l-Leucine, as an essential branched-chain amino acid for humans and animals, has recently been attracting much attention because of its potential for a fast-growing market demand. The applicability ranges from flavor enhancers, animal feed additives and ingredients in cosmetic to specialty nutrients in pharmaceutical and medical fields. Microbial fermentation is the major method for producing l-leucine by using Escherichia coli and Corynebacterium glutamicum as host bacteria. This review gives an overview of the metabolic pathway of l-leucine (i.e. production, import and export systems) and highlights the main regulatory mechanisms of operons in E. coli and C. glutamicum l-leucine biosynthesis. We summarize here the current trends in metabolic engineering techniques and strategies for manipulating l-leucine producing strains. Finally, future perspectives to construct industrially advantageous strains are considered with respect to recent advances in biology.
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http://dx.doi.org/10.1080/07388551.2019.1577214 | DOI Listing |
Nat Commun
January 2025
Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, 01003, USA.
The extensive application of graphene nanosheets (GNSs) has raised concerns over risks to sensitive species in the aquatic environment. The humic acid (HA) corona is traditionally considered to reduce GNSs toxicity. Here, we evaluate the effect of sorbed HA (GNSs-HA) on the toxicity of GNSs to Gram positive Bacillus tropicus.
View Article and Find Full Text PDFJ Appl Biomech
January 2025
Department of Health and Kinesiology, The University of Utah, Salt Lake City, UT, USA.
Shoes or insoles embedded with carbon fiber materials to increase longitudinal stiffness have been shown to enhance running and walking performance in elite runners, and younger adults, respectively. It is unclear, however, if such stiffness modifications can translate to enhanced mobility in older adults who typically walk with greater metabolic cost of transport compared to younger adults. Here, we sought to test whether adding footwear stiffness via carbon fiber insoles could improve walking outcomes (eg, distance traveled and metabolic cost of transport) in older adults during the 6-minute walk test.
View Article and Find Full Text PDFJ Environ Manage
January 2025
School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhoushan, 316000, China; National & Local Joint Engineering Research Center of Harbor Oil & Gas Storage and Transportation Technology, Zhejiang Key Laboratory of Petrochemical Environmental Pollution Control, Zhoushan, 316000, China. Electronic address:
The lack of cost-effective nutrient sources and harvesting methods is currently a major obstacle to the production of sustainable biofuels from microalgae. In this study, Chlorella pyrenoidosa was cultured with saline wastewater in a stirred photobioreactor, and lipid-rich flocculent microalgae particles were successfully constructed. As the influent salinity of the photobioreactor increased from 0% to 3%, the particle size and sedimentation rate of flocculent microalgae particles gradually increased, and the lipid accumulation of microalgae also increased gradually.
View Article and Find Full Text PDFMicrobiol Res
December 2024
Guangdong Key Laboratory of Regional Immunity and Diseases, Department of Pathogen Biology, Shenzhen University School of Medicine, Shenzhen 518000, China. Electronic address:
This review addresses the significant advancements in the identification of blood-based prognostic biomarkers for tuberculosis (TB), highlighting the importance of early detection to prevent disease progression. The manuscript discusses various biomarker categories, including transcriptomic, proteomic, metabolomic, immune cell-based, cytokine-based, and antibody response-based markers, emphasizing their potential in predicting TB incidence. Despite promising results, practical application is hindered by high costs, technical complexities, and the need for extensive validation across diverse populations.
View Article and Find Full Text PDFMicrob Cell Fact
January 2025
Department of Chemical & Biological Engineering, Korea University, Seoul, 136-763, Korea.
Background: 2'-Fucosyllactose (2'-FL) is a predominant human milk oligosaccharide that significantly enhances infant nutrition and immune health. This study addresses the need for a safe and economical production of 2'-FL by employing Generally Recognized As Safe (GRAS) microbial strain, Priestia megaterium ATCC 14581. This strain was chosen for its robust growth and established safety profile and attributing suitable for industrial-scale production.
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