Cladosporium cladosporioides from the perspectives of medical and biotechnological approaches

Cladosporium psychrotolerans strain T01 enhances plant biomass and also exhibits antifungal activity against pathogens

An increasing number of microorganisms are being identified to enhance plant growth and inhibit phytopathogens. Some Cladosporium species form beneficial associations with plants, either as endophytes or by colonizing the rhizosphere. Herein, we evaluated the influence of the Cladosporium psychrotolerans (T01 strain) fungus on the in vitro growth of Arabidopsis thaliana plantlets through direct and split interactions. After 9 days post-inoculation with C. psychrotolerans, Arabidopsis plantlets exhibited a notable increase in fresh weight and lateral roots, particularly in split interactions. Chlorophyll content increased in both plant-fungus interaction conditions, whereas the primary root was inhibited during direct interaction. We observed an increase in the GUS signal from the Arabidopsis auxin-inducible DR5:uidA marker in lateral root tips in both contact and split fungal interactions, and primary root tips in a split interaction. Arabidopsis and tomato plants cultivated in soil pots and inoculated with C. psychrotolerans (T01 strain) showed a positive effect on biomass production. GC/MS analysis detected that the T01 strain emitted volatile organic compounds (VOCs), predominantly alcohols and aldehydes. These VOCs displayed potent inhibitory effects, with a 60% inhibition against Botrytis cinerea and a 50% inhibition against C. gloeosporioides. Our study demonstrates that C. psychrotolerans T01 has the potential to enhance biomass production and inhibit pathogens, making it a promising candidate for green technology applications.

Characterization and removal mechanism of fluoroquinolone-bioremediation by fungus Cladosporium cladosporioides 11 isolated from aquacultural sediments

Antibiotics have been widely detected in aquatic environments, and fungal biotransformation receives considerable attention for antibiotic bioremediation. Here, a fungus designated Cladosporium cladosporioides 11 (CC11) with effective capacity to biotransform fluoroquinolones was isolated from aquaculture pond sediments. Enrofloxacin (ENR), ciprofloxacin (CIP) and ofloxacin (OFL) were considerably abated by CC11, and the antibacterial activities of the fluoroquinolones reduced significantly after CC11 treatment. Transcriptome analysis showed the removal of ENR, CIP and OFL by CC11 is a process of enzymatic degradation and biosorption which consists well with ligninolytic enzyme activities and sorption experiments under the same conditions. Additionally, CC11 significantly removed ENR in zebrafish culture water and reduced the residue of ENR in zebrafish. All these results evidenced the potential of CC11 as a novel environmentally friendly process for the removal of fluoroquinolones from aqueous systems and reduce fluoroquinolone residues in aquatic organisms.

The Genus Cladosporium: A Prospective Producer of Natural Products

Cladosporium, a genus of ascomycete fungi in the Dematiaceae family, is primarily recognized as a widespread environmental saprotrophic fungus or plant endophyte. Further research has shown that the genus is distributed in various environments, particularly in marine ecosystems, such as coral reefs, mangroves and the polar region. Cladosporium, especially the marine-derived Cladosporium, is a highly resourceful group of fungi whose natural products have garnered attention due to their diverse chemical structures and biological activities, as well as their potential as sources of novel leads to compounds for drug production. This review covers the sources, distribution, bioactivities, biosynthesis and structural characteristics of compounds isolated from Cladosporium in the period between January 2000 and December 2022, and conducts a comparative analysis of the Cladosporium isolated compounds derived from marine and terrestrial sources. Our results reveal that 34% of Cladosporium-derived natural products are reported for the first time. And 71.79% of the first reported compounds were isolated from marine-derived Cladosporium. Cladosporium-derived compounds exhibit diverse skeletal chemical structures, concentrating in the categories of polyketides (48.47%), alkaloids (19.21%), steroids and terpenoids (17.03%). Over half of the natural products isolated from Cladosporium have been found to have various biological activities, including cytotoxic, antibacterial, antiviral, antifungal and enzyme-inhibitory activities. These findings testify to the tremendous potential of Cladosporium, especially the marine-derived Cladosporium, to yield novel bioactive natural products, providing a structural foundation for the development of new drugs.

