Soil contamination by heavy metals has increased noticeably within the past years. Unlike organic compounds, metals cannot degrade; therefore effective cleanup is required to reduce its toxicity. This experiment was undertaken to investigate the comparative potential of Panicum maximum and Axonopus compressus to bioremediate zinc polluted soils, the impact of Zn on the antioxidant defense system of the plant, assaying for activities of antioxidants proteins. Zinc salts were mixed with soil at various concentrations 5 mg/kg, 10 mg/kg, 20 mg/kg and 40 mg/kg in triplicates and control was setup. After 4 months, the plants (root, shoot and leaf) and soil were analyzed for morphological, biochemical parameters and Zn concentration. The root length of P. maximum and A. compressus decreased as the concentration of zinc increased. The least shoot length inhibition of A. compressus was 6.16% (5 mg/kg) while the highest shoot length inhibition was 40.14% (40 mg/kg). The least shoot length inhibition of Panicum maximum was 6.16% exposed to 5 mg/kg and the highest shoot length inhibition was 53.13% (40 mg/kg). There was significant reduction of the heavy metals in vegetated soils for P. maximum and A. compressus at the end of the study compared to the heavy metals in the soils at the beginning of the study (p<0.05). P. maximum, is a better removal of Zn than A. compressus, however, it was not significant. Glutathione levels varied significantly (p≤ 0.05) with respect to heavy metals. A. compressus has more effects on Glutathione activities than P. maximum. Zn caused a decrease in metallothionein level in P. maximum while A. compressus metallothionein level increased.

The widespread presence and persistence of perfluorooctane sulfonate (PFOS) in wastewater treatment plants, as well as its toxicity and bioaccumulation potential, necessitates the investigation on their impact on bioreactor performance. A 48-day exposure test was adopted to study the effects of low (10 μg L-1) and high (1000 μg L-1) PFOS concentrations in a sequencing batch reactor on the performance, composition, and microbial community of activated sludge. The results suggested that adding PFOS at low and high concentrations lowered the removal efficiency of total nitrogen by 22.48% (p < 0.01) and 16.30% (p < 0.01) respectively, while enhanced that of total phosphorus by 1.87% (p > 0.05) and 7.07% (p < 0.05) respectively, compared with the control group. The addition of PFOS also led to the deterioration of activated sludge dewatering performance. Composition and spectroscopic measurements revealed that the PFOS dosage changed the composition of the activated sludge. Furthermore, the PFOS altered the structure and function of the activated sludge microbial community as well as key enzyme activities.

GABA, a four-carbon non-protein amino acid, plays an important role in animals and plants. We previously found GABA could alleviate alkali stress in apple seedlings. However, its physiological mechanism under heavy metal cadmium (Cd) stress need to be further studied. Thus, we explored its biological role in response to Cd stress. It was verified that 0.5 mM GABA could effectively alleviate Cd toxicity. Using NMT technique, we found that exogenous GABA could significantly reduce the net Cd²⁺ fluxes in apple roots, and Cd content was significantly lower than that in roots under Cd stress. Further analysis indicated exogenous GABA could significantly reduce the expression of genes related to the uptake and transport of Cd in apples under Cd stress. In addition, exogenous GABA could significantly increase the content of amino acids in apple roots under Cd stress. GAD is a key enzyme in GABA synthesis, we obtained transgenic apple roots of overexpression MdGAD1. Compared with the control, transgenic roots accumulated less Cd, maintained lower Cd uptake by roots, and lower expression of related transport genes. These results showed that GABA could effectively alleviate Cd toxicity in apple seedlings and provide a new perspective of GABA to alleviate Cd stress.

