Complex environments alter competitive dynamics in fungi

2021 ◽  
Author(s):  
Justin Chan ◽  
Stephen Bonser ◽  
Michael M. Kasumovic ◽  
Jeff Powell ◽  
William Kirkham Cornwell
Keyword(s):  
Interspecific Interactions ◽  
Fungal Species ◽  
Wood Block ◽  
Complex Environments ◽  
Biotic Factor ◽  
Pairwise Interactions ◽  
Agar Media ◽  
Contextual Environment ◽  
Natural Settings ◽  
Natural Communities

Competition is a key biotic factor that often structures natural communities. Many attempts to disentangle how competition shapes natural communities have relied on experiments on simplified systems or through simple mathematical models. But these simplified approaches are limited in their ability to represent the complexity seen in more natural settings. Here, we considered the competitive pairwise dynamics between four saprotrophic fungal species. We tested whether the contextual environment changed these dynamics, repeating competitive experiments in a simple agar media and a more ecologically realistic wood block setting. We found that the competitive outcomes on agar media differed from those within the wood blocks. While superior competitors were identified across all pairwise interactions on agar, within the wood blocks, two of six interactions resulted in deadlock, where neither competitor could breach territory of the other, and one interaction resulted in a reversed competitive outcome. These results suggest that the complexity within natural substrates can alter the strength of interspecific interactions and may contribute to coexistence and the resulting high diversity of fungi often observed within wood.

scholarly journals A study of air borne fungal distribution and species diversity in Hill Fort Region of Channagiri, Karnataka, India

2013 ◽  
Vol 1 (2) ◽  
pp. 59-61 ◽  
Author(s):  
S. Thirumala ◽  
Pradeep Nathu M. ◽  
H. B. Aravinda
Keyword(s):  
Species Diversity ◽  
Fungal Spores ◽  
Fungal Species ◽  
Environmental Condition ◽  
Maximum Contribution ◽  
Exposure Method ◽  
Fungal Distribution ◽  
Alternaria Species ◽  
Agar Media ◽  
Investigation Period

Air borne fungi of Hill fort region of Channagiri is studied with help of Petriplate exposure method using Pottato dextrose agar media, petriplate exposure time is 15min. Sampling is taken in the month of  January 2013 total 74 fungal colonies represented 07 fungal types were observed during the present investigation period. Environmental condition plays an importance role in the distribution of the fungal spores. Out of 07 fungal species most numbers of fungi are anamorphic groups. The fungal species were Aspergillus, Pencillium, Curvilaria, Cladosporium, Fusarium Rhizopus, Alternaria species were identified. Aspergillus species (47.2%) showing maximum contribution is observed where as Rhizopus shows minimum contribution.DOI: http://dx.doi.org/10.3126/ijasbt.v1i2.8203 Int J Appl Sci Biotechnol, Vol. 1(2): 60-62

Ochratoxin A Production by Some Fungal Species in Relation to Water Activity and Temperature

1979 ◽  
Vol 42 (6) ◽  
pp. 485-490 ◽  
Author(s):  
M. D. NORTHOLT ◽  
H. P. VAN EGMOND ◽  
W. E. PAULSCH
Keyword(s):  
Ochratoxin A ◽  
Water Activity ◽  
Minimum Temperature ◽  
Fungal Species ◽  
Aspergillus Ochraceus ◽  
Optimum Temperature ◽  
Temperature Range ◽  
Penicillium Cyclopium ◽  
Agar Media ◽  
Penicillium Viridicatum

The effects of water activity (aw) and temperature on growth of and ochratoxin A (OA) production by strains of Aspergillus ochraceus, Penicillium cyclopium, and Penicillium viridicatum were investigated. On agar media in which the aw had been adjusted by addition of sucrose or glycerol, the minimum aw values for OA production by A. ochraceus, P. cyclopium and P. viridicatum lay between 0.83–0.87, 0.87–0.90, and 0.83–0.86, respectively. At 24 C, optimum aw values for OA production by A. ochraceus and P. cyclopium were 0.99 and 0.95–0.99, respectively, whereas that of P. viridicatum varied and was 0.95 and 0.99 for the two strains tested. At optimum aw, the temperature range for OA production by A. ochraceus was 12–37 C, whereas that of P. cyclopium and P. viridicatum was 4–31 C. Optimum temperature for OA production by A. ochraceus was 31 C, whereas that of P. cyclopium and P. viridicatum was 24 C. On Edam cheese of 0.95 aw the minimum temperature for OA production by P. cyclopium was 20 C. On barley meal, P. viridicatum produced maximal quantities of OA at 0.97 aw and could produce OA at temperatures as low as 12 C.

