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Life (Basel, Switzerland) Jan 2023Unique natural objects, such as the caves of the Gobustan National Historical and Artistic Preserve, are also of great cultural and historical value due to rock art and...
Unique natural objects, such as the caves of the Gobustan National Historical and Artistic Preserve, are also of great cultural and historical value due to rock art and sites of ancient people. A favorable microclimate makes these habitats convenient for colonization by microbiota, including phototrophs. In arid regions with intense seasonal fluctuations of microclimatic parameters, the conditions for survival are the least favorable; therefore, it becomes especially important to determine the composition of communities that are the most adapted to specific conditions. This work aimed to identify the biodiversity of communities of caves and grottoes of the Gobustan Reserve. The studies were carried out in July 2019. Samples were analyzed for cyanobacteria and algae by microscopy and cultivation methods, microfungi were isolated by soil dilution, and the fouling glass method was also used. In total, 29 taxa of cyanobacteria and algae, 18 taxa of fungi, and 3 species of mosses were identified. The studied habitats were dominated by the algae Chlorella vulgaris, Aphanocapsa sp., and Stichococcus bacillaris; the subdominants were Jaaginema subtilissimum, Leptolyngbya tenuis, Chlorococcum minutum, and Humidophila contenta. Microfungi had the highest occurrence of Aspergillus niger, Aureobasidium pullulans, Alternaria alternata, and Talaromyces ruber. It was noted that cyanobacteria dominated in morphologically differentiated biofilms and green algae on the rocks. The greatest number of microfungi was found in the aphotic zone and bryophyte tufts. The dominance of green algae is atypical for most caves of other regions and may be associated with intense lighting of habitats. The absence of protonema is a consequence of the aridity and low moisture content of the substrates.
PubMed: 36676113
DOI: 10.3390/life13010164 -
Journal of Applied Microbiology Feb 2023To investigate fungal diversity and biosurfactant-producing fungi in four oil-contaminated sites.
AIMS
To investigate fungal diversity and biosurfactant-producing fungi in four oil-contaminated sites.
METHODS AND RESULTS
Water and sediment samples were collected from four sites in Brittany (France), over two periods, in winter/spring and summer. Fungal diversity was investigated using a metagenetic approach targeting the ITS2 region. Surface-active compound production of 701 fungal isolates collected from these samples after direct plating or following enrichment was assessed using oil spreading and Parafilm M tests. Fungal communities were highly diverse and the main dominant fungal taxa were members of the Cladosporium, Penicillium, Pseudeurotium, Phoma, Aspergillus, and Trichoderma as well as Ochroconis, Fusicolla, and Aureobasidium genera in specific sites. A total of 179 isolates (25.5% of total isolates) were positive to at least one of the screening tests, while 105 were positive to both tests. Major genera among the positive isolates were Fusarium, Trichoderma, Candida, and Penicillium. Six isolates belonging to Aureobasidium pullulans, Mucor griseocyanus, Trichoderma citrinoviride, Trichoderma harzianum, Trichodermalongibrachiatum, and Diaporthe eres showed promising activities.
CONCLUSIONS
The present study highlighted the fungal diversity of oil-contaminated environments and the fact that surface-active compound production is widespread in fungi originating from these habitats.
