Background
Inspiration
Circuits
Development Prospect
Herbicides huge contribution to global agriculture, and in various countries around the world about using herbicides continues to increase, and with the invasive species, a breakthrough before there was any, climate change and adaptability of pathogens resistance to solve the problem of refractory diseases and insect pests, a new type of environmental health herbicides and using a method of research is imminent.
Herbicides huge contribution to global agriculture, and in various countries around the world about using herbicides continues to increase, and with the invasive species, a breakthrough before there was any, climate change and adaptability of pathogens resistance to solve the problem of refractory diseases and insect pests, a new type of environmental health herbicides and using a method of research is imminent.
Herbicides, as a group of pesticides, are crucial to global agricultural production. Increasing crop yields to quantify the impact of herbicides is only one aspect. The increased yields contribute to several indirect economic effects, according to CropLife America 2011: The economic proliferation of crop protection technologies and the contribution of crop protection to the balance of trade, with herbicide use having the greatest impact.
Data from 18 field crops, 26 vegetable crops, and 38 fruit and nut crops were collected for each of the 50 states. In the analysis, the use of crop protection products resulted in an additional $51.4 billion in value for field crops, $18.9 billion in value for fruits and nuts, and $11.5 billion in value for vegetables, for a total of about $82 billion in new crop value. For field crops, 36% of total output ($51.4 billion of $141.3 billion) was attributed to crop protection products across the United States, with herbicide use having the greatest impact.
According to data from the National Bureau of Statistics, the amount of pesticide used in China has reached more than 1.8 million tons, and the latest research on pesticide use shows that the utilization rate of pesticides in China only accounts for 35%, that is, more than 65% of pesticides are wasted. According to relevant research, the general situation of pesticide application is: Only about 25 to 35 percent of the pesticide sprayed from the application machine can be deposited on the leaves of the crop. Others drift away into the air with the airflow, mainly small fog droplets, generally accounting for about 20%. There are missed targets lost or due to the accumulation of fog droplets from the target (crop) rolled down to the ground, accounting for about 40%. Less than 1% of the pesticides can be deposited on the target pests, and only less than 0.03% of the pesticides can play an insecticidal role. Therefore, no matter how efficient the pesticides are, the inefficient utilization rate will lead to insignificant pesticide application effects and increase the use cost in vain.
Therefore, it is necessary to reasonably control the distance between the sprinkler head and the crop to make it easier for the droplets to form a drug film on the crop so that the effect of the drug will be prominent. The spray nozzle atomization degree is not the smaller the droplets, the better, will float in the air and be difficult to deposit on the crop, which will certainly cause waste; If the droplets are too large, the amount of liquid medicine rolling on the ground will increase, which is also a waste.
The most widely used herbicide: Glyphosate. Glyphosate, chemical name N-(methyl phosphate) glycine, chemical formula C3H8NO5P, is an organic phosphine herbicide, is a broad-spectrum herbicide of internal absorption conduction.
Glyphosate in the recommended dose range have little impact on human and other mammals (high dose can stimulate mammals in the stomach and cause aspiration pneumonia, killed), but with the current widespread popularization and cultivation of genetically modified (gm) crops, glyphosate usage can be high, has a great potential threat on the ecological environment. Glyphosate (GLyphosate) is a potential source of environmental and ecological hazards that has attracted increasing attention in recent years. Its acute toxicity to aquatic organisms and its effect on soil microbial population are urgent problems to be solved.
Glyphosate is the number one selling herbicide in the world due to its excellent herbicidal activity, broad herbicidal spectrum, low taxisoil residue, and long grass control time, combined with the widespread cultivation of herbicide-resistant GM crops. However, the problem of weed resistance has been very prominent due to the long-time single and continuous use of weed. So far, 31 species of weeds with 100 organisms have been reported to be resistant.
The current price of glyphosate is about 8.5 times that of glyphosate and 9 times that of paraquat. From the end market point of view, the biggest obstacle restricting the large-scale application of glyphosate ammonium is the high price. The cost of glyphosate per mu is about 15-18 yuan, the cost of glyphosate per mu is about 10-12 yuan, and the cost of paraquat per mu is about 7-9 yuan. Therefore, from the point of view of my cost, the popularity of glyphosate is not as high as everyone imagined, the acceptance of users still need to carry out more work, so reducing the production cost of glyphosate, with low cost and controllable will promote improvement the acceptance of users for glyphosate.
