Publications by authors named "Xiao-man Sun"

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are important polyunsaturated fatty acids (PUFAs) used as nutritional supplements. The natural EPA content in sp. is low, and traditional strategies to increase EPA levels often compromise DHA content or lipid accumulation, hindering industrial coproduction.

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When constructing cell factories, it is crucial to reallocate intracellular resources towards the synthesis of target compounds. However, imbalanced resource allocation can lead to a tradeoff between cell growth and production, reducing overall efficiency. Reliable gene expression regulation tools are needed to coordinate cell growth and production effectively.

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Article Synopsis
  • Squalene is a beneficial compound with anticancer and antioxidative properties, making it important for food and pharmaceuticals.
  • Microbial fermentation, particularly using Schizochytrium sp., is a promising method for producing squalene due to the limited natural resources.
  • The study involved cloning and testing 13 endogenous promoters to enhance the expression of the squalene synthase gene, resulting in a transformed strain (SQS-3626) that produced squalene at 2.8 times the level of the wild-type strain after optimizing fermentation conditions.
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Thraustochytrids are marine microorganisms known for their fast growth and ability to store lipids, making them useful for producing polyunsaturated fatty acids (PUFAs), biodiesel, squalene, and carotenoids. However, the high cost of production, mainly due to expensive fermentation components, limits their wider use. A significant challenge in this context is the need to balance production costs with the value of the end products.

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Schizochytrium sp. hasreceived much attention for itsability to synthesize and accumulate high-level docosahexaenoic acid (DHA), which can reach nearly 40 % of total fatty acids. In this study, the titer of DHA in Schizochytrium sp.

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Background: Eicosapentaenoic acid (EPA) is widely used in the functional food and nutraceutical industries due to its important benefits to human health. Oleaginous microorganisms are considered a promising alternative resource for the production of EPA lipids. However, the storage of EPA in triglyceride (TG) becomes a key factor limiting its level.

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Schizochytrium sp., a microalga with high lipid content, holds the potential for co-producing docosahexaenoic acid (DHA) and carotenoids. In this study, the ability of Schizochytrium sp.

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Article Synopsis
  • Polyunsaturated fatty acids (PUFAs) like DHA, EPA, and ARA help reduce cholesterol and improve memory, but their traditional production methods are unsustainable.
  • Oleaginous microorganisms offer a more sustainable alternative for PUFA production and can be categorized into universal hosts, like Yarrowia lipolytica, which produce a range of fatty acids, and specialized hosts, which produce specific fatty acids.
  • This review discusses metabolic engineering and fermentation approaches for enhancing PUFA production in both types of hosts, along with broader strategies applicable to all microbial lipid production.
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Docosahexaenoic acid (DHA) as one of ω-3 polyunsaturated fatty acids (PUFAs), plays a key role in brain development, and is widely used in food additives and the pharmaceutical industry. Schizochytrium sp. is often considered as a satisfactory strain for DHA industrialization.

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The isopentenol utilization pathway (IUP) is potential in terpenoids synthesis. This study aimed to construct IUP-employed Escherichia coli chassis for stably synthesizing terpenoids. As to effectiveness, promotor engineering strategy was employed to regulate IUP expression level, while ribosome-binding site (RBS) library of the key enzyme was constructed for screening the optimal RBS, followed by optimization of concentration of inducer and substrates, the titer of reporting production, lycopene, from 0.

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Odd chain fatty acids (OCFAs) are high-value-added compounds with great application in the field of food and medicine. As an oleaginous microorganism, sp. has the potential to produce OCFAs efficiently.

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Base editors (BE) based on CRISPR systems are practical gene-editing tools which continue to drive frontier advances of life sciences. BEs are able to efficiently induce point mutations at target sites without double-stranded DNA cleavage. Hence, they are widely employed in the fields of microbial genome engineering.

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In order to find a more effective way to obtain docosahexaenoic acid (DHA) rich lipid from Schizochytrium sp., a widespread propionate wastewater (PW) is used. PW is a common industrial and domestic wastewater, and transforming it into valuable products is a potential treatment method.

