Spatial Organization of the Metabolic Pathway for Enhancing l-Fucose Biosynthesis in Engineered .

Synthetic biology and metabolic engineering have revolutionized the microbial biosynthesis of high-value compounds, yet conventional strategies are frequently confronted with metabolic burden and flux competition. Inspired by natural systems that employ spatial organization to enhance catalytic efficiency, we have developed advanced techniques to optimize pathway performance in engineered microbes. In this study, we present a systematic implementation of spatial organization strategies─consisting of scaffold-free enzyme assembly mediated by interacting peptides and engineered protein compartments─to improve l-fucose biosynthesis in .

Glycosyltransferases for Human Milk Oligosaccharide Synthesis: From Structural Understanding to Engineering.

Human milk oligosaccharides (HMOs) are vital for infant health by modulating gut microbiota and immune function. Due to challenges in natural extraction of HMOs, metabolic engineering using glycosyltransferases (GTs) offers a promising alternative. This review systematically explores GTs-mediated HMO biosynthesis, covering mechanisms, structural characterization, and protein engineering.

Construction and application of a bifunctional enzyme for the simultaneous enzymatic transformation of zearalenone and deoxynivalenol.

Zearalenone (ZEN) and deoxynivalenol (DON) are two common toxins that often coexist and observed simultaneously in foods. In this study, we constructed and characterized the fusion enzymes consisting of ZEN lactonase (ZENM) from Monosporascus sp. GIB2.

NADPH regeneration for efficient biosynthesis of indigo by flavin-containing monooxygenase and formate dehydrogenase.

Indigo is an important blue pigment widely used in textile, food, and medicine industries. Biological production of indigo attracts increasing attention recently. Cell factory production of indigo encounters the problem of the toxicity of the precursor indole.

Structural and Functional Insights into the Molecular Mechanism of Tagatose 4-Epimerase from Archaeon.

Tagatose 4-epimerase (T4Ease) has been demonstrated as a valuable enzyme for the bioproduction of d-tagatose, a low-calorie sugar substitute with various physiological benefits. The recently identified T4Ease from archaeon (Thar-T4Ease) exhibits the highest naturally occurring C4-epimerization activity reported to date and is capable of catalyzing the interconversion of d-fructose and d-tagatose. In this study, we elucidated the high-resolution crystal structure of Thar-T4Ease and conducted a detailed investigation of its structural features.

Microbial and enzymatic strategies for aflatoxin control: Integrating intelligent detection and computational design.

Aflatoxins (AFs), potent carcinogenic mycotoxins, pose a major global threat to human health. This review offers an in-depth summary of microorganisms capable of degrading AFs, including bacteria, probiotics, and fungi, and highlights the key enzymes responsible for detoxification. We propose an integrated system combining smartphone-based detection, machine learning-driven enzyme discovery, and computationally optimized biocatalyst design for effective AFs mitigation.

Transcriptome-assisted sugar transporter screening for enhanced lacto-N-tetraose biosynthesis in Escherichia coli MG1655.

The biocatalytic upgrading of renewable substrates to human milk oligosaccharides (HMOs) via cell factory offers a green and safety synthesis pathway toward value-added chemicals. The manipulation of cell factory and transporter is the key to realize the green synthesis of Lacto-N-tetraose (LNT), a neutral non-fucosylated oligosaccharide in breast milk. In current study, we present a plasmid-free approach for the de novo synthesis of LNT with increased sugar transport efficiency.

Recent Advances on Biological Production of a Functional Low-Calorie Sugar d-Tagatose.

d-Tagatose, a rare sugar of growing interest, has attracted significant attention due to its low caloric content and associated health benefits. This review summarizes four major biological approaches for d-tagatose production. d-Tagatose can be synthesized from d-galactose either via enzymatic isomerization catalyzed by l-arabinose isomerase or through an oxidoreductive conversion pathway involving galactitol dehydrogenase and xylose reductase.

Enhancing indirubin biosynthesis in Escherichia coli by engineering Methylophaga aminisulfidivorans favin-containing monooxygenase.

