-
Applied and Environmental Microbiology May 2024Given the multitude of extracellular enzymes at their disposal, many of which are designed to degrade nature's polymers (lignin, cutin, cellulose, etc.), fungi are adept...
Given the multitude of extracellular enzymes at their disposal, many of which are designed to degrade nature's polymers (lignin, cutin, cellulose, etc.), fungi are adept at targeting synthetic polyesters with similar chemical composition. Microbial-influenced deterioration of xenobiotic polymeric surfaces is an area of interest for material scientists as these are important for the conservation of the underlying structural materials. Here, we describe the isolation and characterization of the 5307AH () cutinase, Plcut1. is basidiomycete yeast with the ability to disperse Impranil-DLN (Impranil), a colloidal polyester polyurethane, in agar plates. To test whether the fungal factor involved in this clearing was a secreted enzyme, we screened the ability of culture supernatants to disperse Impranil. Using size exclusion chromatography (SEC), we isolated fractions that contained Impranil-clearing activity. These fractions harbored a single ~22 kD band, which was excised and subjected to peptide sequencing. Homology searches using the peptide sequences identified, revealed that the protein Papla1 543643 (Plcut1) displays similarities to serine esterase and cutinase family of proteins. Biochemical assays using recombinant Plcut1 confirmed that this enzyme has the capability to hydrolyze Impranil, soluble esterase substrates, and apple cutin. Finally, we confirmed the presence of the Plcut1 in culture supernatants using a custom antibody that specifically recognizes this protein. The work shown here supports a major role for the Plcut1 in the fungal degradation of natural polyesters and xenobiotic polymer surfaces.IMPORTANCEFungi play a vital role in the execution of a broad range of biological processes that drive ecosystem function through production of a diverse arsenal of enzymes. However, the universal reactivity of these enzymes is a current problem for the built environment and the undesired degradation of polymeric materials in protective coatings. Here, we report the identification and characterization of a hydrolase from 5307AH, an aircraft-derived fungal isolate found colonizing a biodeteriorated polymer-coated surface. We show that secretes a cutinase capable of hydrolyzing soluble esters as well as ester-based compounds forming solid surface coatings. These findings indicate that this fungus plays a significant role in biodeterioration through the production of a cutinase adept at degrading ester-based polymers, some of which form the backbone of protective surface coatings. The work shown here provides insights into the mechanisms employed by fungi to degrade xenobiotic polymers.
Topics: Carboxylic Ester Hydrolases; Fungal Proteins; Recombinant Proteins; Polyesters; Hydrolysis
PubMed: 38624219
DOI: 10.1128/aem.01694-23 -
Revista Da Sociedade Brasileira de... 2024Previously considered saprobe and non-pathogenic, the fungus Papiliotrema laurentii (formerly known as Cryptococcus laurentii), is rarely associated with human...
Previously considered saprobe and non-pathogenic, the fungus Papiliotrema laurentii (formerly known as Cryptococcus laurentii), is rarely associated with human infection. Nevertheless, there has been an increase in reported infections by non-neoformans cryptococci. After a literature search on the Cochrane Library, LILACS, SciELO, MEDLINE, PubMed, and PMC (PubMed Central) databases, we conclude that this is the first case report of fungemia and probable meningitis caused by Papiliotrema laurentii in a previously immunocompetent host with associated COVID-19.
Topics: Humans; Fungemia; Cryptococcosis; COVID-19; SARS-CoV-2; Cryptococcus; Basidiomycota
PubMed: 38324809
DOI: 10.1590/0037-8682-0480-2024 -
JPMA. the Journal of the Pakistan... Oct 2023Infections caused by non-neoformans Cryptococcus spp., including Cryptococcus laurentii, previously thought to be saprophyte and non-pathogenic, have become more common...
Infections caused by non-neoformans Cryptococcus spp., including Cryptococcus laurentii, previously thought to be saprophyte and non-pathogenic, have become more common during the past few years, particularly in immunocompromised hosts. To the best of our knowledge here, we present the first case of meningitis in an immunocompromised patient due to a fungus that has never been reported in Pakistan. Our patient, a 40-year old male, who had acquired immunodeficiency syndrome (AIDS) was diagnosed as Cryptococcus laurentti meningitis, with a rare neurological manifestation i.e., cryptococcomas and lepto-meningitis. We presume that exposure to pigeon droppings and acquired immunodeficiency syndrome were the risk factors for this case report. He was treated with liposomal Amphotericin (LAMB) and fluconazole but unfortunately, he rapidly deteriorated and ultimately succumbed to the infection. This case underscores the significance of prompt diagnosis and vigorous treatment of Cryptococcus laurentii meningitis, as well as the need for continued surveillance in immunocompromised individuals.
