2,795 research outputs found
The role of active movement in fungal ecology and community assembly
Movement ecology aims to provide common terminology and an integrative framework of movement research across all groups of organisms. Yet such work has focused on unitary organisms so far, and thus the important group of filamentous fungi has not been considered in this context. With the exception of spore dispersal, movement in filamentous fungi has not been integrated into the movement ecology field. At the same time, the field of fungal ecology has been advancing research on topics like informed growth, mycelial translocations, or fungal highways using its own terminology and frameworks, overlooking the theoretical developments within movement ecology. We provide a conceptual and terminological framework for interdisciplinary collaboration between these two disciplines, and show how both can benefit from closer links: We show how placing the knowledge from fungal biology and ecology into the framework of movement ecology can inspire both theoretical and empirical developments, eventually leading towards a better understanding of fungal ecology and community assembly. Conversely, by a greater focus on movement specificities of filamentous fungi, movement ecology stands to benefit from the challenge to evolve its concepts and terminology towards even greater universality. We show how our concept can be applied for other modular organisms (such as clonal plants and slime molds), and how this can lead towards comparative studies with the relationship between organismal movement and ecosystems in the focus
Basic principles of temporal dynamics
All ecological disciplines consider temporal dynamics, although relevant concepts have been developed almost independently. We here introduce basic principles of temporal dynamics in ecology. We figured out essential features that describe temporal dynamics by finding similarities among about 60 ecological concepts and theories. We found that considering the hierarchically nested structure of complexity in temporal patterns (i.e. hierarchical complexity) can well describe the fundamental nature of temporal dynamics by expressing which patterns are observed at each scale. Across all ecological levels, driver–response relationships can be temporally variant and dependent on both short- and long-term past conditions. The framework can help with designing experiments, improving predictive power of statistics, and enhancing communications among ecological disciplines
Effect of different root endophytic fungi on plant community structure in experimental microcosms
Understanding the effects of root-associated microbes in explaining plant
community patterns represents a challenge in community ecology. Although
typically overlooked, several lines of evidence point out that nonmycorrhizal,
root endophytic fungi in the Ascomycota may have the potential to drive
changes in plant community ecology given their ubiquitous presence, wide host
ranges, and plant species-specific fitness effects. Thus, we experimentally
manipulated the presence of root endophytic fungal species in microcosms and
measured its effects on plant communities. Specifically, we tested whether (1)
three different root endophyte species can modify plant community structure;
(2) those changes can also modified the way plant respond to different soil
types; and (3) the effects are modified when all the fungi are present. As a
model system, we used plant and fungal species that naturally co-occur in a
temperate grassland. Further, the soil types used in our experiment reflected
a strong gradient in soil texture that has been shown to drive changes in
plant and fungal community structure in the field. Results showed that each
plant species responded differently to infection, resulting in distinct
patterns of plant community structure depending on the identity of the fungus
present. Those effects depended on the soil type. For example, large positive
effects due to presence of the fungi were able to compensate for less
nutrients levels in one soil type. Further, host responses when all three
fungi were present were different from the ones observed in single fungal
inoculations, suggesting that endophyte–endophyte interactions may be
important in structuring plant communities. Overall, these results indicate
that plant responses to changes in the species identity of nonmycorrhizal
fungal community species and their interactions can modify plant community
structure
Catalytic wet peroxide oxidation of vanillic acid as a lignin model compound towards the renewable production of dicarboxylic acids
tLignin can be depolymerised and used as a feedstock to obtain renewable raw-materials,providing a green alternative to fossil counterparts. Among others, C4dicarboxylic acids(DCA), like succinic, malic, maleic and fumaric acids, which can find applications in phar-maceuticals, food industry, and act as solvents, can be obtained from lignin oxidation. Toinvestigate their formation, the oxidation of vanillic acid (VA), a lignin model compound, wasstudied under catalytic wet peroxide oxidation (CWPO) conditions, using titanium silicalite-1 (TS-1) as the catalyst. The effect of temperature, pH, and reaction time were studied. Ina second phase, catalyst modification with transition metal oxides (Fe, Co, Cu) was tested.Results showed that oxidation under pH = 10.5 gives rise to complete VA conversion withhydroxylated DCA, namely malic (15 mol%) and tartaric (5 mol%) acids, as the main products.At pH = 4.0, the production of succinic acid was improved (7.4 mol%), with VA conversionachieving 78% after 2.0 h of reaction. At alkaline pH, H2O2reactivity is higher, leading to C4-DCA degradation to low-molecular weight compounds. Catalyst desilication was observed,pointed out for the convenience of using neutral and acidic pH. In acidic pH, Fe and Cu cat-alysts enhanced VA conversion, and Fe catalyst was more selective towards succinic acidproduction.The authors gratefully acknowledge support from Fundac¸ãopara a Ciência e a Tecnologia (FCT), Portugal, Grant num-bers: UID/EQU/50020/2019, UID/AGR/00690/2019; European Cooperation in Science and Technology, Grant numbers: Lig-noCOST (CA17128) and Costa Rican Science, Technology andTelecommunications Ministry, Costa Rica. Scholarship num-ber: MICITT-PINN-CON-2-1-4-17-1-002.info:eu-repo/semantics/publishedVersio
Lignin conversion into C4 dicarboxylic acids by catalytic wet peroxide oxidation using titanium silicalite-1
Lignin valorisation towards added-value products has become a relevant topic to consolidate a future circular
bioeconomy. In this context lignin oxidation to C4 dicarboxylic acids (C4-DCA) by catalytic wet peroxide
oxidation is emerging as a value-added strategy, supported by the extensive use of these building blocks in
several industrial fields. In this work, lignins from different sources and processes (Indulin AT, Lignol, alkali and
E. globulus kraft lignins) were oxidised using H2O2 and titanium silicalite-1 catalyst (TS-1) under different
operating conditions (temperature, pH, time, H2O2, and TS-1 load). Indulin AT was the lignin leading to the
highest succinic acid yield (11.3 wt%), and TS-1 catalyst enhanced its production four times over the noncatalysed
reaction. Malic acid was also produced at high yields, especially for Lignol lignin. The other lignins
(E. globulus kraft, and alkali lignins) also produced these C4 acids but at lower yields. The catalyst remained stable
at the used experimental conditions, and showed potential to be reused for several cycles without being deactivated.