At present, the main synthesis process of glyphosate ammonium (Strecker synthesis method) has the following disadvantages: Although Strecker synthesis grass ammonium phosphonic technology has been mature, the process requires highly toxic cyanide and acrolein material, the production process is very complex, the demand is higher, the external environment in the operation personnel safety hidden trouble, and in the reaction by-products generated will have a lot of ammonium chloride, and the target product ammonium grass phosphonic separation is difficult, The treatment of "three wastes" is complicated, and the purification process is cumbersome, and the whole process takes a long time.
Plastic film planting will cover a lot of plastic film in the field, and the crops will remain in the soil after harvest, which is difficult to degrade, causing pollution and damage to the soil. As the main component of plastic film is still plastic (polyethylene), with the spread of plasticizer storms, whether the plastic film can not settle will lead to the high content of plasticizer in the soil and affect people's health is still being tested. Therefore, the development of biodegradable bioplastic film is still a hot direction.
Through background research, our team found that the widespread use of chemical herbicides in agriculture has led to global safety problems, serious environmental pollution, and biodiversity reduction. Therefore, from the perspective of the healthy development of the industry, if we cannot seek breakthroughs in key issues such as process transformation, de-homogenization, and accelerated promotion and application, and production costs cannot be reduced, we will not have core competitiveness. Therefore, we provide environmentally friendly biofortification, trying to solve the above problems through synthetic biology. An engineered Escherichia coli is being constructed to produce a novel herbicide, aspartic acid and extracellular polysaccharide (EPS), under blue light and can be released into the soil in a controlled manner at a high temperature of 42 ° C, avoiding overuse of herbicides and possible residue, while promoting water retention and sand fixation of EPS. The intelligent synthesis and release of our biofertilizers will maximize the effects of herbicides and EPS, contributing to the environment and society.
Our circuit is mainly divided into two parts, consisting of a proplasmid that converts glucose into the key precursor GPP and a multifunctional plasmid that synthesizes herbicides and EPS under the control of blue light commonly used in the greenhouse. Meanwhile, our engineered cells lysed at a high temperature above 42 ° C to release herbicide and EPS-expressing lytic genes. With the sun shining. About 10% of the engineered bacteria will escape the lysis process and recover, facilitating a new round of controlled production and release of herbicides and EPS.
After determining the idea, we arranged a careful plan. There were a lot of plasmid gene fragments synthesized by the precursor, which took a lot of time. However, because the functions of the fragments were closely connected, the synthesis was relatively smooth and verification was convenient. And multi-function plasmid although fragments are relatively fewer, contains the function is more, so we designed the different plasmid, respectively, are used to verify the system to adjust the blue light-induced EPS synthesis, AA product synthesis, as well as the temperature cracking functions, can be normal, that the ideas to help us gain great breakthrough.
This worthy of mention is the way the project considered product release and security issues, affected by blue light control synthesis at first, we want to suicide cracking control bacteria with, a red light control system to release the product, and after a literature investigation we found, however, red light regulation of instability, poor effect, it is not desirable for environmental protection. Therefore, we adjusted the direction in time and re-investigated. Finally, we found the excellent performance of cleavage genes regulated by temperature and designed a validation plasmid for this purpose.
This is the goal we set in the early stage of the project. However, due to the impact of the COVID-19 epidemic, our project has not been perfectly completed as expected. However, this does not mean that our team will give up this meaningful project, and we still want to try to realize the engineering of bacterial powder containing double plasmids.
In field investigation, we traveled to China's Shaanxi province xi 'an * * village herbicide use interviews, local farmers are very friendly to us not only to share their experience in using pesticides but also really looking forward to our "new" herbicide, even hope that we can give the final product, it is fuelling the confidence of the team to complete our products, We also look forward to the day when the engineered bacterial powder can be used in practice.
Bill Gates mentioned in his "Climate Economy and Human Future" that carbon emissions from agriculture, planting, and breeding account for 19% of the world's total emissions, making it the third largest source of emissions. Emerging biological solutions such as synthetic biology and microbiology will contribute to global environmental protection and zero carbon goals.
