layers, and the absence of a lower cortex. Peltula pseudoboletiformis is different from the similar species P. boletiformis in greener lobes, more yellow-green umbilici and certain phylogenetic differences. Moreover, a key to the species of Peltula in China is also provided here.

10.
IMA Fungus ; 12(1): 18, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34256869

RESUMO

The unambiguous application of fungal names is important to communicate scientific findings. Names are critical for (clinical) diagnostics, legal compliance, and regulatory controls, such as biosafety, food security, quarantine regulations, and industrial applications. Consequently, the stability of the taxonomic system and the traceability of nomenclatural changes is crucial for a broad range of users and taxonomists. The unambiguous application of names is assured by the preservation of nomenclatural history and the physical organisms representing a name. Fungi are extremely diverse in terms of ecology, lifestyle, and methods of study. Predominantly unicellular fungi known as yeasts are usually investigated as living cultures. Methods to characterize yeasts include physiological (growth) tests and experiments to induce a sexual morph; both methods require viable cultures. Thus, the preservation and availability of viable reference cultures are important, and cultures representing reference material are cited in species descriptions. Historical surveys revealed drawbacks and inconsistencies between past practices and modern requirements as stated in the International Code of Nomenclature for Algae, Fungi, and Plants (ICNafp). Improper typification of yeasts is a common problem, resulting in a large number invalid yeast species names. With this opinion letter, we address the problem that culturable microorganisms, notably some fungi and algae, require specific provisions under the ICNafp. We use yeasts as a prominent example of fungi known from cultures. But viable type material is important not only for yeasts, but also for other cultivable Fungi that are characterized by particular morphological structures (a specific type of spores), growth properties, and secondary metabolites. We summarize potential proposals which, in our opinion, will improve the stability of fungal names, in particular by protecting those names for which the reference material can be traced back to the original isolate.

11.
MycoKeys ; (47): 75-95, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30853836

RESUMO

In the present study, a total of 33 Tremella specimens in China were collected and examined using molecular phylogenetic analysis based on a combined sequence dataset of the nuc rDNA internal transcribed spacer (ITS) region and nuc 28S rDNA D1/D2 domain in conjunction with the morphological characters. Four new species, namely Tremellabasidiomaticola, T.cheejenii, T.erythrina, and T.salmonea, are newly described based on their distinct phylogenetic relationships and the comparison of morphological characters with known Tremella species. Our results indicate a high species diversity of Tremella waiting to be discovered.

12.
Antonie Van Leeuwenhoek ; 111(1): 155-160, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28871444

RESUMO

Two strains, GT-165T and GT-261, isolated from plant leaves collected from Gutian Mountain in Zhejiang province in China were identified as a novel species of the genus Kondoa by the sequence analysis of the internal transcribed spacer (ITS) region, the D1/D2 domains of the large subunit of rRNA (LSU rRNA) and the RNA polymerase II second largest subunit (RPB2), complemented by physiological tests. Phylogenetic analysis based on the concatenated sequences of ITS, D1/D2 and RPB2 showed that the closest known relatives of the new species are three undescribed Kondoa species and Kondoa thailandica. The ITS and D1/D2 sequences of the new species differ from the closely related species by 11-22% and 2-9%, respectively. The name Kondoa gutianensis f.a. sp. nov. (MB 820648, holotype = CGMCC 2.5703T; isotype: CBS 14811T = CGMCC 2.5703T) is proposed to accommodate the new taxon.


Assuntos
Basidiomycota/classificação , Microbiologia Ambiental , Folhas de Planta/microbiologia , Basidiomycota/genética , Basidiomycota/isolamento & purificação , DNA Espaçador Ribossômico , Genes de RNAr , Técnicas de Tipagem Micológica , Filogenia
13.
Int J Syst Evol Microbiol ; 67(11): 4534-4540, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28933322

RESUMO

Nine anamorphic yeast strains isolated from various plant leaves collected in southern China were phylogenetically characterized based on sequences of the internal transcribed spacer (ITS) region, the D1/D2 domains of the large subunit (LSU) rRNA gene, the small subunit (SSU) rRNA gene, the two subunits of the RNA polymerase II gene (RPB1 and RPB2) and the translation elongation factor 1-α (TEF1). Phylogenetic analysis of the combined sequences of the six genes showed that the new strains formed a distinct clade in the class Microbotryomycetes but could not be assigned to any of the existing genera, families or orders of the class. Three separate groups were consistently resolved from the nine new strains based on the combined sequences of the six genes and single gene sequences of ITS, RPB1, RPB2 and TEF1. The results suggest that the nine yeast strains compared represent three novel species in a novel genus. The names Heitmania gen. nov. (MycoBank registration number MB819987), Heitmania litseae sp. nov. (MB820112, type strain CGMCC 2.5697T=CBS 14756T), Heitmania castanopsis sp. nov. (MB819988, CGMCC 2.5698T=CBS 14750T) and Heitmania elacocarpi sp. nov. (MB820113, CGMCC 2.5695T=CBS 14752T) are proposed for the new taxa.