Microbial Exudates as Biostimulants: Role in Plant Growth Promotion and Stress Mitigation

Microbes hold immense potential, based on the fact that they are widely acknowledged for their role in mitigating the detrimental impacts of chemical fertilizers and pesticides, which were extensively employed during the Green Revolution era. The consequence of this extensive use has been the degradation of agricultural land, soil health and fertility deterioration, and a decline in crop quality. Despite the existence of environmentally friendly and sustainable alternatives, microbial bioinoculants encounter numerous challenges in real-world agricultural settings. These challenges include harsh environmental conditions like unfavorable soil pH, temperature extremes, and nutrient imbalances, as well as stiff competition with native microbial species and host plant specificity. Moreover, obstacles spanning from large-scale production to commercialization persist. Therefore, substantial efforts are underway to identify superior solutions that can foster a sustainable and eco-conscious agricultural system. In this context, attention has shifted towards the utilization of cell-free microbial exudates as opposed to traditional microbial inoculants. Microbial exudates refer to the diverse array of cellular metabolites secreted by microbial cells. These metabolites enclose a wide range of chemical compounds, including sugars, organic acids, amino acids, peptides, siderophores, volatiles, and more. The composition and function of these compounds in exudates can vary considerably, depending on the specific microbial strains and prevailing environmental conditions. Remarkably, they possess the capability to modulate and influence various plant physiological processes, thereby inducing tolerance to both biotic and abiotic stresses. Furthermore, these exudates facilitate plant growth and aid in the remediation of environmental pollutants such as chemicals and heavy metals in agroecosystems. Much like live microbes, when applied, these exudates actively participate in the phyllosphere and rhizosphere, engaging in continuous interactions with plants and plant-associated microbes. Consequently, they play a pivotal role in reshaping the microbiome. The biostimulant properties exhibited by these exudates position them as promising biological components for fostering cleaner and more sustainable agricultural systems.

Fungal Contamination of Building Materials and the Aerosolization of Particles and Toxins in Indoor Air and Their Associated Risks to Health: A Review

It is now well established that biological pollution is a major cause of the degradation of indoor air quality. It has been shown that microbial communities from the outdoors may significantly impact the communities detected indoors. One can reasonably assume that the fungal contamination of the surfaces of building materials and their release into indoor air may also significantly impact indoor air quality. Fungi are well known as common contaminants of the indoor environment with the ability to grow on many types of building materials and to subsequently release biological particles into the indoor air. The aerosolization of allergenic compounds or mycotoxins borne by fungal particles or vehiculated by dust may have a direct impact on the occupant’s health. However, to date, very few studies have investigated such an impact. The present paper reviewed the available data on indoor fungal contamination in different types of buildings with the aim of highlighting the direct connections between the growth on indoor building materials and the degradation of indoor air quality through the aerosolization of mycotoxins. Some studies showed that average airborne fungal spore concentrations were higher in buildings where mould was a contaminant than in normal buildings and that there was a strong association between fungal contamination and health problems for occupants. In addition, the most frequent fungal species on surfaces are also those most commonly identified in indoor air, regardless the geographical location in Europe or the USA. Some fungal species contaminating the indoors may be dangerous for human health as they produce mycotoxins. These contaminants, when aerosolized with fungal particles, can be inhaled and may endanger human health. However, it appears that more work is needed to characterize the direct impact of surface contamination on the airborne fungal particle concentration. In addition, fungal species growing in buildings and their known mycotoxins are different from those contaminating foods. This is why further in situ studies to identify fungal contaminants at the species level and to quantify their average concentration on both surfaces and in the air are needed to be better predict health risks due to mycotoxin aerosolization.

