供应限制了在土中的甲基产量
Huan Zhong1, Yao Su1, Xinda Wu1
1School of Environment, Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, Nanjing, Jiangsu Province, China.
The Science of the total environment
|April 11, 2024
概括
在土中,无机 (IHg) 供应,而不是微生物活动,限制了甲基 (MeHg) 产量. 草修正案显著增加了IHg的可用性,突出了来自动员的风险.
科学领域:
- 环境科学 环境科学
- 环境化学环境化学
- 微生物学 微生物学
背景情况:
- 甲基 (MeHg) 是一种神经毒素,由无机 (IHg) 通过微生物过程形成.
- 米土壤是MeHg形成的重要热点,但控制这一过程的主导因素仍然不清楚.
- 改是一种常见的农业实践,可能对甲基化产生影响.
研究的目的:
- 调查微生物活动或IHg供应是否控制了在米土壤中的Hg甲基化.
- 通过改变微生物活动和IHg供应来量化草修改对MeHg生产的影响.
主要方法:
- 在草修改条件下分析了63个米土壤样本.
- 根据微生物活动和IHg供应量化MeHg产生的量化.
- 确定主要的微生物Hg甲基化剂,包括减少硫酸盐的细菌 (SRB).
主要成果:
- IHg供应,而不是SRB活动,被确定为在米土壤中Hg甲基化的限制因素.
- 草修正案显著增加了IHg供应 (336747%).
- 高SRB活动并没有限制MeHg的产生,尽管它们作为主要甲基化剂的作用.
结论:
- 在大米土壤中甲基化主要由无机的可用性控制.
- 农业实践,如草修改可以提高IHg供应,可能增加MeHg产量.
- 由于人类活动和气候变化的遗留的调动,可能会导致食物链中MeHg的增加.
相关概念视频
C4 Pathway and CAM
Most plants use the C3 pathway for carbon fixation. However, some plants, such as sugar cane, corn, and cacti that grow in hot conditions, use alternative pathways to fix carbon and conserve energy loss due to photorespiration. Photorespiration is the process that occurs when the oxygen concentration is high. Under such conditions, the rubisco enzyme in the Calvin cycle binds O2 instead of CO2, which halts photosynthesis and consumes energy.
C4 Pathway
The C4 pathway is used by plants such as...
C4 Pathway
The C4 pathway is used by plants such as...
Key Elements for Plant Nutrition
Like all living organisms, plants require organic and inorganic nutrients to survive, reproduce, grow and maintain homeostasis. To identify nutrients that are essential for plant functioning, researchers have leveraged a technique called hydroponics. In hydroponic culture systems, plants are grown—without soil—in water-based solutions containing nutrients. At least 17 nutrients have been identified as essential elements required by plants. Plants acquire these elements from the atmosphere, the...
Limiting Reactant
The relative amounts of reactants and products represented in a balanced chemical equation are often referred to as stoichiometric amounts. However, in reality, the reactants are not always present in the stoichiometric amounts indicated by the balanced equation.
The Calvin Benson Cycle
Ribulose 1,5- bisphosphate carboxylase/oxygenase (RuBisCo) is a critical enzyme that catalyzes carbon dioxide assimilation during photosynthesis. However, it is an inefficient enzyme, having an extremely slow catalytic rate. A typical enzyme can process about a thousand molecules per second; however, RuBisCo fixes only around three-carbon dioxides per second. Photosynthetic cells compensate for this slow rate by synthesizing very high amounts of RuBisCo, making it the most abundant single...
Inorganic Nitrogen Assimilation
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme nitrate reductase...
Production of Biopesticides
Biopesticides offer a sustainable alternative to chemical pesticides, utilizing microbial agents to control agricultural pests. Bacillus thuringiensis (Bt) is a widely employed bacterium known for its potent insecticidal activity. Bt biopesticides are favored for their specificity to insect pests, minimal environmental impact, and natural degradability.Mechanism of Bt Toxin Action Bt produces insecticidal crystal (Cry) proteins during its sporulation phase. These proteins form parasporal...


