SARS-CoV-2 variants and environmental effects of lockdowns,masks and vaccination: a review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously evolving and four variants of concern have been identified so far, including Alpha, Beta, Gamma and Delta variants. Here we review the indirect effect of preventive measures such as the implementation of lockdowns, mandatory face masks, and vaccination programs, to control the spread of the different variants of this infectious virus on the environment. We found that all these measures have a considerable environmental impact, notably on waste generation and air pollution. Waste generation is increased due to the implementation of all these preventive measures. While lockdowns decrease air pollution, unsustainable management of face mask waste and temperature-controlled supply chains of vaccination potentially increases air pollution.

     

Mercury remediation potential of a mercury resistant strain Sphingopyxis sp. SE2 isolated from contaminated soil

A mercury resistant bacterial strain SE2 was isolated from contaminated soil.The 16 s rRNA gene sequencing confirms the strain as Sphingopyxis belongs to the Sphingomonadaceae family of the α-Proteobacteria group.The isolate showed high resistance to mercury with estimated concentrations of Hg that caused 50%reduction in growth(EC_(50)) of 5.97 and 6.22 mg/L and minimum inhibitory concentrations(MICs) of 32.19 and 34.95 mg/L in minimal and rich media,respectively.The qualitative detection of volatilized mercury and the presence of mercuric reductase enzyme proved that the strain SE2 can potentially remediate mercury.ICP-QQQ-MS analysis of the remaining mercury in experimental broths indicated that a maximum of 44%mercury was volatilized within 6 hr by live SE2 culture.Furthermore a small quantity(23%) of mercury was accumulated in live cell pellets.While no volatilization was caused by dead cells,sorption of mercury was confirmed.The mercuric reductase gene merA was amplified and sequenced.Homology was observed among the amino acid sequences of mercuric reductase enzyme of different organisms from a-Proteobacteria and ascomycota groups,     

Kinetics of carbofuran insecticide conversion under methanogenic conditions

Abstract

This study reports on the kinetics of carbofiiran insecticide transformation under controlled aquatic methanogenic conditions. Attempts were also made to investigate the effects of culture acclimation on the kinetics of carbofiiran transformation.

The results indicate that in an anaerobic system carbofuran was hydrolyzed to carbofiiran phenol and monomethyl amine by hydrolysis. Analysis of the kinetic parameters showed that active anaerobic cultures (both acclimated and unnacclimated) do not enhance the rate of hydrolysis of carbofuran. The hydrolysis product, monomethyl amine, was further mineralized by the methanogenic culture. The major product of carbofuran hydrolysis, carbofiiran phenol, was resistant to further degradation.