Yeasts are unicellular fungi that occur in a wide range of ecological niches, where they perform numerous functions. Furthermore, these microorganisms are used in industrial processes, food production, and bioremediation. Understanding the physiological and adaptive characteristics of yeasts is of great importance from ecological, biotechnological, and industrial perspectives. In this context, we evaluated the abilities to assimilate and ferment different carbon sources, to produce extracellular hydrolytic enzymes, and to tolerate salt stress, heavy metal stress, and UV-C radiation of two isolates of Eremothecium coryli, isolated from Momordica indica fruits. The two isolates were molecularly identified based on sequencing of the 18S-ITS1-5.8S-ITS2 region. Our isolates were able to assimilate nine carbon sources (dextrose, galactose, mannose, cellobiose, lactose, maltose, sucrose, melezitose, and pectin) and ferment three (glucose, maltose, and sucrose). The highest values of cellular dry weight were observed in the sugars maltose, sucrose, and melezitose. We observed the presence of hyphae and pseudohyphae in all assimilated carbon sources. The two isolates were also capable of producing amylase, catalase, pectinase, and proteases, with the highest values of enzymatic activity found in amylase. Furthermore, the two isolates were able to grow in media supplemented with copper, iron, manganese, nickel, and zinc and to tolerate saline stress in media supplemented with 5% NaCl. However, we observed a decrease in CFU at higher concentrations of these metals and NaCl. We also observed morphological changes in the presence of metals, which include changes in cell shape and cellular dimorphisms. The isolates were sensitive to UV-C radiation in the shortest exposure time (1 min). Our findings reinforce the importance of endophytic yeasts for biotechnological and industrial applications and also help to understand how these microorganisms respond to environmental variations caused by human activities.
- MeSH
- Endophytes * isolation & purification genetics metabolism physiology classification radiation effects MeSH
- Fermentation MeSH
- Phylogeny MeSH
- Stress, Physiological * MeSH
- Carbohydrate Metabolism * MeSH
- Fruit * microbiology MeSH
- Saccharomycetales * isolation & purification genetics physiology metabolism radiation effects classification MeSH
- Metals, Heavy toxicity MeSH
- Ultraviolet Rays MeSH
- Publication type
- Journal Article MeSH
This study profiled the various endophytic fungi isolated from the orchid Cymbidium sp. and their L-asparaginase production and antioxidant potential. The L-asparaginase production was first screened through qualitative plate screening then quantified by the Nesslerization method. The antioxidant potential was quantified via the 2,2-diphenyl-1-picrylhydrazyl assay. A total of 30 endophytic fungi were isolated and all fungal isolates exhibited various degrees of radical scavenging activities (45.28% to 76.4%). Isolate Lasiodiplodia theobromae (C11) had the highest antioxidant capacity, represented by the lowest IC50 value (5.75 mg/mL) and highest ascorbic acid equivalent antioxidant capacity value (12.17 mg/g). Additionally, 16 isolates produced L-asparaginase (53.33%), which includes primarily species of Fusarium proliferatum, Fusarium fujikuroi, Fusarium incarnatum, and Fusarium oxysporum. A new isolate has also been discovered from Cymbidium orchid, Buergenerula spartinae (C28), which showed the highest L-asparaginase activity (1.736 unit/mL). These findings supported the postulation that medicinal species of Orchidaceae such as Cymbidium sp. harbor endophytes that are producers of L-asparaginase and antioxidants with various potential applications.
