1.Research progress of testicular torsion
Jiuzhou PU ; Shuai LIU ; Xu LI ; Zhilong DONG
Chinese Journal of Urology 2020;41(4):318-320
Testicular torsion is one of the most common scrotal emergencies in urology, which often requires emergency surgery to preserve the turned testicle. There are many studies suggest that testis still has ischemia-reperfusion injury after detorsion, which will threaten the sex hormone levels and fertility of patients. This paper reviewed the research progress of testicular torsion in order to improve clinicians’ understanding of testicular torsion.
2.Advances of development and application amino acid biosensors.
Wei PU ; Jiuzhou CHEN ; Yu WANG ; Ping ZHENG ; Jibin SUN
Chinese Journal of Biotechnology 2023;39(6):2485-2501
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
3.Deficiency of succinic dehydrogenase or succinyl-coA synthetase enhances the production of 5-aminolevulinic acid in recombinant Escherichia coli.
Wei PU ; Jiuzhou CHEN ; Cunmin SUN ; Ning CHEN ; Jibin SUN ; Ping ZHENG ; Yanhe MA
Chinese Journal of Biotechnology 2013;29(10):1494-1503
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