Solve the following pain points and combine synthetic biology with polymer material polymerization technology

The bio-based industry is a core component of the bio-economy, helping us build a more innovative, sustainable and resource-efficient society. Although the market size of the bio-based industry is still relatively small, its impact and disruption on traditional industries, especially petroleum-based industries, have been obvious in recent years. At present, the bio-based industry is expected to be an effective supplement to the petroleum-based industry in the short term, and a large-scale replacement solution in the medium and long term.

To achieve this goal, bio-based products must first meet market demand in terms of performance, then achieve a high degree of stability in production processes, and finally form a clear advantage in terms of cost. Synthetic biology, as the third biotechnology revolution after the discovery of the DNA double helix structure and genome sequencing, will help the rapid and high-quality development of the bio-based industry and promote mankind from the industrial revolution to the ecological revolution.

Synthetic biology can solve the three major pain points of industrialization

The core of synthetic biology is to use various metabolic functional elements and gene editing tools to transform organisms so that they can use biomass (such as glucose, straw hydrolysate, food waste processing products, etc.) as raw materials to produce various products needed by human society.

Synthetic biology has made great progress since the famous geneticist Waclaw Szybalski first proposed this concept in the 1970s. In 2020, French biologist Emmanuelle Charpentier and American biologist Jennifer Doudna shared the Nobel Prize in Chemistry and brought their invention of CRISPR gene editing technology to the public eye. This new genome editing method allows scientists to rewrite the genetic genes of almost all organisms, and is simpler, cheaper and more precise than previous gene editing technologies, further promoting the synthetic biology industry forward. According to a McKinsey estimate, more than 60% of the global economic material will be produced by synthetic biology. Therefore, the development of this bio-based industry is also due to the maturity of synthetic biology technology.

The core reason why synthetic biology can promote the rapid development of the bio-based industry lies in its ability to solve three important pain points in the industrialization process: performance to meet market demand, process to achieve high stability, and cost to form obvious advantages. By transforming microorganisms through synthetic biology, materials with new properties can be developed to fill unmet market spaces; by optimizing microorganisms from an engineering perspective, the biomanufacturing process can be simplified, and stability can be improved through step-by-step amplification; By substituting substrates and shortening the production cycle, raw material and production costs can be significantly reduced, thereby forming a cost advantage.

As a professional team that has long been committed to the research and development and production of a variety of green bio-based products through synthetic biology, Microstructure Factory has taken the lead in establishing a process system for large-scale production of a biodegradable material, polyhydroxyalkanoate (PHA).

Examples of synthetic biology promoting the development of bio-based industries

Synthetic biology has played a vital role in promoting the development of a new round of bio-based industries. Next, PHA will be used as an example to introduce it.

PHA is a natural polymer material synthesized by microorganisms. As a reserve material for microbial carbon sources and energy, PHA has more than 150 structures, which makes PHA a wide variety of materials with diverse properties. As a bio-based material with biological origin and biopolymerization, PHA has extremely low carbon emissions throughout its life cycle and is an ideal low-carbon material. In addition, PHA is biodegradable in water, soil, and environments with both, and even under anaerobic conditions, and will not impose any burden on the natural environment. Therefore, PHA has become a very ideal substitute for plastics, which will help to completely solve the problem of white pollution and achieve sustainable development.

Although PHA has excellent performance, there are still some areas that can be optimized. For example, the mainstream PHA materials on the market, including other types of biodegradable materials, generally have problems such as low transparency. In areas where highly transparent plastics are required, such as infusion tubes, transparent packaging materials, and food packaging, they are greatly restricted, which has also created a huge unmet market. To this end, the Microstructure Factory team and Tsinghua University conducted a systematic study and analysis on the molecular structure of PHA, and found that the PHA obtained by copolymerization of traditional monomers or two monomers has low transparency due to its own structural characteristics. The PHA material obtained by copolymerization of three monomers has three monomers with different structures, which greatly reduces the phenomenon of post-crystallization and has good transparency and material toughness. To this end, we used Halomonas as the base bacteria, transformed it through synthetic biology, developed a diol-PHA conversion platform, and successfully synthesized a new PHA material with different proportions-P (53% 3HB-co-20% 4HB-co-27% 5HV), which has transparency, thermal stability and ductility, and can be used in the field of flexible wearable devices and many application scenarios with high transparency requirements.