Assuntos
Basidiomycota/classificação , Filogenia , Folhas de Planta/microbiologia , Basidiomycota/genética , Basidiomycota/isolamento & purificação , China , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Técnicas de Tipagem Micológica , Fator 1 de Elongação de Peptídeos/genética , RNA Polimerase II/genética , RNA Ribossômico/genética , Análise de Sequência de DNA
14.
Mycology ; 7(3): 102-111, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-30123622

RESUMO

A concerted evolution model has been proposed to explain the observed lack of sequence variation among the multiple ribosomal RNA (rRNA) gene copies in many different eukaryotic species. Recent studies on the level of intragenomic variations in the rRNA gene repeats of fungi resulted in controversial conclusions. In this study, we clearly showed that significant polymorphisms of the internal transcribed spacers (ITS1 and ITS2) of ribosomal DNA (rDNA) exist within the genome of a strain of the yeast species Pichia membranifaciens. More interestingly, we showed that the intragenomic ITS sequence polymorphisms were formed by intergenomic rDNA recombination among different P. membranifaciens strains with significantly different ITS sequences. Intergenomic rDNA recombination was also responsible for the diversification of rDNA sequences in different strains of the species. After the events bring together different rDNA types in individual genomes of the P. membranifaciens strains compared, rDNA sequence heterogeneity has remained in the genome of one but eliminated by homogenisation in the genomes of other strains. Our findings show new clue for further investigation on the mechanism of concerted evolution of rRNA genes in eukaryotes.

15.
Int J Syst Evol Microbiol ; 62(Pt 4): 996-1001, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21571928

RESUMO

Among ballistoconidium-forming yeast strains isolated from various plant leaves collected from subtropical forests in eastern and central China, four strains forming cream to yellowish coloured colonies were revealed to represent three novel Derxomyces species by conventional and molecular characterization. Phylogenetic analysis based on combined sequences of the internal transcribed spacer (ITS) and 26S rRNA gene D1/D2 domain showed that strains GT-753 and ZJJ-890T were conspecific and closely related to Derxomyces boninensis, Derxomyces mrakii and Derxomyces qinlingensis. Strain ZJJ-394T was basal to the branch formed by Derxomyces komagatae, Derxomyces pseudoschimicola and Derxomyces schimicola with strong bootstrap support. Strain GT-475T was closely related to Derxomyces linzhiensis. The strains differed significantly from their close relatives in D1/D2 and ITS sequences and in physiological criteria. Three novel species are proposed: Derxomyces amylogenes sp. nov. (type strain ZJJ-890T=CGMCC 2.4407T=CBS 12233T), Derxomyces bambusicola sp. nov. (type strain GT-475T=CGMCC 2.4411T=CBS 12234T) and Derxomyces corylopsis sp. nov. (type strain ZJJ-394T=CGMCC 2.4409T=CBS 12259T).


Assuntos
Basidiomycota/classificação , Filogenia , Folhas de Planta/microbiologia , Sequência de Bases , Basidiomycota/genética , Basidiomycota/isolamento & purificação , China , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , RNA Ribossômico/genética , Análise de Sequência de DNA , Esporos Fúngicos/genética
16.
J Environ Sci (China) ; 22(12): 1936-43, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21462713

RESUMO

Soil samples were collected from three plots under different land utilization patterns including degradation, farming, and restoration. The abundances of methanotrophs were quantified using real-time polymerase chain reaction (PCR) based on the pmoA and 16S rRNA genes, and the community fingerprint was analyzed using denaturing gradient gel electrophoresis (DGGE) aiming at pmoA gene. Significantly lower 16S rRNA and pmoA genes copies were found in the degradation treatment than in farming and restoration. Higher abundances of Type I than those of Type II methanotrophs were detected in all treatments. The treatment of farming was clearly separated from degradation and restoration according to the DGGE profile by cluster analysis. The lowest diversity indices were observed in the F (farming plot), suggesting that the community structure was strongly affected by farming activities. There were significantly positive correlations between the copy numbers of pmoA also Type II-related 16S rRNA genes and soil available K content. Strong negative and positive correlations were found between Type I and soil pH, and available P content, respectively. We concluded that the vegetation cover or not, soil characteristics including pH and nutrients of P and K as a result of anthropogenic disturbance may be key factors affecting methanotrophic communities in upland soil.


Assuntos
Agricultura/métodos , Euryarchaeota/isolamento & purificação , Microbiologia do Solo , Biodiversidade , China , Eletroforese em Gel de Gradiente Desnaturante , Meio Ambiente , Euryarchaeota/genética , Genes Arqueais , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética
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