Topics: Fungi; Surface-Active Agents; Mitosporic Fungi; Aspergillus; Candida; Penicillium; Trichoderma
PubMed: 36724275
DOI: 10.1093/jambio/lxac070 -
Drug Delivery Dec 2022Drug distribution relies heavily on polymers, which also offer a variety of benefits like controlled release, targeted release, prolonged release, etc. Due to their low... (Review)
Review
Drug distribution relies heavily on polymers, which also offer a variety of benefits like controlled release, targeted release, prolonged release, etc. Due to their low toxicity and great safety, biodegradable polymers are highly preferred. The exopolysaccharide known as pullulan is generated from a fungus known as . It has many different qualities, including biodegradability, appropriate adhesion, antioxidant, film-forming capacity, blood compatibility, mucosal adhesion, etc. However, its application in the pharmaceutical industry is restricted by its insolubility in organic solvents, mechanical characteristics, and lack of macromolecule-carrying ability groups. This review provides an overview of the modifications made to pullulan, including periodate oxidation, etherification, esterification, sulfation, urethane derivatization, PEG incorporation, and cationization, to enhance its solubility in organic solvents, mechanical properties, pH sensitivity, drug delivery, anticoagulant, and antimicrobial properties. Pullulan has nine active hydroxyl groups in its structure that react chemically that can be used for physicochemical modification to produce pullulan derivatives. A key area of pullulan research has been pullulan modification, which has demonstrated enhanced solubility, pH-sensitive targeting, broadened horizons for delivery systems, anticoagulation, and antibacterial properties.
Topics: Glucans; Drug Delivery Systems; Pharmaceutical Preparations; Polymers; Solvents
PubMed: 36369833
DOI: 10.1080/10717544.2022.2144544 -
Critical Reviews in Biotechnology Feb 2022Liamocins synthesized by spp. are glycolipids composed of a single mannitol or arabitol headgroup linked to either three, four or even six 3,5-dihydroxydecanoic ester...
Liamocins synthesized by spp. are glycolipids composed of a single mannitol or arabitol headgroup linked to either three, four or even six 3,5-dihydroxydecanoic ester tail-groups. The highest titer of liamocin achieved was over 40.0 g/L. The substrates for liamocins synthesis include glucose, sucrose, xylose, mannitol, and others. The Pks1 is responsible for the biosynthesis of the tail-group 3,5-dihydroxydecanoic acid, both mannitol dehydrogenase (MDH) and mannitol 1-phosphate 5-dehydrogenase (MPDH) catalyze the mannitol biosynthesis and the arabitol biosynthesis is controlled by arabitol dehydrogenase (ArDH). The ester bond formation between 3,5-dihydroxydecanoic acid and mannitol or arabitol is catalyzed by the esterase (Est1). Liamocin biosynthesis is regulated by the specific transcriptional activator (Gal1), global transcriptional activator (Msn2), various signaling pathways, acetyl-CoA flux while Pks1 activity is controlled by PPTase activity. The synthesized liamocins have high bioactivity against the pathogenic bacteria spp. and some kinds of cancer cells while Massoia lactone released liamocins which exhibited obvious antifungal and anticancer activities. Therefore, liamocins and Massoia lactone have many applications in various sectors of biotechnology.
Topics: Ascomycota; Aureobasidium; Bacteria; Mannitol; Xylose
PubMed: 34154468
DOI: 10.1080/07388551.2021.1931017 -
Journal of Fungi (Basel, Switzerland) Oct 2022Transcription factors (TFs) can regulate the synthesis of secondary metabolites through different metabolic pathways in spp. In this study, a set of 16 superfamilies,...
Transcription factors (TFs) can regulate the synthesis of secondary metabolites through different metabolic pathways in spp. In this study, a set of 16 superfamilies, 45 PFAM families of TFs with the DNA-binding domains, seven zinc finger families and eight categories of the C2H2 TFs have been identified in spp. Among all the identified TFs, four superfamilies and six PFAM families are the fungal-specific types in this lineage. The Zn2Cys6 and fungal-specific domain regulators are found to be overwhelmingly predominated, while the C2H2 zinc finger class comprises a smaller regulator class. Since there are currently no databases that allow for easy exploration of the TFs in spp., based on over 50 references and 2405 homologous TFs, the first TFs pipeline-the Transcription Factor Database (ATFDB)-has been developed to accelerate the identification of metabolic regulation in various species. It would be useful to investigate the mechanisms behind the wide adaptability and metabolite diversity of spp.