scholarly journals Below-ground plant–fungus network topology is not congruent with above-ground plant–animal network topology

2015 ◽  
Vol 1 (9) ◽  
pp. e1500291 ◽  
Author(s):  
Hirokazu Toju ◽  
Paulo R. Guimarães ◽  
Jens M. Olesen ◽  
John N. Thompson
Keyword(s):  
Network Topology ◽  
Network Architecture ◽  
Community Dynamics ◽  
Species Coexistence ◽  
Interspecific Interactions ◽  
Fungal Species ◽  
Sequencing Data ◽  
Phylogenetic Groups ◽  
Form Complex ◽  
Below Ground

In nature, plants and their pollinating and/or seed-dispersing animals form complex interaction networks. The commonly observed pattern of links between specialists and generalists in these networks has been predicted to promote species coexistence. Plants also build highly species-rich mutualistic networks below ground with root-associated fungi, and the structure of these plant–fungus networks may also affect terrestrial community processes. By compiling high-throughput DNA sequencing data sets of the symbiosis of plants and their root-associated fungi from three localities along a latitudinal gradient, we uncovered the entire network architecture of these interactions under contrasting environmental conditions. Each network included more than 30 plant species and hundreds of mycorrhizal and endophytic fungi belonging to diverse phylogenetic groups. The results were consistent with the notion that processes shaping host-plant specialization of fungal species generate a unique linkage pattern that strongly contrasts with the pattern of above-ground plant–partner networks. Specifically, plant–fungus networks lacked a “nested” architecture, which has been considered to promote species coexistence in plant–partner networks. Rather, the below-ground networks had a conspicuous “antinested” topology. Our findings lead to the working hypothesis that terrestrial plant community dynamics are likely determined by the balance between above-ground and below-ground webs of interspecific interactions.

scholarly journals Keystone species and food webs

2009 ◽  
Vol 364 (1524) ◽  
pp. 1733-1741 ◽  
Author(s):  
Ferenc Jordán
Keyword(s):  
Current Knowledge ◽  
Interspecific Interactions ◽  
Keystone Species ◽  
Ecosystem Functions ◽  
General Interest ◽  
Interaction Structure ◽  
Structure And Dynamics ◽  
Rich Interaction ◽  
Natural Communities

Different species are of different importance in maintaining ecosystem functions in natural communities. Quantitative approaches are needed to identify unusually important or influential, ‘keystone’ species particularly for conservation purposes. Since the importance of some species may largely be the consequence of their rich interaction structure, one possible quantitative approach to identify the most influential species is to study their position in the network of interspecific interactions. In this paper, I discuss the role of network analysis (and centrality indices in particular) in this process and present a new and simple approach to characterizing the interaction structures of each species in a complex network. Understanding the linkage between structure and dynamics is a condition to test the results of topological studies, I briefly overview our current knowledge on this issue. The study of key nodes in networks has become an increasingly general interest in several disciplines: I will discuss some parallels. Finally, I will argue that conservation biology needs to devote more attention to identify and conserve keystone species and relatively less attention to rarity.

scholarly journals Habitat fragmentation causes coevolutionary burning spots

2017 ◽  
Author(s):  
H. De Kort ◽  
M. Baguette ◽  
J.G Prunier ◽  
M. Tessier ◽  
J. Monsimet ◽  
...  
Keyword(s):  
Habitat Fragmentation ◽  
Extinction Risk ◽  
Natural Community ◽  
Natural Conditions ◽  
Community Network ◽  
Community Functioning ◽  
Conservation Concern ◽  
Sustainable Conservation ◽  
Natural Settings ◽  
Natural Communities

