Saprobic Fungi Research Articles

Marine fungi recorded from Avicennia marina (Forsk.) Vierh. and their secondary product potential

In this review, we compiled a list of marine fungi reported from the lower parts of Avicennia marina, which are permanently or intermittently inundated with sea water from different geographical regions of the world. From 1955 to 2020 a total of 41 publications reporting marine mycota of A. marina were published that include: 12 studies reporting taxa along with their frequency of occurrence, 10 studies without frequency of occurrence and 19 studies described new taxa from the host. A total of 149 marine fungi (120 ascomycetes, 24 asexual ascomycetes and 5 basidiomycetes) were reported from intertidal and submerged wood, pneumatophores and leaves of Avicennia marina from different geographical locations. This figure is the highest number of marine fungi reported from a single mangrove host. Two new families, 11 new genera and 39 new species were described as new to science from A. marina. The highest number of species were recorded from the Indian Ocean (117), while only 75 taxa were recorded from the Pacific Ocean with 43 fungi common to both oceans. However, fewer studies have been carried out in the latter ocean. Intertidal samples of A. marina were collected from nine countries of which India supported the highest fungal diversity from the host with 68 species, followed by Malaysia (57) and Egypt (42). Marine mycota of A. marina were latitudinally distributed with species from subtropics differing largely from those from tropical regions, but were less investigated. Sordariomycetes, Pleosporales and Halosphaeriaceae were the most-species rich class, order and family, respectively. The high percentages of new species recorded from only a single location (67%) indicate that marine fungi from A. marina and other mangrove plants are understudied. Twenty-six species were recorded exclusively from A. marina, of which 23 were described fairly recently as new taxa from the host and this supports the non-specific nature of the saprobic marine fungi. This review represents the first exclusive list of marine fungi from a single mangrove tree species. Out of the 149 species reported from A. marina, only fourteen fungi were explored for their secondary products. Explored species produced new bioactive compounds; many of them have antimicrobial, cytotoxic, phytotoxic, antimalarial and antidiabetic effects.

Soil fungal mycelia have unexpectedly flexible stoichiometric C:N and C:P ratios.

Soil ecological stoichiometry provides powerful theories to integrate the complex interplay of element cycling and microbial communities into biogeochemical models. One essential assumption is that microbes maintain stable C:N:P (carbon:nitrogen:phosphorus) ratios independent of resource supply, although such homeostatic regulations have rarely been assessed in individual microorganisms. Here, we report an unexpected high flexibility in C:N and C:P values of saprobic fungi along nutrient supply gradients, overall ranging between 7-126 and 20-1488, respectively, questioning microbial homeostasis. Fungal N:P varied comparatively less due to simultaneous reductions in mycelial N and P contents. As a mechanism, internal recycling processes during mycelial growth and an overall reduced N and P uptake appear more relevant than element storage. The relationships among fungal stoichiometry and growth disappeared in more complex media. These findings affect our interpretation of stoichiometric imbalances among microbes and soils and are highly relevant for developing microbial soil organic carbon and nitrogen models.

Secondary Metabolites and Their Bioactivities Produced by Paecilomyces.

Paecilomyces, a common saprobic filamentous fungus, not only plays an important role in biological control, but also has applications in medicine, food, and environmental protection. In this paper, 223 secondary metabolites and their bioactivities from 13 known species and various unidentified strains of Paecilomyces are reviewed. Their structures can be described as polyketide, terpenoid, peptide, alkaloid, quinone, pyrone, sterol, and fatty acid. They have been demonstrated varying biological activities, including antimicrobial, antitumor, insecticidal, antiplasmodial, antimalarial, nematicidal, herbicidal, and enzyme-inhibiting. This review provides a comprehensive overview of secondary metabolites and their biological activities from strains of Paecilomyces.

