Production of Gibberellins via a Non-Natural Pathway Using Steviol as a Substrate

Abstract

Gibberellins (GAs) are plant hormones widely used in agriculture. At present, GAs are produced by fermentation of the fungus Fusarium fujikuroi. However, fungal growth is too slow, resulting in slow fungal fermentation and a low yield. Here, to develop an alternative production source of GAs, an artificial pathway was engineered in Escherichia coli. By selecting and combining enzymes derived from plants and bacteria, a novel 4-enzyme pathway was successfully constructed to produce GAs using steviol, a readily available and less valuable byproduct during enzymatic refining of rebaudioside A, as a feedstock. Whole-cell biotransformation with E. coli strain expressing the novel pathway produced 71.17 ± 2.00 mg/L GA 1 and a trace amount of GA 3 from steviol in 48 h. This report presents a significant advancement in the fast production of GAs and establishes a method for the metabolism of terpenoids to produce target products in microbial hosts.