Search results for "ichen"

Lichen microalgae are sensitive to environmental concentrations of atrazine

2017

The identification of new organisms for environmental toxicology bioassays is currently a priority, since these tools are strongly limited by the ecological relevance of taxa used to study global change. Lichens are sensitive bioindicators of air quality and their microalgae are an untapped source for new low-cost miniaturized bioassays with ecological importance. In order to increase the availability of a wider range of taxa for bioassays, the sensitivity of two symbiotic lichen microalgae, Asterochloris erici and Trebouxia sp. TR9, to atrazine was evaluated. To achieve this goal, axenic cultures of these phycobionts in suspension were exposed to a range of environmental concentrations of …

Lichen rehydration in heavy metal polluted environments: Pb modulates the oxidative response of both Ramalina farinacea thalli and its isolated micro…

2014

Lichens are adapted to desiccation/rehydration and accumulate heavy metals, which induce ROS especially from the photobiont photosynthetic pigments. Although their mechanisms of abiotic stress tolerance are still to be unravelled, they seem related to symbionts' reciprocal upregulation of antioxidant systems. With the aim to study the effect of Pb on oxidative status during rehydration, the kinetics of intracellular ROS, lipid peroxidation and chlorophyll autofluorescence of whole Ramalina farinacea thalli and its isolated microalgae (Trebouxia TR1 and T. TR9) was recorded. A genetic characterization of the microalgae present in the thalli used was also carried out in order to assess possib…

Determination of usnic and perlatolic acids and identification of olivetoric acids in Northern reindeer lichen (Cladonia stellaris) extracts

2010

AbstractThe ecologically important lichen Cladonia stellaris forms thick carpets in boreal forest floors. In addition to affecting temperature and water conditions in the soil underneath, the secondary metabolites formed by the lichen layer are of ecological interest. In this paper, we investigated the distribution of lichen acids in C. stellaris collected at different latitudes in Finland and developed methods to quantify the two optical enantiomers of usnic acid separately. The lichen extracts were analysed by high-performance liquid chromatography (HPLC) with UV and mass spectrometric (MS) detection and by gas chromatography with flame ionization (GC-FID) and MS detection. Usnic acid and…

Pierwsze stwierdzenie Lichenophanes varius (ILLIGER, 1801) (Coleoptera: Bostrichidae) na Pojezierzu Pomorskim

2013

Prevalence of vulval lichen planus in a cohort of women with oral lichen planus: an interdisciplinary study

2006

Summary Background  Lichen planus (LP) is a mucocutaneous inflammatory dermatosis that frequently involves the oral and genital mucosae. Patients with LP affecting these sites are often seen by oral medicine specialists or gynaecologists who work in isolation and depend heavily on histopathologists to help them in confirming the diagnosis. There are few studies in the literature combining the experiences of these specialists who share the care of patients with both oral and genital LP. Objectives  To estimate the prevalence of vulval LP (VLP) in a cohort of patients with histologically confirmed oral LP (OLP). Methods  The study group consisted of 42 women histologically diagnosed with OLP.…

Ecological Efficiency of Voluntary Conservation of Boreal-Forest Biodiversity

2008

Current networks of protected areas are biased in many countries toward landscapes of low productivity. Voluntary conservation incentives have been suggested as a socially acceptable way to supplement existing networks with more productive, privately owned areas of high priority for nature conservation. The limited resources committed to nature conservation demand cost-efficiency. Efficiency, however, depends not only on costs incurred to society from alternative ways of maintaining biodiversity but also on ecological values that can be captured. We examined the ecological efficiency of the new market-based voluntary program to preserve forest habitats on private land in southwestern Finlan…

Coping with uncertainty in the assessment of atmospheric pollution with lichen transplants

2019

In the assessment of atmospheric deposition using lichen transplants, coping with uncertainty is mandatory in cases of environmental forensics, when understanding whether an area is polluted or not, or tracing a given pollution source is of paramount importance. In this article, we have suggested a method based on the calculation of exposed-to-control ratios of element concentrations and on the quantification of the overall uncertainty associated with such calculation, which proved to be very robust and can be applied in most cases using a minimum of three replicates. The method allowed the selection of significantly accumulated elements i.e. those polluting the site under study, as well as…

Biological Strategies of Lichen Symbionts to the Toxicity of Lead (Pb)

2019

Lichens are symbiotic organisms, originated by mutualistic associations of heterotrophic fungi (mycobiont), photosynthetic partners (photobionts) which can be either cyanobacteria (cyanobionts) or green microalgae (phycobionts), and bacterial consortia. They are poikilohydric organisms without cuticles or nutrient absorption organs adapted to anhydrobiosis. They present a large range of tolerance to abiotic stress (UV radiation, extreme temperatures, high salinity, mineral excess, etc.) and prosper all around the Earth, especially in harsh habitats, including Antarctica and warm deserts. Their biodiversity is widely used as a bioindicator of environmental quality due to this diversity of to…

Mucilaginibacter frigoritolerans sp. nov., Mucilaginibacter lappiensis sp. nov. and Mucilaginibacter mallensis sp. nov., isolated from soil and liche…

2010

Five cold-adapted bacteria belonging to the genus Mucilaginibacter were isolated from lichen and soil samples collected from Finnish Lapland and investigated in detail by phenotypic and phylogenetic analyses. Based on 16S rRNA gene phylogeny, the novel strains represent three new branches within the genus Mucilaginibacter. The strains were aerobic, chemo-organotrophic, non-motile rods and formed pigmented, smooth, mucoid colonies on solid media. The strains grew between 0 and 33 °C (optimum growth at 25 °C) and at pH 4.5–8.0 (optimum growth at pH 6.0). The main cellular fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1 ω7c/iso-C15 : 0 2-OH) and iso-C17 : 0 3-OH and the major respirato…

Growth form matters – Crustose lichens on dead wood are sensitive to forest management

2022

Lichens have a vital role in forest ecosystems and they are a threatened group in boreal forests. However, the conservation ecology of the total lichen community has very rarely been studied. Here we studied lichen species and communities, including macrolichens (=foliose and fruticose growth forms) and rarely studied crustose li-chens, on decaying wood in boreal spruce-dominated forests in Finland. We also studied obligate lignicoles that grow only on dead wood and are mostly crustose in growth form. Species richness and community composition were examined on decaying logs and natural or cut stumps of Picea abies at different decay stages (2-5) in 14 stands, half of which were natural or s…