APPLIED SOIL ECOLOGY
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2025
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IF 5
Xian Zhou,Xuwei Li,Chao Lu,Jian Wang,Chao Qin,Wanting Ling
Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental pollutants threatening soil ecosystems and human health. While soil microbial communities possess intrinsic PAH degradation potential, the dynamics of bacterial populations and degradation-associated genes during natural attenuation remain poorly understood. This study investigated the self-purification capacity of PAH-contaminated soil through a 32-day microcosm experiment using three model PAHs: naphthalene (NAP), phenanthrene (PHE), and pyrene (PYR). Results demonstrated high PAH dissipation rates (94.36 %, 72.60 %, and 47.70 % for NAP, PHE, and PYR, respectively). High-throughput sequencing revealed that PAH exposure (10–100 mg kg −1 ) shifted bacterial community structure, enriching Actinobacterial taxa (Mycobacterium, Rhodococcus, Nocardioides) linked to PAH degradation and strengthening bacterial interactions. Quantitative PCR further indicated substrate-specific gene responses: Actinobacteria harboring nahAC preferentially degraded NAP, while nidA and phe genes were upregulated under PHE/PYR stress. These findings highlight Actinobacteria as keystone degraders and propose leveraging microbial community assembly strategies to optimize bioremediation of PAH-contaminated soils.
研究领域:
环境科学
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微生物学
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DOI
高影响因子
Animals
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2025
·Vol. 15
·期 16
·2370
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IF 2.7
Can Zhang,Bo Cheng,Lei Xue,Ling Liu,Fenglai Wang,Jianjun Zang
Corn distiller’s dried grains with solubles (DDGSs) are a highly attractive alternative to corn and soybean meal in animal feeds. Accurately determining the net energy (NE) value of corn DDGSs is essential for formulating precise diets for pregnant sows. The substitution method has been widely employed to determine the available energy value of feed ingredients that cannot be fed directly to pigs. However, the appropriate substitution level of corn DDGSs in the test diets of the substitution method, which influences the accuracy of the assessed energy, and its corresponding net energy in pregnant sows remain unclear. Therefore, this study aims to establish the appropriate substitution level of corn DDGSs in test diets relative to the energy-supplying portion of the basal diet, and to accurately measure the digestive energy, metabolizable energy and NE values of different corn DDGSs types in pregnant sows. Based on an established appropriate substitution level for corn distillers dried grains with solubles (DDGSs) replacing energy-supplying components in the basal diet for pregnant sows, the substitution method was employed to determine the available energy values of corn DDGSs. In Exp. 1, forty pregnant sows (gestation day = 50 ± 5 d; body weight = 220 ± 24.9 kg; parity, 4 to 6) were randomly allocated into five treatments. The control group was fed a corn–soybean basal diet, while test diets contained 20%, 30%, 40%, 50% corn DDGSs replacing the energy-supplying portion of the basal diet. In Exp. 2, the available energy of five corn DDGS sources was determined using the substitution method at a 30% substitution level. Twelve pregnant sows (gestation day = 50 ± 5 d; body weight = 225.4 ± 29.2 kg; parity, 4 to 6) were arranged in a 6 × 3 Youden square design. Dietary treatments consisted of the corn–soybean basic diet and five test diets incorporating different corn DDGS types. Increasing the substitution level of corn DDGSs displayed both linear and quadratic effects ( p < 0.05) on the apparent total tract digestibility (ATTD) of dry matter (DM), organic matter (OM), acid detergent fiber (ADF), ether extract (EE) and gross energy (GE) in diets. The ATTD of neutral detergent fiber (NDF), digestible energy (DE) and metabolizable energy (ME) was quadratically affected by different substitution levels ( p < 0.05), with the highest value achieved at the 30% substitution level. As the substitution level of corn DDGSs increased, the ATTD of ADF in corn DDGSs decreased. In contrast, the ATTD of crude protein (CP) increased either linearly or quadratically ( p < 0.05), and a significant quadratic effect was observed for the ATTD of EE in corn DDGSs ( p < 0.05). Although the GE, DE, and ME of corn DDGSs were not significantly influenced by the substitution level, the 30% corn DDGSs resulted in the lowest coefficients of variation (CV). Therefore, a 30% substitution level of corn DDGSs is recommended for energy-supplying components in the basal diet of pregnant sows using the substitution method. The ranges of DE, ME and net energy (NE) of five corn DDGSs samples were 15.58–18.07, 12.17–16.42 and 8.76–15.88 MJ/kg DM, respectively. The absolute value of relative error (|RE|) between the predicted available energy values obtained from the prediction equations established in Exp. 2 and the determined values were below 5%, except for ME for corn DDGSs N3 (5.81%).
研究领域:
动物营养学
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畜牧学
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饲料科学
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能量代谢
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妊娠生理
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2019
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IF 7.149
Chenyu Xu,Jiahui Cai,Zhihua Wang,Mingjiang Ni,Kefa Cen,Yanwei Zhang
In this work, to achieve both clean energy production and carbon emission reduction, a united conversion to couple CO2 mineralization with thermochemical hydrogen production is proposed. Natural magnesium silicate minerals are used to fix CO2 in the form of carbonate minerals, whereas H2O is dissociated to produce H2 in the thermochemical cycle. The integration provides a new solution to the challenges of the high energy consumption and poor economic value of conventional CO2 mineralization processes, and the technical feasibility has been proven. Moreover, the energy economy and CO2 conversion capacity were investigated. Hydrolyzation and carbonation experiments were performed in a homemade reactor, and it was found that an optimal MgI2 hydrolyzation rate of 75% could be achieved without alkali consumption. A detailed simulation of the whole system was also developed. The optimal energy conversion efficiency of the cycle reached 47.6%, which is higher than most of the published theoretical energy efficiency values for sulfur–iodine thermochemical cycles. A modified calculation of the net energy requirement for CO2 mineralization was carried out. Finally, a comparison and an evaluation of the energy efficiencies were made based on the calculation. In the optimal case, the modified net energy requirement is 1.4 MJ/kg CO2, which means that this method is competitive compared to those of previous works.
研究领域:
环境科学
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能源工程
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DOI
PubMed
高影响因子
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