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[前沿资讯 ] 中科院天津工业生物所开发定量异源途径设计方法，助力微生物产品合成途径的高效设计 进入全文
中国科学院天津工业生物技术研究所
中国科学院天津工业生物技术研究所生物设计中心开发了一个定量异源途径设计方法QHEPath。利用该方法，研究团队系统地评估了五种常用工业微生物在四种底物下合成300种生化产品的12,000个生物合成场景。结果表明，超过70%产品途径的理论得率有潜力通过引入合适的异源反应得到提升。同时，团队还总结了13种通用的途径优化策略，这些策略主要分为碳节约和能量节约两大类，其中五种策略对100多种产品的得率提升均有效。为了使生物学家能够更便捷地应用这一方法，团队还搭建了一个在线异源途径设计平台QHEPath (https://qhepath.biodesign.ac.cn/)。该平台能够定量计算并可视化35种微生物宿主中产品的高得率合成途径，并且成功预测了文献中多种产品的途径优化策略。
[前沿资讯 ] Ginkgo Bioworks and Novus team up on enzyme development 进入全文
Feed Navigator
By focusing on more efficient, cost-effective enzymeproduction, the partnership seeks to bolster the well-being of chickens, pigs, and cows. With the agricultural sector facing increased volatility due to rising feed costs and narrowingmargins, the companies say this collaborative effort comes at an opportune time. Innovationsin feed enzyme technology are expected to support producers by lowering costs whilemaintaining or even improving the nutritional quality of animal products, they add. The initial focus of the collaboration is on developing next-generation enzymes, withimproved efficacy. Protease enzymes, for instance, can increase the availability of aminoacids in poultry and swine feed, while also mitigating the negative effects of anti-nutritionalfactors like trypsin inhibitors, which means reduced excess indigestible protein in the cecumthat can lead to enteric challenges. “This ultimately supports gut health and overallperformance,” says Gaurav Shah, associate director of external innovation and businessdevelopment at Novus.
[学术文献 ] Versatile filamentous fungal host highly-producing heterologous natural products developed by genome editing-mediated engineering of multiple metabolic pathways 进入全文
COMMUNICATIONS BIOLOGY
Natural secondary metabolites are medically, agriculturally, and industrially beneficial to humans. For mass production, a heterologous production system is required, and various metabolic engineering trials have been reported in Escherichia coli and Saccharomyces cerevisiae to increase their production levels. Recently, filamentous fungi, especially Aspergillus oryzae, have been expected to be excellent hosts for the heterologous production of natural products; however, large-scale metabolic engineering has hardly been reported. Here, we elucidated candidate metabolic pathways to be modified for increased model terpene production by RNA-seq and metabolome analyses in A. oryzae and selected pathways such as ethanol fermentation, cytosolic acetyl-CoA production from citrate, and the mevalonate pathway. We performed metabolic modifications targeting these pathways using CRISPR/Cas9 genome editing and demonstrated their effectiveness in heterologous terpene production. Finally, a strain containing 13 metabolic modifications was generated, which showed enhanced heterologous production of pleuromutilin (8.5-fold), aphidicolin (65.6-fold), and ophiobolin C (28.5-fold) compared to the unmodified A. oryzae strain. Therefore, the strain generated by engineering multiple metabolic pathways can be employed as a versatile highly-producing host for a wide variety of terpenes.