The lichens of the northern shore of the Gulf of Finland in the limits of St. Petersburg, Russia – diversity on the edge of the megapolis


 
 
 We present a lichen checklist for the northern shore of the Gulf of Finland in the limits of St. Petersburg, Russia. This area has diverse lichen biota within the city limits, and has been comprehensively studied since 1893, which gives a good base for analysis of historical changes in lichen diversity. The documented lichen biota comprises 469 species (430 lichenized, 24 lichenicolous, 3 facultatively lichenicolous, and 12 non-lichenized saprobic fungi), of them 191 species are known from herbaria and literature for the period before 1991, and 436 species were recorded since 1991 to 2019. Thirty-three taxa were excluded from the lichen list of the study area as erroneous or dubious records. Altogether 48 species are new to St. Petersburg, including: Lecidea malmeana and Micarea czarnotae – new to Russia; Caloplaca lucifuga, Gyalecta nigricans, Micarea soralifera – new to European Russia; Agonimia flabelliformis, Endococcus verrucosus, Lecania turicensis, Micarea fallax, M. tomentosa, Xanthomendoza huculica – new to Northwestern European Russia; Lichenoconium lichenicola, Ramalina europaea, Sarcogyne hypophaea – not known also from the Leningrad Region. The studied lichen biota is moderately rich compared to other city territories. The history of economic development of the region has caused its serious transformation, degradation of natural habitats and therefore partial loss of lichen diversity. At the same time, human-made substrates and anthropogenic plant communities are inhabited by lichens, including species unknown in the natural habitats of the study area. However, 44 species recorded in the study area are red-listed in St. Petersburg, with 13 of them known only from historical collections. Forest communities, as well as historical parks, in NW part of St. Petersburg are important source of biodiversity on regional level nowadays and hopefully in future, and deserve protection.
 
 

Quadracaea mediterranea, a new record from Kumaun Himalaya region, India

Quadracaea mediterranea was collected during our continuing mycological survey of saprobic conidial fungi on decaying leaf litter of Quercus floribunda from the Ramgarh forest, Nainital, Uttarakhand, India. Detailed taxonomic information on Q. mediterranea includes morphological description, geographical distribution, comments, illustrations, and a comparison with allied taxa. This finding extends the geographic distribution of the species, previously recorded only in China, Italy, and Brazil.

Parasexual recombination enablesAspergillus fumigatusto persist in cystic fibrosis

Aspergillus fumigatus is a saprobic fungus that causes a range of pulmonary diseases, some of which are characterised by fungal persistence such as is observed in cystic fibrosis (CF) patients. Creation of genetic variation is critical for A. fumigatus to adapt to the lung environment, but biofilm formation, especially in CF patients, may preclude mutational supply in A. fumigatus due to its confinement to the hyphal morphotype. We tested our hypothesis that genetic variation is created through parasexual recombination in chronic biofilms by phenotypic and genetic analysis of A. fumigatus isolates cultured from different origins.As diploids are the hallmark of parasex, we screened 799 A. fumigatus isolates obtained from patients with CF, chronic pulmonary lung disease and acute invasive aspergillosis, and from the environment for spore size. Benomyl sensitivity, nuclear content measurements through fluorescence-activated cell sorting and scanning electron microscopy were used to confirm the diploid state of large size spores. Whole genome sequencing was used to characterise diploid-associated genetic variation.We identified 11 diploids in isolates recovered from six of 11 (55%) CF patients and from one of 24 (4%) chronic aspergillosis patients, but not in 368 isolates from patients with acute Aspergillus infection and the environment. Diploid formation was associated with accumulation of mutations and variable haploid offspring including a voriconazole-resistant isolate.Parasexual recombination allows A. fumigatus to adapt and persist in CF patients, and plays a role in azole resistance development. Our findings are highly significant for understanding the genetics and biology of A. fumigatus in the human lung.

