Applied Technology

QIBEBT Develops Novel Biosynthesis System for Degradable Plastic

Poly (3-hydroxypropionate) (P3HP) is a new type of biodegradable plastic with good material properties and broad range of applications. Unfortunately, all known organisms cannot produce P3HP naturally. Recently, biobased Chemicals Group at Qingdao Institute of Bioenergy and Bioprocess Technology, CAS has made a series of progress on the biosynthesis of P3HP. A large numbers of genes probably involved in the P3HP synthesis from various organisms were cloned and expressed in E. coli strains, and the corresponding proteins were purified and characterized in vitro. Based on the results of enzyme activity tests, appropriate genes were selected and assembled into two novel P3HP biosynthetic pathways. The engineered E. coli strain harboring either pathway can produce P3HP using renewable inexpensive carbon sources, such as glucose and glycerol. Under optimized growth conditions, the engineered strain accumulated 10.1 g/L P3HP in fed-batch fermentation, which represented the highest production so far. To further improve the material properties, a second monomer, 3-hydroxybutarate (3HB), was incorporated into P3HP polymer. Two parallel synthetic pathways controlled by independent regulatory systems were used to produce the 3HP and 3HB monomers, respectively. Through tuning the expression level of appropriate genes, copolymers were synthesized with a wide range of 3HP fraction. The mechanic and thermal properties of copolymers was significantly improved. The relevant results have been published in journals of Bioresour Technol, ACS Macro Lett and J. Microbiol.

Advancement in Continuous and Effective Oil/Water Separation

Researchers in CAS Key Laboratory of Organic Solids, Institute of Chemistry, CAS (ICCAS) and collaborators in Tsinghua University and Peking University have achieved new breakthrough in continuous and effective oil/water separation. The environmental protection and economic development require advanced technology for oil/water separation, the frequent oil spill accidents and the development of industry make this requirement more urgent. Through the research on the natural creatures, researchers find that cactus spines could collect water from fog continuously, the water droplets collected can be self-driven towards the base of the spines by their conical structure. Inspired by this phenomenon, researchers fabricate similar conical needles with oleophilic materials, mimicking the micro- and nano-structures of cactus spines. Continuous and effective oil/water separation is achieved, and the efficiency is higher than 99%. Further more, this method has many advantages such as high throughput, environmental benefits, and corrosion resistance, which are difficult to achieve by current methods. This research provides a new idea for the design of new oil/water separation methods, which is of great significance to the development of environment and petroleum industry. This result was published as an Article in Nature Communications (Nat Commun. 4:2276 doi: 10.1038/ncomms3276 2013)