Oribatid communities and heavy metal bioaccumulation in selected species associated with lichens in a heavily contaminated habitat

The study examines oribatid communities and heavy metal bioaccumulation in selected species associated with different microhabitats of a post-smelting dump, i.e. three lichen species of Cladonia with various growth forms and the slag substrate. The abundance of oribatids collected from the substrate was significantly lower than observed in lichen thalli. The morphology and chemical properties of lichens, and to some extent varying concentrations of heavy metals in thalli, are probably responsible for significant differences in oribatid communities inhabiting different Cladonia species. Some oribatids demonstrate the ability to accumulate zinc and cadmium with unusual efficiency, whereas lead is the most effectively regulated element by all species. A positive correlation was found between Zn content in all studied oribatids and their microhabitats. Oribatids exploring different food resources, i.e. fungivorous and non-fungivorous grazers, show considerable differences in bioconcentrations of certain elements

New Syntheses of Thiazole and Thiophene Derivatives

A novel synthesis of methylenebis(A2-l,3-thiaizoline-4-one) via reaction of chloroacetic acid wiith (A2-l,3-thiazoline-4-one- -2-yl)thioacetamide and a new route for synthesis of 2-aryl-4- -oxothiolane-3,3-dicarbonitrile via the reaction of thioglycolic acid with 3-aryl-2-cyanothioacrylamides are reported. The reaction of aromatic aldehydes and arenediazonium Chloride with active methylene compounds is discussed. The structures of all new compounds are established and the mechanism proposed for some reactions

New Syntheses of Thiazole and Thiophene Derivatives

A novel synthesis of methylenebis(A2-l,3-thiaizoline-4-one) via reaction of chloroacetic acid wiith (A2-l,3-thiazoline-4-one- -2-yl)thioacetamide and a new route for synthesis of 2-aryl-4- -oxothiolane-3,3-dicarbonitrile via the reaction of thioglycolic acid with 3-aryl-2-cyanothioacrylamides are reported. The reaction of aromatic aldehydes and arenediazonium Chloride with active methylene compounds is discussed. The structures of all new compounds are established and the mechanism proposed for some reactions

The effect of natural antioxidant(s) on date palm (Phoenix dactylifera L.) in vitro

Date palm (Phoenix dactylifera L.) is one of the most valuable economic resources in the Middle East and North Africa that grow on monocotyledonous trees. To increase crop yield of palm trees, in vitro micro-propagation has become an attractive alternative for large-scale production of date palm. A problem that frequently damages tissues in the early micro-propagation is the brown color that advances in the callus culture due to the creation of quinones. Quinones seize plant cellular developments which lead to cellular decay. This study advocates the use of antioxidant factors found in spinach, kale and strawberries within various concentrations (50, 150 and 300 mg/L) with respect to the medium culture, in an attempt to reduce the level of total phenol and browning which occurs, and also to improve growth and development in different in vitro stages of date palm (P. dactylifera L.). The results indicate that better growth value of callus was achieved using 150 mg/L of kale concentration; allowing the total phenol level to be reduced to 0.9237 mg/g D.W, presenting a significant growth value in comparison to the other treatments in the embryonic callus stage. In the date palm’s somatic embryogenesis stage, the results show that the use of 50 mg/L of spinach, 50 mg/L of kale, 150 mg/L of strawberries, achieved a high number of somatic embryos and the total phenol level was reduced to 0.6167 mg/g D.W. Results from date palm shoot proliferation shows that high numbers of shoot (16.3) was achieved using 50 to 300 mg/L of kale; however, total phenol level was reduced to 0.04567 at 150 mg/L of spinach concentration. The fluctuation of reducing total phenol level in date palm was recorded when the explants were grown on medium supplemented with 50 mg/L of kale concentration.Keywords: Date palm, tissue culture, natural antioxidants, browning, quionones.African Journal of Biotechnology, Vol 13(31) 3366-337