[学术文献 ] Increased artemisinin production in Artemisia annua L. by co-overexpression of six key biosynthetic enzymes 进入全文
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
Malaria remains a global health issue, especially in resource-limited regions. Artemisinin, a key antimalarial compound from Artemisia annua, is crucial for treatment, but low natural yields hinder large-scale production. In this study, we employed advanced transgenic technology to co-overexpress six key biosynthetic enzymes-Isopentenyl Diphosphate Isomerase (IDI), Farnesyl Pyrophosphate Synthase (FPS), Amorpha 4,11-diene Synthase (ADS), cytochrome P450 monooxygenase (CYP71AV1), cytochrome P450 oxidoreductase (AACPR) and artemisinic aldehyde D11 reductase (DBR2)-in A. annua to significantly enhance artemisinin production. Our innovative approach utilized a co-expression strategy to optimize the artemisinin biosynthetic pathway, leading to a remarkable up to 200 % increase in artemisinin content in T1 transgenic plants compared to nontransgenic controls. The stability and efficacy of this transformation were confirmed in subsequent generations (T2), achieving a potential 232 % increase in artemisinin levels. Additionally, we optimized transgene expression to maintain plant growth and development, and performed untargeted metabolite analysis using GC-MS, which revealed significant changes in metabolite composition among T2 lines, indicating effective diversion of farnesyl diphosphate into the artemisinin pathway. This metabolic engineering breakthrough offers a promising and scalable solution for enhancing artemisinin production, representing a major advancement in the field of plant biotechnology and a potential strategy for more cost-effective malaria treatment.
[学术文献 ] Engineering lipase TLL to improve its acid tolerance and its biosynthesis in Trichoderma reesei for biodiesel production from acidified oil 进入全文
Bioresource Technology
Lipases catalyze the synthesis of biodiesel, which is an important renewable alternative energy source. Cost-efficient conversion of waste acidified oil to biodiesel entails acid-tolerant lipases which have not been extensively studied. This study showed that the commonly used Thermomyces lanuginosus lipase TLL displayed a weak acid tolerance and an unsatisfactory performance in biodiesel production from acidified oil. Directed evolution of TLL identified one TLL-T3 variant with three residue substitutions (A69S/V150P/N222G). TLL-T3 displayed significantly enhanced acid tolerance, and its application in acidified oil treatment led to a biodiesel yield up to 90 % (w/w). A scaled-up production of TLL-T3 in Trichoderma reesei was further achieved and the highest extracellular lipase activity reached 16,123 U/mL after fermentation optimization. These results provide new insights into structural adaptation to acid tolerance by lipases and show that TLL-T3 holds great potential in commercial biodiesel production from waste acidified oil.
[学术文献 ] Homologous expression, purification, and characterization of a recombinant acetylxylan esterase from Aspergillus nidulans 进入全文
International Journal of Biological Macromolecules
Acetylxylan esterases (AXEs) are essential enzymes that break down the acetyl groups in acetylated xylan found in plant cell walls polysaccharides. They work synergistically with backbone-depolymerizing xylanolytic enzymes to accelerate the degradation of complex polysaccharides. In this study, we cloned the gene axeA, which encodes the acetylxylan esterase from Aspergillus nidulans FGSC A4 (AxeAN), into the pEXPYR expression vector and introduced it into the high protein-producing strain A. nidulans A773. The purified AxeAN, with a molecular weight of 33.5 kDa as confirmed by SDS-PAGE, was found to be active on ρ-nitrophenyl acetate (ρNPA), exhibiting a remarkably high specific activity (170 U mg−1) at pH 7.0 and 55 °C. AxeAN demonstrated stability over a wide pH range (5.5–9.0), retaining >80% of its initial activity after 24 h. The KM and Vmax were 0.098 mmol L−1 and 320 U mg−1, respectively, using ρNPA as a substrate. We also evaluated the synergistic effect of AxeAN with an endo-1,4-β-xylanase from Malbranchea pulchella (MpXyn10) in the hydrolysis of four different xylans (Birchwood, Beechwood, Oat spelt, and Arabinoxylan) to produce xylooligosaccharides (XOS). The best results were obtained using Birchwood xylan as substrate and MpXyn10-AxeAN as biocatalysts after 24 h of reaction (50 °C), with a XOS-yield of 91%, value 41% higher when compared to MpXyn10 (XOS-yield of 63%). These findings showed the potential of the application of AxeAN, together with other xylanases, to produce xylooligosaccharides with high purity and other products with high added value in the field of lignocellulosic biorefinery.
