Hypothesis and Theory: Fungal Spores in Stemflow and Potential Bark Sources

The study of stemflow fungi began over 50 years ago. Past work has been performed in different climatic regions of the world, with different sampling methods, by mycologists focusing on different taxonomical groups. Therefore, we aim to synthesize this work to delineate major conclusions and emerging hypothesis. Here, we present: (1) a systematic compilation of observations on stemflow conidial concentration, flux, and species composition; (2) an evaluation of the methods underlying these observations; (3) a testable theory to understand spatiotemporal dynamics in stemflow (including honeydews) conidial assemblages, with a focus on their relationship to bark structure and microhabitats; and (4) a discussion of major hypotheses based on past observations and new data. This represents a knowledge gap in our understanding of fungal dispersal mechanisms in forests, in a spatially-concentrated hydrologic flux that interacts with habitats throughout the forest microbiome. The literature synthesis and new data represent observations for 228 fungal species’ conidia in stemflow collected from 58 tree species, 6 palm species, and 1 bamboo species. Hypothetical relationships were identified regarding stemflow production and conidial concentration, flux, and species composition. These relationships appear to be driven by bark physico-chemical properties, tree canopy setting, the diversity of in-canopy microenvironments (e.g., tree holes, bark fissures, and epiphytes), and several possible conidia exchange processes (teleomorph aerosols, epi-faunal exchanges, fungal colonization of canopy microhabitats, and droplet impacts, etc.). The review reveals a more complex function of stemflow fungi, having a role in self-cleaning tree surfaces (which play air quality-related ecoservices themselves), and, on the other hand, these fungi may have a role in the protection of the host plant.

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Cohort Study of Airway Mycobiome in Adult Cystic Fibrosis Patients: Differences in Community Structure between Fungi and Bacteria Reveal Predominance of Transient Fungal Elements

Journal of Clinical Microbiology ◽

10.1128/jcm.01094-15 ◽

2015 ◽

Vol 53 (9) ◽

pp. 2900-2907 ◽

Cited By ~ 35

Author(s):

Rolf Kramer ◽

Annette Sauer-Heilborn ◽

Tobias Welte ◽

Carlos A. Guzman ◽

Wolf-Rainer Abraham ◽

...

Keyword(s):

Cystic Fibrosis ◽

Fungal Spores ◽

Rare Event ◽

Single Strand Conformation Polymorphism ◽

Fungal Species ◽

Fungal Communities ◽

Fungal Colonization ◽

Molecular Fingerprinting ◽

High Exposure ◽

Entire Cohort

The respiratory mycobiome is an important but understudied component of the human microbiota. Like bacteria, fungi can cause severe lung diseases, but their infection rates are much lower. This study compared the bacterial and fungal communities of sputum samples from a large cohort of 56 adult patients with cystic fibrosis (CF) during nonexacerbation periods and under continuous antibiotic treatment. Molecular fingerprinting based on single-strand conformation polymorphism (SSCP) analysis revealed fundamental differences between bacterial and fungal communities. Both groups of microorganisms were taxonomically classified by identification of gene sequences (16S rRNA and internal transcript spacer), and prevalences of single taxa were determined for the entire cohort. Major bacterial pathogens were frequently observed, whereas fungi of known pathogenicity in CF were detected only in low numbers. Fungal species richness increased without reaching a constant level (saturation), whereas bacterial richness showed saturation after 50 patients were analyzed. In contrast to bacteria, a large number of fungal species were observed together with high fluctuations over time and among patients. These findings demonstrated that the mycobiome was dominated by transient species, which strongly suggested that the main driving force was their presence in inhaled air rather than colonization. Considering the high exposure of human airways to fungal spores, we concluded that fungi have low colonization abilities in CF, and colonization by pathogenic fungal species may be considered a rare event. A comprehensive understanding of the conditions promoting fungal colonization may offer the opportunity to prevent colonization and substantially reduce or even eliminate fungus-related disease progression in CF.

