Amino acids are the basic building blocks of protein that are very important to the nutrition and health of humans and animals, and widely used in feed, food, medicine and daily chemicals. At present, amino acids are mainly produced from renewable raw materials by microbial fermentation, forming one of the important pillar industries of biomanufacturing in China. Amino acid-producing strains are mostly developed through random mutagenesis- and metabolic engineering-enabled strain breeding combined with strain screening. One of the key limitations to further improvement of production level is the lack of efficient, rapid, and accurate strain screening methods. Therefore, the development of high-throughput screening methods for amino acid strains is very important for the mining of key functional elements and the creation and screening of hyper-producing strains. This paper reviews the design of amino acid biosensors and their applications in the high-throughput evolution and screening of functional elements and hyper-producing strains, and the dynamic regulation of metabolic pathways. The challenges of existing amino acid biosensors and strategies for biosensor optimization are discussed. Finally, the importance of developing biosensors for amino acid derivatives is prospected.
Animals ; Humans ; Amino Acids ; Biosensing Techniques ; Metabolic Engineering ; High-Throughput Screening Assays ; China

Lateral epicondylitis is a common clinical disease with characteristics of lateral elbow pain, insidious onset and easy recurrence, which can cause forearm pain and decreased wrist strength, seriously affecting patients′ daily life and work. Although there are various treatment methods for lateral epicondylitis with different effects, standard treatments are still lacking nowadays. Platelet-rich plasma (PRP) has good effects on bone and tendon repair, and is now widely used in the treatment of lateral epicondylitis. However, there is a lack of a unified understanding of the technology and specifications of PRP in the treatment of lateral epicondylitis. Therefore, the Sports Medicine Branch of the Chinese Medical Association and Physical Medicine and Rehabilitation Branch of the Chinese Medical Association organized experts in the fields of sports medicine and rehabilitation medicine in China to formulate the "clinical expert consensus on platelet-rich plasma treatment for lateral epicondylitis (2022 version)", and proposed suggestions based on evidence-based medicine mainly from the concept, epidemiology and pathophysiology of lateral epicondylitis, symptoms, signs and imaging manifestations of lateral epicondylitis, PRP concept and application component requirements, quality control of PRP preparation technology, indications and contraindications of PRP in the treatment of lateral epicondylitis, PRP injection in the treatment of lateral epicondylitis, application of PRP in the operation of lateral epicondylitis, related problems after PRP treatment of lateral epicondylitis, evaluation of the results after PRP treatment of lateral epicondylitis, and health and economic evaluation of PRP treatment of lateral epicondylitis, so as to provide guidance for clinical diagnosis and treatment.

5-aminolevulinic acid (ALA), a precursor for biosynthesis of pyrrole compounds in living organisms, has been widely used in agriculture and medical photodynamics therapy and is regarded as a promising value-added bio-based chemical. In the previous investigations on ALA production with recombinant Escherichia coli expressing heterogenous C4 pathway gene, LB media supplemented with glucose and ALA precursors succinate and glycine is widely used, leading to high production cost. Succinate participates in ALA biosynthesis in a form of succinyl-CoA. In this study, genes involved in succinyl-CoA consumption, sdhAB (encoding succinic dehydrogenase) or sucCD (encoding succinyl-CoA synthetase) of E. coli MG1655 was knocked out and tested for ALA accumulation. In comparison with the recombinant E. coli strain expressing heterogenous ALA synthetase, the sdhAB- or sucCD-deficient strain accumulate 25.59% and 12.40%, respectively, more ALA in a 5 L fermentor using a defined synthetic medium with glucose as main carbon source and without supplementation of succinate, providing a novel cost-effective approach for industrial production of ALA.
Aminolevulinic Acid ; metabolism ; Escherichia coli ; enzymology ; genetics ; metabolism ; Industrial Microbiology ; methods ; Metabolic Engineering ; methods ; Recombinant Proteins ; genetics ; metabolism ; Succinate Dehydrogenase ; genetics ; metabolism ; Succinate-CoA Ligases ; genetics ; metabolism

This study aimed to establish characteristic chromatogram and content determination method for Chan Taoren formula granules,evaluate the production processes of Chan Taoren formula granules based on the correlation of characteristic chromatogram and the transfer rate of D-amygdalin,and clarify the key control points. The optimized analytical method was carried out on a Waters CORTECS C18 column(4. 6 mm×150 mm,2. 7 μm) with acetonitrile-0. 1% phosphoric acid aqueous solution as the mobile phase at a flow rate of 0. 6 m L·min-1. The detection wavelength was 207 nm,and the column temperature was 20 ℃ ． As compared with the standard decoction of Chan Taoren,there were five characteristic peaks in the decoction pieces,extracts,concentrates,spray-dried powders and formula granules,basically consistent in relative retention time and peak pattern; in addition,the transfer rate of D-amygdalin from Chan Taoren pieces to the formula granules was within the transfer rate range of standard decoction. The average transfer rate of D-amygdalin was 56.65%,72.85%,94.58% and 99.29% respectively in the extraction,concentration,spray drying and granulation processes. Therefore,the factors affecting D-amygdalin in the extraction process were further studied. The results showed that D-amygdalin was easily converted to L-amygdalin in the water extraction process,leading to a low transfer rate of D-amygdalin in this process.D-amygdalin was unstable under alkaline conditions and prone to isomerization. Both liquid to solid ratio and extraction time had significant effects on the extraction rate of D-amygdalin. In this study,the key links in the production process of Chan Taoren formula granules was clarified based on the characteristic chromatogram and the quantity transmission of D-amygdalin,which provided a theoretical basis for production and quality control.
Amygdalin ; Chromatography, High Pressure Liquid ; Drugs, Chinese Herbal ; Quality Control ; Water