AbstractHabitat fragmentation increasingly threatens the services provided by natural communities and ecosystem worldwide. An understanding of the underlying eco-evolutionary processes in natural settings is lacking, yet critical to realistic and sustainable conservation. Through integrating the multivariate genetic, biotic and abiotic facets of a natural community network experiencing various degrees of habitat fragmentation, we provide unique insights into the processes underlying community functioning in real, natural conditions. The focal community network comprises a parasitic butterfly of conservation concern, and its two obligatory host species, a plant and an ant. We show that fragmentation of butterfly habitat has the potential to impair the balance between dispersal and coevolution. This process can cause coevolutionary burning spots of decreased genetic diversity and therefore of increased extinction risk. We stress that ignoring such eco-evolutionary feed-backs inherent to the very functioning of natural communities can strongly impact their persistence.One Sentence Summary:Communities under threat of habitat fragmentation suffer increased extinction risk through coevolutionary overheating.

scholarly journals Minor environmental concentrations of antibiotics can modify bacterial virulence in co-infection with a non-targeted parasite

2018 ◽  
Vol 14 (12) ◽  
pp. 20180663 ◽  
Author(s):  
Lotta-Riina Sundberg ◽  
Anssi Karvonen
Keyword(s):  
Disease Ecology ◽  
Interspecific Interactions ◽  
Parasite Community ◽  
Fish Host ◽  
Bacterial Virulence ◽  
Flavobacterium Columnare ◽  
Bacterial Strains ◽  
Environmental Concentrations ◽  
Diplostomum Pseudospathaceum ◽  
Natural Communities

Leakage of medical residues into the environment can significantly impact natural communities. For example, antibiotic contamination from agriculture and aquaculture can directly influence targeted pathogens, but also other non-targeted taxa of commensals and parasites that regularly co-occur and co-infect the same host. Consequently, antibiotics could significantly alter interspecific interactions and epidemiology of the co-infecting parasite community. We studied how minor environmental concentrations of antibiotic affects the co-infection of two parasites, the bacterium Flavobacterium columnare and the fluke Diplostomum pseudospathaceum , in their fish host. We found that antibiotic in feed, and particularly the minute concentration in water, significantly decreased bacterial virulence and changed the infection success of the flukes. These effects depended on the level of antibiotic resistance of the bacterial strains. Antibiotic, however, did not compensate for the higher virulence of co-infections. Our results demonstrate that even very low environmental concentrations of antibiotic can influence ecology and epidemiology of diseases in co-infection with non-targeted parasites. Leakage of antibiotics into the environment may thus have more complex effects on disease ecology than previously anticipated.

scholarly journals Use of a Fluorescent Analog of Glucose (2-NBDG) To Identify Uncultured Rumen Bacteria That Take Up Glucose

2019 ◽  
Vol 85 (7) ◽  
Author(s):  
Junyi Tao ◽  
Courtney McCourt ◽  
Halima Sultana ◽  
Corwin Nelson ◽  
John Driver ◽  
...  
Keyword(s):  
Cell Sorting ◽  
Stable Isotope Probing ◽  
Fluorescent Label ◽  
Major Advance ◽  
New Paradigm ◽  
Fluorescent Substrate ◽  
Substrate Analogs ◽  
Uncultured Bacteria ◽  
Agar Media ◽  
Natural Communities

ABSTRACTFew characteristics are more important to a bacterium than the substrates it consumes. It is hard to identify what substrates are consumed by bacteria in natural communities, however, because most bacteria have not been cultured. In this study, we developed a method that uses fluorescent substrate analogs, cell sorting, and DNA sequencing to identify substrates taken up by bacteria. We deployed this method using 2[N-(7-nitrobenz-2-oxa-1,2-diaxol-4-yl)amino]-2-deoxyglucose (2-NBDG), a fluorescent glucose analog, and bacteria of the bovine rumen. This method revealed over 40 different bacteria (amplicon sequence variants [ASVs]) from the rumen that take up glucose. Nearly half of these ASVs represent previously uncultured bacteria. We attempted to grow these ASVs on agar media, and we confirmed that nearly two-thirds resisted culture. In coculture experiments, the fluorescent label of 2-NBDG was not transferred to nontarget bacteria by cross-feeding. Because it is not affected by cross-feeding, our method has an advantage over stable isotope probing. Though we focus on glucose, many substrates can be labeled with the fluorophore NBD. Our method represents a new paradigm for identifying substrates used by uncultured bacteria. It will help delineate the niche of bacteria in their environment.IMPORTANCEWe introduce a method for identifying what substrates are consumed by bacteria in natural communities. Our method offers significant improvement over existing methods for studying this characteristic. Our method uses a fluorescently labeled substrate which clearly labels target bacteria (glucose consumers in our case). Previous methods use isotope-labeled substrates, which are notorious for off-target labeling (due to cross-feeding of labeled metabolites). Our method can be deployed with a variety of substrates and microbial communities. It represents a major advance in connecting bacteria to the substrates they take up.