Human activities such as dams disturb the structure and function of wetlands, triggering large soil CO₂ and CH₄ emissions. However, controls over field CO₂ and CH₄ emissions and their carbon isotopic signatures in reservoir wetlands are not yet fully understood. We investigated in situ CO₂ and CH₄ emissions, the δ¹³C values of CO₂ and CH₄, and associated environments in the saturated and drained states under four elevations (i.e., the water column, <147 m, permanent inundation area without plants; the low, 145–160 m, frequently flooded area with revegetation; the high, 160–175 m, rarely flooded area with revegetation; and the upland area as the control, >175 m, nonflooded area with original plants) in the Three Gorges Reservoir area. The CO₂ emissions was significantly higher in high elevation, and they also significantly differed between the saturated and drained states. In contrast, the CH₄ emissions on average (41.97 μg CH₄ m⁻² h⁻¹) were higher at high elevations than at low elevations (22.73 μg CH₄ m⁻² h⁻¹) during the whole observation period. CH₄ emissions decreased by 90% at low elevations and increased by 153% at high elevations from the saturated to drained states. The δ¹³C of CH₄ was more enriched at high elevations than in the low and upland areas, with a more depleted level under the saturated state than under the drained state. We found that soil CO₂ and CH₄ emissions were closely related to soil substrate quality (e.g., C: N ratio) and enzyme activities, whereas the δ¹³C values of CO₂ and CH₄ were primarily associated with root respiration and methanogenic bacteria, respectively. Specifically, the effects of the saturated and drained states on soil CO₂ and CH₄ emissions were stronger than the effect of reservoir elevation, thereby providing an important basis for assessing carbon neutrality in response to anthropogenic activities.

The presence of heavy metals in municipal solid waste (MSW) is considered as prevalent global pollutants that cause serious risks to the environment and living organisms. Due to industrial and anthropogenic activities, the accumulation of heavy metals in the environmental matrices is increasing alarmingly. MSW causes several adverse environmental impacts, including greenhouse gas (GHG) emissions, river plastic accumulation, and other environmental pollution. Indigenous microorganisms (Pseudomonas, Flavobacterium, Bacillus, Nitrosomonas, etc.) with the help of new pathways and metabolic channels can offer the potential approaches for the treatment of pollutants. Microorganisms, that exhibit the ability of bioaccumulation and sequestration of metal ions in their intracellular spaces, can be utilized further for the cellular processes like enzyme signaling, catalysis, stabilizing charges on biomolecules, etc. Microbiological techniques for the treatment and remediation of heavy metals provide a new prospects for MSW management. This review provides the key insights on profiling of heavy metals in MSW, tolerance of microorganisms, and application of indigenous microorganisms in bioremediation. The literatures revealed that indigenous microbes can be exploited as potential agents for bioremediation.

Grape pomace (GP) is a low-value by-product that contains a significant amount of high value-added products. The huge amount of non-edible residues of GP wastes (seeds, skins, leaves and, stems) produced by wine industries causes’ environmental pollution, management issues as well as economic loss. Studies over the past 15–20 years revealed that GP could serve as a potential source for valuable bioactive compounds like antioxidants, bioactive, nutraceuticals, single-cell protein, and volatile organic compounds with an increasing scientific interest in their beneficial effects on human and animal health. However, the selection of appropriate techniques for the extraction of these compounds without compromising the stability of the extracted products is still a challenging task for the researcher. Based on the current scenario, the review mainly summarizes the novel applications of winery wastes in many sectors such as agriculture, pharmaceuticals, cosmetics, livestock fields, and also the bio-energy recovery system. We also summarize the existing information/knowledge on several green technologies for the recovery of value-added by-products. For the promotion of many emerging technologies, the entrepreneur should be aware of the opportunities/techniques for the development of high-quality value-added products. Thus, this review presents systematic information on value-added by-products that are used for societal benefits concerning the potential for human health and a sustainable environment.

