A new fatty acid from Usnea meridensis

The structure of a new fatty acid from Usnea meridensis was established by chemical and spectroscopic methods as methyl 3,4-dicarboxy-3- hydroxy-19oxoeicosanoate.     

The Study of Microbial Communities of Rudkhan Castle

Abstract

Rudkhan Castle, one of the most valuable monuments in Iran, belongs to the Sasanian Empire, and nearly all of the parts are made of bricks. The castle had been exposed to physicochemical and biological factors over the years. Locating in a humid environment and possessing porous surface has made it appropriate substrata for microorganisms’ colonization. This study is an attempt to identify the major microorganisms involved in biodeterioration of Rudkhan Castle. The samples were taken from brick surfaces and were sub-cultured onto culture media. Scanning electron microscope (SEM), stereomicroscope and Periodic Acid Schiff (PAS) staining were also employed to illustrate the growth and pattern of penetration into the substratum. Energy dispersion X-ray analysis (EDX) and X-ray diffraction (XRD) were used to show alteration of elements of deteriorated brick samples, which are caused by microorganisms’ activities. First, Samples were identified by morphological characteristics. Next, some of the isolates were identified according to molecular methods, polymerase chain reaction (PCR). The first step to protect the cultural heritage is identification of deteriorating agents.     

The lichen algaTrebouxia: does it occur free-living?

Recent evidence indicates that the most common photobiont of lichens,Trebouxia, has evolved from the soil algaPleurastrum terrestre. The fewTrebouxia cells that have been seen in unlichenized condition probably were released from asexual propagules or thallus fragments.Trebouxia appears to be a lichenized form ofPleurastrum and does not exist free-living.Dedicated to Prof.Elisabeth Tschermak-Woess on the occasion of her 70. birthday.     

In Vitro Anthelminthic Activity and Ultrastructural Analysis of Barbatic Acid against Schistosomulae and Juvenile Worms of Schistosoma mansoni**

Schistosomiasis affects about 260 million people worldwide and the search for new schistosomicidal compounds is urgent. In this study we evaluated the in vitro effect of barbatic acid against schistosomulae and young worms of Schistosoma mansoni. The barbatic acid was evaluated through the bioassay of motility and mortality, cellular viability and ultrastructural analysis of juvenile stages through Scanning Electron Microscopy. Barbatic acid showed a schistosomicidal effect against schistosomulae and young worms of S. mansoni after 3 h of exposure. At the end of 24 h, barbatic acid showed 100 %, 89.5 %, 52 % and 28.5 % of lethality for schistosomulae at the concentrations of 200, 100, 50 and 25 μM, respectively. For young worms, barbatic acid showed 100 % and 31.7 % of lethality at the concentrations of 200 and 100 μM, respectively. Motility changes were observed at all sublethal concentrations. There was a significant reduction in the viability of young worms after exposure to barbatic acid at 50, 100 and 200 μM. Extensive damage to the schistosomulae and young worm's tegument, was observed from 50 μM. This report provides data showing the schistosomicidal effect of barbatic acid on schistosomulae and young worms of S. mansoni, causing death, motility changes and ultrastructural damage to worms.     

The Sodium Hypochlorite Solution for the Removal of Lichen from Vertebrate Track Surfaces

The removal of extraneous biological materials from vertebrate ichnological specimens may be necessary if they have been exposed to subaerial processes in the field for long periods of time. It is not uncommon for fossil track specimens to be found nearly completely covered with lichen colonies, especially those recovered from alpine areas. This paper describes a technique using a sodium hypochlorite solution (bleach) to remove lichen from a track surface containing numerous avian prints and small theropod prints with skin impressions.     

Intensive local surveys can complement rapid survey techniques to provide insights into the population size and ecology of lichenised fungi

We propose that insights to population ecology of lichenised fungi can be efficiently obtained by combining rapid biodiversity surveys, which representatively sample large areas, with intensive studies in selected populations discovered. To illustrate this approach, we compared results from an Estonian rapid survey scheme with an intensive local population survey of the poorly known epiphytic crustose lichen, Lecanora thysanophora. In contrast to what the data from rapid surveys suggested, the intensive survey revealed that this typically sterile species can occur in remarkably dense populations obviously limited by host tree availability; we also recorded emerging sexual reproduction in the population centre. Our results imply that the detection of even poorly identifiable species may mostly depend on total field effort.