scholarly journals Microbial Degradation of Pesticide Residues and an Emphasis on the Degradation of Cypermethrin and 3-phenoxy Benzoic Acid: A Review

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2313 ◽  
Author(s):  
Yichen Huang ◽  
Lijuan Xiao ◽  
Feiyu Li ◽  
Mengshi Xiao ◽  
Derong Lin ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Microbial Degradation ◽  
Pesticide Residues ◽  
Degradation Process ◽  
Soil Environment ◽  
Natural Conditions ◽  
Factors Affecting ◽  
Degrading Bacteria ◽  
Pyrethroid Pesticides ◽  
Intermediate Metabolite

Nowadays, pesticides are widely used in preventing and controlling the diseases and pests of crop, but at the same time pesticide residues have brought serious harm to human’s health and the environment. It is an important subject to study microbial degradation of pesticides in soil environment in the field of internationally environmental restoration science and technology. This paper summarized the microbial species in the environment, the study of herbicide and pesticides degrading bacteria and the mechanism and application of pesticide microbial degrading bacteria. Cypermethrin and other pyrethroid pesticides were used widely currently, while they were difficult to be degraded in the natural conditions, and an intermediate metabolite, 3-phenoxy benzoic acid would be produced in the degradation process, causing the secondary pollution of agricultural products and a series of problems. Taking it above as an example, the paper paid attention to the degradation process of microorganism under natural conditions and factors affecting the microbial degradation of pesticide. In addition, the developed trend of the research on microbial degradation of pesticide and some obvious problems that need further solution were put forward.

scholarly journals Comparison of Different Home/Commercial Washing Strategies for Ten Typical Pesticide Residue Removal Effects in Kumquat, Spinach and Cucumber

2019 ◽  
Vol 16 (3) ◽  
pp. 472 ◽  
Author(s):  
Yangliu Wu ◽  
Quanshun An ◽  
Dong Li ◽  
Jun Wu ◽  
Canping Pan
Keyword(s):  
Sodium Bicarbonate ◽  
Pesticide Residue ◽  
Pesticide Residues ◽  
Tap Water ◽  
Active Oxygen ◽  
Alkaline Solutions ◽  
Electrolyzed Water ◽  
Pyrethroid Pesticides ◽  
Oxygen Solution ◽  
Alkaline Electrolyzed Water

Home processing can reduce pesticide residues in agricultural products, and the common forms of treatment include washing, peeling, blanching, and cooking. In this study, the removal effects of tap water, micron calcium solution, alkaline electrolyzed water (AlEW), ozone water, active oxygen, and sodium bicarbonate on 10 typical pesticide residues in kumquat, cucumber, and spinach were investigated. The residue magnitudes were determined by chromatography–tandem mass spectrometry (GC-MS/MS, LC-MS/MS), combined with the QuEChERS pretreatment method. The model tests showed that the results of soaking and greenhouse were close. The removal effects of pesticide residues in kumquat and cucumber washing by alkaline electrolyzed water with a high pH value, micron calcium, and active oxygen solution were better than other washing solutions. The sodium bicarbonate solution, ozone water, and active oxygen solution were more effective in reducing pesticide residues in spinach than others. Active oxygen solution showed a better removal efficiency for the 10 pesticides than other treatments because of its alkalinity and oxidizability. Among the ten pesticides, pyrethroid pesticides had a higher removal rate. Additionally, chlorpyrifos were the most difficult to remove. For the majority of pesticides, the pesticide residue magnitudes showed a gradual reduction when increasing the washing time. The results indicated that alkaline solutions were effective for the reduction of pesticide residues when the washing time was longer than 15 min.