- MeSH
- Antioxidants * metabolism MeSH
- Asparaginase * metabolism MeSH
- Endophytes * isolation & purification metabolism enzymology classification MeSH
- Fusarium enzymology metabolism isolation & purification MeSH
- Phylogeny MeSH
- Fungi classification isolation & purification enzymology MeSH
- Orchidaceae * microbiology MeSH
- Publication type
- Journal Article MeSH
Three endophytic bacteria, namely BvV, BvP and BvL, were newly isolated from the root nodules of bean, pea and lentil plants respectively cultivated in Mascara the northwest of Algeria, and identified by 16S ribosomal RNA gene sequencing as Brevundimonas naejangsanensis. These strains were able to produce hydrolytic enzymes and hydrogen cyanide. All strains produced a growth-promoting hormone, indole acetic acid, varying in concentration from 83.2 to 171.7 μg/mL. The phosphate solubilizing activity of BvV, BvP and BvL varied from 25.5 to 42.02 μg/mL for tricalcium phosphate. The three antagonistic Brevundimonas spp. showed in vitro the most inhibitory effect on mycelial growth of Fusarium redolens FRC (from 78.33 to 85.55%). Strain BvV, BvP and BvL produced also volatile metabolites which inhibited mycelial FRC growth up to 39.2%. All strains showed significant disease reduction in pot experiments. Chickpea Fusarium yellows severity caused by FRC was reduced significantly from 89.3 to 96.6% in the susceptible cultivar ILC 482 treated with antagonistic B. naejangsanensis. The maximum stimulatory effect on chickpea plants growth was observed by inoculation of strain BvV. This treatment resulted in a 7.40-26.21% increase in shoot height as compared to the control plants. It is concluded that the endophytic bacterial strains of B. naejangsanensis having different plant growth promoting (PGP) activities can be considered as beneficial microbes for sustainable agriculture. To our knowledge, this is the first report to use B. naejangsanensis strains as a new biocontrol agent against F. redolens, a new pathogen of chickpea plants causing Fusarium yellows disease in Algeria.
- MeSH
- Antibiosis * MeSH
- Biological Control Agents pharmacology MeSH
- Burkholderiales genetics growth & development metabolism MeSH
- Cicer * microbiology growth & development MeSH
- Endophytes isolation & purification genetics classification physiology metabolism MeSH
- Phosphates metabolism MeSH
- Fusarium * growth & development physiology genetics MeSH
- Phylogeny MeSH
- Plant Roots microbiology MeSH
- Indoleacetic Acids metabolism MeSH
- Plant Diseases * microbiology prevention & control MeSH
- Plant Growth Regulators metabolism MeSH
- RNA, Ribosomal, 16S * genetics MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Algeria MeSH
Medicinal plants have been studied for potential endophytic interactions and numerous studies have provided evidence that seeds harbor diverse microbial communities, not only on their surfaces but also within the embryo. Adenosine deaminase (ADA) is known as a potential therapeutic target for the treatment of lymphoproliferative disorders and cancer. Therefore, in this study, 20 types of medicinal plant seeds were used to screen endophytic fungi with tissue homogenate and streak. In addition, 128 morphologically distinct endophyte strains were isolated and their ADA inhibitory activity determined by a spectrophotometric assay. The strain with the highest inhibitory activity was identified as Cochliobolus sp. Seven compounds were isolated from the strain using a chromatography method. Compound 3 showed the highest ADA inhibitory activity and was identified as 5-hydroxy-2-hydroxymethyl-4H-pyran-4-one, based on the results of 1H and 13C NMR spectroscopy. The results of molecular docking suggested that compound 3 binds to the active site and the nonspecific binding site of the ADA. Furthermore, we found that compound 3 is a mixed ADA inhibitor. These results indicate that endophytic strains are a promising source of ADA inhibitors and that compound 3 may be a superior source for use in the preparation of biologically active ADA inhibitor compounds used to treat cancer.
