Oxidative stress and antioxidant defence systems were assessed in a marine brown alga Padina tetrastromatica, commonly occurring from the tropics. Lipid peroxidation （LPX） and H2O2 were measured as oxidative stress ...Oxidative stress and antioxidant defence systems were assessed in a marine brown alga Padina tetrastromatica, commonly occurring from the tropics. Lipid peroxidation （LPX） and H2O2 were measured as oxidative stress markers, and antioxidant defences were measured as catalase （CAT）, glutathione S-transferase （GST） and ascorbic acid （ASA）, in order to understand their dissimilarity with respect to pollution levels from selective locations along the central west coast of India. A significant increased levels of LPX, H2O2, CAT and GST were observed in samples from relatively polluted localities （Colaba and Karwar） when compared to less polluted locality （Anjuna）, while AsA concentration was higher in algal samples from worst polluted region of Colaba. Heavy metals such as Cd and Pb were also higher in the vicinity of polluted areas compared to reference area. Variation of oxidative stress indices in response to accumulation of heavy metals within P. tetrastromatica could be used as molecular biomarkers in assessment and monitoring environmental quality of ecologically sensitive marine habitats.展开更多
Utilization of renewable marine resources for the biosynthesis of metal nanoparticles is an innovative area in the current nanotechnology research.The present article reports a simple environmentally benign method for...Utilization of renewable marine resources for the biosynthesis of metal nanoparticles is an innovative area in the current nanotechnology research.The present article reports a simple environmentally benign method for the synthesis of silver nanoparticles using aqueous extract of marine brown seaweed Padina Tetrastromatica,which act as both the reducing and stabilising agent.The formation,morphology and crystalline nature of the synthesised silver nanoparticles were determined using UV-Visible Spectroscopy,Transmission electron microscopy,Selected area electron diffraction and X-ray diffraction techniques.The surface plasmon resonance peak at 424 nm in the UV-Visible spectrum confirmed the formation of silver nanoparticles.The biosynthesised silver nanoparticles were almost spherical with an average size of 15 nm.Crystalline nature of silver nanoparticles is evident from the characteristic peaks in the X-ray diffraction pattern,bright circular spots in the selected area electron diffraction pattern and clear lattice fringes in the High resolution Transmission electron microscopy images.Fourier transform infrared spectroscopic analysis revealed the presence of functional bio active metabolites in seaweed extract which is responsible for the formation and efficient stabilization of the nanoparticles.The biosynthesised silver nanoparticles show excellent antimicrobial activity against Escherichia coli and Aeromonas hydrophila.They also show very good catalytic activity for the reduction of methylene blue in the presence of NaBH4 in aqueous medium.Thus the green synthesised nanoparticles are expected to be a promising candidate for the application in diverse fields.展开更多
基金carried under the funds from CSIR,Network Project 0018
文摘Oxidative stress and antioxidant defence systems were assessed in a marine brown alga Padina tetrastromatica, commonly occurring from the tropics. Lipid peroxidation （LPX） and H2O2 were measured as oxidative stress markers, and antioxidant defences were measured as catalase （CAT）, glutathione S-transferase （GST） and ascorbic acid （ASA）, in order to understand their dissimilarity with respect to pollution levels from selective locations along the central west coast of India. A significant increased levels of LPX, H2O2, CAT and GST were observed in samples from relatively polluted localities （Colaba and Karwar） when compared to less polluted locality （Anjuna）, while AsA concentration was higher in algal samples from worst polluted region of Colaba. Heavy metals such as Cd and Pb were also higher in the vicinity of polluted areas compared to reference area. Variation of oxidative stress indices in response to accumulation of heavy metals within P. tetrastromatica could be used as molecular biomarkers in assessment and monitoring environmental quality of ecologically sensitive marine habitats.
文摘Utilization of renewable marine resources for the biosynthesis of metal nanoparticles is an innovative area in the current nanotechnology research.The present article reports a simple environmentally benign method for the synthesis of silver nanoparticles using aqueous extract of marine brown seaweed Padina Tetrastromatica,which act as both the reducing and stabilising agent.The formation,morphology and crystalline nature of the synthesised silver nanoparticles were determined using UV-Visible Spectroscopy,Transmission electron microscopy,Selected area electron diffraction and X-ray diffraction techniques.The surface plasmon resonance peak at 424 nm in the UV-Visible spectrum confirmed the formation of silver nanoparticles.The biosynthesised silver nanoparticles were almost spherical with an average size of 15 nm.Crystalline nature of silver nanoparticles is evident from the characteristic peaks in the X-ray diffraction pattern,bright circular spots in the selected area electron diffraction pattern and clear lattice fringes in the High resolution Transmission electron microscopy images.Fourier transform infrared spectroscopic analysis revealed the presence of functional bio active metabolites in seaweed extract which is responsible for the formation and efficient stabilization of the nanoparticles.The biosynthesised silver nanoparticles show excellent antimicrobial activity against Escherichia coli and Aeromonas hydrophila.They also show very good catalytic activity for the reduction of methylene blue in the presence of NaBH4 in aqueous medium.Thus the green synthesised nanoparticles are expected to be a promising candidate for the application in diverse fields.
