Dr. Stefan Pflügl

acib GmbH

Host: Michael Sauer

Bacterial microcompartments (BMCs), macromolecular structures entirely made up from proteins, are
simple organelles with a large number of different structures and functions (Chowdhury et al., 2014,
Axen et al., 2014). The main function of BMCs is thought to be the optimization of metabolic pathways
by creating high enzyme “density“ within the BMC and blocking of by-product formation. Furthermore,
the rest of the cell is protected from toxic intermediates (Chowdhury et al., 2014). Recombinant
production of empty BMCs with a minimal set of shell proteins as well as targeting of foreign enzymes
to recombinant BMCs by fusion of enzymes with small signal peptides has previously been shown
(Parsons et al., 2010, Fan et al., 2010). BMCs might therefore be exploited as bespoke nanobioreactors,
localizing entire metabolic pathways to a compartment (Lawrence et al., 2014).
In this study, the possibility to exploit BMCs for itaconic acid production was evaluated. To that end,
two enzymes were targeted to recombinantly produced BMCs, aconitase A of E. coli and cis-aconitic
acid decarboxylase from A. terreus. The effect of signal peptides on enzyme activities from purified
enzymes and purified BMCs containing the enzymes of interest was evaluated. Strains expressing
tagged and untagged enzymes with and without shell proteins were studied in vivo to assess the
production potential of the created strains.