Biotransformation Of l‐Tryptophan To Produce Arcyriaflavin A With Pseudomonas putida KT2440

Abstract

Natural products such as indolocarbazoles are a valuable source of highly bioactive compounds with numerous potential applications in the pharmaceutical industry. Arcyriaflavin A, isolated from marine invertebrates and slime molds, is one representative of this group and acts as a cyclin D1‐cyclin‐dependent kinase 4 inhibitor. To date, access to this compound has mostly relied on multi‐step total synthesis. In this study, biosynthetic access to arcyriaflavin A was explored using recombinant Pseudomonas putida KT2440 based on a previously generated producer strain. We used a Design of Experiment approach to analyze four key parameters, which led to the optimization of the bioprocess. By engineering the formation of outer membrane vesicles and using an adsorbent in the culture broth, we succeeded to increase the yield of arcyriaflavin A in the cell‐free supernatant, resulting in a nearly eight‐fold increase in the overall production titers. Finally, we managed to scale up the bioprocess leading to a final yield of 4.7 mg arcyriaflavin A product isolated from 1 L of bacterial culture. Thus, this study showcases an integrative approach to improve a biotransformation and moreover also provides starting points for further optimization of indolocarbazole production in P. putida.

Biosynthesis of Arcyriaflavin F fromStreptomyces venezuelaeATCC 10712

“…Bacterial biosynthesis of indolocarbazoles is either low or variable, therefore either synthetic chemistry [10–14] or recombinant approaches are used to make these molecules. A number of indolocarbazole variants were recombinantly biosynthesised from metagenomic sources by the Brady group [15–18] , while indolocarbazoles have been overproduced in Pseudomonas putida [19] and Streptomyces albus J1074 [20] .…”