Food Chemistry-X
·
2024
·
IF 6.5
Wentao Qian,Xiaobing Wang,Hongliang Li,Yinhua Zhu,Pengjie Wang,Xiaolu Geng,Jinhui Yang,Huiyuan Guo,Menghui Wang,Chong Chen
Introducing Holstein cows on Qinghai-Tibetan Plateau is a potential solution to enhance local milk production. However, the relationship between milk quality and altitude in China remains unknown. Therefore, the components and plasmin (PL) system of raw milk from different altitudes (sea level, 1600, 2700, and 3800 m) were investigated. The daily milk production of Holstein cows and PL activity decreased as the altitude increased. However, the components content of raw milk, plasminogen (PLG)/PL ratio, activities of PLG and plasmin activator (PA) increased with altitude. The pasteurization resulted a significant decrease in PA activity of all milk and a significant increase in PL activity in milk collected at higher altitudes (2700 and 3800 m), suggesting the pasteurization was unsuitable for preserving milk at higher altitudes. This study offered references for the production and storage of milk after introducing Holstein cows on Qinghai-Tibetan Plateau.
研究领域:
农业
·
乳品科学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Wantong Zhang,Xiuping Tao,Zhengyi Hu,Enze Kang,Zhongqing Yan,Xiaodong Zhang,Jinzhi Wang
Alpine peatlands are recognized as a weak or negligible source of nitrous oxide (N 2 O). Anthropogenic activities and climate change resulted in the altered water table (WT) levels and increased nitrogen (N) deposition, which could potentially transition this habitat into a N 2 O emission hotspot. However, the underlying mechanism related with the effects is still uncertain. Hence, we conducted a mesocosm experiment to address the response of growing-season N 2 O emissions and the gene abundances of nitrification (bacterial amoA ) and denitrification ( narG , nirS , norB and nosZ ) to the increased N deposition (20 kg N ha −1 yr −1 ) at two WT levels (WT − 30 , 30 cm below soil surface; WT 10 , 10 cm above soil surface) in the Zoige alpine peatland, Qinghai-Tibetan Plateau. The results showed that the WT did not affect N 2 O emissions, and this was attributed with the limitation of soil NO 3 − . The higher WT level increased denitrification ( narG and nirS gene abundance) resulting in the depletion of soil NO 3 − , but the consequent NO 3 − deficiency further limited denitrification, while the WT did not affect nitrification (bacterial amoA gene abundance). Meanwhile, the N deposition increased N 2 O emissions, regardless of WT levels. This was associated with the N-deposition induced increase in denitrification-related gene abundances of narG , nirS , norB and nosZ at WT − 30 and narG at WT 10 . Additionally, the N 2 O emission factor assigned to N deposition was 1.3 % at WT − 30 and 0.9 % at WT 10 , respectively. Our study provided comprehensive understanding of the mechanisms referring N 2 O emissions in response to the interactions between climate change and human disturbance from this high-altitude peatland.
研究领域:
环境科学
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生态学
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微生物生态学
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气候变化
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DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2024
·
IF 6.2
Dong Zhao,Hongyu Chen,Shuo Shen,Enyu Lu,Junlong Feng,Hui Zhi,Lei Wang,Wei Li
Flurochloridone (FLC) is a pyrrolidone herbicide used to control broad-leaved weeds in various crop fields. However, there is still a lack of comprehensive research on the environmental fate of the Qinghai-Tibet Plateau (QTP) and the toxicity of its potential transformation products (TPs). In this study, laboratory experiments were conducted to investigate the degradation kinetics, pathways, and toxicity of FLC’s TPs. Nine TPs were identified in soil using Ultra-Performance Liquid Chromatography Quadrupole-Orbitrap Mass Spectrometry (UPLC-Q-Exactive Orbitrap MS) and Compound Discoverer software, employing suspect and nontarget screening strategies. The initial report of two TPs, TP204, and TP191 was confirmed through the acquisition or synthesis of their standards. High Performance Liquid Chromatography coupled with Tandem Mass Spectrometry (HPLC-MS/MS) was subsequently used for further quantification of these TPs in all samples under examination. The primary transformation reactions of FLC in the environment include oxidative dechlorination, reductive dechlorination, reductive defluorination, acetylation, and hydrolysis. Predictive assessments via ECOSAR, alongside empirical laboratory experiments, revealed that most novel TPs exhibit significantly lower acute toxicity towards Danio rerio , Daphnia magna Straus , and Algae compared to FLC. However, TP204 demonstrated neutral chronic toxicity towards Daphnia magna Straus and Green algae , potentially posing a latent threat to aquatic ecosystems. These results are crucial for elucidating the environmental fate of FLC, assessing environmental risks, and guiding scientific and reasonable use. This research holds significant importance for the ecological environment protection in the Tibetan Plateau region.