scholarly journals Enhanced Lignocellulolytic Enzyme Activities on Hardwood and Softwood during Interspecific Interactions of White- and Brown-Rot Fungi

2021 ◽  
Vol 7 (4) ◽  
pp. 265
Author(s):  
Junko Sugano ◽  
Ndegwa Maina ◽  
Janne Wallenius ◽  
Kristiina Hildén
Keyword(s):  
Enzyme Activities ◽  
Interspecific Interactions ◽  
Wood Decay ◽  
Brown Rot ◽  
Species Interaction ◽  
Fungal Species ◽  
White Rot ◽  
White Rot Fungus ◽  
Wood Decomposition ◽  
Brown Rot Fungi

Wood decomposition is a sophisticated process where various biocatalysts act simultaneously and synergistically on biopolymers to efficiently break down plant cell walls. In nature, this process depends on the activities of the wood-inhabiting fungal communities that co-exist and interact during wood decay. Wood-decaying fungal species have traditionally been classified as white-rot and brown-rot fungi, which differ in their decay mechanism and enzyme repertoire. To mimic the species interaction during wood decomposition, we have cultivated the white-rot fungus, Bjerkandera adusta, and two brown-rot fungi, Gloeophyllum sepiarium and Antrodia sinuosa, in single and co-cultivations on softwood and hardwood. We compared their extracellular hydrolytic carbohydrate-active and oxidative lignin-degrading enzyme activities and production profiles. The interaction of white-rot and brown-rot species showed enhanced (hemi)cellulase activities on birch and spruce-supplemented cultivations. Based on the enzyme activity profiles, the combination of B. adusta and G. sepiarium facilitated birch wood degradation, whereas B. adusta and A. sinuosa is a promising combination for efficient degradation of spruce wood, showing synergy in β-glucosidase (BGL) and α-galactosidase (AGL) activity. Synergistic BGL and AGL activity was also detected on birch during the interaction of brown-rot species. Our findings indicate that fungal interaction on different woody substrates have an impact on both simultaneous and sequential biocatalytic activities.

scholarly journals Mycological Profile in Otomycosis Patients: A Cross Sectional Hospital Based Study in Tertiary Care Centre

2019 ◽  
Vol 27 (3) ◽  
pp. 193-197
Author(s):  
Nitin Ankale ◽  
Jyoti M Nagmoti ◽  
Utkarsh Anand
Keyword(s):  
Fungal Pathogens ◽  
Tertiary Care ◽  
Fungal Species ◽  
Tropical Region ◽  
Common Symptom ◽  
Tertiary Care Centre ◽  
Humid Climate ◽  
Cross Sectional ◽  
Agar Media ◽  
Hot Humid Climate

Introduction This study was conducted to study the fungal profile in otomycosis patients in the tropical region of North Karnataka. A total of 108 samples of symptomatic otomycosis were investigated in this study. Materials and Methods Aural swabs were collected on 1st visit and these swabs were immediately inoculated over Sabouraud’s dextrose agar media and incubated at 37 degree Celsius for culture of fungi. Results Fungal pathogens were isolated in 89 samples, 18 samples were negative and 1 sample was reported as being contaminated. Fungi belonging to genus Aspergillus was isolated in 92.11% of cases of which Aspergillus niger was commonest isolated in 38(41.57%) followed br Aspergillus flavus 32(35.95%) and Aspergillus fumigatus 7(7.86%). Candida species were found in 2(2.24%) and Mucor in 1(1.12%). The most common symptom was Itching 91(84.25%). In this study ear discharge was the commonest finding (44.44%) followed by Black mycotic plug (28.70%). Conclusion Otomycosis is a condition encountered in hot, humid climate with symptoms like itching and ear discharge. Aspergillus and Candida are the fungal species responsible for majority of cases. Local antifungal treatment with measures like keeping the ear dry resolves most of the cases.

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