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Fungi associated with Tomicus minor on Pinus sylvestris in Poland and their succession into the sapwood of beetle-infested windblown trees

Canadian Journal of Forest Research ◽

10.1139/x08-101 ◽

2008 ◽

Vol 38 (10) ◽

pp. 2579-2588 ◽

Cited By ~ 15

Author(s):

Robert Jankowiak

Keyword(s):

Species Composition ◽

Pinus Sylvestris ◽

Initial Phase ◽

Bark Beetles ◽

General Scheme ◽

Fungal Species ◽

Fungal Colonization ◽

Fungal Succession ◽

Tomicus Minor ◽

Insect Fungi

The study identified and measured frequency of fungal species associated with Tomicus minor (Hart.) on Pinus sylvestris L. (Scots pine) in Poland. Additionally, fungal succession in P. sylvestris sapwood was investigated during a 12 week period following an attack by this insect. Fungi were isolated from five populations of overwintered adult beetles and their galleries with 59 species of fungi being represented among the 2880 cultures obtained. The most frequent species, Ophiostoma canum (Münch) Syd. & P. Syd., Hormonema dematioides Lagerb. & Melin, and Ambrosiella tingens (Lagerb. & Melin) L.R. Batra, appeared to be specifically associated with T. minor. The succesional changes in species composition during a 12 week period following an attack by T. minor were observed. The pattern of fungal succession in P. sylvestris sapwood essentially agreed with a general scheme of fungal succession in tree sapwood infested by bark beetles. Ambrosiella tingens was the first invader of sapwood and occurred most frequently in its deeper layers. Ophiostoma canum, H. dematioides, and other molds were also often isolated from the sapwood; however, they were most common at a depth of 5 mm during the initial phase of fungal colonization. Later, Ophiostoma canum followed A. tingens in the sapwood invasion.

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First Speleomycological Study on the Occurrence of Psychrophilic and Psychrotolerant Aeromycota in the Brestovská Cave (Western Tatras Mts., Slovakia) and First Reports for Some Species at Underground Sites

Biology ◽

10.3390/biology10060497 ◽

2021 ◽

Vol 10 (6) ◽

pp. 497

Author(s):

Rafał Ogórek ◽

Mateusz Speruda ◽

Justyna Borzęcka ◽

Agata Piecuch ◽

Magdalena Cal

Keyword(s):

Global Warming ◽

Immune System ◽

Biological Material ◽

Fungal Spores ◽

Airborne Fungi ◽

Fungal Species ◽

Air Samples ◽

Cold Adapted ◽

First Report

Most underground ecosystems are heterotrophic, fungi in these objects are dispersed in the air in the form of spores, and they may be potentially hazardous to mammals. Research in underground sites has focused on mesophilic airborne fungi and only a few concerned cold-adapted species. Therefore, the goal of our research was the first report of psychrophilic and psychrotolerant aeromycota in the Brestovská Cave using culture-based techniques with genetic and phenotypic identification. Plates with PDA medium containing sampled biological material were incubated at 8 ± 0.5 °C. The density of mycobiota inside the cave ranged from 37.4 to 71 CFU 1 m−3 of air and 63.3 CFU 1 m−3 of air outside the cave. Thus, the level of fungal spores did not exceed the standards for the mycological quality of the air. A total of 18 species were isolated during the study, and some species may be potentially dangerous to people with weakened immune system. All fungal species were present inside the cave and only seven of them were outside. Cladosporium cladosporioides dominated in the external air samples and Mortierella parvispora was cultured most frequently from internal air samples. To our knowledge, this is the first discovery of the fungal species such as Coniothyrium pyrinum, Cystobasidium laryngis, Filobasidium wieringae, Leucosporidium drummii, M. parvispora, Mrakia blollopis, Nakazawaea holstii, and Vishniacozyma victoriae in the air inside the underground sites. Moreover, C. pyrinum, C. laryngis, L. drummii, M. blollopis, and N. holstii have never been detected in any component of the underground ecosystems. There are possible reasons explaining the detection of those species, but global warming is the most likely.

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Generation and Characterization of Indoor Fungal Aerosols for Inhalation Studies

Applied and Environmental Microbiology ◽

10.1128/aem.04063-15 ◽

2016 ◽

Vol 82 (8) ◽

pp. 2479-2493 ◽

Cited By ~ 18

Author(s):

Anne Mette Madsen ◽

Søren T. Larsen ◽

Ismo K. Koponen ◽

Kirsten I. Kling ◽

Afnan Barooni ◽

...

