Biology subjects

Camenzind, T.

Publications and source records attributed to Camenzind, T..

6 recordsLinked to original sources

bioRxiv2026

The hidden multiverse of ecological roles in Fungi

Ecological roles are treated as discrete, bounded units of biological organization, even as evidence shows that many taxa are versatile, performing more than one of them. Each record of versatility represents a boundary crossing, yet current categorical paradigms prevent this cumulative evidence from reshaping the roles themselves. We solve this by introducing the ecological multiverse, a self-correcting framework that turns boundary crossings into a network of role connectivity. Applied to Fungi, the multiverse recasts the major form of plant pathogenicity from an isolated disease role into a central hub linking much of fungal functional space, especially benign plant symbioses and decomposition. By exposing this topology, the multiverse transforms categorical views of ecological function into a dynamic map, revealing pathways of role change as organisms and knowledge evolve.

ecology↗

bioRxiv2026

Carbon and nitrogen availability affect biofilm growth and morphology of the extremotolerant fungus Knufia petricola

Rock-inhabiting fungi thrive in subaerial oligotrophic environments such as desert rocks, solar panels and marble monuments where organic carbon and nitrogen are scarce. We tested whether the rock-inhabiting fungus Knufia petricola showed a preference regarding nitrogen ([Formula] or [Formula]) and carbon (glucose or sucrose) sources and whether it was sensitive towards carbon and nitrogen limitation. As this fungus produces the carbon-rich, nitrogen-free 1,8-dihydroxynaphthalene (DHN) melanin, we tested whether a melanin-deficient mutant would be less sensitive to carbon limitation. The carbon and nitrogen concentrations were the primary predictors of growth, with a broad optimum partially explained by an optimal fungal C:N ratio. Limiting carbon or nitrogen supply decreased biomass formation, CO2 production and biofilm thickness but promoted substratum penetration through filamentous growth. The nitrogen content of the biomass was flexible within limits, increasing upon increasing nitrogen supply or decreasing carbon supply. The carbon use efficiency was fairly constant, whereas melanization correlated with a higher nitrogen content of the biomass despite melanin being nitrogen-free. In conclusion, in vitro, K. petricola switches to explorative growth under nutrient limitations, like fast-growing fungi, revealing universal fungal resource-acquisition patterns. Graphical abstract text and imageCarbon and nitrogen availability affect biofilm growth and morphology of the extremotolerant fungus Knufia petricola Abolfazl Dehkohneh, Julia Schumacher, Bastiaan J. R. Cockx, Karin Keil, Tessa Camenzind, Jan-Ulrich Kreft, Anna A. Gorbushina, Ruben Gerrits Growth of the rock-inhabiting fungus Knufia petricola was studied by varying carbon and nitrogen sources and concentrations. Overall, growth was best predicted by the carbon and nitrogen concentrations. Carbon and nitrogen limitation promoted substratum penetration through filamentous growth. O_FIG O_LINKSMALLFIG WIDTH=158 HEIGHT=200 SRC="FIGDIR/small/712823v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@6d98bdorg.highwire.dtl.DTLVardef@146aac5org.highwire.dtl.DTLVardef@757fa8org.highwire.dtl.DTLVardef@ff709_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2025

What are all these soil fungi doing? Complex carbon use ability as a predictive trait for fungal community functions

Fungal communities in soil play important roles in decomposition processes and soil organic carbon cycling. These communities are tremendously diverse, making it challenging to assign relevant functions to individual species. Fungal communities may be differentiated at the level of functional guilds; beyond such broad classification we have little delimitation, especially in fungal taxa common in grassland and agricultural soils. To resolve the level of functional similarity in fungal communities and define traits predictive of soil carbon cycling, we characterized fungal isolates abundant in agricultural soils to test the hypotheses that (i) the majority of saprobic soil fungi have the ability to use complex carbon sources, (ii) differences in complex carbon use abilities correlate with fungal enzymatic profiles, following principles of the fungal economics spectrum and (iii) carbon use ability is a predictive trait for fungal community functions. Using specialized growth media, we isolated and characterized 105 isolates and developed a novel FungiResp approach that directly tests fungal activity on complex carbon sources. The largest amount of variance between isolates was explained by differential abilities to use cellulose and starch, with only few phylogenetically distinct fungal clades showing high respiratory activity on these biopolymers. A preference for bacterial necromass was another major distinction among taxa. These key traits correlated with soil fungal community shifts in response to carbon substrate availability. By contrast, enzymatic activity was a poor predictor of fungal carbon use ability, except for correlations in lignin use and laccase activity. The newly established functional trait of carbon use ability offers important insights into diverse fungal communities: Many taxa lack the ability to use complex carbon (on their own), while the most common enzymes analyzed in soil showed little correlation with fungal mineralization potential. The discovery of key functional traits is an important step towards predicting the significance of fungal community shifts for soil carbon cycling.