scholarly journals ASSESSMENT OF THE INFLUENCE OF ABIOTIC FACTORS ON THE ENZYMATIVE ACTIVITY OF THE SOIL

ÈKOBIOTEH ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 128-134
Author(s):  
E.V. Tovstik ◽  
◽  
A.S. Olkova ◽  
Keyword(s):  
Enzymatic Activity ◽  
Soil Solution ◽  
Ph Value ◽  
Abiotic Factors ◽  
Inverse Correlation ◽  
Invertase Activity ◽  
Soil Environment ◽  
Factors Affecting ◽  
Activity Of Enzymes ◽  
Made In

Аn attempt is made in this work to establish correlations between the level of enzymatic activity of the soil and factors of an abiotic nature. It was found that the activity of invertase and urease in the soils of more southern territories is higher than that of northern ones. In soils with a pH value of the soil environment close to neutral reaction, the level of enzymatic activity is higher than in more acidic ones. The most sensitive to soil acidity among the studied urease enzymes. In relation to zinc, an inverse correlation was established between its content in the soil and the level of invertase activity. According to the degree of resistance to salinity, the enzymes are arranged in the following order: catalase> invertase> urease. An increase in the mineralization of the soil solution leads to an increase in the activity of urease. Of the studied enzymes, the most labile are representatives of the class of hydrolases (invertase and urease), less labile are oxidoreductases (catalase). Thus, when diagnosing the state of the soil by the level of enzymatic activity, it is necessary to take into account the main abiotic factors affecting the activity of enzymes: the average annual air temperature; pH and mineralization of the soil solution; the content of substances that inhibit microorganisms and block exozymes.

scholarly journals Steroid Degradation in Comamonas testosteroni TA441: Identification of the Entire β-Oxidation Cycle of the Cleaved B Ring

2019 ◽  
Vol 85 (20) ◽  
Author(s):  
Masae Horinouchi ◽  
Hiroyuki Koshino ◽  
Michal Malon ◽  
Hiroshi Hirota ◽  
Toshiaki Hayashi
Keyword(s):  
Gene Clusters ◽  
Degradation Process ◽  
Degradation Pathway ◽  
Ring Cleavage ◽  
Comamonas Testosteroni ◽  
Content Type ◽  
Coa Transferase ◽  
Degrading Bacteria ◽  
Globally Distributed

ABSTRACT Comamonas testosteroni TA441 degrades steroids via aromatization of the A ring, followed by degradation of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid, mainly by β-oxidation. In this study, we revealed that 7β,9α-dihydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostanoic acid-coenzyme A (CoA) ester is dehydrogenated by (3S)-3-hydroxylacyl CoA-dehydrogenase, encoded by scdE (ORF27), and then the resultant 9α-hydroxy-7,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid-CoA ester is converted by 3-ketoacyl-CoA transferase, encoded by scdF (ORF23). With these results, the whole cycle of β-oxidation on the side chain at C-8 of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid is clarified; 9-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid-CoA ester is dehydrogenated at C-6 by ScdC1C2, followed by hydration by ScdD. 7β,9α-Dihydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostanoic acid-CoA ester then is dehydrogenated by ScdE to be converted to 9α-hydroxy-17-oxo-1,2,3,4,5,6,10,19-octanorandrostan-7-oic acid-CoA ester and acetyl-CoA by ScdF. ScdF is an ortholog of FadA6 in Mycobacterium tuberculosis H37Rv, which was reported as a 3-ketoacyl-CoA transferase involved in C ring cleavage. We also obtained results suggesting that ScdF is also involved in C ring cleavage, but further investigation is required for confirmation. ORF25 and ORF26, located between scdF and scdE, encode enzymes belonging to the amidase superfamily. Disrupting either ORF25 or ORF26 did not affect steroid degradation. Among the bacteria having gene clusters similar to those of tesB to tesR, some have both ORF25- and ORF26-like proteins or only an ORF26-like protein, but others do not have either ORF25- or ORF26-like proteins. ORF25 and ORF26 are not crucial for steroid degradation, yet they might provide clues to elucidate the evolution of bacterial steroid degradation clusters. IMPORTANCE Studies on bacterial steroid degradation were initiated more than 50 years ago primarily to obtain materials for steroid drugs. Steroid-degrading bacteria are globally distributed, and the role of bacterial steroid degradation in the environment as well as in relation to human health is attracting attention. The overall aerobic degradation of the four basic steroidal rings has been proposed; however, there is still much to be revealed to understand the complete degradation pathway. This study aims to uncover the whole steroid degradation process in Comamonas testosteroni TA441 as a model of steroid-degrading bacteria. C. testosteroni is one of the most studied representative steroid-degrading bacteria and is suitable for exploring the degradation pathway, because the involvement of degradation-related genes can be determined by gene disruption. Here, we elucidated the entire β-oxidation cycle of the cleaved B ring. This cycle is essential for the following C and D ring cleavage.