- MeSH
- Adenosine Deaminase chemistry metabolism MeSH
- Ascomycota chemistry classification genetics isolation & purification MeSH
- Endophytes chemistry classification genetics isolation & purification MeSH
- Adenosine Deaminase Inhibitors chemistry pharmacology MeSH
- Plants, Medicinal microbiology MeSH
- Humans MeSH
- Magnetic Resonance Spectroscopy MeSH
- Neoplasms drug therapy enzymology MeSH
- Seeds microbiology MeSH
- Molecular Docking Simulation MeSH
- Binding Sites MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
The most diverse and versatile endophytic actinobacteria are relatively unexplored potential sources of bioactive metabolites useful for different medical, agricultural, and other commercial applications. Their diversity in symbiotic association with traditionally utilized medicinal plants of northeast India is scantly available. The present investigation assessed the genetic diversity of endophytic actinobacteria (n = 120) distributed around the root, stem, and leaf tissues of six selected medicinal plants (Emblica officinalis, Terminalia chebula, T. arjuna, Murraya koenigii, Rauwolfia serpentina, and Azadirachta indica) from three different protected areas of evergreen forest-the Gibbon Wildlife Sanctuary (GWS), the Kaziranga National Park (KNP), and the North East Ecological Park (NEEP) of Assam, India. The samples were collected in two seasons (summer and winter). The overall phylogenetic analysis showed significant genetic diversity with 18 distinct genera belonging to 12 families. Overall, the occurrence of Streptomyces genus was predominant across all three sampling sites (76.66%), in both the sampling season (summer and winter). Shannon's and Simpson's diversity estimates showed their presence at A. indica (1.496, 0.778), R. serpentina (1.470, 0.858), and E. officinalis (0.975, 0.353). Among the site sampled, GWS had the most diverse community of actinobacteria (Shannon = 0.86 and Simpson = 0.557). The isolates were antagonistically more active against the investigated plant pathogenic bacteria than fungal pathogens. Further analysis revealed the prevalence of polyketide synthase genes (PKS) type II (84%) and PKS type I (16%) in the genome of the antimicrobial isolates. The overall findings confirmed the presence of biosynthetically active diverse actinobacterial members in the selected medicinal plants which offer potential opportunities towards the exploration of biologically active compounds.
- MeSH
- Actinobacteria classification genetics isolation & purification physiology MeSH
- Antibiosis * MeSH
- Bacteria MeSH
- Bacterial Proteins genetics metabolism MeSH
- Endophytes classification genetics isolation & purification physiology MeSH
- Phylogeny * MeSH
- Bacterial Physiological Phenomena MeSH
- Fungi physiology MeSH
- Plants, Medicinal microbiology MeSH
- Polyketide Synthases genetics metabolism MeSH
- Seasons MeSH
- Symbiosis MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- India MeSH
Numerous studies demonstrated that endophytic microbes can promote plant growth and increase plant stress resistance. We aimed at isolating poplar endophytes able to increase their hosts' fitness both in nutrient-limited and polluted environments. To achieve this goal, endophytic bacteria and fungi were isolated from roots and leaves of hybrid poplars (Populus nigra × P. maximowiczii clone Max-4) on an unpolluted and a risk element-polluted site in the Czech Republic and subsequently screened by a number of in vitro tests. Bacterial communities at the unpolluted site were dominated by Gammaproteobacteria with Pseudomonas sp. as the prominent member of the class, followed by Bacilli with prevailing Bacillus sp., whereas Alphaproteobacteria, mostly Rhizobium sp., prevailed at the polluted site. The fungal endophytic community was dominated by Ascomycetes and highly distinct on both sites. Dothideomycetes, mostly Cladosporium, prevailed at the non-polluted site while unclassified Sordariomycetous fungi dominated at the polluted site. Species diversity of endophytes was higher at the unpolluted site. Many tested endophytic strains solubilized phosphate and produced siderophores, phytohormones, and antioxidants. Some strains also exhibited ACC-deaminase activity. Selected bacteria showed high tolerance and the ability to accumulate risk elements, making them promising candidates for use in inocula promoting biomass production and phytoremediation. Graphical Abstract ᅟ.
