Effects of cadmium sulfide nanoparticles on sulfate bioreduction and oxidative stress in Desulfovibrio desulfuricans

Abstract

Sulfate-containing wastewater has a serious threat to the environment and human health. Microbial technology has great potential for the treatment of sulfate-containing wastewater. It was found that nano-photocatalysts could be used as extracellular electron donors to promote the growth and metabolic activity of non-photosynthetic microorganisms. However, nano-photocatalysts could also induce oxidative stress and damage cells. Therefore, the interaction mechanism between photosynthetic nanocatalysts and non-photosynthetic microorganisms is crucial to determine the regulatory strategies for microbial wastewater treatment technologies. In this paper, the mechanism and regulation strategy of cadmium sulfide nanoparticles (CdS NPs) on the growth of sulfate-reducing bacteria and the sulfate reduction process were investigated. The results showed that the sulfate reduction efficiency could be increased by 6.4% through CdS NPs under light conditions. However, the growth of Desulfovibrio desulfuricans C09 was seriously inhibited by 55% due to the oxidative stress induced by CdS NPs on cells. The biomass and sulfate reduction efficiency could be enhanced by 6.8% and 5.9%, respectively, through external addition of humic acid (HA). At the same time, the mechanism of the CdS NPs strengthening the sulfate reduction process by sulfate bacteria was also studied which can provide important theoretical guidance and technical support for the development of microbial technology combined with extracellular electron transfer (EET) for the treatment of sulfate-containing wastewater. Graphical Abstract

Cadmium effects on net N2O production by the deep-sea isolate Shewanella loihica PV-4

“…As opposed to Fe or Cu, necessary for the catalytic activity of NO 2 − and N 2 O reductase enzymes and potential direct impact on enzyme activity (Glass and Orphan 2012 , Giannopoulos et al 2020 ), Cd is not known to be a structural component of these metalloenzymes. Thus, Cd effects on N 2 O production and consumption are expected to be associated with cellular toxic effects, such as effects on cell growth, metabolism, and oxidative stress (Kaakoush et al 2008 , Behera et al 2014 , Cheng et al 2022 ) as well as community effects, such as changes in microbial community structure and diversity in the environment (Yu et al 2021 , Sun et al 2022 ). To our knowledge, no previous studies have investigated the effects of Cd on N 2 O metabolism using pure cultures or bacterial isolates.…”

Recycling of spent lithium-ion batteries for a sustainable future: recent advancements

“…155 The acidophilic bacteria which are used in bioleaching experiments are mainly from the following three genera namely Acidithiobacillus, Sulfobacillus and Leptospirillum. 156 The IOB microbes used for bioleaching studies include Acidithiobacillus ferrooxidans, Sulfobacillus spp. and Leptospirillum ferriphilum, while Acidithiobacillus thiooxidans, Alicyclobacillus spp, and Sulfobacillus thermosulfidooxidans are the key SOB microorganisms employed for bioleaching experiments.…”

“…Depending on the microbe-material interactions, the bacteria-based bioleaching mechanisms are broadly divided into (1) the direct/contact mechanism, and (2) the indirect/non-contact mechanism. 156 In the direct/contact mechanism, the microorganisms attach themselves onto the surface of the spent LIB particles through electrostatic attraction or hydrophobicity, and then form a biofilm. 156 The attached microorganisms oxidize the substrates (e.g., S 0 and Fe 2+ ) present in the leaching medium under an aerobic condition.…”

“…156 In the direct/contact mechanism, the microorganisms attach themselves onto the surface of the spent LIB particles through electrostatic attraction or hydrophobicity, and then form a biofilm. 156 The attached microorganisms oxidize the substrates (e.g., S 0 and Fe 2+ ) present in the leaching medium under an aerobic condition. The microbial oxidation of sulfur produces biogenic H 2 SO 4 .…”

“…In the indirect/noon-contact mechanism, the microbial cells do not directly attach themselves to the solid particles of spent batteries. 156 However, the leaching is driven by the metabolites produced by the microbial agent. For example, in the IOB-based bioleaching system, Fe 2+ is used as a source of energy which is oxidized to Fe 3+ .…”