Antagonism of saprobe fungi from semiarid areas of the Northeast of Brazil against Sclerotinia sclerotiorum and biocontrol of soybean white mold

The antagonistic activity of 25 saprobe fungi from semiarid areas of Northeast Brazil was evaluated against Sclerotinia sclerotiorum (Lib.) de Bary (Helotiales: Sclerotiniaceae). Four fungi [Myrothecium sp. Tode (Hypocreales: Stachybotryaceae) isolate 2, Volutella minima Höhn. (Hypocreales: Nectriaceae), Phialomyces macrosporus P.C. Misra & P.H.B. Talbot (Pezizomycotina) and Dictyosporium tetraseriale Goh, Yanna & K.D. Hyde (Pleosporales: Dictyosporiaceae)] were selected and further tested their ability to inhibit mycelial growth, sclerotia formation and ascospore germination of S. sclerotiorum and to control white mold on soybean plants. V. minima and P. macrosporus filtrates at 50% effectively suppressed mycelial growth and Myrothecium sp. isolate 2 completely suppressed sclerotia formation and inhibited ascospore germination by over 95%, the same result as commercial fungicide fluazinam. Soybean plants pre-treated with Myrothecium sp. isolate 2, P. macrosporus, and V. minima and inoculated with S. sclerotiorum showed a reduction of 55.8%, 79.7%, and 83.2% of area under disease progress curve (AUDPC) of white mold, respectively, in relation to water. Collectively, these results underline the antagonistic activity of V. minima, P. macrosporus, and Myrothecium sp. isolate 2 against S. sclerotiorum and their potential as biocontrol agents of soybean white mold.

A culture based diversity of saprobic fungi associated with leaf litter of Hevea brasiliensis along a chronosequence of plantations in Tripura, Northeast India

The present study aimed to assess the diversity of saprobic fungi associated with three decompositional stages of Hevea brasiliensis (Wild. ex Juss.) Mull. Arg. leaves along a chronosequence of plantations. The modified surface disinfection culture method was followed for isolation of saprobic fungi from three different phases (G1, G2 and G3) of decomposing leaves. The result revealed 51 species of fungi isolated from three plantations. There was an increasing trend of number of species along a chronosequence of plantations. Cladosporium sp. was isolated from all the phases of decomposition from all the three plantations. There is an increasing trend in diversity and a decreasing trend in dominance of fungi along a chronosequence of plantations. Overall, higher number of species and maximum diversity was recorded in G2 (Hʹ = 3.61) among the decompositional phases. The study suggests increase in diversity along a chronosequence of plantations and the similarity index suggests distinct fungal occurrence pattern in the leaf litter along a chronosequence of plantations.

INDUCTION OF DEFENSE MECHANISMS IN TOMATO PLANTS BY SAPROBIC FUNGI FILTRATES AGAINST EARLY BLIGHT DISEASE

ABSTRACT Tomato plants can be attacked by several diseases. The early blight disease causes large losses to tomato growers and requires many applications of fungicide for its control. Thus, the objective of this work was to evaluate the effect of saprobic fungi filtrates on the control of early blight (Alternaria solani) in tomato plants. The treatments consisted of fungi filtrates (Stachylidium bicolor - SBI; Periconia hispidula - PHI; Brachysporiella pulchra - BPU; Myrothecium leucotrichum - MLE; and Pycnoporus sanguineus - PSA) diluted at 20%, a control (water), and acibenzolar-S-methyl (ASM). Tomato plants with five leaves were treated with the filtrates, and A. solani was inoculated after three days. The variables analyzed were: area under the disease progress curve (AUDPC), and specific activity of the enzymes: catalase, lipoxygenase, peroxidase, and polyphenol oxidase. The SBI filtrate decreased the AUDPC in 80% for the third leaf and 96% for the fourth leaf. Catalase activity increased due to the application of BPU and PHI filtrates, at 96 hours post-inoculation (hpi). Lipoxygenase activity increased in 130%, 72%, 130%, and 81% at 24 hpi when applying the SBI, PHI, MLE, and ASM filtrates, respectively. The application of SBI, BPU, MLE, and PSA filtrates increased lipoxygenase activity in 30%, 26%, 12%, and 22%, respectively, at 120 hpi. Peroxidase activity increased 74% at 120 hpi, when applying the SBI filtrate. Polyphenol oxidase activity was not affected by the treatments. S. bicolor filtrate is efficient to control the severity of the early blight disease in tomato plants.

