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The functional role of microcystins (MC) is poorly understood. Here, we investigated the effect of pure MC-LR recovered from the freshwater planktonic cyanobacterium Nostoc sp. BHU001 on five closely related cyanobacteria (Nostoc muscorum, Nostoc commune, Anabaena fertilissima, Anabaena doliolum, and Cylinderospermum majus) isolated from different habitats as well as on the producer itself (Nostoc sp. BHU001). MC-LR was found to be a general growth inhibitor active at nanomolar range (25-100 μg L −1 ). It inhibited the growth of all cyanobacterial strains in a concentration-dependent manner, except the producer. A. fertilissima was the most sensitive species. MC-LR affected vital metabolic processes such as photosynthesis, respiration, and nitrogen fixation. Nitrogenase activity showed maximum sensitivity, followed by respiration, photosynthesis, and general growth. The photosynthetic electron transport activity was maximally inhibited at PSI, followed by whole chain and PSII activities. Thus, MC-LR is active at multiple sites causing energy constraint to the vital metabolic processes of the target organisms. However, its requirement at high concentration, which is environmentally irrelevant, and lack of quantitative information on the extracellular release of MC-LR suggest that MC-LR has no allelopathic function and could be a part of a quantitative chemical defense system.

Nostoc sp. BHU001, a planktonic cyanobacterium isolated from an agricultural pond in India, was examined for its toxicity. Mice, administered intraperitoneally with Nostoc sp. BHU001 crude extract (50 mg kg -1 body weight) died at 4.5 h. Examination of liver and spleen showed microcystin (MC)-like symptoms. Serum enzyme aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities increased by 1.6-1.8 and 2.6-3.0-folds, respectively at 50 and 100 mg crude extract kg -1 body weight. Thin layer chromatography of the crude extract produced five bands (N-1 to N-5). UV absorption maxima of band N-4 corresponded to that of standard microcystin-LR. Further analysis of the band N-4 by highperformance liquid chromatography gave a retention time (R t ) of 4.61 min similar to that of standard microcystin-LR (LR stands for lysine and arginine). Total MC content was quantified by enzyme-linked immunosorbent assay, and was 189.9 lg g -1 of crude extract, 9.8 lg l -1 of spent medium and 5.5 lg l -1 of pond water. Exposure of rice (Oryza sativa var. Sonam) seeds to the crude extract did not affect their germination, but inhibited the root and shoot growth of seedlings by 27.3 and 42.89 folds at 3 mg ml -1 crude extract, respectively.Keywords ALT and AST serum enzymes Á Cyanotoxins Á ELISA Á HPLC Á Liver and spleen histology Á Microcystins Á TLC

Background: Diabetes, a chronic disease, is presently a rapidly growing epidemic globally. The risk of diabetes type 2 is greatly increasing with change in lifestyle factors, urbanization, high blood pressure, overweight or obesity, physical inactivity and poor diet. It’s one of the reasons for premature death and disability and the number of cases are drastically increasing every year.Methods: 81 subjects above 18 years of age were considered for the screening. Random blood glucose levels were tested using the Thyrocare Sugar scan glucometer strips. Physical activity data was collected using a questionnaire. Based on the extent of physical activity, the subjects we grouped into three different categories. Data was analyzed and expressed using basic statistical tools in MS Excel 2007.Results: 6.17% of the rural population of Kendri, with mean age 47.4 years, had undiagnosed diabetes. The mean blood glucose level in diabetes positive cases was 279.8 mg/dL. A correlation of random blood glucose levels of the subjects with the extent of their physical activity was observed, where a decrease in physical activity/increase in physical inactivity showed an increase in blood glucose levels.Conclusions: From our study we conclude that undiagnosed diabetes is prevalent amongst the rural populations of Kendri, Chhattisgarh and low physical activity correlated with an increase of blood glucose levels, suggesting an urgent need to create health awareness, with emphasis on increase in physical activity, literacy and diabetes management, obesity, specifically among the illiterate and underprivileged rural populations.

Arbuscular Mycorrhizal Fungi (AMF) are obligate biotrophs living in symbiotic association with roots of plants. They are among the most widespread soil microorganisms that provide the host plant with nutrients and pathogen protection. Modern farming practices like frequent tillage, high input inorganic fertilization and pesticide along changing climatic conditions due to global warming, have huge impacts on AMF colonization, interaction with plants and on crop productivity. AMF positively affect the plant tolerance to biotic and abiotic stresses, harsh ecosystems and plant pathogens by altering root structure, exudation, rhizosphere microflora, production of antifungals, antibacterials, and competing with pathogens for nutrient uptake. Thus, it plays a significant role in plant growth, productivity and quality. Further, the effect of a fungicide is varied depending on its mode of action and the associated AMF species, suggesting that these fungi have a strong potential as a tool for eco-friendly sustainable farming in the present scenario of global warming.