Differential action of Hg2+ and Cd2+ on the phycobilisomes and chlorophyll a fluorescence, and photosystem II dependent electron transport in the cyanobacterium Anabaena flos-aquae

Singh, Devendra P.; Sharma, SK; Bisen, Prakash S.

doi:10.1007/bf00140114

Cited by 8 publications

(6 citation statements)

References 26 publications

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“…Organisms have advanced to endure in environments of high concentrations of metals (Bisen et al, 1987(Bisen et al, , 1996Khare and Bisen, 1991). These organisms may alter the chemical nature of the toxic metals by lowering their toxicity or making them nontoxic (Singh et al, 1989(Singh et al, , 1993Sharma and Bisen, 1992;Sharma et al, 2001). The formation of nanoparticles is the "consequence" of the resistance mechanism of an organism in contrast to a specific metal (Figure 2).…”

Section: Biological Synthesis Of Nanoparticlesmentioning

confidence: 99%

RETRACTED: Green Synthesis of Metallic Nanoparticles and Their Potential Applications to Treat Cancer

et al. 2020

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Nanoparticle synthesis using microorganisms and plants by green synthesis technology is biologically safe, cost-effective, and environment-friendly. Plants and microorganisms have established the power to devour and accumulate inorganic metal ions from their neighboring niche. The biological entities are known to synthesize nanoparticles both extra and intracellularly. The capability of a living system to utilize its intrinsic organic chemistry processes in remodeling inorganic metal ions into nanoparticles has opened up an undiscovered area of biochemical analysis. Nanotechnology in conjunction with biology gives rise to an advanced area of nanobiotechnology that involves living entities of both prokaryotic and eukaryotic origin, such as algae, cyanobacteria, actinomycetes, bacteria, viruses, yeasts, fungi, and plants. Every biological system varies in its capabilities to supply metallic nanoparticles. However, not all biological organisms can produce nanoparticles due to their enzymatic activities and intrinsic metabolic processes. Therefore, biological entities or their extracts are used for the green synthesis of metallic nanoparticles through bio-reduction of metallic particles leading to the synthesis of nanoparticles. These biosynthesized metallic nanoparticles have a range of unlimited pharmaceutical applications including delivery of drugs or genes, detection of pathogens or proteins, and tissue engineering. The effective delivery of drugs and tissue engineering through the use of nanotechnology exhibited vital contributions in translational research related to the pharmaceutical products and their applications. Collectively, this review covers the green synthesis of nanoparticles by using various biological systems as well as their applications.

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Section: Biological Synthesis Of Nanoparticlesmentioning

confidence: 99%

RETRACTED: Green Synthesis of Metallic Nanoparticles and Their Potential Applications to Treat Cancer

et al. 2020

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“…The stimulation of Chl a emission intensity at 695 nm in the lower concentration of both Cd 2+ and Pb 2+ (25 µg mL -1 each), along with about 4 nm blue shift in presence of Cd 2+ , indicated inhibition of energy transfer from Chl a to PSII center as well as conformational changes in the core pigment antenna. Similar results were reported in the cyanobacterium Anacystis nidulans by Pakrasi and Sherman (1985) and in Anabaena flos-aquae by Singh et al (1993). However, unlike Cd 2+ , a higher concentration of Pb 2+ (100 µg mL -1 ) resulted in quenching of emission peak at 695 nm, which might be either due to nonphotochemical quenching or due to thermal dissipation of energy caused by structural damage to the inner core of pigment antenna (Oxborough and Horton 1986).…”

Section: Discussionsupporting

confidence: 79%

Differential response of photosynthetic apparatus of cyanobacterium Nostoc muscorum to Pb and Cd toxicity

Dixit¹,

Singh²

2015

Photosynt.

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Nostoc muscorum cells showed metal-induced decrease in the relative growth, pigment contents, O 2 evolution, and Hill activity in response to lead (Pb 2+ ) and cadmium (Cd 2+ ) treatment, which was further accentuated with increase in metal exposure time and metal concentration. I 50 concentrations (50% growth inhibitory concentrations) of Pb 2+ and Cd 2+ for growth of N. muscorum were 55 and 21 g mL -1 , respectively. These results indicated that the cells of N. muscorum were more susceptible to Cd 2+ in comparison to Pb 2+ . The O 2 production was relatively more sensitive to both heavy metals (I 50 : 16 and 10 µg mL -1 of Pb 2+ and Cd 2+ , respectively) than the Hill activity (I 50 : 61 and 39 µg mL -1 of Pb 2+ and Cd 2+ , respectively). Further, measurement of Hill activity in the presence of metals and electron donors showed that inhibition sites of both Pb 2+ and Cd 2+ were located on the oxidizing site of PSII. The chlorophyll a (Chl a) and phycobilisome (PB) fluorescence emission spectra showed that energy transfer from Chl a and PB to PSII reaction center was more susceptible to Cd 2+ than Pb 2+ .

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“…Its toxicity seems to be associated to the high affinity to sulfhydryl groups, the displacement or substitution of essential metal ions (such as Zn) and the modification of the conformation of the bio molecules [3]. Toxic effects of cadmium on algae include the inhibition of growth [4,5] and photosynthesis [6]. Cd affects the ultra-structure and photosynthesis of the unicellular freshwater green alga Micrasterias denticulata as a consequence of the disturbance of calcium homeostasis probably by displacement of Ca by Cd [7].…”

Section: Introductionmentioning

confidence: 99%

Responses of the alga Pseudokirchneriella subcapitata to long-term exposure to metal stress

Machado

Lopes

Soares

2015

Journal of Hazardous Materials

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The green alga Pseudokirchneriella subcapitata has been widely used in ecological risk assessment, usually based on the impact of the toxicants in the alga growth. However, the physiological causes that lead algal growth inhibition are not completely understood. This work aimed to evaluate the biochemical and structural modifications in P. subcapitata after exposure, for 72 h, to three nominal concentrations of Cd(II), Cr(VI), Cu(II) and Zn(II), corresponding approximately to 72 h-EC10 and 72 h-EC50 values and a high concentration (above 72 h-EC90 values). The incubation of algal cells with the highest concentration of Cd(II), Cr(VI) or Cu(II) resulted in a loss of membrane integrity of ~16, 38 and 55%, respectively. For all metals tested, an inhibition of esterase activity, in a dose-dependent manner, was observed. Reduction of chlorophyll a content, decrease of maximum quantum yield of photosystem II and modification of mitochondrial membrane potential was also verified. In conclusion, the exposure of P. subcapitata to metals resulted in a perturbation of the cell physiological status. Principal component analysis revealed that the impairment of esterase activity combined with the reduction of chlorophyll a content were related with the inhibition of growth caused by a prolonged exposure to the heavy metals.

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Differential action of Hg2+ and Cd2+ on the phycobilisomes and chlorophyll a fluorescence, and photosystem II dependent electron transport in the cyanobacterium Anabaena flos-aquae

Cited by 8 publications

References 26 publications

RETRACTED: Green Synthesis of Metallic Nanoparticles and Their Potential Applications to Treat Cancer

RETRACTED: Green Synthesis of Metallic Nanoparticles and Their Potential Applications to Treat Cancer

Differential response of photosynthetic apparatus of cyanobacterium Nostoc muscorum to Pb and Cd toxicity

Responses of the alga Pseudokirchneriella subcapitata to long-term exposure to metal stress

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