Microplastics (MPs) are widely found in coastal areas and oceans worldwide. The MPs are environmentally concerning due to their bioavailability and potential impacts on a wide range of marine biota, so assessing their impact on the biota has become an urgent research priority. In the present study, we exposed Crassostrea gigas oysters to irregular MPs of two polymer types (polyethylene (PE) and polyethylene terephthalate (PET)) at concentrations of 10 and 1000 μg L⁻¹ for 21 days. Accumulation of MPs, changes in metabolic enzyme activity, and histological damage were evaluated, and metabolomics analysis was conducted. Results demonstrated that PE and PET MPs were detected in the gills and digestive gland following exposure to both tested concentrations, confirming ingestion of MPs by the organisms. Moreover, both PE and PET MPs inhibited lipid metabolism, while energy metabolism enzyme activities were activated in the oysters. Histopathological damage of exposed oysters was also observed in this study. Integrated biomarker response (IBR) results showed that MPs toxicity increased with increasing MPs concentration, and the toxic effects of PET MPs on oysters was greater than PE MPs. In addition, metabolomics analysis suggested that MPs exposure induced alterations in metabolic profiles in oysters, with changes in energy metabolism and inflammatory responses. This study reports new insights into the consequences of MPs exposure in marine bivalves at environmentally relevant concentrations, providing valuable information for ecological risk assessment of MPs in a realistic conditions.

Glyphosate is the most widely used herbicide in the world. In recent years, many studies have demonstrated that exposure to glyphosate-based herbicides (GHBs) was related to the decrease of serum testosterone and the decline in semen quality. However, the molecular mechanism of glyphosate-induced testosterone synthesis disorders is still unclear. In the present study, the effects of glyphosate on testosterone secretion and the role of endoplasmic reticulum (ER) stress in the process were investigated in TM3 cells. The effects of glyphosate at different concentrations on the viability of TM3 cells were detected by CCK8 method. The effect of glyphosate exposure on testosterone secretion was determined by enzyme-linked immunosorbent assay (ELISA). The expression levels of testosterone synthases and ER stress-related proteins were detected by Western blot and Immunofluorescence stain. Results showed that exposure to glyphosate at concentrations below 200 mg/L had no effect on cell viability, while the glyphosate above 0.5 mg/L could inhibit the testosterone secretion in TM3 cells. Treatment TM3 cells with glyphosate at 5 mg/L not only reduced the protein levels of testosterone synthase StAR and CYP17A1, inhibited testosterone secretion, but also increased the protein level of ER stress molecule Bip and promoted the phosphorylation of PERK and eIF2α. Pretreatment cells with PBA, an inhibitor of ER stress, alleviated glyphosate-induced increase in Bip, p-PERK and p-eIF2α protein levels, meanwhile rescuing glyphosate-induced testosterone synthesis disorders. When pretreatment with GSK2606414, a PERK inhibitor, the glyphosate-induced phosphorylation of PERK and eIF2α was blocked, and the glyphosate-inhibited testosterone synthesis and secretion was also restored. Overall, our findings suggest that glyphosate can interfere with the expression of StAR and CYP17A1 and inhibit testosterone synthesis and secretion via ER stress-mediated the activation of PERK/eIF2α signaling pathway in Leydig cells.

Di (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) are important pollutants that contaminate agricultural soils. We determined the effects of di (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) on the production of reactive oxygen species, photosynthesis, and activity of antioxidant enzymes in wheat planted in fluvo-aquic soils. DBP- and DEHP-induced oxidative stress decreased the values of the photosynthetic/fluorescence parameters (except for intercellular carbon dioxide concentration) and chlorophyll content at the seedling, jointing, and booting stages. Moreover, the non-stomatal factor responsible for the net decrease in photosynthetic efficiency was identified as the decrease in fluorescence resulting from the decreased amount of chlorophyll a returning from the excited to the ground energy state. The content of superoxide anions and hydrogen peroxide in wheat leaves and roots increased with increasing DBP and DEHP supplementation, compared to the control. Antioxidant enzyme activities in the leaves and roots at the seedling stage increased at DBP and DEHP levels of 10 and 20 mg kg⁻¹, respectively, and the enzyme activities at the jointing and booting stages increased with increasing concentrations of the chemicals, compared to the control. These results demonstrated that increased levels of antioxidant enzymes play a significant role in protecting plant growth under DBP and DEHP stress.