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)

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An automated digital colony picker monitors growth and metabolite production, eliminating the need for culturing cells

https://www.nature.com/articles/s41467-025-63929-7

http://english.cas.cn/newsroom/research_news/life/202510/t20251014_1089412.shtml

The group around Jian XU from the CAS Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) has developed a fully automated “Digital Colony Picker” (DCP). This device identifies and retrieves high-performance microbial clones by simultaneously monitoring their growth and metabolite production—eliminating the need for culture plates, sampling needles, or manual picking.

Designed for the “design-build-test-learn” framework widely adopted in synthetic biology, the DCP streamlines the traditionally slow, labor-intensive “test” phase into a fast, parallel workflow with little hands-on time. It has a microfluidic chip containing 16,000 addressable microchambers that isolate single cells and track their expansion into micro-colonies. An integrated AI engine conducts time-lapse analysis of both brightfield and biosensor signals to quantify growth kinetics and metabolite production in real time. Once target colonies are identified, a laser-induced bubble technique exports them as droplets directly into standard culture plates. This contact-free transfer minimizes cross-contamination and preserves cell viability.

The equipment which was tested for identifying high-yield or lactate-tolerant Zymomonas mobilis mutants is broadly applicable to adaptive evolution studies, functional gene discovery, and phenotype screening across diverse microbial species.

Epigenetic modifications help algae to adapt to low CO2 environments

http://english.cas.cn/newsroom/research_news/life/202510/t20251010_1089023.shtml

https://www.cell.com/plant-communications/pdf/S2590-3462(25)00296-2.pdf?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2590346225002962%3Fshowall%3Dtrue

A research team from the Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT) of the Chinese Academy of Sciences has identified a specific histone modification as the key regulator governing microalgae’s adaptation to low-CO₂environments.

The study focused on Nannochloropsis oceanica, tracking its epigenomic dynamics as it transitioned from an environment with 5% CO₂ to one with just 0.01% CO₂. Using multi-dimensional epigenomic sequencing techniques, the researchers discovered that global DNA methylation in the alga remained stable at 0.13%, effectively ruling out DNA methylation as a major driver of its low-CO₂response. By contrast, H3K4me2 methylationwas found to be closely associated with 43.1% of the genes that respond to low-CO₂ conditions. These genes include those critical to photosynthesis and ribosome biogenesis, two processes essential for the alga’s survival under carbon-limited stress. Further analysis revealed that H3K4me2 appears to regulate gene transcription by altering chromatin accessibility, a mechanism that aligns with its role as a central regulator of low-CO₂ adaptation.

To validate their findings, the team used CRISPR/Cas9 gene-editing technology. They knocked out NO24G02310—a gene that encodes an H3K4 methyltransferase, the enzyme responsible for adding methyl groups to H3K4. The modified algae showed a roughly 22% reduction in growth rate and a 15% decrease in biomass. Additionally, the levels of another histone modification (H3K4me1) dropped, and the genome-wide localization of H3K4me2 shifted—providing direct evidence of H3K4me2’s role in low-CO₂ adaptation. Further experiments uncovered that H3K4 modification may act via two pathways: by regulating enzyme networks and by modulating chloroplast transmembrane pH gradients. Both mechanisms work to optimize the alga’s use of available CO₂, enhancing its survival under low-carbon conditions.

Sorting cells by Raman fingerprint

Nachrichten aus der Chemie (2025) 73, p. 37 – 39 (in English)

Raman article

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