Surface sorption and nanoparticle production as a silver detoxification mechanism of the freshwater alga Parachlorella kessleri.
SEM, EDS, TEM, FTIR and UV-vis analysis were used to investigate the biosorption, bioaccumulation and bioreduction of silver by the freshwater green alga Parachlorella kessleri. The dead algal biomass showed high potential for silver removal; 75% of silver was removed within 2min. Surface sorption was the main mechanism; bioreduction contributed to the biosorption only to a small extent. In the presence of living P. kessleri cells a 68% decrease of silver concentration was observed within 24h, but subsequently the majority of silver was released back into the solution within the next 14days. According to UV-vis spectrometry, silver nanoparticles were formed in that time. The nanoparticles produced by the alga exhibited a lower toxicity against algal cells than silver ions at the same silver concentrations. The study demonstrated that living algal cells used a combination of two main mechanisms (sorption and reduction) for silver detoxification in their environment.
Department of Microbiology, Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Safarik University, Srobarova 2, 04154 Kosice, Slovakia. Electronic address: jana.kadukova@upjs.sk.
Jana
J
Kadukova
D018533:Biomass; D000460:Chlorophyta; D005618:Fresh Water / Q000737:chemistry; D008658:Inactivation, Metabolic; D053768:Metal Nanoparticles / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties; D018508:Water Purification / Q000379:methods*
D012834:Silver
Bioaccumulation; Bioreduction; Biosorption; Parachlorella kessleri; Silver nanoparticles