Authors: Khalid Habib Ningthoujam Manikar Sabbir Ansari Tasneem Fatma
Publish Date: 2012/10/04
Volume: 20, Issue: 2, Pages: 862-871
Abstract
Cyanobacterial biofertilizers are affected by paddy field pesticides as nontarget organism Carbaryl is a carbamate pesticide and is commonly used against rice thrip pest in paddy fields In the present work cellular changes caused by exposure of the cyanobacterial biofertilizer namely Calothrix brevissima to carbaryl were studied with special reference to fatty acids electrolyte leakage sulfur metabolism and osmolytes To study the toxic effect of carbaryl the test cyanobacterium was exposed to varying concentrations of pesticide 0 10 20 30 and 40 mg L−1 for biochemical analyses At 40 mg L−1 carbaryl polyunsaturated fatty acids were reduced by 32 and membrane leakage was increased by 27 suggesting that free radicalmediated lipid peroxidation took place The sulfurcontaining metabolites namely cysteine cystine and methionine were increased by 79 64 and 52 respectively The enzymatic and nonenzymatic antioxidants namely glutathione Stransferase glutathione reductase reduced glutathione and oxidized glutathione were increased to 56 71 72 and 60 respectively Osmolytes that serve as stress enzyme protectors as well as nonenzymatic free radical scavenger were also increased indicating their protective nature in context with carbarylinduced stress The respective increase in mannitol trehalose and glycogen were 158 98 and 159 In C brevissima carbarylinduced membrane leakage was counteracted by increasing enzymatic and nonenzymatic parameters that helped in scavenging free radicalsWe are thankful to DST and UGC New Delhi India for financial support the National Centre for Utilization and Conservation of Blue Green Algae IARI New Delhi for providing the C brevissima culture and Mr Brahamdutt Technical Assistant IARI New Delhi and Mr Ajay Kumar Senior Technical Assistant JNU New Delhi for providing necessary technical help
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