Keyword(s):

Species Composition ◽

Indoor Environment ◽

Building Materials ◽

Inhalation Exposure ◽

Single Species ◽

Fungal Species ◽

Exposure Level ◽

Exposure System ◽

Content Type ◽

Water Damage

ABSTRACTIn the indoor environment, people are exposed to several fungal species. Evident dampness is associated with increased respiratory symptoms. To examine the immune responses associated with fungal exposure, mice are often exposed to a single species grown on an agar medium. The aim of this study was to develop an inhalation exposure system to be able to examine responses in mice exposed to mixed fungal species aerosolized from fungus-infested building materials. Indoor airborne fungi were sampled and cultivated on gypsum boards. Aerosols were characterized and compared with aerosols in homes. Aerosols containing 107CFU of fungi/m3air were generated repeatedly from fungus-infested gypsum boards in a mouse exposure chamber. Aerosols containedAspergillus nidulans,Aspergillus niger,Aspergillus ustus,Aspergillus versicolor,Chaetomium globosum,Cladosporiumherbarum,Penicillium brevicompactum,Penicillium camemberti,Penicillium chrysogenum,Penicillium commune,Penicillium glabrum,Penicillium olsonii,Penicillium rugulosum,Stachybotrys chartarum, andWallemia sebi. They were all among the most abundant airborne species identified in 28 homes. Nine species from gypsum boards and 11 species in the homes are associated with water damage. Most fungi were present as single spores, but chains and clusters of different species and fragments were also present. The variation in exposure level during the 60 min of aerosol generation was similar to the variation measured in homes. Through aerosolization of fungi from the indoor environment, cultured on gypsum boards, it was possible to generate realistic aerosols in terms of species composition, concentration, and particle sizes. The inhalation-exposure system can be used to study responses to indoor fungi associated with water damage and the importance of fungal species composition.

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Microbiology and atmospheric processes: chemical interactions of primary biological aerosols

Biogeosciences ◽

10.5194/bg-5-1073-2008 ◽

2008 ◽

Vol 5 (4) ◽

pp. 1073-1084 ◽

Cited By ~ 103

Author(s):

L. Deguillaume ◽

M. Leriche ◽

P. Amato ◽

P. A. Ariya ◽

A.-M. Delort ◽

...

Keyword(s):

Metabolic Activity ◽

Atmospheric Chemistry ◽

Ph Value ◽

Chemical Constituents ◽

Fungal Spores ◽

Chemical Properties ◽

Nutrient Concentrations ◽

Chemical Interactions ◽

Biological Aerosols ◽

Micro Organisms

Abstract. This paper discusses the influence of primary biological aerosols (PBA) on atmospheric chemistry and vice versa through microbiological and chemical properties and processes. Several studies have shown that PBA represent a significant fraction of air particulate matter and hence affect the microstructure and water uptake of aerosol particles. Moreover, airborne micro-organisms, namely fungal spores and bacteria, can transform chemical constituents of the atmosphere by metabolic activity. Recent studies have emphasized the viability of bacteria and metabolic degradation of organic substances in cloud water. On the other hand, the viability and metabolic activity of airborne micro-organisms depend strongly on physical and chemical atmospheric parameters such as temperature, pressure, radiation, pH value and nutrient concentrations. In spite of recent advances, however, our knowledge of the microbiological and chemical interactions of PBA in the atmosphere is rather limited. Further targeted investigations combining laboratory experiments, field measurements, and modelling studies will be required to characterize the chemical feedbacks, microbiological activities at the air/snow/water interface supplied to the atmosphere.