- MeSH
- Antioxidants metabolism MeSH
- Bacteria classification drug effects isolation & purification metabolism MeSH
- Biodegradation, Environmental MeSH
- Biodiversity MeSH
- Biomass MeSH
- Endophytes classification drug effects isolation & purification metabolism MeSH
- Phosphates metabolism MeSH
- Phylogeny MeSH
- Fungi classification drug effects isolation & purification metabolism MeSH
- Plant Roots microbiology MeSH
- Environmental Pollutants toxicity MeSH
- Plant Leaves microbiology MeSH
- Carbon-Carbon Lyases metabolism MeSH
- Microbiota drug effects physiology MeSH
- Populus microbiology MeSH
- Soil chemistry MeSH
- Soil Microbiology * MeSH
- Plant Growth Regulators metabolism MeSH
- Siderophores metabolism MeSH
- In Vitro Techniques MeSH
- Drug Tolerance MeSH
- Plant Development * MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
Putative endophytes of Miscanthus × giganteus were isolated, and screened in the laboratory, greenhouse and field for their plant growth promoting properties in this host. Pantoea ananatis and Pseudomonas savastanoi were the predominant bacteria in leaves whereas other pseudomonads prevailed in roots. Almost all fungal endophytes belonged to the Pezizomycotina and most were isolated from roots; Fusarium oxysporum was most abundant, followed by the genera Periconia, Exophiala, Microdochium and Leptodontidium. All endophytic groups produced phytohormones and some bacteria also produced siderophores, solubilised P and exhibited ACC-deaminase activity in vitro. In subsequent pot experiments with pre-selected endophytes, several isolates including pseudomonads, Variovorax paradoxus, Verticillium leptobactrum, Halenospora sp. and Exophiala sp. enhanced Miscanthus growth in gamma-sterilised soil. These promising Miscanthus-derived isolates were tested either as single or mixed inocula along with a mixed bacterial inoculum originating from poplar. No significant effects of inocula were detected in a pot experiment in non-sterilised soil. On two marginal field sites the mixture of bacterial endophytes from poplar had a consistently negative effect on survival and growth of Miscanthus. Contrarily, mixtures consisting of bacteria or fungi originating from Miscanthus promoted growth of their host, especially on the heavy metals-polluted site. The combination of bacteria and fungi was inferior to the mixtures consisting of bacteria or fungi alone. Our observations indicate extensive potential of mixed bacterial and fungal endophytic inocula to promote establishment and yield of Miscanthus grown on marginal and polluted land and emphasise the necessity to test particular microbial-plant host combinations. Morphotypes of fungi isolates from Miscanthus × giganteus.
- MeSH
- Ascomycota MeSH
- Bacteria classification genetics isolation & purification metabolism MeSH
- DNA, Bacterial genetics MeSH
- DNA, Fungal genetics MeSH
- Endophytes classification genetics isolation & purification physiology MeSH
- Fungi classification genetics isolation & purification physiology MeSH
- Plant Roots microbiology MeSH
- Soil Pollutants * MeSH
- Poaceae microbiology MeSH
- Plant Leaves microbiology MeSH
- Populus microbiology MeSH
- Soil chemistry MeSH
- Plant Growth Regulators metabolism MeSH
- Siderophores metabolism MeSH
- Metals, Heavy MeSH
- Plant Development * MeSH
- Environmental Pollution MeSH
- Publication type
- Journal Article MeSH
Arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) form symbiotic relationships with plants influencing their productivity, diversity and ecosystem functions. Only a few studies on these fungi, however, have been conducted in extreme elevations and none over 5500 m a.s.l., although vascular plants occur up to 6150 m a.s.l. in the Himalayas. We quantified AMF and DSE in roots of 62 plant species from contrasting habitats along an elevational gradient (3400-6150 m) in the Himalayas using a combination of optical microscopy and next generation sequencing. We linked AMF and DSE communities with host plant evolutionary history, ecological preferences (elevation and habitat type) and functional traits. We detected AMF in elevations up to 5800 m, indicating it is more constrained by extreme conditions than the host plants, which ascend up to 6150 m. In contrast, DSE were found across the entire gradient up to 6150 m. AMF diversity was unimodally related to elevation and positively related to the intensity of AMF colonization. Mid-elevation steppe and alpine plants hosted more diverse AMF communities than plants from deserts and the subnival zone. Our results bring novel insights to the abiotic and biotic filters structuring AMF and DSE communities in the Himalayas.
