Nano Research
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2021
·Vol. 16
·期 4
·4531-4538
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IF 8.897
Liu Guangyu,Gao Feng,Zhang Hongwei,Wang Lei,Gao Chao,Xiong Yujie
Synergistically combining biological whole-cell bacteria with man-made semiconductor materials innovates the way for sustainable solar-driven CO 2 fixation, showing great promise to break through the bottleneck in traditional chemical photocatalyst systems. However, most of the biohybrids require uneconomical organic nutrients and anaerobic conditions for the successful cultivation of the bacteria to sustain the CO 2 fixation, which severely limits their economic viability and applicability for practical application. Herein, we present an inorganic-biological hybrid system composed of obligate autotrophic bacteria Thiobacillus thioparus ( T. thioparus ) and CdS nanoparticles (NPs) biologically precipitated on the bacterial surface, which can achieve efficient CO 2 fixation based entirely on cost-effective inorganic salts and without the restriction of anaerobic conditions. The optimized interface between CdS NPs and T. thioparus formed by biological precipitation plays an essential role for T. thioparus efficiently receiving photogenerated electrons from CdS NPs and thus changing the autotrophic way from chemoautotroph to photoautotroph. As a result, the CdS- T. thioparus biohybrid realizes the solar-driven CO 2 fixation to produce multi-carbon glutamate synthase and biomass under visible-light irradiation with CO 2 as the only carbon source. This work provides significant inspiration for the further exploration of the solar-driven self-replicating biocatalytic system to achieve CO 2 fixation and conversion.
研究领域:
微生物学
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环境科学
·
合成生物学
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产品关联
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Yuancheng Li,Chuling Guo,Siyu Zhang,Changdong Ke,Yanping Deng,Zhi Dang
The widespread distribution of nanoplastics and dissolved organic matter (DOM) in sewage raises concerns about the potential impact of DOM on the bioavailability of nanoplastics. In this study, the effects of different sizes (100 nm and 350 nm) of polystyrene nanoplastics (PS-NPs, 50 mg/L) and combined with 10 mg/L or 50 mg/L DOMs (fulvic acid, humic acid and sodium alginate) on the growth and denitrification ability of Thiobacillus denitrificans were investigated. Results showed that 100 nm PS-NPs (50 mg/L) cause a longer delay in the nitrate reduction (3 days) of T. denitrificans than 350 nm PS-NPs (2 days). Furthermore, the presence of DOM exacerbated the adverse effect of 100 nm PS-NPs on denitrification, resulting in a delay of 1–4 days to complete denitrification. Fulvic acid (50 mg/L) and humic acid (50 mg/L) had the most significant adverse effect on increasing 100 nm PS-NPs (50 mg/L), causing a reduction of 20 mmol/L nitrate by T. denitrificans in nearly 7 days. It is noteworthy that the presence of DOM did not modify the adverse effect of 350 nm PS-NPs on denitrification. Further analysis of toxicity mechanism of PS-NPs revealed that they could induce reactive oxygen species (ROS) and suppressed denitrification gene expression. The results suggested that DOM may assist in the cellular internalization of PS-NPs by inhibiting PS-NPs aggregation, leading to the increased ROS levels and accelerated T. denitrificans death. This study highlights the potential risk of nanoplastics to autotrophic denitrifying bacteria in the presence of DOM and provides new insights for the treatment of nitrogen-containing wastewater by T. denitrificans .
研究领域:
环境科学
·
微生物学
·
废水处理
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产品关联
DOI
PubMed
高影响因子
ACS ES&T Engineering
·
2024
·
IF 7.4
Yong Li,Bohan Chen,Xiaolei Zhang,Zhizhan Luo,Mengen Lei,Tao Song,Youcheng Wei,Ji Li,Zhiyun Long,Jun Ma
Elemental sulfur autotrophic partial denitrification (S0-PDN) can supply nitrite for anaerobic ammonium oxidation without an organic carbon requirement. This study aimed to evaluate the impact of high salinity on S0-PDN and investigate the feasibility of an enhanced strategy involving the addition of glycine betaine (GB). The results showed that high salinity inhibited S0-PDN by over 60% as salinity increased from low (0 and 5 g/L) to high (10 and 15 g/L) levels, even though Thiobacillus (65.9%–84.0%) was always the dominant genus. The reason might be the suppression of high salinity on the bioactivity. Surprisingly, the addition of GB (1 mmol/L) effectively enhanced the performance of S0-PDN under high salinity conditions (10 g/L), resulting in a 5.1-fold increase in the NO3–-N conversion efficiency and a 3.1-fold increase in the effluent NO2–-N concentration. Metagenomics analysis revealed that high salinity did not alter the dominant microbial composition. GB facilitated the recovery of the nitrate conversion capacity of sulfur autotrophic denitrifying bacteria with the up-regulation of nitrate reductase genes (by 18.1%) and Sox genes (by 21.4%). However, GB also stimulated the growth of heterotrophic denitrifying bacteria. Part of the nitrite produced in S0-PDN was reduced through heterotrophic denitrification with GB as an electron donor. Overall, the addition of GB was demonstrated as an effective approach to mitigate the inhibitory effects of high salinity on S0-PDN, which offers valuable theoretical support for its application in high-salinity wastewater treatment.