Multi-gene phylogenetic evidence suggests Dictyoarthrinium belongs in Didymosphaeriaceae (Pleosporales, Dothideomycetes) and Dictyoarthrinium musae sp. nov. on Musa from Thailand.

Dead leaves of Musa sp. (banana) were collected in northern Thailand during an investigation of saprobic fungi. Preliminary morphological observations revealed that three specimens belong to Dictyoarthrinium. Phylogenetic analyses of combined SSU, LSU, ITS and tef1-α sequence data revealed that Dictyoarthrinium forms a clade in Didymosphaeriaceae (Massarineae, Pleosporales, Dothideomycetes) sister to Spegazzinia. Based on contrasting morphological features with the extant taxa of Dictyoarthrinium, coupled with the multigene analyses, Dictyoarthrinium musae sp. nov. is introduced herein. Our study provides the first detailed molecular investigation for Dictyoarthrinium and supports its placement in Didymosphaeriaceae (Massarineae, Pleosporales, Dothideomycetes). Previously, Dictyoarthrinium was classified in Apiosporaceae (Xylariales, Sordariomycetes).

Growth rate trades off with enzymatic investment in soil filamentous fungi

Saprobic soil fungi drive many important ecosystem processes, including decomposition, and many of their effects are related to growth rate and enzymatic ability. In mycology, there has long been the implicit assumption of a trade-off between growth and enzymatic investment, which we test here using a set of filamentous fungi from the same soil. For these fungi we measured growth rate (as colony radial extension) and enzymatic repertoire (activities of four enzymes: laccase, cellobiohydrolase, leucine aminopeptidase and acid phosphatase), and explored the interaction between the traits based on phylogenetically corrected methods. Our results support the existence of a trade-off, however only for the enzymes presumably representing a larger metabolic cost (laccase and cellobiohydrolase). Our study offers new insights into potential functional complementarity within the soil fungal community in ecosystem processes, and experimentally supports an enzymatic investment/growth rate trade-off underpinning phenomena including substrate succession.

Diversity of Growth Responses of Soil Saprobic Fungi to Recurring Heat Events.

As a consequence of ongoing climate change, the frequency of extreme heat events is expected to increase. Recurring heat pulses may disrupt functions supported by soil microorganisms, thus affecting the entire ecosystem. However, most perturbation experiments only test effects of single heat events, and therefore it remains largely unknown how soil microorganisms react to repeated pulse events. Here we present data from a lab experiment exposing 32 filamentous fungi, originally isolated from the same soil, to sequential heat perturbations. Soil saprobic fungi isolates were exposed to one or two heat pulses: mild (35°C/2 h), strong (45°C/1 h), or both in sequence (35°C/2 h+45°C/1 h), and we assessed growth rate. Out of the 32 isolates 13 isolates showed an antagonistic response, 3 isolates a synergistic response and 16 isolates responded in an additive manner. Thus the 32 filamentous fungal isolates used here showed the full range of possible responses to an identical heat perturbation sequence. This diversity of responses could have consequences for soil-borne ecosystem services, highlighting the potential importance of fungal biodiversity in maintaining such services, particularly in the context of climate change.