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Studies on the arbuscular mycorrhizal fungal association in some medicinal plant species of paithal hills, western ghats kannur district, kerala

Kongunadu Research Journal ◽

10.26524/krj.2020.19 ◽

2020 ◽

Vol 7 (2) ◽

pp. 30-38

Author(s):

Santhoshkumar S ◽

Nagarajan N ◽

Sree Priya S

Keyword(s):

Plant Species ◽

Root Colonization ◽

Rhizosphere Soil ◽

Fungal Spores ◽

Arbuscular Mycorrhizal ◽

Soil Samples ◽

Fungal Colonization ◽

The Family ◽

Spore Population ◽

Arbuscular Mycorrhizal Fungal

In the present study to analyzed that the arbuscular mycorrhizal fungal spores in root colonization and spore population in rhizosphere soils samples in various medicinal at Paithal hills,Western Ghats of Kannur district, Kerala, India. Root and rhizosphere soil samples were collected during the month of August, 2018-March, 2019 from the surface to 30 cm depth as well as pH were also recorded. Totally 30 plant species belonging to 19 families were collected and identified. The present result showed arbuscular mycorrhizal spore population in the rhizosphere soil and root colonization of all the plant species. A total of 19 AM fungal spores were recovered from the rhizosphere soil samples in this study region. The Glomus was dominant had seen in rhizosphere soil samples in all the medicinal plant species. The maximum spore population was found in the rhizosphere soil samples of Mimosa pudica (590/100g of soil) which belongs to the family Mimosaceae and the lowest spore population was observed in the Terminalia bellirica 135/100g of soil) belongs to Combretaceae family. The highest 78 % AM fungal colonization was found in roots of Euphorbia hirta belongs to the family Euphorbiaceae. While the lowest 11 % AM fungal colonization was found in the root of Sida acuta belongs to the family Malvaceae.

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Molds in museum environments: Biodeterioration of art photographs and wooden sculptures

Archives of Biological Sciences ◽

10.2298/abs1303955g ◽

2013 ◽

Vol 65 (3) ◽

pp. 955-962 ◽

Cited By ~ 19

Author(s):

Milica Ljaljevic-Grbic ◽

M. Stupar ◽

Jelena Vukojevic ◽

Ivana Maricic ◽

Natasa Bungur

Keyword(s):

Aspergillus Niger ◽

Indoor Air ◽

Trichoderma Viride ◽

Fungal Species ◽

Chaetomium Globosum ◽

Fungal Colonization ◽

Cellulolytic Activity ◽

Cultural Center ◽

Fungal Propagules ◽

Alternaria Sp

Pieces of art stored in museum depots and display rooms are subject to fungal colonization that leads to bio-deterioration processes. Deteriorated wooden sculptures and art photographs temporarily stored in the quarantine room of the Cultural Center of Belgrade were subject to mycological analyses. Twelve fungal species were identified on the wooden substratum and five species were detected on photograph surfaces. Trichoderma viride, Chaetomium globosum and Alternaria sp. were the fungi with proven cellulolytic activity detected on the examined cellulose substrata. Indoor air mycobiota were estimated to 210.09 ? 8.06 CFU m-3, and the conidia of fungus Aspergillus niger were the dominant fungal propagules in the air of the examined room.

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Ericoid mycorrhizal diversity increases with soil age and progressive phosphorus limitation across a 4.1 million-year chronosequence

10.1101/2020.08.27.270413 ◽

2020 ◽

Author(s):

Devin R. Leopold ◽

Kabir G. Peay ◽

Peter M. Vitousek ◽

Tadashi Fukami

Keyword(s):

Species Composition ◽

Nutrient Limitation ◽

Mycorrhizal Fungi ◽

Fungal Diversity ◽

Species Turnover ◽

Phosphorus Limitation ◽

Fungal Species ◽

Direct Role ◽

Ericoid Mycorrhizal Fungi ◽

Soil Age

AbstractEricaceous plants rely on ericoid mycorrhizal fungi for nutrient acquisition. However, the factors that affect the composition and structure of these fungal communities remain largely unknown. Here, we use a 4.1-myr soil chronosequence in Hawaii to test the hypothesis that changes in nutrient availability with soil age determine the diversity and species composition of fungi associated with ericoid roots. We sampled roots of a native Hawaiian plant, Vaccinium calycinum, and used DNA metabarcoding to quantify changes in fungal diversity and species composition. We also used a fertilization experiment at the youngest and oldest sites to assess the importance of nutrient limitation. We found an increase in diversity and a clear pattern of species turnover across the chronosequence, driven largely by putative ericoid mycorrhizal fungi. Fertilization with nitrogen at the youngest site and phosphorus at the oldest site reduced total fungal diversity, suggesting a direct role of nutrient limitation. Our results also reveal the presence of novel fungal species associated with Hawaiian Ericaceae and suggest a greater importance of phosphorus availability for communities of ericoid mycorrhizal fungi than is generally assumed.