研究领域:
环境工程
·
微生物学
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DOI
高影响因子
WATER RESEARCH
·
2025
·
IF 12.4
Bobo Xing,Ji Li,Linlin Li,Nigel J.D. Graham,Xian Li,Wenzheng Yu
Excessive accumulation of nitrate in natural ecosystems can lead to eutrophication of water bodies, resulting in environmental impacts such as algal blooms and red tides that pose serious threats to environmental and human health. Autotrophic denitrification is a resource-efficient biological nitrogen removal technology, but the slow growth and low electron transfer efficiency of autotrophic denitrifiers limit their practical application. In this study, the heterotrophic denitrifying bacterium Pseudomonas sp. JM-7 ( P. JM-7) was used in mixed culture with the autotrophic denitrifying Thiobacillus denitrificans ATCC 25259 to form a heterotrophic-autotrophic synergistic denitrification process (mixPT) to enhance electron transfer and improve the denitrification efficiency. Our results for an initial nitrate concentration of 430 mg/L showed that P. JM-7 reduced approximately 210 mg/L nitrate (48.8 %) in 90 h, with 1 g/L yeast extract powder (YEP) as the electron donor, while Thiobacillus denitrificans barely removed nitrate. In contrast, the mixPT system reduced approximately 360 mg/L nitrate (83.3 %), nearly 1.7 times greater than P. JM-7 alone. The mixPT culture also exhibited excellent denitrification in low carbon waters (10 mg/L), and removed 40 mg/L nitrate completely within 120 h. Cytochrome c produced by Pseudomonas sp. JM-7, which is an excellent electron transfer mediator for denitrification by Thiobacillus denitrificans , played a crucial role in the heterotrophic-autotrophic syntrophic denitrification. The adsorption effect of Pseudomonas sp. JM-7 shortened the contact distance between the autotrophic denitrifying bacteria and cytochrome c, which made it easy for cytochrome c to transfer the electrons to the autotrophic bacteria directly, thereby reducing the loss of electrons in the process of transfer, and improved the electron utilization efficiency. These findings have demonstrated the potential applications of mixPT system in controlling eutrophic waters and propose cytochrome c of Pseudomonas sp. JM-7 could serve as a novel and high-quality electron transfer mediator. Furthermore, this study have overcome the restriction of low denitrification efficiency exhibited by heterotrophic denitrifying bacteria Pseudomonas sp. JM-7 in low-carbon environments and expanded the utilisation of Pseudomonas sp. JM-7 in low carbon environments.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Peng Wang,Chen Zhu,Yingji Gao,Zhonghua Cai,Ye ye,Yi Tao
Nitrate-driven sulfide oxidation has been proven to be a cost-effective approach for controlling sediment odor. However, injecting liquid nitrate (LN) directly into sediment carries ecological risks of nitrate escape and release of pollutants into overlying water. In this study, slow-release nitrate granules (GN) were prepared and applied in a continuous flow reactor to assess the differences between GN and LN in sediment remediation and control of this ecological risk. The results showed that the GN slowly released calcium nitrate, resulting in a decrease in acid volatile sulfide (AVS) from an initial 1328 ± 42.7 mg/kg to 490 ± 341 and 212 ± 32.8 mg/kg in the upper (U) and deeper (D) layers of the sediment, respectively. No significant decrease in AVS concentrations was observed in the LN treatments. Compared with LN-D and -U, the NH 4 + -N production and PO 4 3- -P release doses were reduced by 29.5% and 52.0% for GN-D and 41.2% and 37.8% for GN-U, respectively. Taxonomic analysis showed that sulfide-driven denitrifiers such as Thiobacillus , Rhodanobacter , Sulfurimonas , and Pseudomonas became dominant in the GN treatments, which were 2.8–6.7, 27.0–201.8, 1.5–3.0, and 3.0–496 times that of the LN treatments, respectively. The abundance of sulfur oxidation genes (e.g., sat and aprB ) and denitrifying genes (e.g., nirS and nosZ ) were also upregulated to higher levels by GN. Moreover, the genes (e.g., nrfA ) responsible for the isomerization of nitrate into ammonium were down-regulated by GN. The results showed that the slow-released calcium nitrate should be a promising way for in-situ remediation of sulfide-rich sediment.
研究领域:
环境科学
·
微生物学
·
沉积物修复
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）