Indirubin, a naturally occurring bisindole alkaloid, has demonstrated clinical efficacy in the management of chronic myeloid leukemia while exhibiting multiple pharmacological activities including antitumor, anti-inflammatory, and broad-spectrum antibacterial effects. To enhance indirubin biosynthesis in the engineered Escherichia coli BL21 (DE3) host, an integrated metabolic engineering strategy was systematically executed in a sequential manner. Firstly, the Methylophaga aminisulfidivorans flavin-containing monooxygenase (MaFMO) was heterologously overexpressed under the regulation of the strong P promoter.

Recent Advances on Natural Pigment Indigoidine: Occurrence, Biosynthetic Approaches, and Applications.

Indigoidine, a natural biopigment with a planar conjugated structure comprising two pyrrolidinone rings linked by a central double bond, exhibits unique chromogenic properties. Growing environmental concerns over synthetic and plant-derived pigments have driven interest in microbial pigments as sustainable alternatives. Despite the potential of nonribosomal peptide synthetases (NRPSs) to optimize indigoidine biosynthesis, mechanistic insights into their catalytic functions remain limited.

Simonsiella muelleri α2,6-sialyltransferase enables efficient biosynthesis of 6'-sialyllactose in both plasmid-dependent and plasmid-free engineered Escherichia coli.

6'-Sialyllactose (6'-SL) is the most abundant sialylated human milk oligosaccharide in breast milk. Its health effects have been widely confirmed, and its biological production attracts increasing attention. The metabolic pathway of 6'-SL synthesis is clear, and the typical metabolic engineering strategies for its production improvement have been reported.

Identification and application of the reductase from Wickerhamomyces ciferrii for the degradation of patulin.

Patulin (PAT) is a mycotoxin widely found in fruits, which has various toxicological effects and seriously affects the safety of fruits and related products. Since PAT is stable in nature, developing bio-enzymatic degradation methods has become the predominant focus of current research. This study cloned a potential reductase gene capable of PAT degradation from Wickerhamomyces ciferrii and characterized the recombinant enzyme properties in detail.

Nonclassical Secretion and Translational Optimization for Enhancing Alginate Lyase Expression in .

Alginate lyase is a crucial enzyme for the production of alginate oligosaccharides, a versatile functional sugar widely utilized in the pharmaceutical, agricultural, and food industries. However, achieving high-level expression of alginate lyase in food-grade remains a significant challenge. This study revealed that the alginate lyase from sp.

Construction and Systematic Optimization of Plasmid-free Engineered for Efficient Lacto--Neotetraose Biosynthesis.

Lacto--neotetraose (LNnT) is a key human milk oligosaccharide (HMO) with important prebiotic functions, supporting the growth of beneficial gut microbiota and contributing to infant health. Constructing plasmid-free strains via metabolic engineering for LNnT biosynthesis represents a feasible strategy for efficient industrial-scale production. This study integrates various strategies to construct plasmid-free strains capable of efficiently producing LNnT.

Structure-Guided Tunnel Engineering to Reveal the Molecular Basis of Sugar Chain Extension of Inulosucrase.

Inulosucrase (IS) is a key enzyme in the synthesis of inulin, a multifunctional polysaccharide with significant physiological benefits and wide-ranging applications. Lactobacillus IS has the unique capability to produce both high-molecular-weight polysaccharides and oligosaccharides with diverse degrees of polymerization. Understanding the mechanism of sugar chain extension by IS is essential for modulating chain length and engineering custom-designed inulin.

Enhancement of Sialyllacto--tetraose a Biosynthesis in BL21(DE3) by Combinatorial Metabolic Engineering Strategies.

Sialyllacto--tetraose a (LST-a, Neu5Ac2,3Gal1,3GlcNAc1,3Gal1,4Glc) is a typical sialylated human milk oligosaccharide (HMO). Metabolic engineering synthesis of LTS-a should require the introduction of three key glycosyltransferases for the sequential glycosylation extension of lactose, including 1,3--acetylglucosaminyltransferase (1,3-GlcNAcT), 1,3-galactosyltransferase (1,3-GalT), and 2,3-sialyltransferase (2,3-SiaT). In this study, BL21(DE3) was engineered to produce LST-a using multilevel metabolic engineering strategies efficiently.

Characterization of a tagatose 4-epimerase and optimizing its expression for efficient D-tagatose bioconversion from fructose.