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Distribution of stem-end rot on the canopy in ‘Hass’ avocado trees in two coastal areas in Peru

Peruvian Journal of Agronomy ◽

10.21704/pja.v5i2.1771 ◽

2021 ◽

Vol 5 (2) ◽

pp. 60-70

Author(s):

Alejandro Kepler Llanos Melo ◽

Walter Eduardo Apaza-Tapia

Keyword(s):

Disease Incidence ◽

Management Strategies ◽

Elongation Factor ◽

Fungal Species ◽

Coastal Areas ◽

Tree Canopy ◽

Fruit Rot ◽

Internal Site ◽

External Site ◽

Hass Avocado

Stem-end rot (SER) of avocado is caused by several fungal species, and it is presented worldwide. This plant disease currently affects several avocado producer regions in Peru, causing fruit rot, impacting the industry negatively. Research about SER distribution in the canopy of avocado trees is limited. Thus, the present study aimed to compare which areas in the canopy are prone to have more SER in ‘Hass’ avocado harvested fruit in two different coastal areas in Peru. The experiment was conducted in the northern (Barranca) and southern (Cañete) of Lima. ‘Hass’Avocado fruits from both producer areas were collected to identify the causal agent; Lasiodiplodia theobromae was isolated from infected fruits. Identification was conducted based on morphological features and a partial DNA sequence of the translation elongation factor 1-α gene (tef1-α). The results showed that fruits inside the tree canopy were prone to have a higher disease incidence than the fruits located in the external site (P<0.001). Besides, internal-site fruits displayed a higher percentage of infected fruit for each grade disease (P<0.001) than external-site fruits, except for grade 0 (fruits without symptoms) and grade 1. Finally, the results suggested that the altitude where the fruit is positioned on the canopy could influence the incidence of SER, where fruits located in the high part revealed less incidence than the low section. The results are valuable for enhancing management strategies and avoiding postharvest loss of avocado fruits in our region.

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Wild Apple-Associated Fungi and Bacteria Compete to Colonize the Larval Gut of an Invasive Wood-Borer Agrilus mali in Tianshan Forests

Frontiers in Microbiology ◽

10.3389/fmicb.2021.743831 ◽

2021 ◽

Vol 12 ◽

Author(s):

Tohir A. Bozorov ◽

Zokir O. Toshmatov ◽

Gulnaz Kahar ◽

Daoyuan Zhang ◽

Hua Shao ◽

...

Keyword(s):

Gut Microbiota ◽

Inhibitory Concentration ◽

Fungal Species ◽

Gut Bacteria ◽

Recent Analysis ◽

Fungal Colonization ◽

Antifungal Compound ◽

Concentration Method ◽

Malus Sieversii ◽

Wood Borer

The gut microflora of insects plays important roles throughout their lives. Different foods and geographic locations change gut bacterial communities. The invasive wood-borer Agrilus mali causes extensive mortality of wild apple, Malus sieversii, which is considered a progenitor of all cultivated apples, in Tianshan forests. Recent analysis showed that the gut microbiota of larvae collected from Tianshan forests showed rich bacterial diversity but the absence of fungal species. In this study, we explored the antagonistic ability of the gut bacteria to address this absence of fungi in the larval gut. The results demonstrated that the gut bacteria were able to selectively inhibit wild apple tree-associated fungi. Among them, Pseudomonas synxantha showed strong antagonistic ability, producing antifungal compounds. Using different analytical methods, such as column chromatography, mass spectrometry, HPLC, and NMR, an antifungal compound, phenazine-1-carboxylic acid (PCA), was identified. Activity of the compound was determined by the minimum inhibitory concentration method and electron microscopy. Moreover, our study showed that the gut bacteria could originate from noninfested apple microflora during infestation. Overall, the results showed that in newly invaded locations, A. mali larvae changed their gut microbiota and adopted new gut bacteria that prevented fungal colonization in the gut.

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