Vitreoscilla hemoglobin enhances the catalytic performance of industrial oxidases in vitro.

Oxidases are a group of oxidoreductases and need molecular oxygen in the catalytic process. Vitreoscilla hemoglobin (VHb) can improve the growth and productivity of host cells under hypoxic conditions, rendering it attractive for industrial application. In this work, we demonstrated the addition of immobilized VHb increased the catalytic activity of immobilized D-amino acid oxidase of Trigonopsis variabilis by two-fold when catalyzing cephalosporin C under oxygen-limited conditions.

Bacterial mandelic acid degradation pathway and its application in biotechnology.

Mandelic acid and its derivatives are an important class of chemical synthetic blocks, which is widely used in drug synthesis and stereochemistry research. In nature, mandelic acid degradation pathway has been widely identified and analysed as a representative pathway of aromatic compounds degradation. The most studied mandelic acid degradation pathway from Pseudomonas putida consists of mandelate racemase, S-mandelate dehydrogenase, benzoylformate decarboxylase, benzaldehyde dehydrogenase and downstream benzoic acid degradation pathways.

Progress of metabolic engineering for the production of eicosapentaenoic acid.

Eicosapentaenoic Acid (EPA) is an essential ω-3 polyunsaturated fatty acid for human health. Currently, high-quality EPA production is largely dependent on the extraction of fish oil, but this unsustainable approach cannot meet its rising market demand. Biotechnological approaches for EPA production from microorganisms have received increasing attention due to their suitability for large-scale production and independence of the seasonal or climate restrictions.

Precision strategies for cancer treatment by modifying the tumor-related bacteria.

Research on the roles of the bacteria in tumor development and progression is a rapidly emerging field. Increasing evidence links bacteria with the modification of the tumor immune microenvironment, which greatly influences the antitumor response. In view of the individual immune effects of various bacteria in various tumors, developing personalized bacteria-modulating therapy may be a key to successful antitumor treatment.

Developing Clostridia as Cell Factories for Short- and Medium-Chain Ester Production.

Short- and medium-chain volatile esters with flavors and fruity fragrances, such as ethyl acetate, butyl acetate, and butyl butyrate, are usually value-added in brewing, food, and pharmacy. The esters can be naturally produced by some microorganisms. As ester-forming reactions are increasingly deeply understood, it is possible to produce esters in non-natural but more potential hosts.

Advances and Perspectives for Genome Editing Tools of .

has been considered a promising synthetic biological platform for biomanufacturing and bioremediation. However, there are still some challenges in genetic manipulation of . Recently, more and more genetic parts or elements (replicons, promoters, reporter genes, and selectable markers) have been mined, characterized, and applied.

Engineering of for l-Proline Production.

l-Proline is an important amino acid that has various industrial applications. Industrial l-proline-producing strains are obtained by the mutagenesis of . In this study, the optimized genome-editing tools were further applied in the construction of a hyper-l-proline-producing strain.

Multicopy Chromosomal Integration Using CRISPR-Associated Transposases.

Controlling the copy number of gene expression cassettes is an important strategy to engineer bacterial cells into high-efficiency biocatalysts. Current strategies mostly use plasmid vectors, but multicopy plasmids are often genetically unstable, and their copy numbers cannot be precisely controlled. The integration of expression cassettes into a bacterial chromosome has advantages, but iterative integration is laborious, and it is challenging to obtain a library with varied gene doses for phenotype characterization.

Optical fiber temperature sensor based on a Mach-Zehnder interferometer with single-mode-thin-core-single-mode fiber structure.

A Mach-Zehnder interferometer for measurement of temperature is proposed and experimentally demonstrated, which consists of two sections of single mode fiber (SMF) and a section of thin core fiber spliced between the two SMFs. The two welding areas are heated and stretched to improve the split and recombination of light. The wavelength of the resonant dip will shift when temperature varies due to the thermo-optic and thermal expansion effect.

Genome editing and transcriptional repression in Pseudomonas putida KT2440 via the type II CRISPR system.

Background: The soil bacterium Pseudomonas putida KT2440 is a "generally recognized as safe"-certified strain with robust property and versatile metabolism. Thus, it is an ideal candidate for synthetic biology, biodegradation, and other biotechnology applications. The known genome editing approaches of Pseudomonas are suboptimal; thus, it is necessary to develop a high efficiency genome editing tool.

Mutagenesis of Key Residues in the Binding Center of l-Aspartate-b-Semialdehyde Dehydrogenase from Escherichia coli Enhances Utilization of the Cofactor NAD(H).

L-Aspartate-β-semialdehyde dehydrogenase (ASADH) is a key enzyme in the aspartate pathway. In bacteria, ASADH is highly specific for the cofactor NADP(+) rather than NAD(+). Limited information on cofactor utilization is available, and neither the wild-type protein nor the available mutants could utilize NAD(+) efficiently.