The Pedogenic Action of Parmelia Conspersa, Rhizocarpon Geographicum and Umbjlicaria Pustulata

1976 ◽  
Vol 8 (2) ◽  
pp. 151-171 ◽  
Author(s):  
C. Ascaso ◽  
J. Galvan ◽  
C. Ortega
Keyword(s):  
Rhizocarpon Geographicum ◽  
Parmelia Conspersa

The Weathering of Mafic Rocks by Lichens

1993 ◽  
Vol 25 (3) ◽  
pp. 285-297 ◽  
Author(s):  
P. Adamo ◽  
A. Marchetiello ◽  
P. Violante
Keyword(s):  
Oxalic Acid ◽  
Chemical Substance ◽  
Mineral Surfaces ◽  
Secondary Products ◽  
Mafic Rocks ◽  
Crustose Lichens ◽  
Parmelia Conspersa

AbstractThe weathering phenomena resulting from the growth of six foliose and crustose lichens (Parmelia subrudecta, Xanthoria ectaneoides, Parmelia conspersa, Aspicilia radiosa, Caloplaca sp. and Ochrolechia parella) on three mafic rocks have been studied. The bioweathering results in more or less extensive fragmentation and corrosion of the mineral surfaces immediately beneath the lichen thalli and in the formation, in the thallus or at the rock-lichen interface, of secondary products. The significant amounts of whewellite found in all interfaces, and the bipiramids of weddellite detected at the serpentine rock-Ochrolechia parella interface, suggest that the oxalic acid secreted by the mycobiont is the chemical substance principally involved. The capacity of the lichens to alter their rock substrata does not appear to be related to their thallus morphology.

scholarly journals tert-Butylphenolic Derivatives from Paenibacillus odorifer—A Case of Bioconversion

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1951 ◽  
Author(s):  
Thi-Bach-Le Nguyen ◽  
Olivier Delalande ◽  
Isabelle Rouaud ◽  
Solenn Ferron ◽  
Laura Chaillot ◽  
...  
Keyword(s):  
Bacterial Strain ◽  
2D Nmr ◽  
One Dimensional ◽  
Spectroscopic Analyses ◽  
Human Keratinocyte ◽  
Rhizocarpon Geographicum ◽  
Ionisation Mass Spectrometry ◽  
Keratinocyte Cell ◽  
Ic50 Values ◽  
First Time

Two compounds (1) and (2) containing tert-butylphenol groups were, for the first time, produced during the culture of Paenibacillus odorifer, a bacterial strain associated with the crustose lichen, Rhizocarpon geographicum. Their entire structures were identified by one-dimensional (1D) and two-dimensional (2D) NMR and high-resolution electrospray ionisation mass spectrometry (HRESIMS) spectroscopic analyses. Among them, Compound 1 exhibited significant cytotoxicity against B16 murine melanoma and HaCaT human keratinocyte cell lines with micromolar half maximal inhibitory concentration (IC50) values. Furthermore, after supplementation studies, a putative biosynthesis pathway was proposed for Compound 1 throughout a bioconversion by this bacterial strain of butylated hydroxyanisole (BHA), an antioxidant polymer additive.

Colonization by Lichens and the Development of Lichen-Dominated Communities in the Maritime Antarctic

1995 ◽  
Vol 27 (6) ◽  
pp. 473-483 ◽  
Author(s):  
R.I. Lewis Smith
Keyword(s):  
Growth Rates ◽  
High Growth ◽  
Percentage Increase ◽  
Maritime Antarctic ◽  
Small Individual ◽  
Nitrogenous Compounds ◽  
Orkney Islands ◽  
Signy Island ◽  
Rhizocarpon Geographicum

AbstractThree long-term studies of lichen growth and colonization have been undertaken at Signy Island, South Orkney Islands, in the maritime Antarctic. Small individual thalli of several crustose species and uncolonized plots on 12 fresh rock surfaces were photographically monitored at intervals of 3–4 years over a period of up to 20 years. The development of Ochrolechia frigida colonies on a regenerating moss bank, recently uncovered by a receding glacier, was similarly monitored. The results indicate that many lichens growing in sites enriched by nitrogenous compounds derived from populations of sea birds, have relatively rapid colonization and growth rates. Mean percentage increase in thallus area can be as high as 15–32% per annum in some nitrophilous saxicolous species (e.g. Acarospora macrocyclos, Xanthoria elegans and species of Buellia and Caloplaca), but as low as, 0·4–4% in nitrophobous species (Lecanora physciella, Lecidea sp., Rhizocarpon geographicum). Umbilicaria antarctica and Usnea Antarctica also yielded data indicating high growth rates, with colonist plants reaching several centimetres after 20 years. Colonization by mixed assemblages of lichens of new rock surfaces can attain 40->90% cover after 20 years in nutrient-enriched sites, and even 20–25% in non-biotically influenced sites. Colonization by or increase in extant O. frigida on the regenerating moribund moss bank was also quite rapid. It is suggested that the exceptionally large thalli of several lichen species and the locally extensive dense lichen fellfield communities in the maritime Antarctic may be much younger than previously supposed.

Accurate lifespan estimates cannot be obtained from 14C profiles in the crustose lichen Rhizocarpon geographicum (L.) DC.

2001 ◽  
Vol 33 (6) ◽  
pp. 539-542 ◽  
Author(s):  
G. Bench ◽  
B.M. Clark ◽  
N.F. Mangelson ◽  
L. L. St. Clair ◽  
L. B. Rees ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Carbon Cycling ◽  
Accelerator Mass Spectrometry ◽  
Isotope Ratio ◽  
Growth Patterns ◽  
Molecular Replacement ◽  
Crustose Lichen ◽  
Rhizocarpon Geographicum ◽  
The Relationship ◽  
Isotope Ratio Measurements

AbstractRadial 14C/C profiles across three individuals of the crustose lichen Rhizocarpon geographicum (L.) DC. have been determined using accelerator mass spectrometry. These data were used to assess whether lifespan estimates can be determined in this species using 14C/C isotope ratio measurements. 14C/C profiles are relatively flat with Δ14C values (deviations from the modern radiocarbon standard) for the radial samples displaying a small spread ranging from 130 to 200 per mil. The data are consistent with carbon cycling based on growth patterns involving replacement and fusion of areoles within the thallus as well as or instead of cellular or molecular replacement. Consequently, lifespan estimates cannot be obtained from 14C/C measurements of this species and the Δ14C profiles provide no insights into whether the relationship between size and age is linear or curvilinear in this species.

Les Apothecies et les Asques du Parmelia conspersa (Discolichen Parmeliacee)

1970 ◽  
Vol 73 (1) ◽  
pp. 39 ◽  
Author(s):  
Marie-Agnes Letrouit-Galinou
Keyword(s):  
Parmelia Conspersa
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