PubMed: 36294661
DOI: 10.3390/jof8101096 -
Mycoses Sep 2019Aureobasidium pullulans and A. melanogenum are black-yeast-like surface colonisers and are commonly encountered as contaminants in the hospital. The species are able to... (Comparative Study)
Comparative Study
Aureobasidium pullulans and A. melanogenum are black-yeast-like surface colonisers and are commonly encountered as contaminants in the hospital. The species are able to produce melanin which play a role in protection against environmental stress and irradiation. Aureobasidium melanogenum shows higher frequency in opportunistic infections compared to A. pullulans. Comparative pathogenicity of opportunistic black yeasts between Aureobasidium pullulans and A. melanogenum to explain the observed differences in frequency in infection. Degrees of melanisation and thermotolerance were measured, and virulence of strains from different sources was examined in Galleria mellonela and murine infection models. Aureobasidium melanogenum responds with increased melanisation to temperature stress and generally survives at 37°C, A. pullulans on average scored less on these parameters. In the murine model, differences between species were not significant, but the melanised A. melanogenum group showed the highest virulence. This result was not reproducible in Galleria mellonella larvae at 25°C. The A. melanogenum black group showed higher pathogenicity in murine model, indicating that the combination of melanisation and thermotolerance rather than species affiliation is instrumental. Galleria larvae did not survive very well at 37°C, and hence, this model is judged insufficient to detect the small virulence differences observed in Aureobasidium.
Topics: Animals; Ascomycota; Disease Models, Animal; Female; Larva; Melanins; Mice; Moths; Mycoses; Opportunistic Infections; Thermotolerance; Virulence
PubMed: 31107996
DOI: 10.1111/myc.12931 -
Environmental Research Nov 2022Pullulan and melanin have become important secondary metabolites that are now widely studied. In this study, a strain of Aureobasidium pullulans HIT-LCY3 was used to...
Pullulan and melanin have become important secondary metabolites that are now widely studied. In this study, a strain of Aureobasidium pullulans HIT-LCY3 was used to ferment potato starch industrial waste to produce pullulan and melanin. After optimization, the culture conditions for the fermentation medium were obtained: inoculum age of 48 h, initial pH of 6.0, inoculation quantity of 1.5%, temperature of 26 °C, fermentation time of 5 d and speed of 160 rpm. Under these conditions, the yield of pullulan was 23.47 g/L with a molecular weight (MW) of 1.21 × 10 Da and the yield of melanin was 18.98 g/L. In addition, the adaptive evolution could significantly increase the yield of pullulan and melanin and the air-floating fermenters was more conductive to product accumulation. Through the 5 L small-scale test and 1000 L pilot test, the yield of pullulan reached 16.52 g/L with molecular weight of 0.92 × 10 Da and the yield of melanin was 12.08 g/L at the trial production of 30,000 L. This work could provide strong support for industrial production and new guidance for waste utilization and environmental protection.
Topics: Ascomycota; Aureobasidium; Fermentation; Industrial Waste; Melanins; Solanum tuberosum; Starch
PubMed: 35931191
DOI: 10.1016/j.envres.2022.113947 -
Applied Microbiology and Biotechnology May 2022Microbial communities colonising outdoor sculptures form intricate and dynamic ecosystems, which can accelerate the deterioration processes of the artworks and pose...
Microbial communities colonising outdoor sculptures form intricate and dynamic ecosystems, which can accelerate the deterioration processes of the artworks and pose challenges to their conservation. In this study, the bacterial and fungal communities colonising the surfaces of five contemporary outdoor sculptures were characterised by high-throughput sequencing. The sculptures, made of marble, granite, Ançã limestone and mortar, are in urban parks and squares in the district of Porto, Portugal. The analysis of the microbial populations revealed great taxonomic diversity and species richness, including in well-preserved sculptures showing few visible traces of contamination. Proteobacteria, namely the genera Pseudomonas and Sphingomonas, were the core taxa common to all the sculptures, while Massilia and Aureobasidium were dominant only in granite. An abundance of pigment-producing microorganisms, such as Deinococcus, Methylobacterium, Rhodotorula and Sporobolomyces, was also found in granite. These are relevant taxonomic groups that can negatively impact stone and mortar artworks. The study was complemented with colourimetric analyses and bioluminescence assays to measure the adenosine triphosphate (ATP) content of samples collected from specific contaminated areas of the sculptures. The characterisation of the microbiomes of sculptures can provide further knowledge on the deterioration risks of this type of artwork in the region and help outline future targeted conservation strategies. KEY POINTS: • Rich and abundant microbiomes expose sculptures' vulnerability to deterioration. • Well-preserved sculptures are at risk of deterioration by pigment-producing taxa. • ATP and colourimetry quickly identified the most relevant contaminated areas.