研究领域:
环境科学
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毒理学
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农业科学
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DOI
PubMed
高影响因子
Nature Geoscience
·
2023
·Vol. 16
·期 11
·989-996
·
IF 18.3
Zhu Xiaojing,Yang Fan,Li Zhen,Fang Mingliang,Ma Suping,Zhang Ting,Li Cunlin,Guo Qiulei,Wang Xiaoping,Zhang Gan,Ji Rong,Schäffer Andreas,Wang Xiaofei,Ye Xingnan,Chen Yingjun,Wang Lin,Chen Jianmin,Xing Baoshan,Wang Zimeng,Schwarzbauer Jan
Permafrost in the polar regions potentially stores large amounts of toxic chemicals, including organic compounds bound with halogens. The release of such halogenated organic chemicals (HOC) from thawing permafrost represents a potential global concern with climate change. However, the exact inventory of HOC remains uncertain because conventional analytical techniques largely overlook nonextractable residues. Here we present an inventory of HOC in permafrost soils sampled from the Tibetan Plateau using stepwise chemical treatment following conventional solvent extraction to release and analyse the nonextractable residues. We identify more than 270 types of HOC, with total mean concentration of 310,000 ng g −1 , of which 180,000 ng g −1 are naturally sourced based on their molecular structures. We also find unexpectedly high fractions of the nonextractable residues, contributing more than 99% of the total HOC, much higher than those reported for other soils and sediments. Up to 85% of the nonextractable residues are physically entrapped in soils rather than chemically bound, such that they could readily be remobilized if soil properties change. We suggest that this substantial stock of HOC in Tibetan Plateau permafrost poses potentially important future risks to local ecosystems in a warming climate.
研究领域:
环境科学
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气候变化
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土壤化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Hu Xu,Mukan Ji,Dawei Xu,Yongqin Liu
Cellobiose 2-epimerase (CE) catalyzes the conversion of the lactose into its high-value derivatives, epilactose and lactulose, which has great prospects in food applications. In this study, CE sequences from the Qinghai-Tibet Plateau gene catalogue, we screened these for structural flexibility through molecular dynamics simulation to identify potential psychrophilic CE candidates. One such psychrophilic CE we termed psyCE demonstrated exceptional epimerization activity, achieving an optimum activity of 122.2 ± 1.6 U/mg. Its kinetic parameters (K cat and K m ) for epimerization activity were 219.9 ± 5.6 s −1 and 261.9 ± 18.1 mM, respectively, representing the highest K cat recorded among known cold-active CEs. Notably, this is the first report of a psychrophilic CE. The psyCE can effectively produce epilactose at 8 °C, converting 20.3 % of 200 mM lactose into epilactose within four hours. These findings suggest that psyCE is highly suitable for cryogenic food processing, and glaciers may serve as a valuable repository of psychrophilic enzymes.
研究领域:
生物化学
·
酶学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Feiwei Cao,Mingming Liang,Jianxin Liu,Yu Liu,John A. Renye,Phoebe X. Qi,Daxi Ren
Yak yogurt, one of the naturally fermented dairy products prepared by local herdsmen in the Qinghai-Tibet Plateau, contains a diverse array of microorganisms. We isolated and identified a novel Streptococcus thermophilus strain, ZJUIDS-2-01, from the traditional yak yogurt. We further purified and carried out detailed structural, physiochemical, and bioactivity studies of an exopolysaccharide (EPS-3A) produced by S. thermophilus ZJUIDS-2-01. The weight-average molecular weight (Mw) of EPS-3A was estimated to be 1.38 × 10 6 Da by High-Performance Gel Permeation Chromatography (HPGPC). The monosaccharide analysis established its composition to be glucose, galactose, N -acetyl-D-galactosamine, and rhamnose in a ratio of 5.2:2.5:6.4:1.0. The molecular structure of EPS-3A was determined by the combination of permethylation analysis, FT-IR, and NMR spectroscopic techniques. The ζ-potential measurements indicated that EPS-3A had a p K a value of ~4.40. The DSC yielded a melting point (T m ) of 80.4 °C and enthalpy change (ΔH) of 578 J/g for EPS-3A, comparable to those of the xanthan gum (XG), a commercial EPS. EPS-3A exhibited better O/W emulsion stability and flocculating capacity than XG. Furthermore, it also demonstrated similar antioxidant activity to XG and promising in vitro antibacterial properties. This work evidenced that EPS-3A derived from S. thermophilus ZJUIDS-2-01 holds the potential for food and industrial applications.
研究领域:
食品科学
·
微生物学
·
生物化学
·
生物技术
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产品关联
DOI
PubMed
高影响因子
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