Soil Saprobic Fungi Differ in Their Response to Gradually and Abruptly Delivered Copper

The overwhelming majority of studies examining environmental change deliver treatments abruptly, although, in fact, many important changes are gradual. One example of a gradually increasing environmental stressor is heavy metal contamination. Essential heavy metals, such as copper, play an important role within cells of living organisms but are toxic at higher concentrations. In our study, we focus on the effects of copper pollution on filamentous soil fungi, key players in terrestrial ecosystem functioning. We hypothesize that fungi exposed to gradually increasing copper concentrations have higher chances for physiological acclimation and will maintain biomass production and accumulate less copper, compared to fungi abruptly exposed to the highest copper concentration. To test this hypothesis, we conducted an experiment with 17 fungal isolates exposed to gradual and abrupt copper addition. Contrary to our hypothesis, we find diverse idiosyncratic responses, such that for many fungi gradually increasing copper concentrations have more severe effects (stronger growth inhibition and higher copper accumulation) than an abrupt increase. While a number of environmental change studies have accumulated evidence based on the magnitude of changes, the results of our study imply that the rate of change can be an important factor to consider in future studies in ecology, environmental science, and environmental management.

Habitat enhancements for reptiles in a beech forest may increase fungal species richness

The success of habitat enhancements is typically assessed by subsequent monitoring of the focal taxonomic group. However, enhancement actions are likely to affect other, non-targeted species. On a south-facing slope in the Swiss Jura mountains, a mixed-forest stand was thinned out by irregular removal cuttings to improve the habitat conditions for reptiles. We used this enhancement action as a case study to monitor changes in the macrofungal community that came along with it. During 3 years before and after forest thinning, the site was visited between six and twelve times per year. Thereby, all apparent fungal species were recorded along a ringlike transect, split into 32 transect sections. We used site-occupancy models to estimate fungal species richness and abundance. These models allow to separately estimate occurrence probability and detection probability of species, and to account for differences in detection probability, depending on habitat and season. After the forest thinning, the occurrence probabilities of ectomycorrhizal and saprobic fungi were significantly higher than before. As a result, we estimated a mean increase in overall species richness by 4.4% (median 4.3%, CI 2.1–6.8%) and an increase in abundance by 20.0% (median 19.9%, CI 14.8–25.7%). The two major habitat changes associated with forest thinning, the decrease in living wood and the increase in dead wood on most transect sections, could not explain the whole extent of the estimated increase in species richness and abundance. We believe that forest thinning may have fostered fungal species richness by creating a larger density and diversity of suitable microhabitats. With some caution, we conclude that the small-scale habitat enhancement for reptiles at the Bolberg, creating islands of open forest, did not negatively affect species richness and abundance of macrofungi, a non-targeted species group.

Fungal Traits Important for Soil Aggregation.

Soil structure, the complex arrangement of soil into aggregates and pore spaces, is a key feature of soils and soil biota. Among them, filamentous saprobic fungi have well-documented effects on soil aggregation. However, it is unclear what properties, or traits, determine the overall positive effect of fungi on soil aggregation. To achieve progress, it would be helpful to systematically investigate a broad suite of fungal species for their trait expression and the relation of these traits to soil aggregation. Here, we apply a trait-based approach to a set of 15 traits measured under standardized conditions on 31 fungal strains including Ascomycota, Basidiomycota, and Mucoromycota, all isolated from the same soil. We find large differences among these fungi in their ability to aggregate soil, including neutral to positive effects, and we document large differences in trait expression among strains. We identify biomass density, i.e., the density with which a mycelium grows (positive effects), leucine aminopeptidase activity (negative effects) and phylogeny as important factors explaining differences in soil aggregate formation (SAF) among fungal strains; importantly, growth rate was not among the important traits. Our results point to a typical suite of traits characterizing fungi that are good soil aggregators, and our findings illustrate the power of employing a trait-based approach to unravel biological mechanisms underpinning soil aggregation. Such an approach could now be extended also to other soil biota groups. In an applied context of restoration and agriculture, such trait information can inform management, for example to prioritize practices that favor the expression of more desirable fungal traits.