Topics: Male; Humans; Adult; Acquired Immunodeficiency Syndrome; Cryptococcosis; Cryptococcus; Meningitis; Cryptococcus neoformans; Antifungal Agents
PubMed: 37876081
DOI: 10.47391/JPMA.8582 -
Scientific Reports Sep 2023The Cryptococcus genus comprises more than 100 species, of which C. neoformans and C. gattii are the leading cause of cryptococcosis. The distribution of C. gattii and...
The Cryptococcus genus comprises more than 100 species, of which C. neoformans and C. gattii are the leading cause of cryptococcosis. The distribution of C. gattii and C. neoformans species complexes has been extensively studied and widely reported globally. Other species such as Naganishia albida, Papiliotrema laurentii, and Papiliotrema flavescens have been reported as pathogenic yeasts. Since there are no reports of environmental isolation in the Boyacá region (Colombia), this study aimed to isolate and characterize Cryptococcus and Cryptococcus-like yeasts from pigeon feces, Eucalyptus, and olive trees distributed in the municipalities of Tunja and Ricaute Alto. The environmental data was recovered, and the isolations obtained were identified by microscopy, biochemical test, MALDI-TOF MS, URA5-RFLP, and sequencing of the ITS and LSU loci. For the 93 pigeon dropping samples collected in Tunja, 23 yielded to C. neoformans, 3 to N. globosa, 2 N. albida and 1 to P. laurentii. Of the 1188 samples collected from olive trees, 17 (1.43%) positive samples were identified as C. gattii species complex (4), C. neoformans species complex (2), P. laurentii (3), N. albida (2), N. globosa (5) and P. flavescens (1). Likewise, specimens of C. neoformans presented molecular type VNI and molecular type VNII; for C. gattii the molecular types found were VGIII and one VGIV by URA5-RFLP but VGIII by MALDI-TOF and sequencing of the ITS and LSU. Therefore, it can be concluded that the species of Cryptococcus, Naganishia and Papiliotrema genera, are present in the environment of Boyacá, and show a predilection for climate conditions that are typical of this region.
Topics: Animals; Colombia; Cryptococcus neoformans; Cryptococcus gattii; Cryptococcosis; Climate; Columbidae; Olea
PubMed: 37735454
DOI: 10.1038/s41598-023-41994-6 -
AIMS Microbiology 2023The diversity of duckweed () associated yeasts was studied using a culture-dependent method. A total of 252 yeast strains were isolated from 53 duckweed samples out of...
The diversity of duckweed () associated yeasts was studied using a culture-dependent method. A total of 252 yeast strains were isolated from 53 duckweed samples out of the 72 samples collected from 16 provinces in Thailand. Yeast identification was conducted based on the D1/D2 region of the large subunit (LSU) rRNA gene sequence analysis. It revealed that 55.2% and 44.8% yeast species were Ascomycota and Basidiomycota duckweed associated yeasts, respectively. Among all, , a basidiomycetous yeast, was found as the most prevalent species showing a relative of frequency and frequency of occurrence of 21.8% and 25%, respectively. In this study, high diversity index values were shown, indicated by the Shannon-Wiener index (), Shannon equitability index () and Simpson diversity index () values of 3.48, 0.86 and 0.96, respectively. The present results revealed that the yeast community on duckweed had increased species diversity, with evenness among species. Principal coordinate analysis (PCoA) revealed no marked differences in yeast communities among duckweed genera. The species accumulation curve showed that the observed species richness was lower than expected. Investigation of the plant growth promoting traits of the isolated yeast on duckweed revealed that 178 yeast strains produced indole-3-acetic acid (IAA) at levels ranging from 0.08-688.93 mg/L. Moreover, siderophore production and phosphate solubilization were also studied. One hundred and seventy-three yeast strains produced siderophores and exhibited siderophores that showed 0.94-2.55 activity units (AU). One hundred six yeast strains showed phosphate solubilization activity, expressed as solubilization efficiency (SE) units, in the range of 0.32-2.13 SE. This work indicates that duckweed associated yeast is a potential microbial resource that can be used for plant growth promotion.
PubMed: 37649804
DOI: 10.3934/microbiol.2023026 -
Fungal Genetics and Biology : FG & B Jan 2023The production of yeast oil from lignocellulosic biomasses is impaired by inhibitors formed during the pretreatment step, mainly acetic acid. Herein, we applied Adaptive...