Fungal Communities in Re-Emerging Fraxinus excelsior Sites in Lithuania and Their Antagonistic Potential against Hymenoscyphus fraxineus

Fifty-nine fungal taxa, isolated from re-emerging Fraxinus excelsior sites in Lithuania, were in vitro tested against three strains of Hymenoscyphus fraxineus on agar media to establish their biocontrol properties. All tested fungi were isolated from leaves and shoots of relatively healthy Fraxinus excelsior trees (<30% defoliation), which were affected by ash dieback but their phytosanitary condition has not worsened during the last decade. The inhibition of H. fraxineus growth by tested fungal taxa ranged between 16−87%. Occasionally isolated fungal taxa such as Neonectria coccinea, Nothophorma quercina, and Phaeosphaeria caricis were among the most effective fungi inhibiting the growth of H. fraxineus cultures. Among the more commonly isolated fungal taxa, Cladosporium sp., Fusarium sp., Malassezia sp., and Aureobasidium pullulans showed a strong growth inhibition of H. fraxineus.

Degradation of Xenobiotic Pollutants: An Environmentally Sustainable Approach

The ability of microorganisms to detoxify xenobiotic compounds allows them to thrive in a toxic environment using carbon, phosphorus, sulfur, and nitrogen from the available sources. Biotransformation is the most effective and useful metabolic process to degrade xenobiotic compounds. Microorganisms have an exceptional ability due to particular genes, enzymes, and degradative mechanisms. Microorganisms such as bacteria and fungi have unique properties that enable them to partially or completely metabolize the xenobiotic substances in various ecosystems.There are many cutting-edge approaches available to understand the molecular mechanism of degradative processes and pathways to decontaminate or change the core structure of xenobiotics in nature. These methods examine microorganisms, their metabolic machinery, novel proteins, and catabolic genes. This article addresses recent advances and current trends to characterize the catabolic genes, enzymes and the techniques involved in combating the threat of xenobiotic compounds using an eco-friendly approach.

Decontamination and Germination of Buckwheat Grains upon Treatment with Oxygen Plasma Glow and Afterglow

Buckwheat is an alternative crop known for its many beneficial effects on our health. Fungi are an important cause of plant diseases and food spoilage, often posing a threat to humans and animals. This study reports the effects of low-pressure cold plasma treatment on decontamination and germination of common (CB) and Tartary buckwheat (TB) grains. Both plasma glow and afterglow were applied. The glow treatment was more effective in decontamination: initial contamination was reduced to less than 30% in CB and 10% in TB. Fungal diversity was also affected as only a few genera persisted after the glow treatment; however, it also significantly reduced or even ceased the germination capacity of both buckwheat species. Detailed plasma characterisation by optical spectroscopy revealed extensive etching of outer layers as well as cotyledons. Afterglow treatment resulted in a lower reduction of initial fungal contamination (up to 30% in CB and up to 50% in TB) and had less impact on fungal diversity but did not drastically affect germination: 60–75% of grains still germinated even after few minutes of treatment. The vacuum conditions alone did not affect the fungal population or the germination despite an extensive release of water.

Untapped Potential of Marine-Associated Cladosporium Species: An Overview on Secondary Metabolites, Biotechnological Relevance, and Biological Activities

The marine environment is an underexplored treasure that hosts huge biodiversity of microorganisms. Marine-derived fungi are a rich source of novel metabolites with unique structural features, bioactivities, and biotechnological applications. Marine-associated Cladosporium species have attracted considerable interest because of their ability to produce a wide array of metabolites, including alkaloids, macrolides, diketopiperazines, pyrones, tetralones, sterols, phenolics, terpenes, lactones, and tetramic acid derivatives that possess versatile bioactivities. Moreover, they produce diverse enzymes with biotechnological and industrial relevance. This review gives an overview on the Cladosporium species derived from marine habitats, including their metabolites and bioactivities, as well as the industrial and biotechnological potential of these species. In the current review, 286 compounds have been listed based on the reported data from 1998 until July 2021. Moreover, more than 175 references have been cited.