Partial mutual exclusion of ectomycorrhizal and saprobic fungi in a tropical seasonal rainforest

Partial mutual exclusion of ectomycorrhizal and saprobic fungi in a tropical seasonal rainforest

Лишайники острова Малый (Peninsaari) в Финском заливе (Ленинградская область)

A lichen checklist for Maly Island (Leningrad Region, Russia) comprises 160 species, including 150 lichens, 9 lichenicolous fungi and 1 non-lichenized saprobic fungus. Lecidella effugiens is new to North-Western European Russia, Diplotomma pharcidium and Taeniolella delicata are new to the Leningrad Region. The lichen biota of Maly Island is relatively poor due to natural and anthropogenic factors: the island is small, sandy, lacking rocky outcrops, with low diversity of plant communities; all its forests are disturbed and young. The most valuable habitats for lichens on Maly Island are seashore communities and open pine stands on sand.

Дополнения к лихенофлоре заповедника «Кологривский лес» (Костромская область)

New data on the lichen flora of the Kologriv Forest Nature Reserve from the cluster Kologrivskiy are provided. The specimens of lichens, lichenicolous fungi and non-lichenized saprophytic fungi were collected from 9 localities mainly in the Sekha River valley in cluster Kologrivskiy in September 2018. Altogether 110 lichen species, 9 non-lichenized saprobic fungi and 2 lichenicolous fungi are recorded for the first time for the nature reserve, including 69 species and 21 genera new for the Kostroma Region. The genus Leptosillia with species L. wienkampii and lichenicolous fungus Opegrapha phaeophysciae are published for the first time for European Russia. Altogether over 20 indicator species and habitat specialists of biologically valuable forests are known from the study area. Moreover 4 species (Leptogium burnetiae, Lobaria pulmonaria, Menegazzia terebrata, Nephromopsis laureri) are included in the Red Data Book of Russia.

Diversity of Saprobic Fungi on Magnolia garrettii: Do Collecting Sites and Seasons Affect the Fungal Community?

The diversity of saprobic fungi found on woody litter of Magnolia garrettii collected from Phu Hin Rongkla National Park in Phitsanulok Province, Thailand during the wet and dry seasons, from July 2008 to April 2009, was studied, and the fungal diversity and community was compared with a previous study in Doi Suthep-Pui National Park in Chiang Mai Province. Based on morphological characteristics, 141 taxa were obtained and classified as 40 Ascomycetes, 5 Basidiomycetes, 42 lichens, one unidentified taxon and 53 anamorphic fungi. The number of taxa recovered indicated that Dry season samples supported a more diverse fungal community than samples collected in the wet season, for both collecting sites, although the common genera of fungi obtained during each season were similar. Distinct fungal communities of saprobic fungi collected from each site suggest that site characteristics affect the community composition. Samples from Phu Hin Rongkla National Park provided higher numbers of fungi (especially lichens) than were collected in the previous Doi Suthep-Pui National Park study with few species overlapping in the two sites.

К лихенофлоре Северо-Осетинского заповедника (Северная Осетия — Алания). I. Кластер «Шуби»

New data on the lichen flora of the North Ossetia Nature Reserve from cluster “Shubi” are provided. This cluster is located in Skalistyy and Pastbishchnyy ranges. The specimens of lichens, lichenicolous fungi and non-lichenized saprophytic fungi were collected from 8 localities in cluster “Shubi” in June 2016. In total, 273 lichen species, 4 non-lichenized saprobic fungi and 17 lichenicolous fungi were recorded. Among them 254 species are new for North Ossetia Nature Reserve, 214 species are new for Republic of North Ossetia — Alania, 130 species are new for the Central Caucasus, and 14 species are new for the Caucasus. Bacidina mendax, B. sulphurella, Candelariella boleana, Cryptodiscus tabularum, Halecania elaeiza, H. viridescens, Leptorhaphis maggiana, Verrucaria hegetschweileri were not previously reported from Asia. Nine species are reported for the first time for Russia: Bacidina mendax, Bagliettoa steineri, Candelariella boleana, C. xanthostigmoides, Chaenothecopsis trassii, Halecania elaeiza, H. viridescens, Leptorhaphis maggiana, Verrucaria hegetschweileri.