Butyrolactone biosynthesis

Bibb 2005 Martin and Liras 2010). We will refer to the well-known streptomycin and cephamycin/clavnlanic acid regnlatory cascades as model systems, but the tylosin regulatory cascade and other similar cascades are also well known (Cundliffe 2008). In all these cases the top position in the regulatory cascade is occupied by (i) a butyrolactone receptor protein (BRP) in coordination with its cognate butyrolactone molecnle (Takano 2006), or (ii) a pleiotropic regulator (e.g. AreB dgR) that governs butyrolactone biosynthesis, and therefore, the butyrolactone-dependent cascade. 

Many y-butyrolactone receptor homologues have been identified in the genome sequences of Streptomyces. At least 22 out of 33 genes encoding homologues of y-butyrolactone receptors are located close to antibiotic biosynthesis gene clusters or have been shown to regulate antibiotic production. 

The recent isolations of sagecoumarin [35], Fig. (10) (a 3-aryloxy-6,7-dihydroxycoumarin) and 3-hydroxycoumarin [36] led us to investigate their possible obtention from conveniently substituted arylpyruvic acids. Since the dimerisation of arylpyruvic acid has been proposed in the biosynthesis of butyrolactone isolated from Aspergillus terreus [37], Fig. (11), we developed an interest in the potential acid-catalysed dimerisation of these molecules. 

Fig. Z4 Proposed metabolic pathways involved in P(3HB-co-4HB) biosynthesis from weU-known 4HB precursor substrates such as 4-hydroxybutyric acid, 4-chlorobutyric acid, y-butyrolactone, and (o-alkanediols (Doi 1990 Braunegg et al. 1998 Stembiichel and Liitke-Eversloh 2003)...

Dhamankar, H., Tarasova, Y., Martin, C.H., and Prather, K.L.J. (2014) Engineering E. coli for the biosynthesis of 3-hydroxy-y-butyrolactone (3HBL) and 3,4-dihydroxybutyric acid (3,4-DHBA) as value-added chemicals from glucose as a sole carbon source. Metab. Eng.,... 

The microbial biosynthesis of P(3HB-4HB) copolymers was achieved using different nutritional strategies. Most of them are based on the carbon sources used to feed the cultures (butyric acid and different sugars, or a single carbon source structurally related to butyric acid such as 4-hydroxybutyric acid, y-butyrolactone or 1,4 butanediol Saito and Doi 1994 Kunioka et al. 1989). 

Bacterial synthesis is considered to be the most important process for PHA preparation at present. This approach will be discussed in this section in more detail. Besides the bacterial synthesis, the chemical synthesis of PHB via the ring-opening polymerization of butyrolactone, is also possible and will be briefly discussed at the end of this section. Recently, increased attention has been paid to the biosynthesis using genetically modified plants. This procedure has not yet reached an industrially acceptable scale up, but may be developed to an even more efficient and economical process than the bacterial fermentation technology, as discussed below. 

Butyrolactone Autoregulators, Inducers of Virginiamycin in Streptomyees virgimae Their Structures, Biosynthesis, Receptor Proteins, and Induction of Virginiamycin Biosynthesis... 

In this chapter, we describe new aspects concerning the induction of virginiamycin production by butyrolactone-type autoregulacors. The structures, biosynthesis of butyro-lactone autoregulators, and their receptor proteins are also reviewed. 

Sakuda S, Higashi A, Tanaka S, Nihira T, Yamada Y. Biosynthesis of virginiae butanolide A, a butyrolactone autoregulator from Streptomyces. J Am Chem Soc 1992 114 663-668. 

Yamada Y, Nihira T, Sakuda S. Biosynthesis and receptor protein of butyrolactone autorego-lator of Streptomyces virginioe. Actinomycetol 1992 6 1-8. 

Yamada Y. Butyrolactone autoregulatots and their cole in viiginiainycin biosynthesis. Strohl W. ed. Biotechnology of Antibiotics, 2nd ed. New York Marcel Dekker, 1997. 

Besides the three main pathways mentioned above, there are several other metabolic pathways that can be manipulated to produce substrates for PHA biosynthesis. In recombinant E. coli, it has been shown that 4-hydroxybutyryl-CoA can be derived from the intermediates of the tricarboxylic acid (TCA) cycle [137]. By providing external precursor substrates such as 4-hydroxybutyric acid, 1,4-butanediol and y-butyrolactone to certain wild type [59, 60, 62, 63] and recombinant microorganisms [138], 4HB monomers can be incorporated more efficiently. 

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