QIBEBT-led consortium achieves bacterial degradation of PET bottles to provide terephtalic acid in 97% yield

A research team from the Qingdao Institute of Bioenergy and Bioprocess Technology of the Chinese Academy of Sciences, in collaboration with Nanjing Tech University and Greifswald University, has introduced an innovative solution for the depolymerization of polyethylene terephthalate (PET). This solution utilizes an engineered whole-cell biocatalyst based on the thermophilic bacterium Clostridium thermocellum.

This study builds on prior work, where the research team first demonstrated the concept of whole-cell catalytic PET depolymerization. In that study, the genetically engineered C. thermocellum expressed leaf compost cutinase (LCC) via a plasmid for high-temperature PET depolymerization.

In this study, the researchers integrated LCC directly into the chromosome of C. thermocellum, ensuring stable enzyme expression. They further enhanced the system by introducing LCC variants and co-expressing hydrophobic modules.

By optimizing reaction conditions and controlling pH, the researchers achieved a significant improvement in PET depolymerization efficiency with minimal accumulation of the intermediate product mono(2-hydroxyethyl) terephthalate (MHET).

When tested with pretreated PET bottle particles, about 97% of the added PET was converted into terephthalic acid (TPA), a key monomer used in producing new plastics or high-value chemicals. This high level of performance positions the system as a promising green solution for PET recycling.

Additionally, C. thermocellum is naturally capable of degrading cellulose, making it a potential candidate for directly processing mixed textile waste that contains cotton fibers and PET.

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A lipid-rich baker’s yeast mutant provides high yields of palmitoleic acid

http://english.cas.cn/newsroom/research_news/life/202508/t20250801_1048868.shtml

https://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-025-02677-8

A team at CAS Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) has developed a lipid-rich mutant strain of Saccharomyces cerevisiae for microbial production of palmitoleic acid— a rare omega-7 fatty acid with proven anti-inflammatory and metabolic benefits.

The team used a combined mutagenesis approach—employing zeocin, an antibiotic-based mutagen, and Atmospheric and Room Temperature Plasma (ARTP)—to create a diverse library of yeast mutants. They then deployed FlowRACS, a Raman flow cytometry system, to select live yeast cells with elevated lipid levels by analyzing their intrinsic single-cell Raman spectra, eliminating the need for chemical stains or genetic reporters.

This method identified the mutant strain MU2R48, which achieved a lipid content of 40.26%—a 30.85% increase over its parental strain SC018—while maintaining similar biomass production.

Photo: Raman flow cytometry efficiently identifies lipid-rich Saccharomyces cerevisiae  mutants from a Zeocin–ARTP-induced library. (Image by QIBEBT)

Sept. 13 – 16, 2025: 2nd International Conference on Green Carbon in Qingdao and online

Registration is open: https://conf.sciencemate.com/ICGC2025

ICGC aims to provide an interdisciplinary academic exchange platform and academic community for scientific and technological innovation in the area of CO₂ emission reduction and sustainable development. The conference will focus on carbon resources, carbon conversion technologies, carbon life cycle management, and breakthrough developments in green carbon science.

Qingdao Institute of Bioenergy and Bioprocess Technology, CAS/Shandong Energy Institute (QIBEBT/SEI) is a research institute that is active in science and technology developments of bioenergy, fossil energy, hydrogen energy, energy storage devices, and energy informatics, see http://english.qibebt.cas.cn

A hydrogen-powered tugboat in Qingdao port

https://j.people.com.cn/n3/2025/0627/c95952-20333735.html

The tugboat was designed and built by Shandong Port Qingdao Port Group Co., Ltd. and is equipped with a hybrid system of “hydrogen fuel cells + liquid-cooled lithium batteries” to achieve zero carbon dioxide emissions. It can sail for more than 12 hours at a speed of 9 knots and has a towing force of 82 tons. With technologies such as fully automatic smart on-shore charging, it has become the country’s largest port tugboat in terms of horsepower and lithium battery capacity.

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