The production of yeast oil from lignocellulosic biomasses is impaired by inhibitors formed during the pretreatment step, mainly acetic acid. Herein, we applied Adaptive Laboratory Evolution (ALE) to select three Acetic acid Tolerant Strains (ATS) of P. laurentii UFV-1. Different phenotypes emerged alongside evolution. The ATS II presented trade-offs in the absence of acetic acid, suggesting that it displays a specialized phenotype of tolerance to growth on organic acids. On the other hand, ATS I and ATS III presented phenotypes associated with the behavior of generalists. ATS I was considered the most promising evolved strain as it displayed the oleaginous phenotype in all conditions tested. Thus, we applied whole-genome sequencing to detect the mutations that emerged in this strain during the ALE. We found alterations in genes encoding proteins involved in different cellular functions, including multidrug resistance (MDR) transporters, energy metabolism, detoxification, coenzyme recycling, and cell envelope remodeling. To evaluate acetic acid stress responses, both parental and ATS I strains were cultivated in chemostat mode in the absence and presence of acetic acid. In contrast to ATS I, the parental strain presented alterations in the cell envelope and cell size under acetic acid stress conditions. Furthermore, the parental strain and the ATS I presented differences regarding acetic acid assimilation. Contrary to the parental strain, the ATS I displayed an increase in unsaturated fatty acid content irrespective of acetic acid stress, which might be related to improved tolerance to acetic acid. Altogether, these results provided insights into the mechanisms involved with the acetic acid tolerance displayed by ATS I and the responses of P. laurentii to this stressful condition.
Topics: Acetic Acid; Saccharomyces cerevisiae; Phenotype; Membrane Transport Proteins
PubMed: 36528339
DOI: 10.1016/j.fgb.2022.103765 -
Journal of Fungi (Basel, Switzerland) Jun 2022Icariin is the most effective bioactive compound in Herba Epimedii. To enhance the content of icariin in the epimedium water extract, a novel strain, ZJU-L07, producing...
Icariin is the most effective bioactive compound in Herba Epimedii. To enhance the content of icariin in the epimedium water extract, a novel strain, ZJU-L07, producing an intracellular α-L-rhamnosidase was isolated from the soil and mutagenized. The specific activity of α-L-rhamnosidase was 29.89 U·mg through purification, and the molecular mass of the enzyme was 100 kDa, as assayed by SDS-PAGE. The characterization of the purified enzyme was determined. The optimal temperature and pH were 55 °C and 7.0, respectively. The enzyme was stable in the pH range 5.5-9.0 for 2 h over 80% and the temperature range 30-40 °C for 2 h more than 70%. The enzyme activity was inhibited by Ca, Fe, Cu, and Mg, especially Fe. The kinetic parameters of and were 1.38 mM and 24.64 μmol·mg·min using pNPR as the substrate, respectively. When epimedin C was used as a nature substrate to determine the kinetic parameters of α-L-rhamnosidase, the values of and were 3.28 mM and 0.01 μmol·mg·min, respectively. The conditions of enzymatic hydrolysis were optimized through single factor experiments and response surface methodology. The icariin yield increased from 61% to over 83% after optimization. The enzymatic hydrolysis method could be used for the industrialized production of icariin. At the same time, this enzyme could also cleave the α-1,2 glycosidic linkage between glucoside and rhamnoside in naringin and neohesperidin, which could be applicable in other biotechnological processes.
PubMed: 35736128
DOI: 10.3390/jof8060644 -
PloS One 2022Neuromeningeal cryptococcosis (NMC) is a life-threatening opportunistic infection in advanced HIV disease patients (AHDP). It is caused by Cryptococcus spp. complexes...