Topics: Adenosine Triphosphate; Bacteria; Calcium Carbonate; Fungi; Microbiota; Sculpture
PubMed: 35562489
DOI: 10.1007/s00253-022-11957-4 -
TheScientificWorldJournal 2020Some studies have reported the occurrence of microorganisms isolated from water. Considering these microorganisms, fungi are known to occur ubiquitously in the...
INTRODUCTION
Some studies have reported the occurrence of microorganisms isolated from water. Considering these microorganisms, fungi are known to occur ubiquitously in the environment, including water, and some are pathogenic and may cause health problems, especially in immunocompromised individuals. The aim of this study was to identify fungi in hospital water samples and to correlate their presence with the concentration of free residual chlorine.
METHODS
Water samples (100 mL) were collected from taps ( = 74) and water purifiers ( = 14) in different locations in a university hospital. Samples were filtered through a nitrocellulose membrane and placed on Sabouraud dextrose agar and incubated for 24 hours at 30°C. Fungi were identified according to established methods based on macroscopic and microscopic characteristics (filamentous) and physiological tests (yeasts). Free chlorine residual content was measured at the time of sample collection.
RESULTS
Seventy species of fungi were identified in the water samples and about 56% of the water samples contained culturable fungi. , , and were the most common filamentous fungi. and were the most common yeasts. Chemical analyses revealed that free residual chlorine was present in 81.8% of the samples within recommended concentrations. Among samples from water purifiers, 92.9% showed low levels of free residual chlorine (<0.2 mg/L). There was no significant association between chlorine concentrations (either within or outside the recommended range) and the presence of filamentous fungi and yeasts.
CONCLUSIONS
This study showed that hospital water can be a reservoir for fungi, some of which are potentially harmful to immunocompromised patients. Free residual chlorine was ineffective in some samples.
Topics: Aspergillus fumigatus; Aureobasidium; Biodiversity; Biofilms; Brazil; Candida parapsilosis; Chlorine; Cladosporium; Fungi; Hospitals, University; Humans; Mycoses; Penicillium; Water; Water Microbiology; Water Supply
PubMed: 32694957
DOI: 10.1155/2020/9358542 -
Current Medical Mycology Sep 2021The frequency and genetic diversity of black fungi in environmental and clinical settings have not been fully studied in Iran. This study aimed to identify and evaluate...
BACKGROUND AND PURPOSE
The frequency and genetic diversity of black fungi in environmental and clinical settings have not been fully studied in Iran. This study aimed to identify and evaluate intra- and inter-species DNA sequence variation and also understand the phylogenetic relationships of melanized fungi and relatives isolated from different geographical regions of Iran.
MATERIALS AND METHODS
In total, 111 clinical and environmental strains of dematiaceous fungi were isolated, and their internal transcribed spacer ribosomal DNA (rDNA) regions were sequenced and analyzed.
RESULTS
An inter-species nucleotide sequence diversity rate of 1 to 464 nucleotides was observed between the species. Intra-species differences were found in the strains of and by 0-59, 0-22, 0-4, 0-4, 0-3, 0-2, 0-2, 0-2, 0-2, 0-1, and 0-1 nucleotide, respectively.
CONCLUSION
The internal transcribed spacer rDNA is useful for the discrimination of several taxa of dematiaceous fungi. However, a better understanding of the taxonomy of species of requires a larger rDNA region or a library of other gene sequences.
PubMed: 35528626
DOI: 10.18502/cmm.7.3.7798