ABSTRACT
Natural products, important sources of innovative drugs, food, spices and daily chemicals, are closely related to people's healthy life. With the development and integration of modern biological and chemical technologies of natural products, the researches on biosynthesis of natural products have made great progresses in recent years. The biosynthetic pathways of a number of natural products have been analyzed. Many pathway enzymes and modifying enzymes involved in the biosynthesis of natural products have been mined and functionally characterized. Furthermore, genes encoding pathway enzymes have been introduced into chassis to construct cell factories producing natural products through synthetic biology technologies. Also, other biotechnologies including genome editing and genome mining, have been used in the biosynthesis of natural products. In order to further promote the development of researches on biosynthesis of natural products, we edited a Special Issue on the topic of "biosynthesis of natural products", focusing on the researches progress in three aspects: the analysis of biosynthetic pathways of natural products, genome-wide mining and functional characterization of genes encoding tool enzymes, and the scale preparation of natural products by biosynthetic technology. Also included in this Special Issue was the prospect of the biosynthesis of natural products. This Special Issue can provide reference and guidance for the further development of natural product biosynthesis.
Subject(s)
Biological Products , Biosynthetic Pathways/genetics , Biotechnology , Genome , Synthetic BiologyABSTRACT
Aromatic hydrocarbons are capital environmental contaminations. Pseudomonas alcaligenes NCIB 9867 (P25X) is capable of degrading aromatic hydrocarbons via the gentisate pathway. Biochemical characterization indicated that it has isofunctional enzymes for the mono- and dioxygenase- catalysed reactions. One set of the enzymes is constitutive and the other is strictly inducible. To date, only the genes for the constitutively-expressed gentisate dioxygenase and the downstream enzymes have been cloned. A mutant strain of P25X, designated SNZ28, which had the constitutive copy of the gentisate 1, 2-dioxygenase gene interrupted by a streptomycin/spectinomycin resistance gene cassette, was found to still express gentisate dioxygenase when induced by gentisate. The proteome profiles of P25X and mutant SNZ28, grown in the presence and absence of the aromatic inducer gentisate, were compared after 2D-PAGE. Fifteen distinctive protein spots which were observed only in induced cells of P25X and mutant SNZ28 but absent in non-induced cells of both were further analyzed by MALDI-TOF and Q-TOF. Of the 15 proteins, 12 showed significant sequence similarity to proteins with assigned function in other microorganisms . The identification of protein P4 which showed positive identification to a gentisate dioxygenase from Ralstonia species indicated the putative role of this protein to encode gentisate 1, 2-dioxygenase in P.alcaligenes.