ABSTRACT
Acute toxicity of silver nanoparticle (AgNP) for photosynthesis in Chlamydomonas reinhardtii was studied using an M-PEA2 fluorimeter. Analysis of the fluorescence induction curves in the presence of AgNP at low concentrations revealed inhibited electron transport in the PS2 photosystem and increased content of Q(B)-nonreducing centers. No direct effect of AgNP on the reactions of P700 oxidation in PS1 was found, while energization of the photosynthetic membranes was affected. Investigation of the parameters of the prompt and delayed fluorescence is proposed as a method for early detection of AgNP in the environment.
Subject(s)
Chlamydomonas reinhardtii/drug effects , Metal Nanoparticles/toxicity , Silver/toxicity , Chlamydomonas reinhardtii/metabolism , Chlorophyll , Dose-Response Relationship, Drug , Electron Transport/drug effects , Fluorescence , Photosystem II Protein Complex/metabolism , Toxicity Tests, AcuteABSTRACT
Bloom of a cryptomonad alga Rhodomonas sp. (Cryptophyta, Pyrenomonadaceae) was observed in the chemocline of saline basins separating from the White Sea, resulting in red coloration of the relevant water layer. According to the sequence of the 18S nuclear rRNA gene, this species was identical to Rhodomonas sp.RCC2020 (GenBank accession no. JN934672) from the Beaufort Sea. The presence of the red layer formed by mass development of Rhodomonas sp. is considered as an indicator of a certain stage of separation of a basin from the sea.
