Inspiration

Accidentally, we saw the story of Professor Zhanxi Lin through social media publicity. We initially understood the advantages of high biomass content, short growth cycle and strong stress resistance of JUNCAO. Through literature review、online and offline interviews, we deeply understood the characteristics of simple hemicellulose and high cellulose content in lignocellulose of JUNCAO, and thought that it was suitable for production biology. Our project on the raw material of ethanol has been launched.

Biofuel

China has been the world's largest carbon emitter since 2007, and biomass energy, represented by energy crops, has attracted widespread attention in China, given the enormous pressure brought by environmental protection and climate change.Biomass energy refers to the conversion of biomass into gaseous, liquid and solid energy products, which indirectly comes from solar energy, mainly including fuel ethanol, biodiesel, biological natural gas and hydrogen production from biomass, etc.Biomass energy can use the carbon dioxide after emissions, and can return to the body through the carbon cycle, so as to achieve zero CO₂ emissions.As one of the important renewable energy sources, biomass energy has great development potential due to its advantages of clean use and environmental friendliness.At present, bioenergy has become the world's fourth largest energy source after coal, natural gas and oil. Compared with coal resources and oil resources, the proportion of renewable energy consumption is constantly increasing.

Bioethanol

Biofuel has many advantages. Compared with petrochemical diesel, biofuel releases significantly less carbon monoxide, particulate matter and hydrocarbons after combustion, and is recyclable. In addition, bioethanol has better fuel performance, lubrication performance and safety performance. Therefore, bioethanol is an ideal alternative to fossil fuels^[2]

As a safe and clean transportation fuel and gasoline additive, fuel ethanol is regarded as the most promising industrial raw material among renewable resources.

If we want to realize the industrialization of bioethanol, we need a fixed source of raw materials.Here is a supplement to the concept of "land-intensive bioenergy" : bioenergy from land plants grown or harvested for energy.The most advanced significance of bioenergy lies in neutral or even negative carbon emissions!But landintensive bioenergy only makes a meaningful contribution to the global energy system on a spatial scale of hundreds of millions of hectares or more, large enough to weigh heavily against the land used for food production and biodiversity conservation.^[1]

Why do you say so? The essential reason lies in the utilization rate of land resources. On the one hand, it forms a competitive relationship with agricultural production land;On the other hand, occupying a large area of land to intensively plant energy crops will change its original ecological environment and form a mutually beneficial cooperative relationship with ecological protection.So a good solution would be to grow energy crops in the desert.

JUNCAO

JUNCAO is a new field of crossover, research and application between bacteria and grass, and is a new type of grass species.It's called the energy grass;Energy grass refers to all the grass energy plants, is a series of can be used as fuel, energy production of grass plants collectively, generally two years or perennial tall clusters of herbs or shrubs, shrubs, shrubs.It has many advantages, such as short growth cycle, high fiber content, large biomass, strong resistance, etc. Therefore, using fungus grass to produce bioethanol can not only regulate the environment, but also produce energy, which can achieve the win-win effect of promoting economy and regulating the environment. Therefore, we think it is reasonable to develop fungus grass as an energy crop.

According to the research, mycelia have strong adaptability and can grow normally in the area of soil and water loss and collapse, and have strong tiller ability in the root.

JunCao biomass raw materials is a new development direction, can not only expand the sources of raw materials, reduce raw material costs, ensure supply, follow the "do not compete for food with people, not to reclaim land with food" principle, make full use of the marginal land, production of food, feed, fertilizer, materials, energy, etc., realize the solar energy, air, water, soil and other natural resources, comprehensive, efficient, recycling and use green, also can increase farmers' income in remote areas, driving the development of regional economy, in order to realize the organic integration of ecological, economic and social.At present, fungus grass is mainly used in agricultural production and ecological management. For example, farmers will earn income after 7-10 days of planting fungus bags, with an annual output of 1200 kilograms of edible fungi on a land of 10 square meters.Some mycorrhizal varieties can be used as pioneer plants to control desertification. After 80-100 days of planting, there are about 10-20 tillers, and the root system can fix sand of 15 square meters.One hectare of fungus absorbs about 90 tons of carbon dioxide, which can be quickly restored under extreme weather conditions and can mitigate the effects of secondary disasters such as storms.No insecticides, bactericidal agents, herbicides, etc., are used in the cultivation of fungi.The annual output of fresh grass of 1 hectare is 300-500 tons, and the calorific value of fungus grass fuel is 3580 kcal/kg.

Our project

In 2020, FAFU-CHINA integrates the advantages of our school's JUNCAO to carry out this year's project - ethanol production by integrated fermentation with JUNCAO as raw material.

This year, we designed an integrated fermentation system. The system consists of three kinds of chassis (E. coli & K. marxianus & Pichia pastoris) and control elements connecting them. The self-regulation based on biosensor was realized by sensing the concentration changes of various intermediates (glucose, lactose and ethanol) during fermentation. Through the above design, each reaction stage can be organically combined without interference. In addition, we also plan to modify the fibrosomes through rational design of proteins, so that they have the ability to disintegrate the cell wall structure, and finally achieve the effect of degradation of lignin, cellulose and hemicellulose.

Reference

[1] Xiaojing Lv,Alkali-based pretreatment and enzymatic hydrolysis of lignocellulosic biomass and their related mechanisms,162
[2] Ma F, Hanna M A. Biodiesel production: a review. Bioresource Technology, 1999, 70(1): 1-15.