# Using Novosphingobium aromaticivorans for Concurrent Production of Intracellular and Extracellular Products from Aromatics Extracted from Poplar Biomass

## TL;DR

This paper shows how a bacteria strain can produce both internal and external valuable chemicals from poplar biomass using a special bioreactor setup.

## Contribution

A novel bioreactor operation method enables concurrent production of extracellular and intracellular products using engineered bacteria.

## Key findings

- Using a sequencing batch reactor mode improved concurrent production of PDC, astaxanthin, and CoQ10.
- Productivities of 1.14 g/L-h for PDC and 0.04 mg/L-h for astaxanthin were achieved.
- The study highlights the impact of bioreactor operation on microbial product synthesis.

## Abstract

Achieving high biochemical production in biotransformations
of
renewable resources requires using concentrated cultures that not
only generate the product of interest but also produce abundant microbial
cell waste. We explored the concept of gaining value from microbial
cells by producing intracellular products in tandem with a desired
extracellular product. Specifically, we engineered a strain ofNovosphingobium aromaticivorans to extracellularly
produce 2-pyrone-4,6-dicarboxylic acid (PDC) from aromatic substrates
and to intracellularly accumulate astaxanthin along with coenzyme
Q10, all of which are products of industrial interest.
Achieving the goal of concurrent production of intracellular and extracellular
products required the creative application of bioreactor engineering
principles. Although a continuously fed membrane bioreactor (MBR)
maximized extracellular product biosynthesis, it had a negative effect
on intracellular product accumulation. However, operating the MBR
as a sequencing batch reactor (MBR-SBR) with a step-feed resulted
in stable concurrent production of both extracellular and intracellular
products. With aromatics extracted from poplar biomass, we achieved
productivities of 1.14 g of PDC/L-h for the extracellular product
and 0.04 mg of astaxanthin/L-h and 0.64 mg of CoQ10/L-h
for intracellular products, respectively. Our findings demonstrate
that the mode of operation of a bioreactor impacts the simultaneous
production of intracellular and extracellular products byN. aromaticivorans.