D-Tagatose is a promising functional sweetener due to its safety profile and versatile physiological effects. Recently, the bioconversion of D-tagatose from cost-effective natural resources has gained increasing attention. In this study, the hypothetical protein DRJ43_04605 from Thermoprotei archaeon, abbreviated as DRJ43-T4Ease, was identified as a tagatose 4-epimerase capable of efficiently converting d-fructose into D-tagatose.

Mining and identifying a D-mannose isomerase with high fructose isomerization activity and its expression in Bacillus subtilis for D-mannose production.

D-mannose is a functional monosaccharide with numerous positive physiological effects and holds significant commercial potential in the pharmaceutical, nutraceutical, and food industries. In this study, a hypothetical AGE family epimerase/isomerase from Stenotrophomonas maltophilia was identified and characterized as a D-mannose isomerase, named Stma-MIase, capable of efficiently converting d-fructose into D-mannose. Stma-MIase exhibited optimal activity at pH 8.

Enhancement of Indigo Production by a Metabolically Engineered MG1655 Using Membrane Engineering and Two-Stage Cultivation.

Indigo, a natural blue pigment extensively used in the food and textile industries, faces sustainability challenges due to toxic chemicals in its industrial synthesis. In this study, an efficient MG1655 system was developed for indigo biosynthesis. The strain was engineered by genomic integration and plasmid-based expression of flavin-containing monooxygenase (MaFMO) and endogenous tryptophanase (TnaA).

The use of isomerases and epimerases for the production of the functional sugars mannose, allulose and tagatose from Fructose.

Fructose, a common monosaccharide in nature extensively utilized in the food industry, poses a risk of elevated chronic disease incidence with excessive consumption. The global movement for a healthier living has sparked a quest for sugar reduction in foodstuff. The growing concern regarding the adverse impact of excessive sugar consumption on public health has led to significant interest in investigating healthier sugar alternatives.

Dual Antibiotic-Free Plasmid Systems Enable High-Efficiency l-Fucose Biosynthesis.

l-Fucose, a functional monosaccharide with significant commercial potential in the pharmaceutical, nutraceutical, and cosmetic industries, faces challenges in microbial production due to antibiotic-dependent plasmid maintenance systems. This study presents a dual antibiotic-free plasmid strategy in engineered BL21(DE3) to achieve high-efficiency l-fucose biosynthesis. By integration of the toxin-antitoxin system and a -based auxotrophic selection into two plasmids, genetic stability and plasmid retention were ensured without antibiotics.

Characterization of a novel short-chain dehydrogenase from Sugiyamaella lignohabitans and its application in the degradation of patulin.

Patulin (PAT) is a widespread and hazardous fungal toxin that is commonly found in fruits and grain crops, threatening global food safety. Increasing attention has been focused on biological approaches for PAT decontamination in recent years. This study successfully identified a short-chain dehydrogenase with PAT-degrading activity derived from Sugiyamaella lignohabitans and made a preliminary characterization of the recombinant enzyme Suli-SDR.

Efficient Biosynthesis of Sialyllacto--tetraose a by a Metabolically Engineered BL21(DE3) Strain.

Recently, the construction of metabolically engineered strains for the microbial synthesis of human milk oligosaccharides (HMOs) has attracted increasing attention. However, fewer efforts were made in the in vivo biosynthesis of complex HMOs, especially sialylated complex HMOs. In this study, we engineered BL21(DE3) to efficiently produce sialyllacto--tetraose a (LST-a) efficiently.

Multidimensional Engineering of MG1655 for the Efficient Biosynthesis of Difucosyllactose.

Difucosyllactose (DFL), a representative bisfucosylated oligosaccharide found in human milk, has garnered significant attention due to its immense health benefits. To date, several plasmid-based engineered strains have been established for DFL synthesis. However, these strains face challenges such as antibiotic dependence and plasmid instability, which limit their commercial application in the food industry.

Thermal stability enhancement of erythromycin esterase C from Enterobacter hormaechei through a combinatorial greedy accumulated strategy.

The presence of macrolides in food and the environment poses a substantial threat to the sustainable development of natural ecosystems and presents risks to human health. Previous research has demonstrated that microbial esterases can degrade erythromycin (Ery), roxithromycin (Rox), and clarithromycin (Clr), rendering them candidates for bioremediation of macrolide residues. However, the efficacy of esterases is limited by insufficient thermal stability, restricting their widespread application.