ABSTRACT
Polymalic acid, known as a bioactive material, is completely biodegradable, and has far reaching application potential in medical field. Combined with our own findings, we summarized advances in polymalic acid metabolism, microbial fermentation synthesis, and application research in the medical field. Finally, prospect for further research was addressed.
Subject(s)
Fermentation , Industrial Microbiology , Malates , Chemistry , Polymers , ChemistryABSTRACT
Streptomycetes are Gram-positive bacteria of Actinomycetales. These organisms can produce many economically important secondary metabolites. With the development of molecular biology, gene sequencing technology and synthetic biology, people gained a better understanding of the Streptomyces family. The means to transform genome on the molecular level is also increasing. By simplifying the Streptomyces genome rationally and efficiently, it will improve the yield and quality of the metabolites as well as reduce the consumption of the substrates. Markerless knockout is an important way to carry out genetic modification. Here we describe novel genome modification techniques developed for Streptomyces in recent years with focus on the markerless knockout technologies.
Subject(s)
Chromosomes, Bacterial , Genetics , Gene Knockout Techniques , Methods , Genes, Bacterial , Genetics , Streptomyces , GeneticsABSTRACT
In this study, we found that when Pseudomonas mendocina NK-01 accumulated intracellular carbon reserve, medium chain length poly (3-hydroxyalkanoates), it also synthesized extracellular saccharides, alginate oligosaccharides. The high carbon nitrogen ratio of culture medium facilitated alginate oligosaccharides production. We analyzed the structure of alginate oligosaccharide by Ultraviolet-Visible Spectrophotometry, Fourier Transform Infrared Spectroscopy, 1H and 13C of Nuclear Magnetic Resonance, and found that it was compounded in line from beta-D-mannuronic acids and alpha-L-gluronic acids via beta-(1-->4)/ alpha-(1-->4) bonds, which acetylated partly on the 2- and/or 3-hydroxy. In addition, we determined the weight-average molecular weight of alginate oligosaccharides by gel permeation chromatography to be 2054.