Search

Summary: Singlet oxygen (1O2) is a harmful species that functions also as a signaling molecule. In chloroplasts, 1O2 is produced via charge recombination reactions in photosystem II, but which recombination pathway(s) produce triplet Chl and 1O2 remains open. Furthermore, the role of 1O2 in photoinhibition is not clear.We compared temperature dependences of 1O2 production, photoinhibition, and recombination pathways.1O2 production by pumpkin thylakoids increased from −2 to +35°C, ruling out recombination of the primary charge pair as a main contributor. S2QA− or S2QB− recombination pathways, in turn, had too steep temperature dependences. Instead, the temperature dependence of 1O2 production matched that of misses (failures of the oxygen (O2) evolving complex to advance an S‐state). Photoinhibition in vitro and in vivo (also in Synechocystis), and in the presence or absence of O2, had the same temperature dependence, but ultraviolet (UV)‐radiation‐caused photoinhibition showed a weaker temperature response.We suggest that the miss‐associated recombination of P680+QA− is the main producer of 1O2. Our results indicate three parallel photoinhibition mechanisms. The manganese mechanism dominates in UV radiation but also functions in white light. Mechanisms that depend on light absorption by Chls, having 1O2 or long‐lived P680+ as damaging agents, dominate in red light. [ABSTRACT FROM AUTHOR]

A major apprehension is over microplastic pollution in the aquatic environment. These microplastics particles represent a novel medium in the aquatic environment, providing a substratum for various organic contaminants and for colonization of microorganisms. Microorganisms form a biofilm on the exterior of pollutants, consequential in a region known as a plastisphere, in which they interrelate and generate acid and different enzymes for microplastic degradation. The use of microbes for microplastic degradation has become a contentious exit indication as society focuses more on environmentally friendly pollution reduction methods. After both substantial and elemental degradation, biodegradation occurs, weakening the arrangement of polymers. Natural resource microbes have a significant effect on the reduction of plastic waste in the environment. The current review article discusses microbial colonization and degradation of microplastics present in aquatic ecosystems and the processes involved. While studying and considering how these microplastic particles have now turn out to be a recent environmental position within various aquatic environments, we emphasized the significance of colonization and microbial-assisted degradation of aquatic microplastics in this article. [ABSTRACT FROM AUTHOR]

A novel process for the separation of Sm (III) and Co (II) from chloride medium using lactic acid in the aqueous feed employing Di-2-ethylhexyl phosphoric acid (DEHPA) in petrofin as organic phase solvent has been developed. Complete separation has been accomplished with 1 M HLac and 0.1 M DEHPA in the pH range 1–3 and using 2.2 M HLac at pH 3 with 0.2 M DEHPA. Sm (III) could be entirely stripped off the loaded organic solvent by means of 1.2 M HCl and HNO3. The extraction process is heat releasing for Sm (III) and heat absorbing for Co (II). [ABSTRACT FROM AUTHOR]