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Due to the complexity of metabolic and regulatory networks in microorganisms, it is difficult to obtain robust phenotypes through artificial rational design and genetic perturbation. Adaptive laboratory evolution (ALE) engineering plays an important role in the construction of stable microbial cell factories by simulating the natural evolution process and rapidly obtaining strains with stable traits through screening. This review summarizes the application of ALE technology in microbial breeding, describes the commonly used methods for ALE, and highlights the important applications of ALE technology in the production of lipids and terpenoids in yeast and microalgae.

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Polyunsaturated fatty acids (PUFAs) are important nutrients for humans and animals. Microorganisms, such as yeast, filamentous fungi, and microalgae, have successfully been modified to produce PUFAs. Apart from strain improvement and fermentation optimization, efficient and cost-effective downstream processing will determine whether production can advance from the laboratory to the factory.

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It is well known that polyunsaturated fatty acids (PUFAs) in sp. are mainly synthesized via the polyketide synthase (PKS) pathway. However, the specific mechanism of PKS in fatty acid synthesis is still unclear.

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The increasing market demand for squalene requires novel biotechnological production platforms. Schizochytrium sp. is an industrial oleaginous host with a high potential for squalene production due to its abundant native acetyl-CoA pool.

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Background: Schizochytrium sp. is a heterotrophic, oil-producing microorganism that can efficiently produce lipids. However, the industrial production of bulk chemicals using Schizochytrium sp.

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Noroviruses (NoVs) are the primary cause of acute gastroenteritis worldwide. Histo-blood group antigens (HBGAs) are receptors or attachment factors that affect the prevalence and host susceptibility of NoVs. GII.

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Two new thymol derivatives () were isolated from the aerial parts of . Their structures were elucidated on the basis of comprehensive spectroscopic data analysis as 8,9-dehydrothymol-3---glucoside (), and 9-(acetyloxy)thymol-3-yl (3-methylbut-2-enoate) (). All isolates were evaluated for cytotoxic activities with IC50 values greater than 50 μM against MCF-7, HeLa, A549, and Hep G-2 cancer cells.

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Escherichia coli, one of the most efficient expression hosts for recombinant proteins (RPs), is widely used in chemical, medical, food and other industries. However, conventional expression strains are unable to effectively express proteins with complex structures or toxicity. The key to solving this problem is to alleviate the host burden associated with protein overproduction and to enhance the ability to accurately fold and modify RPs at high expression levels.

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The combination of Escherichia coli BL21 (DE3) and the pET expression system is used extensively for the expression of various recombinant proteins (RPs). However, RP overexpression often introduces a growth burden for the host, especially in the case of toxic proteins. The key to solving this problem is to reduce the host burden associated with protein overproduction, which is often achieved by regulating the expression or activity of T7 RNAP or growth-decoupled systems.

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Non-homologous end-joining (NHEJ)-mediated random integration in has been demonstrated to be an effective strategy for screening hyperproducer strains. However, there was no multigene assembly method applied for NHEJ integration, which made it challenging to construct and integrate metabolic pathways. In this study, a Golden Gate modular cloning system (YALIcloneNHEJ) was established to develop a robust DNA assembly platform in .

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Schizochytrium sp. has received increasing attention as promising commercial resource for the sustainable production of lipids, due to their fast growth rate and high lipid content. However, the price of glucose represents a significant proportion of the total substrate cost.

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Article Synopsis
  • Schizochytrium sp. is a microorganism valued for lipid production, but its efficiency is hindered by low glucose-to-lipid conversion rates and lipid productivity.
  • The lipase inhibitor orlistat improved the glucose-to-lipid conversion rate by 21.88% and increased lipid productivity by 1.34 times, along with higher yields of saturated and polyunsaturated fatty acids.
  • The research also revealed that orlistat affects metabolic processes, directing carbon allocation and boosting energy supply, which provides insights into enhancing lipid accumulation in oleaginous microorganisms.
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