Neuromeningeal cryptococcosis (NMC) is a life-threatening opportunistic infection in advanced HIV disease patients (AHDP). It is caused by Cryptococcus spp. complexes and mainly occurs in sub-Saharan Africa. In this study, we performed molecular characterization and antifungal susceptibility profiling of Cryptococcus isolates from AHDP in Kinshasa (DRC). Additionally, we investigated a possible association between NMC severity factors and the Cryptococcus neoformans (Cn) multilocus sequence typing (MLST) profiles. We characterized the isolates using PCR serotyping, MALDI-TOF MS, internal transcribed spacer (ITS) sequencing, and MLST. Susceptibility testing for the major antifungal drugs was performed according to the EUCAST guidelines. Parameters associated with NMC severity, such as hypoglycorrhachia (< 50 mg/dL), increased cerebral spinal fluid opening pressure (> 30 cm H2O), and poor therapeutic outcome were compared with the Cn MLST sequences type (ST). Twenty-three out of 29 Cryptococcus isolates were identified as serotype A using PCR serotyping (79.3%; 95% IC: 65.5-93.1), while six (20.7%; 95% IC: 6.9-34.5) were not serotypable. The 29 isolates were identified by ITS sequencing as follows: Cryptococcus neoformans (23/29, 79.3%), Cutaneotrichosporon curvatus (previously called Cryptococcus curvatus) (5/29, 17.2%), and Papiliotrema laurentii (Cryptococcus laurentii) (1/29, 3.5%). Using the ISHAM MLST scheme, all Cn isolates were identified as molecular type VNI. These comprised seven different STs: ST93 (n = 15), ST5 (n = 2), ST53 (n = 1), ST31 (n = 1), ST4 (n = 1), ST69 (n = 1), and one novel ST that has not yet been reported from other parts of the world and was subsequently assigned as ST659 (n = 2). Of the included strains, only Papiliotrema laurentii was resistant to amphoterin B (1/29, 3.5%), 6.8% (2/29) were resistant to 5-flucytosine (the single Papiliotrema laurentii strain and one Cryptococcus neoformans isolate), and 13.8% (4/29) to fluconazole, including two of five (40%) Cutaneotrichosporon curvatus and two of 23 (8.7%) C. neoformans strains. We found a significative association between poor therapeutic outcome and a non-ST93 sequence type of causative strains (these concerned the less common sequence types: ST53, ST31, ST5, ST4, ST659, and ST69) (87.5% versus 40%, p = 0.02). Molecular analysis of Cryptococcus spp. isolates showed a wide species diversity and genetic heterogenicity of Cn within the VNI molecular type. Furthermore, it is worrying that among included strains we found resistances to several of the commonly used antifungals.
Topics: Antifungal Agents; Basidiomycota; Cryptococcosis; Cryptococcus neoformans; Democratic Republic of the Congo; Genetic Variation; Genotype; HIV Infections; Humans; Multilocus Sequence Typing; Mycological Typing Techniques
PubMed: 35587939
DOI: 10.1371/journal.pone.0267842 -
BMJ Case Reports May 2022A man in mid-50s presented with progressive blurred vision in his left eye for over 6 weeks. He was a known diabetic with history of COVID-19 pneumonia treated with...
A man in mid-50s presented with progressive blurred vision in his left eye for over 6 weeks. He was a known diabetic with history of COVID-19 pneumonia treated with steroids and remdesivir. He had pyelonephritis and urinary culture grown He was referred as a case of non-resolving vitreous haemorrhage. Visual acuity (VA) was hand movements with fundus showing dense vitritis. He underwent pars plana vitrectomy, vitreous biopsy with intraocular antibiotics (imipenem) suspecting as a case of endogenous bacterial endophthalmitis. Vitreous biopsy did not yield organisms on the smear/culture. The patient's condition worsened with perception of light and fundus showing dense vitritis with discrete yellowish white deposits on the surface of the retina. A repeat vitreous biopsy done along with intravitreal injection of voriconazole (suspecting fungal aetiology) grown fungal colonies and the organism was identified as At 4-month follow-up, the VA improved to 6/24.
Topics: Anti-Bacterial Agents; Basidiomycota; COVID-19; Endophthalmitis; Eye Infections, Bacterial; Humans; Male; Retrospective Studies; Vitrectomy
PubMed: 35545307
DOI: 10.1136/bcr-2021-246637 -
G3 (Bethesda, Md.) Dec 2021Papiliotrema terrestris strain LS28 is a biocontrol agent selected for its antagonistic activity against several plant pathogens both in the field and postharvest. The...
Papiliotrema terrestris strain LS28 is a biocontrol agent selected for its antagonistic activity against several plant pathogens both in the field and postharvest. The availability of a genome sequencing sets the foundation for the identification of the genetic mechanisms of its antagonistic activity. The genome size is 21.29 Mbp with a G+C content of 58.65%, and genome annotation predicts 8,626 protein-encoding genes. Phylogenetic analysis based on whole-genome data confirms that P. terrestris is a Tremellomycetes more closely related to Papiliotrema flavescens than Papiliotrema laurentii.
Topics: Basidiomycota; High-Throughput Nucleotide Sequencing; Phylogeny; Saccharomyces cerevisiae; Sequence Analysis, DNA
PubMed: 34534326
DOI: 10.1093/g3journal/jkab332