ecology↗

bioRxiv2024

Revisiting soil fungal biomarkers and conversion factors: Interspecific variability in phospholipid fatty acids, ergosterol and rDNA copy numbers

The abundances of fungi and bacteria in soil are used as simple predictors for carbon dynamics, and represent widely available microbial traits. Soil biomarkers serve as quantitative estimates of these microbial groups, though not quantifying microbial biomass per se. The accurate conversion to microbial carbon pools, and an understanding of its comparability among soils is therefore needed. We refined conversion factors for classical fungal biomarkers, and evaluated the application of quantitative PCR (qPCR, rDNA copies) as a biomarker for soil fungi. Based on biomarker contents in pure fungal cultures of 30 isolates, combined with available references, we propose average conversion factors of 95.3 g fungal C g-1 ergosterol, 32.0 mg fungal C {micro}mol-1 PLFA 18:2{omega}6,9 and 0.264 pg fungal C ITS1 DNA copy-1. As expected, interspecific variability was most pronounced in rDNA copies, though qPCR results showed the least phylogenetic bias. A modeling approach based on exemplary agricultural soils further supported the hypothesis that high diversity in soil buffers against biomarker variability, whereas also phylogenetic biases impact the accuracy of comparisons in biomarker estimates. Our analyses suggest that qPCR results cover the fungal community in soil best, though with a variability only partly offset in highly diverse soils. PLFA 18:2{omega}6,9 and ergosterol represent accurate biomarkers to quantify Ascomycota and Basidiomycota. To conclude, the ecological interpretation and coverage of biomarker data prior to their application in global models is important, where the combination of different biomarkers may be most insightful.

ecology↗

bioRxiv2022

Fungal traits help to understand the decomposition of simple and complex plant litter

Litter decomposition is a key ecosystem process, responsible for the release and storage of nutrients and carbon. Soil fungi are one of the dominant drivers of organic matter decomposition, but fungal taxa differ substantially in their functional ability to decompose plant litter. We used a trait-based approach to better understand functional differences among saprotrophic soil fungi (originating from a natural grassland ecosystem) in decomposing leaf and wood litter. Decomposition strongly varied among phyla and isolates, with Ascomycota decomposing the most and Mucoromycota decomposing the least. In this study, the phylogeny of the fungi in our dataset, but also the ability of fungi to use more complex carbon were important predictors for decomposition. While some enzymes (e.g. laccase and cellulase) influenced decomposition, the majority of enzyme activities was not correlated with decomposition. Thus, we suggest using more directly assessed traits as predictors for decomposition, such as the ability to use carbon substrates, rather than a single enzyme activity, which could misrepresent the degradation potential of certain isolates. The findings of our study offer important new insights for the trait-based prediction of fungal litter decomposition in grassland soils.

ecology↗

bioRxiv2021

Non-mycorrhizal root associated fungi of a tropical montane forest are relatively robust to the long-term addition of moderate rates of nitrogen and phosphorus

Andean forests are biodiversity hotspots and globally important carbon (C) repositories. This status might be at risk due to increasing rates of atmospheric nutrient deposition. As fungal communities are key in the recirculation of soil nutrients, assessing their responses to soil eutrophication can help establish a link between microbial biodiversity and the sustainability of the C sink status of this region. Beyond mycorrhizal fungi, which have been studied more frequently, a wide range of other fungi associate with the fine root fraction of trees. Monitoring these communities can offer insights into how communities composed of both facultative and obligate root associated fungi are responding to soil eutrophication. Here we document the response of non-mycorrhizal root associated fungal (RAF) communities to a long-term nutrient manipulation experiment. The stand level fine root fraction of an old growth tropical montane forest was sampled after seven years of nitrogen (N) and phosphorus (P) additions. RAF communities were characterized by a deep sequencing approach. As per the resource imbalance model, we expected that asymmetries in the availability of C, N and P elicited by fertilization will lead to mean richness reductions and alterations of the community structure. We recovered moderately diverse fungal assemblages composed by sequence variants classified within a wide set of trophic guilds. While mean richness remained stable, community composition shifted, particularly among Ascomycota and after the addition of P. Fertilization factors, however, only accounted for a minor proportion of the variance in community composition. These findings suggest that, unlike mycorrhizal fungi, RAF communities are less sensitive to shifts in soil nutrient availability. A plausible explanation is that non-mycorrhizal RAF have fundamentally different nutrient acquisition and life history traits, thus allowing them greater stoichiometric plasticity and an array of functional acclimation responses that collectively express as subtle shifts in community level attributes.

microbiology↗