In terms of technology, we performed a series of gene edits on the chassis bacteria to give them characteristics that are more in line with industrial production, thereby reducing process complexity and improving stability. For example, traditional high-density fermentation requires a large amount of oxygen supply, which poses a challenge to the use of air compressors in the process. A microorganism with a total weight of 100 grams requires 3 to 5 liters of air/minute, but can only utilize 1% to 2% of the oxygen in the air. In contrast, a person with a total weight of 70 kilograms only needs 1 to 2 liters of air per minute and can use up almost all the oxygen in the air. Therefore, the oxygen utilization rate of humans is at least 700 times that of bacteria, and the core of this is that humans have hemoglobin. To do this, bacterial hemoglobin can be cloned from Oscillator hyalinus and introduced into the chassis strain. The chassis strain configured with hemoglobin significantly improves oxygen utilization, can grow more quickly, and reduces the complexity of the oxygen supply process. In addition, in response to the problem that the cell volume is too small, which makes it difficult to recover PHA products, we edited multiple cytoskeleton-related genes of the chassis strain, increasing the cell volume and the size of accumulated PHA particles by dozens of times, significantly reducing the Process difficulties in downstream extraction. Through a lot of work similar to the above, our production process has been greatly simplified and the corresponding stability has also been greatly improved.

In terms of cost reduction, we first modified the chassis strain and used cheap non-bulk agricultural product carbon sources or even waste carbon sources for production. The Tsinghua research team that founded the microstructure factory developed a new generation of halophilic strains that can produce PHA using a variety of substrates as early as 2015. With the deepening of research and development, the new generation of strains that are constantly being introduced can use many waste carbon sources for production, such as straw hydrolyzate, waste glycerin, food waste, molasses, acetic acid, etc., which can significantly reduce production costs while achieving " Don’t compete with others for food.” In addition, we also further improve the production efficiency per unit time by shortening the production cycle. Ordinary bacteria grow from 1 to 2, and the growth rate is 2 to the Nth power. If the growth of the chassis strain is changed from 1 to 3 or even 1 to 4, then the growth rate will become 3 to the Nth power or even 4 to the Nth power, greatly increasing the growth rate. We mutated the gene minCD related to the division of chassis strains to achieve the growth modes of 1 to 3 and 1 to 4, significantly shortening the fermentation time and reducing the overall production cost.

Based on the above series of work, we have established a system for large-scale production of PHA. At present, Micro-structure Factory has established its headquarters in Zhaoquanying Town, Shunyi District, Beijing, and built an intelligent demonstration production line of 1,000 tons/year of high-end biomaterial PHA. At the same time, it has built a Sino-German synthetic biology research and development center in the starting area of ​​the Sino-German Industrial Park. At the same time, Micro-structure Factory has also established a joint venture "Micro-Qi Bio" with Angel Yeast, the world's second largest yeast company, to jointly promote the industrialization of synthetic biology technology and start the construction of a 30,000-ton/year PHA production base project in Yichang, Hubei. In addition, this large-scale production capacity based on synthetic biology work can also be reused for other bio-based products, including pharmaceutical intermediate tetrahydropyrimidine, nylon 56 precursor pentamethylenediamine, etc.

Synthetic biology plays a vital role in this round of bio-based industry. Through metabolic functional elements and gene editing tools, it is possible to carry out targeted transformation of microorganisms to meet large-scale production. In the future, synthetic biology will become the engine of a new round of bio-based industry, leading the transformation of green and low-carbon technologies!