Biodiversity and biocatalyst activity of culturable hydrocarbonoclastic fungi isolated from Marac-Moruga mud volcano in South Trinidad

Mud volcanoes (MVs) are visible signs of oil and gas reserves present deep beneath land and sea. The Marac MV in Trinidad is the only MV associated with natural hydrocarbon seeps. Petrogenic polyaromatic hydrocarbons (PAHs) in its sediments must undergo biogeochemical cycles of detoxification as they can enter the water table and aquifers threatening ecosystems and biota. Recurrent hydrocarbon seep activity of MVs consolidates the growth of hydrocarbonoclastic fungal communities. Fungi possess advantageous metabolic and ecophysiological features for remediation but are underexplored compared to bacteria. Additionally, indigenous fungi are more efficient at PAH detoxification than commercial/foreign counterparts and remediation strategies remain site-specific. Few studies have focused on hydrocarbonoclastic fungal incidence and potential in MVs, an aspect that has not been explored in Trinidad. This study determined the unique biodiversity of culturable fungi from the Marac MV capable of metabolizing PAHs in vitro and investigated their extracellular peroxidase activity to utilize different substrates ergo their extracellular oxidoreductase activity (> 50% of the strains decolourized of methylene blue dye). Dothideomycetes and Eurotiomycetes (89% combined incidence) were predominantly isolated. ITS rDNA sequence cluster analysis confirmed strain identities. 18 indigenous hydrocarbonoclastic strains not previously reported in the literature and some of which were biosurfactant-producing, were identified. Intra-strain variability was apparent for PAH utilization, oil-tolerance and hydroxylase substrate specificity. Comparatively high levels of extracellular protein were detected for strains that demonstrated low substrate specificity. Halotolerant strains were also recovered which indicated marine-mixed substrata of the MV as a result of deep sea conduits. This work highlighted novel MV fungal strains as potential bioremediators and biocatalysts with a broad industrial applications.

Cryptic Diversity in Cladosporium cladosporioides Resulting from Sequence-Based Species Delimitation Analyses

Cladosporium cladosporioides is an extremely widespread fungus involved in associations ranging from mutualistic to pathogenic and is the most frequently represented Cladosporium species in sequence databases, such as Genbank. The taxonomy of Cladosporium species, currently based on the integration of molecular data with morphological and cultural characters, is in frequent need of revision. Hence, the recently developed species delimitation methods can be helpful to explore cryptic diversity in this genus. Considering a previous study that reported several hypothetical species within C. cladosporioides, we tested four methods of species delimitation using the combined DNA barcodes internal transcribed spacers, translation elongation factor 1-α and actin 1. The analyses involved 105 isolates, revealing that currently available sequences of C. cladosporioides in GenBank actually represent more than one species. Moreover, we found that eight isolates from this set should be ascribed to Cladosporium anthropophilum. Our results revealed a certain degree of discordance among species delimitation methods, which can be efficiently treated using conservative approaches in order to minimize the risk of considering false positives.

Cascading effects caused by fenoxycarb in freshwater systems dominated by Daphnia carinata and Dolerocypris sinensis

To evaluate the aquatic hazards of the insect juvenile hormone analogue fenoxycarb, a single application (0, 48.8, 156.3, 500, 1600, and 5120 μg/L) of it was done in indoor freshwater systems dominated by Daphnia carinata (daphnid) and Dolerocypris sinensis (ostracoda). The responses of zooplankton (counted by abundance and the activity and immuno-reactive content of free N-Acetyl-β-D-glucosaminidase (NAGase)), phytoplankton (counted by chlorophyll and phycocyanin), planktonic bacteria and fungi, and some water quality parameters were investigated in a period of 35 d. Results of the study showed that the ostracoda was more sensitive than daphnid, with time-weighted average (TWA)-based no observed effect concentrations (NOECs) to be 8.45 and 12.66 μg/L in systems without humic acid addition (HA-) and to be 6.37 and 9.54 μg/L in systems with humic acid addition (HA+). The duration of treatment-related effects in the ostracoda population was longer than the daphnid population (21 vs. 14 days). Besides, the data analysis indicated that the toxicity of fenoxycarb was significantly enhanced in the HA+ systems. Owing to the reduced grazing pressure, the concentrations of chlorophyll and phycocyanin increased in the two highest treatments. The increase in photosynthesis along with a reduced animal excretion led to an increase in pH and a decrease in nutrient contents. These changes seemed to have an effect on the microbial communities. For example, the abundances of some opportunistic pathogens of aquatic animals (e.g. Aeromonas and Cladosporium) and organic-pollutant-degrading microorganisms (e.g. Ancylobacter and Azospirillum) increased significantly in microbial communities, but the abundances of Pedobacter, Candidatus Planktoluna, and Rhodobacter (photosynthetic bacteria) markedly decreased. This study provides useful information to understand the ecotoxicological impacts of fenoxycarb at the population and community levels while integrating the effects of HA on toxicity.