- MeSH
- Biodiversity * MeSH
- Endophytes classification cytology genetics physiology MeSH
- Phylogeny MeSH
- Plant Roots microbiology MeSH
- Microscopy MeSH
- Mycorrhizae classification physiology MeSH
- Altitude MeSH
- Symbiosis * MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- India MeSH
Aerobic methane-oxidizing bacteria (MOB) are an environmentally significant group of microorganisms due to their role in the global carbon cycle. Research conducted over the past few decades has increased the interest in discovering novel genera of methane-degrading bacteria, which efficiently utilize methane and decrease the global warming effect. Moreover, methanotrophs have more promising applications in environmental bioengineering, biotechnology, and pharmacy. The investigations were undertaken to recognize the variety of endophytic methanotrophic bacteria associated with Carex nigra, Vaccinium oxycoccus, and Eriophorum vaginatum originating from Moszne peatland (East Poland). Methanotrophic bacteria were isolated from plants by adding sterile fragments of different parts of plants (roots and stems) to agar mineral medium (nitrate mineral salts (NMS)) and incubated at different methane values (1-20% CH4). Single colonies were streaked on new NMS agar media and, after incubation, transferred to liquid NMS medium. Bacterial growth dynamics in the culture solution was studied by optical density-OD600 and methane consumption. Changes in the methane concentration during incubation were controlled by the gas chromatography technique. Characterization of methanotrophs was made by fluorescence in situ hybridization (FISH) with Mg705 and Mg84 for type I methanotrophs and Ma450 for type II methanotrophs. Identification of endophytes was performed after 16S ribosomal RNA (rRNA) and mmoX gene amplification. Our study confirmed the presence of both types of methanotrophic bacteria (types I and II) with the predominance of type I methanotrophs. Among cultivable methanotrophs, there were different strains of the genus Methylomonas and Methylosinus. Furthermore, we determined the potential of the examined bacteria for methane oxidation, which ranged from 0.463 ± 0.067 to 5.928 ± 0.169 μmol/L CH4/mL/day.
- MeSH
- Bacteriological Techniques MeSH
- Chromatography, Gas MeSH
- DNA, Bacterial chemistry genetics MeSH
- Endophytes classification growth & development isolation & purification metabolism MeSH
- In Situ Hybridization, Fluorescence MeSH
- Culture Media chemistry MeSH
- Methane metabolism MeSH
- Methylomonas classification growth & development isolation & purification metabolism MeSH
- Methylosinus classification growth & development isolation & purification metabolism MeSH
- DNA, Ribosomal chemistry genetics MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Cyperaceae microbiology MeSH
- Sequence Analysis, DNA MeSH
- Vaccinium microbiology MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Poland MeSH
Seagrasses, a small group of submerged marine macrophytes, were reported to lack mycorrhizae, i.e., the root-fungus symbioses most terrestrial plants use for nutrient uptake. On the other hand, several authors detected fungal endophytes in seagrass leaves, shoots, rhizomes, and roots, and an anatomically and morphologically unique dark septate endophytic (DSE) association has been recently described in the roots of the Mediterranean seagrass Posidonia oceanica. Nevertheless, the global diversity of seagrass mycobionts is not well understood, and it remains unclear what fungus forms the DSE association in P. oceanica roots. We isolated and determined P. oceanica root mycobionts from 11 localities in the northwest Mediterranean Sea with documented presence of the DSE association and compared our results with recent literature. The mycobiont communities were low in diversity (only three species), were dominated by a single yet unreported marine fungal species (ca. 90 % of the total 177 isolates), and lacked common terrestrial and freshwater root mycobionts. Our phylogenetic analysis suggests that the dominating species represents a new monotypic lineage within the recently described Aigialaceae family (Pleosporales, Ascomycota), probably representing a new genus. Most of its examined colonies developed from intracellular microsclerotia occupying host hypodermis and resembling microsclerotia of terrestrial DSE fungi. Biological significance of this hitherto overlooked seagrass root mycobiont remains obscure, but its presence across the NW Mediterranean Sea and apparent root intracellular lifestyle indicate an intriguing symbiotic relationship with the dominant Mediterranean seagrass. Our microscopic observations suggest that it may form the DSE association recently described in P. oceanica roots.
- MeSH
- Alismatales microbiology MeSH
- Ascomycota classification genetics growth & development isolation & purification MeSH
- Endophytes classification genetics growth & development isolation & purification MeSH
- Phylogeny MeSH
- Plant Roots microbiology MeSH
- Molecular Sequence Data MeSH
- Spores, Fungal classification genetics growth & development isolation & purification MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Mediterranean Sea MeSH
