Co, Zn and Ag-MOFs evaluation as biocidal materials towards photosynthetic organisms

Abstract

In the present study, the biocidal activity of three different metal organic frameworks (MOFs) based on Co (Co-SIM1), Zn (Zn-SIM1) and Ag (Ag-TAZ) has been evaluated towards one green alga and two cyanobacteria. These organisms are present in fresh- and seawater and take part in the early stages of the biofouling process. The biocidal activity of these materials was evaluated by measuring chlorophyll a concentration and by inhibition zone testing. After 24h of exposure the three different MOFs caused >50% of chlorophyll a concentration inhibition towards both cyanobacteria, however, although the green alga presented a great sensitivity for Ag-TAZ (reaching 90% of chlorophyll a concentration inhibition), it was much more resistant to the rest of MOFs. Bioavailability of these metals was studied using ICP-MS, the chemical speciation program Visual MINTEQ, and a heavy metal bioreporter bioanalytical tool. We have elucidated that the biocidal activity presented by these MOFs was due to the dissolved metals released from them and more exactly, it depended on the bioavailability presented by these metal ions, which was closely related with the free ion concentration. This article highlights the potential use of different MOFs as biocidal material towards photosynthetic organisms and reveals important differences in the sensitivity between these organisms that should be taken into account in order to increase the biocidal spectrum of these materials.

Growth Inhibition of Microcystis aeruginosa by Copper‐based MOFs: Performance and Physiological Effect on Algal Cells

“…At the same time, chlorophyll a was seriously damaged. Keila et al reached the same conclusion that Ag‐TAZ, Co‐SIM1 and Zn‐SIM1 of 50 mg/L had an inhibition effect on chlorophyll a of Anabaena , Chlamydomonas reinhardtii and Synechococcus . All these results on chlorophyll a show that the pigments of the photosynthetic reaction center complex were reduced, and the photosynthetic transmission chain was impaired in the algae cells when contacted with Cu‐MOF‐74 of 1, 5 and 10 mg/L, which would reduce the efficiency of utilization and conversion of light energy of algal cells, and further causing cell death.…”

“…Keila et al found that MOFs have a certain inhibitory effect on Anabaena , Chlamydomonas reinhardtii , and Synechococcus via the addition of Ag‐TAZ, Co‐SIM1 and Zn‐SIM1. However, the effects of MOFs on the physiological characteristics of algae require deep‐going research . Besides, as an expensive metal, silver is unsuitable for environmental treatment and can't be used on a large scale.…”

Heterogeneous ZIF-L membranes with improved hydrophilicity and anti-bacterial adhesion for potential application in water treatment

“…In this connection, porous ZIF-L contains a large number of metal ions showing great potential for anti-bacterial activity. 31 Based on the literature, 32 it is understood that Co-based ZIF-L (Co-ZIF-L) membranes possess better anti-bacterial adhesion capability than Zn-based ZIF-L (Zn-ZIF-L) membranes, and would be more attractive for water purication. However, due to the extremely high reactivity between Co ions and 2-methylimidazole, the heterogeneous nucleation of Co-ZIF-L on substrates is rather difficult.…”

Mechanism of the toxic action of cationic G5 and G7 PAMAM dendrimers in the cyanobacteriumAnabaenasp. PCC7120

“…PCC7120 (hereinafter, Anabaena) was selected as a model organism, given its environmental relevance and ubiquity, as well as the extensive bibliography regarding the genetic, physiology and ecological importance. Furthermore, this cyanobacterium has been used regularly as model for ecotoxicological studies, including the field of nanotoxicology 31,[33][34][35][36][37][38][39][40] .…”