Isolation and identification of alkaline protease producer halotolerantBacillus licheniformis strain BA17

An alkaline protease producerBacillus licheniformis strain was isolated from Van Lake in Turkey. The strain is Gram positive, aerobic, motile, sporulating rod-shaped bacterium. Spores were ellipsoidal and positioned central in nonswollen sporangium. The cells were able to grow well at a pH range of 5.7–10. The optimal growth temperature was found to be 37 °C. Growth at a wide range of NaCl concentration (from 0 to 20%) showed that BA17 is halotolerant. Main fatty acid composition of BA17 was anteiso-C15:0 and iso-C15∶0. The strain was presumptively identified asB. licheniformis according to 16S rDNA gene sequence analysis. The most appropriate medium for the growth and protease production is composed of 0.5% yeast extract, 0.5% NaNO₃, 0.02% MgSO₄\7H₂O, 0.1% K₂HPO₄ and 0.5% maltose. The optimum temperature and pH of the alkaline protease of strain BA17 were found to be 60 °C and pH 11, respectively. The activity was completely lost in the presence of PMSF, suggesting that the preparation contains serine-alkaline protease(s).     

The endangered forests of Bangladesh: why the process of implementation of the Convention on Biological Diversity is not working

Bangladesh has been a signatory to the Convention on Biological Diversity (CBD) although implementation of the convention has been poor. We independently assessed the extent to which the program of work (POW) of the CBD has been implemented in Bangladesh by carrying out workshops involving local communities, conservation organizations, universities, and government departments involved in forest conservation. Our analyses indicate that there is little or no understanding of the ecosystem approach that is central to the CBD; forestry practices remain primitive and largely ineffective; forest destruction continues at high rates; restoration of degraded forests are minimal; protected areas are small and ineffective; indigenous peoples’ rights are nominal and are outside any legislation; threats to species have been identified, but little is being done to reduce threats; there is no work on pollution and its mitigation; some work has been done to adapt to climate change; the institutional environment does not enable effective implementation of the ecosystem approach; laws and policies are ineffective; institutional capacity is poor; government will is limited or totally lacking; and knowledge base remains poor, although reporting has improved and various strategic plans have been formulated but never implemented. Thus, the implementation of CBD in Bangladesh requires systemic changes in policy at the institutional levels as well as complementary changes in attitudes and avenues of alternate income generation.     

Prevalence and distribution of airborne and waterborne fungi and actinomycetes in the Nile river

The objective of this research was to investigate the prevalence and distribution of airborne and waterborne fungi and actinomycetes along the main stream of the Nile river during April to July, 2005. Air and water samples were collected at eight sites within a ~50 km stretch of the river. The distribution and prevalence of air and water microorganisms varied with location. The highest counts of airborne fungi (516 CFU/p/h) and actinomycetes (222 CFU/p/h) were detected at suburban sites near cultivated areas. However, the highest counts of waterborne fungi (56.4 CFU/ml) and actinomycetes (15.4 CFU/ml) were detected at Al-Galaa (city centre) and Kafr-El-elwe (south Cairo), respectively. A total of 1,816 fungal colonies (943 isolates from air and 873 from water samples) belonging to 27 genera were identified. Aspergillus, Alternaria, Cladosporium, and yeasts were the predominant fungal types in both air and water environments. Dreschlera, Emericella, Nigrospora, Spicaria, Stachybotrys, and Verticillium were only detected in the air, and Epicoccum, Philaphora, Phoma and Ulocladium were only detected in the water. Mycotoxin-producing fungi represented by Aspergillus flavus, Aspergillus parasiticus, Penicillium, Fusarium, and Trichoderma were found in the air and water environments. Significant differences (P ≤ 0.05) were found between fungal populations in air and water at different sampling sites. No significant differences (P ≥ 0.05) were found between waterborne actinomycetes. Sampling location, human activity, and pollution load are the main factors affecting the variability and biodiversity of microorganisms in different microenvironments.     

Phytoavailability of Cadmium (Cd) to Pak Choi (Brassica chinensis L.) Grown in Chinese Soils: A Model to Evaluate the Impact of Soil Cd Pollution on Potential Dietary Toxicity

Food chain contamination by soil cadmium (Cd) through vegetable consumption poses a threat to human health. Therefore, an understanding is needed on the relationship between the phytoavailability of Cd in soils and its uptake in edible tissues of vegetables. The purpose of this study was to establish soil Cd thresholds of representative Chinese soils based on dietary toxicity to humans and develop a model to evaluate the phytoavailability of Cd to Pak choi (Brassica chinensis L.) based on soil properties. Mehlich-3 extractable Cd thresholds were more suitable for Stagnic Anthrosols, Calcareous, Ustic Cambosols, Typic Haplustalfs, Udic Ferrisols and Periudic Argosols with values of 0.30, 0.25, 0.18, 0.16, 0.15 and 0.03 mg kg⁻¹, respectively, while total Cd is adequate threshold for Mollisols with a value of 0.86 mg kg⁻¹. A stepwise regression model indicated that Cd phytoavailability to Pak choi was significantly influenced by soil pH, organic matter, total Zinc and Cd concentrations in soil. Therefore, since Cd accumulation in Pak choi varied with soil characteristics, they should be considered while assessing the environmental quality of soils to ensure the hygienically safe food production.