scholarly journals Factors Affecting Egg Deposition of the European Mantis

2020 ◽  
Vol 68 (2) ◽  
pp. 45-49
Author(s):  
Joanna Kajzer-Bonk
Keyword(s):  
Habitat Selection ◽  
Environmental Conditions ◽  
Plant Cover ◽  
Egg Laying ◽  
Natural Conditions ◽  
Factors Affecting ◽  
Egg Deposition ◽  
Predatory Insect ◽  
Egg Case ◽  
Potential Tool

In this paper, we studied the egg-case (oothecae) deposition of the European mantis, Mantis religiosa (Linnaeus 1758), a predatory insect. We hypothesized that the height of ootheca deposition on a plant reflects the insolation requirements of the species, and would increase when plant cover is denser. We found that the taller the plants nearby, the greater the height of egg deposition. Oothecae were also oviposited higher in denser vegetation. The observed behavior may ensure the proper insolation of developing offspring. To our knowledge, this is the first description of an egg laying strategy of this species under natural conditions. This finding allows for a better understanding of habitat selection and the overall ecology of the European mantis. It may be also useful in identifying the mechanisms of the range extension of this species and is a potential tool to effectively conserve xerothermic ootheca-laying animals. Further studies are required to assess the flexibility of this behavior under different environmental conditions.

scholarly journals Influence of natural and climatic factors on the organization of construction

2020 ◽  
Vol 164 ◽  
pp. 08006
Author(s):  
Marat Kuzhin ◽  
Ekaterina Chepik ◽  
Angelina Baranova
Keyword(s):  
Climatic Factors ◽  
Climatic Conditions ◽  
Technical Documentation ◽  
Construction Work ◽  
Natural Conditions ◽  
Factors Affecting ◽  
The Cost ◽  
Monolithic Structures ◽  
Cost Of Construction

In this research the influence of natural and climatic conditions on the organization of construction production are examined. Our purpose was to identify the nature of the dependence of the duration of construction work on natural and climatic factors. The analysis of normative and technical documentation in terms of accounting for the influence of natural and climatic factors was made. The system of estimation of influence of natural conditions on preparatory, ground, facade, roofing works, and also the appliance of monolithic structures, installation of prefabricated ferroconcrete items, and on works – implementation of internal finishing is offered. It was estimated, that the norms of construction production take into account a certain number of natural and climatic factors affecting the performance of work, but most of these factors have not yet been given in the normative and technical documentation. It is necessary to study this issue more comprehensively and to establish exact dependences on natural and climatic conditions, which will allow to quantify these factors already while calculating. This is necessary to compile more accurate calendar plans and schedules of production of works, as close as possible to real conditions. The study of this issue is one of the most important issues in the design of construction production. With insufficient consideration of these factors, the final actual figures are very different from the projected ones, which also lead to an increase in the cost of construction and installation work and the duration of their implementation. Taking into consideration the influence of natural and climatic factors will allow planning construction production more accurate.

scholarly journals Soil Pollution Characteristics and Microbial Responses in a Vertical Profile with Long-Term Tannery Sludge Contamination in Hebei, China