Production and partial purification by PEG/citrate ATPS of a β-galactosidase from the new promising isolate Cladosporium tenuissimum URM 7803

β-Galactosidase production, partial purification and characterization by a new fungal were investigated. Partial purification was performed by aqueous two-phase system (ATPS) using polyethylene glycol (PEG) molar mass, PEG concentration, citrate concentration and pH as the independent variables. Purification factor (PF), partition coefficient (K) and yield (Y) were the responses. After identification by rDNA sequencing and classification as Cladosporium tenuissimum URM 7803, this isolate achieved a maximum cell concentration and β-galactosidase activity of 0.48 g/L and 462.1 U/mL, respectively. β-Galactosidase partitioned preferentially for bottom salt-rich phase likely due to hydrophobicity and volume exclusion effect caused in the top phase by the high PEG concentration and molar mass. The highest value of PF (12.94) was obtained using 24% (w/w) PEG 8000 g/mol and 15% (w/w) citrate, while that of Y (79.76%) using 20% (w/w) PEG 400 g/mol and 25% (w/w) citrate, both at pH 6. The enzyme exhibited optimum temperature in crude and ATPS extracts in the ranges 35-50 °C and 40-55 °C, respectively, and optimum pH in the range 3.0-4.5, with a fall of enzyme activity under alkaline conditions. Some metal ions and detergents inhibited, while others stimulated enzyme activity. Finally, C. tenuissimum URM 7803 β-galactosidase showed a profile suitable for prebiotics production.

Complete mitochondrial genome of Cladosporium cladosporioides YFCC 8621 isolated from a salt mine in Yunnan, southwestern China

Cladosporium cladosporioides is one of the most isolated species in the genus Cladosporium and has a wide medical and industrial usage. Here, we first report the complete mitogenome of C. cladosporioides based on the Illumina sequencing data. The circular mitogenome is 36,768 bp in length, containing 14 protein-coding genes (PCGs), 2 ribosomal RNA (rns and rnl) genes, 2 ORFs (ORF214 and ORF240), and a set of 28 transfer RNA (tRNA) genes. The overall base composition is 35.7% A, 34.0% T(U), 15.3% C, 15.0% G, with a GC content of 30.3%. Phylogenetic analysis shows that C. cladosporioides is clustered in the order Capnodiales and is closely related to the congeneric species Cladosporium zixishanense of Cladosporiaceae.

The Dose of Fungal Aerosol Inhaled by Workers in a Waste-Sorting Plant in Poland: A Case Study

