Microbial production, isoprene

Bott R, Cervin M, Kellis J, McAuliffe J, Miasnikov A, Peres C, Rife C, Wells D, Weyler W, Whited G. (2012) Isoprene synthase variants for improved microbial production of isoprene. US Patent 8,173,410. 

Pioneering studies and piiot scale projects demonstrated the microbial production of isoprene... 

Metabolic Engineering of MVA and MEP Pathways for Microbial Production of Isoprene... 

The microbial production of isoprene or isoprenoids through the MVA or MEP pathway has been reported in a variety of microorganisms. The details of the engineering strategies, especially for isoprene production, are discussed below. The preferred approach of heterologous or endogenous pathway expression is determine d by the me chanism of metabolic regulatory control, the toxicity of the intermediate metabolites, and the characteristics of the key enzymes. 

I 16 Microbial Production of isoprene Opportunities and Challenges Table 16.2 Fermentor scale for isoprene production by different engineered strains. 

Chotani, G.K., Nielsen, A.T., and Vaviline, D.V. (2013) Methods for increasing microbial production of isoprene, isoprenoids, and isoprenoid precursor molecules using glucose and acetate co-metabolism. PCX Patent WO 2013052914 A2. 

In the troposphere, the production of ozone results from the day-time oxidation of methane, nonmethane hydrocarbons, and carbon monoxide in the presence of nitrogen oxides. Under natural conditions, methane, produced in oxygen-deficient environments, is released primarily by wetlands, lakes, and rivers. Nonmethane hydrocarbons, such as isoprene and terpenes, are emitted by various types of trees. Nitric oxide is released by soils as a result of microbial activity and is produced in the atmosphere by lightning in thunderstorm systems. 

Precursor selection An important step in designing a microbial labeling process is the identification of one or more suitable labeled precursors. Generally, secondary metabolites are biosynthesized via primary metabolites from five metabolic sources. These are amino acids, shikimic acid (shikimic acid pathway), acetate and its homologues (polyketide pathway), mevalonic acid (isoprene pathway) and carbohydrates. Selection of a suitable precursor is primarily influenced by the biosynthetic pathway(s) involved, but also depends on the desired position of label in the product and the availability of labeled precursors. 

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