2019 ◽  
Vol 16 (4) ◽  
pp. 563 ◽  
Author(s):  
Xiangke Kong ◽  
Chunhui Li ◽  
Ping Wang ◽  
Guoxin Huang ◽  
Zhitao Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Soil Profile ◽  
Stable State ◽  
Chemical Properties ◽  
Tannery Sludge ◽  
Factors Affecting ◽  
X Ray ◽  
Degrading Bacteria ◽  
Microbial Responses

An investigation was made into the effects of tannery sludge on soil chemical properties and microbial communities in a typical soil profile with long-term tannery sludge contamination, North China. The results showed that trivalent chromium (Cr(III)), ammonium, organic nitrogen, salinity and sulfide were the predominant contaminants in tannery sludge. Although the tannery sludge contained high chromium (Cr, 3,0970 mg/kg), the proportion of mobile Cr forms (exchangeable plus carbonate-bound fraction) only accounted for 1.32%. The X-ray diffraction and X-ray photoelectron spectroscopy results further demonstrated that the Cr existed in a stable state of oxides and iron oxides. The alkaline loam soil had a significant retardation effect on the migration of salinity, ammonium, Cr(III) and sulfide, and the accumulation of these contaminants occurred in soils (0–40 cm). A good correlation (R2 = 0.959) was observed between total organic carbon (TOC) and Cr(III) in the soil profile, indicating that the dissolved organic matter from sludge leachate promoted the vertical mobility of Cr(III) via forming Cr(III)-organic complexes. The halotolerant bacteria (Halomonas and Tepidimicrobium) and organic degrading bacteria (Flavobacteriaceae, Tepidimicrobium and Balneola) became the dominant microflora in the soil profile. High contents of salinity, Cr and nitrogen were the main environmental factors affecting the abundance of indigenous microorganisms in soils.

Detection of pesticide residues in vegetables sold in Changchun City，China

2020 ◽  
Author(s):  
Mengmeng Jiang ◽  
Haicheng Gao ◽  
Xinxin Liu ◽  
Yu Wang ◽  
Jiaqi Lan ◽  
...  
Keyword(s):  
Pesticide Residues ◽  
Detection Rate ◽  
Organophosphorus Pesticides ◽  
Pollution Level ◽  
Potential Health ◽  
Chemical Structures ◽  
Compound Pollution ◽  
Fresh Vegetables ◽  
Relative Standard ◽  
Pyrethroid Pesticides

In this essay we investigate mainly 18 pesticide residues with different chemical structures in fresh vegetables, including organochlorine pesticides, organophosphorus pesticides, carbamate pesticides and pyrethroid pesticides. At the same time, it is estimated that the potential health risks for residents. A total of 313 samples were collected from 12 kinds of vegetables from Changchun, the capital of Jilin Province,China. 18 pesticide residues in 313 samples were analyzed by Gas chromatography and mass spectrometry (GC-MS) . Testing linearity was favorable in the range of 0.01 - 1.00μg/mL, R 2 ≥0.99, and the recovery rate of pesticides was 62% - 110%, the relative standard deviation < 5%, the detection limit of the pesticide is 0.0001 - 0.0167 mg / kg, the limit of quantification is 0.0002 - 0.0556 mg / kg. Overall, the detection rate of pesticides was 28.43%, and the detection rate and over-standard rate of celery were the highest, while the pesticide detection rate of potatoes was the lowest, and the pesticide exceeding rate of cucumber was the lowest. Three pesticides tested were not detected in the 18 pesticides including heptachlor, chlorpyrifos and permethrin. Among the 15 pesticides detected, the maximum risk factor of 7 pesticides is greater than 1 such as carbofuran, omethoate, phorate, dicofol, dimethoate, chlorpyrifos and dichlorvos, which may cause potential harm to human health. In contrast others will be safe. It could not have significant perniciousness for people from the perspective of single pollution level,, but it is not ignored there are multiple pesticide residue compound pollution to endanger persons' health.

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