Bioaerosol monitoring is a rapidly emerging area in the context of work environments because microbial pollution is a key element of indoor air pollution and plays an important role in certain infectious diseases and allergies. However, as yet, relatively little is known about inhaled doses of microorganisms in workplaces. Today, the important issue of social concern is due to waste management, transport, sorting, and processing of wastes and their environmental impact and effects on public health. In fact, waste management activities can have numerous adverse effects on human wellbeing. Health effects are generally linked to exposure (EX), defined as the concentration of a contaminant and the length of time a person is exposed to this concentration. Dose is an effective tool for evaluating the quantity of a contaminant that actually crosses the body’s boundaries and influences the goal tissue. This document presents an analysis of the fungal waste-sorting plant EX dose (FWSPED) inhaled by workers in a waste-sorting plant (WSP) in Poland in March 2019. The main purpose of this research was to assess FWSPED inhaled by workers in two cabins at the WSP: the preliminary manual sorting cabin (PSP) and the purification manual sorting cabin (quality control; QSP). It was found that the FWSPED inhaled by workers was 193 CFU/kg in the PSP and 185 CFU/kg in the QSP. Fungal particles were quantitatively evaluated and qualitatively identified by the GEN III Biolog system. During the research, it was found that isolates belonging to the Aspergilus flavus and Penicillum chrysogenum strains were detected most frequently in the WSP. The total elimination of many anthropogenic sources is not possible, but the important findings of this research can be used to develop realistic management policies and methods to improve the biological air quality of WSPs for effective protection of WSP workers.

Fusarubin and Anhydrofusarubin Isolated from A Cladosporium Species Inhibit Cell Growth in Human Cancer Cell Lines

Cladosporium species are endophytic fungi that grow on organic matter and are considered food contaminants. The anti-microbial and anti-tumor naphthoquinones fusarubin (FUS) and anhydrofusarubin (AFU) were isolated using column chromatography from a Cladosporium species residing inside Rauwolfia leaves. The impact of FUS and AFU on cell growth was assessed in acute myeloid leukemia (OCI-AML3) and other hematologic tumor cell lines (HL-60, U937, and Jurkat). Treatment with FUS or AFU reduced the number of OCI-AML3 cells as evaluated by a hemocytometer. Flow cytometry analyses showed that this effect was accompanied by diverse impairments in cell cycle progression. Specifically, FUS (20 or 10 μg/mL significantly decreased the percentage of cells in S phase and increased the percentage of cells in G2/M phase, whereas AFU increased the percentage of cells in G0/G1 phase (50 and 25 μg/mL) and decreased the percentage of cells in S (50 μg/mL) and G2/M (50 and 25 μg/mL) phases. Both substances significantly increased apoptosis at higher concentrations. The effects of FUS were more potent than those of AFU, with FUS up-regulating p21 expression in a p53-dependent manner, as detected by Western blot analyses, likely the consequence of decreased ERK phosphorylation and increased p38 expression (both of which increase p21 stability). FUS also decreased Akt phosphorylation and resulted in increased Fas ligand production and caspase-8/3-dependent apoptosis. These results suggest that FUS and AFU inhibit proliferation and increase apoptosis in cell lines derived from hematological cancers.

Microparticle-enhanced polygalacturonase production by wild type Aspergillus sojae

Polygalacturonases (PGs), an important industrial enzyme group classified under depolymerases, catalyze the hydrolytic cleavage of the polygalacturonic acid chain through the introduction of water across the oxygen bridge. In order to produce and increase the concentration of this enzyme group in fermentation processes, a new approach called microparticle cultivation, a promising and remarkable method, has been used. The aim of this study was to increase the PG activity of Aspergillus sojae using aluminum oxide (Al₂O₃) as microparticles in shake flask fermentation medium. Results indicated that the highest PG activity of 34.55 ± 0.5 U/ml was achieved with the addition of 20 g/L of Al₂O₃ while the lowest activity of 15.20 ± 0.2 U/mL was obtained in the presence of 0.1 g/L of Al₂O₃. In fermentation without microparticles as control, the activity was 15.64 ± 3.3 U/mL. Results showed that the maximum PG activity was 2.2-fold higher than control. Additionally, smaller pellets formed with the addition of Al₂O₃ where the lowest pellet diameter was 955.1 µm when 10 g/L of the microparticle was used. Also, it was noticed that biomass concentration gradually increased with increasing microparticle concentration in the fermentation media. Consequently, the PG activity was significantly increased in microparticle-enhanced shake flask fermentation. In fact, these promising preliminary data can be of significance to improve the enzyme activity in large-scale bioreactors.