Overall, the catalytic conversion of lignin to C4-DCA can help to guide the pathway to renewable
chemicals production.This work was financially supported by: Base Funding - UIDB/50020/2020 of the Associate Laboratory LSRE-LCM - funded by national funds through FCT/MCTES (PIDDAC); Base Funding - UIDB/00690/2020 of CIMO - Centro de Investigação de Montanha—funded by national
funds through FCT/MCTES (PIDDAC). COST Action LignoCOST
(CA17128). Carlos Vega-Aguilar thanks the Costa Rica Science, Technology
and Telecommunications Ministry for the PhD. Scholarship
MICITT-PINN-CON-2-1-4-17-1-002. The authors thank Dr. Maria José
Sampaio and Prof. Dr. Joaquim Faria (LA LSRE-LCM) for the help with
the ATR measurements.info:eu-repo/semantics/publishedVersio
Effect of methoxy substituents on wet peroxide oxidation of lignin and lignin model compounds: understanding the pathway to c4 dicarboxylic acids
Lignin depolymerization through peroxide oxidation produces dicarboxylic acids (DCA), especially C4-DCA, like succinic acid. In this work, the effect of methoxy substituents on C4-DCA production using peroxide oxidation of lignin model compounds (p-hydroxybenzoic acid, vanillic acid, and syringic acid) and hardwood and softwood lignin samples was studied. It was concluded that methoxy substituents increased the reactivity toward peroxide oxidation. The succinic acid yield was higher for the model compounds with fewer methoxy groups, achieving 5.8 wt % of succinic acid for p-hydroxybenzoic acid. For Eucalyptus globulus kraft lignin (hardwood lignin with guaiacyl and syringyl units), an increased reactivity was verified, and more succinic acid (3.5 wt %) was produced in a shorter time, comparatively with Indulin AT lignin (softwood lignin, with only guaiacyl units), which produced 2.7 wt %. This evidence suggests that E. globulus kraft lignin might be a better raw material than Indulin AT for succinic acid production by peroxide oxidation.This work was financially supported by Base Funding −
UIDB/50020/2020 of the Associate Laboratory LSRE-LCM −
funded by national funds through FCT/MCTES (PIDDAC);
Base Funding−UIDB/00690/2020 of CIMO, Centro de
Investigação de Montanha−funded by national funds through
FCT/MCTES (PIDDAC); COST Action LignoCOST
(CA17128). C.A.V.-A. thanks the Costa Rican Science,
Technology and Telecommunications Ministry for the Ph.D.
Scholarship MICITT-PINN-CON-2-1-4-17-1-002.info:eu-repo/semantics/publishedVersio
Fibroblast Growth Factor 21 and Browning of White Adipose Tissue
Interest has been focused on differentiating anatomical, molecular, and physiological characteristics of the types of mammalian adipose tissues. White adipose tissue (WAT) and brown adipose tissue (BAT) are the two main forms of adipose tissue in humans. WAT functions as an endocrine organ and serves as a reservoir of energy in the form of triglycerides. The hormones released by WAT are called adipokines. BAT consists of a group of specialized cells with abundant uncoupling protein 1 (UCP1) in the inner mitochondrial membrane and also fulfills endocrine functions. Following the identification of functional (BAT) in human adults, there has been a great deal of interest in finding out how it is induced, its localization, and the mechanisms by which it regulates thermogenesis. Fibroblast growth factor 21 (FGF21) is a key regulator of the differentiation to brown adipocytes. The main mechanisms occur through enhancing UCP1 expression. In addition, following exposure to cold or exercise, FGF21 induces upregulation of local peroxisome proliferator-activated receptor gamma co-activator (PGC)-1-alfa and thus promotes thermogenesis in adipose tissue and skeletal muscle. FGF21 integrates several pathways allowing the regulation of human energy balance, glucose levels, and lipid metabolism. Such mechanisms and their clinical relevance are summarized in this review
In vitro activity of bedaquiline against rapidly growing nontuberculous mycobacteria
Bedaquiline (BDQ) has been proven to be effective in the treatment of multidrug-resistant tuberculosis. We hypothesized that BDQ could be a potential agent to treat nontuberculous mycobacterial (NTM) infection. The objective of this study was to evaluate the in vitro activity of BDQ against rapidly growing mycobacteria by assessing the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against 18 NTM strains. For MIC determination we performed the resazurin microtitre assay broth dilution, and for the MBC the c.f.u. was determined. BDQ exhibited a strong inhibitory effect against most NTM tested; however, for some NTM strains the MBC was significantly higher than the MIC. A new finding is that Mycobacterium flavescens has a mutation in the gene atpE associated with natural resistance to BDQ. These preliminary promising results demonstrate that BDQ could be potentially useful for the treatment of NTM
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