Bioderivatization as a concept for renewable production of chemicals that are toxic or poorly soluble in the liquid phase

Abstract

Bio-based production technologies may complement or replace petroleum-based production of chemicals, but they face a number of technical challenges, including product toxicity and/or water insolubility. Plants and microorganisms naturally biosynthesize chemicals that often are converted into derivatives with reduced toxicity or enhanced solubility. Inspired by this principle, we propose a bioderivatization strategy for biotechnological chemicals production, defined as purposeful biochemical derivatization of intended target molecules. As proof of principle, the effects of hydrophobic (e.g., esterification) and hydrophilic (e.g., glycosylation) bioderivatization strategies on the biosynthesis of a relatively toxic and poorly soluble chemical, 1-octanol, were evaluated in Escherichia coli and Synechocystis sp. PCC 6803. The 1-octanol pathway was first optimized to reach product titers at which the host displayed symptoms of toxicity. Solvent overlay used to capture volatile products partially masked product toxicity. Regardless of whether solvent overlay was used, most strains with bioderivatization had a higher molar product titer and product yield, as well as improved cellular growth and glucose consumption, compared with strains without bioderivatization. The positive effect on bioproduction was observed with both the hydrophobic and hydrophilic strategies. Interestingly, in several combinations of genotype/induction strength, bioderivatization had a positive effect on productivity without any apparent effect on growth. We attribute this to enhanced product solubility in the aqueous or solvent fraction of the bioreactor liquid phase (depending on the derivative and medium used), with consequent enhanced product removal. Overall, under most conditions, a benefit of bioproduction was observed, and the bioderivatization strategy could be considered for other similar chemicals as well.

In Vivo Reduction of Medium‐ to Long‐Chain Fatty Acids by Carboxylic Acid Reductase (CAR) Enzymes: Limitations and Solutions

“…[18] Overreduction of aldehydes to alcohols is the intracellular defense-mechanism of the expression host for coping with high concentrations of these toxic compounds. [22] Of the respective acid, aldehyde and alcohol, the fatty acid is the most tolerated compound. [23] However, relatively low concentrations of aliphatic acids and derivatives cause growth inhibition, cell membrane perforation and leakage, thus disrupting the electron transport chain, uncoupling oxidative phosphorylation and ultimately diminish ATP production.…”

Synthetic metabolic pathways for conversion of CO2 into secreted short-to medium-chain hydrocarbons using cyanobacteria

“…Here we sought to engineer Synechocystis for production of shorter alkanes in the hope that they would accumulate extracellularly. To achieve this, we combined either ‘ Uc FatB1 or Cp FatB1.4 (Lozada et al, 2018; Sattayawat et al, 2020) with a fatty acid photodecarboxylase (FAP) from Chlorella variabilis (Fig. 5A).…”

“…Chromosomal integration and transformation of RSF1010 plasmids were performed as described previously (Sattayawat et al, 2020; Yunus et al, 2020, 2018; Yunus and Jones, 2018). All strains generated in this study are listed in Supplementary Table S2.…”

Amino Benzamidoxime (ABAO)‐Based Assay to Identify Efficient Aldehyde‐Producing Pichia pastoris Clones

“…[7] The three‐domain enzyme class acts as peptidyl carrier protein and requires binding of a 4'‐phosphopantetheine moiety from a 4'‐phosphopantetheinyl transferase (PPTase) to be activated [8] . Even though CAR reactions might be the selective answer for sustainable production of b , whole‐cell biocatalysts also need to overcome the host‐defence mechanism, the overreduction of b to the less cytotoxic alcohol ( c , Scheme S1 ) [9] …”

“…[8] Even though CAR reactions might be the selective answer for sustainable production of b, whole-cell biocatalysts also need to overcome the host-defence mechanism, the overreduction of b to the less cytotoxic alcohol (c, Scheme S1). [9] In CAR research, the main workhorse today is Escherichia coli (E. coli). [10][11][12][13] However, the methylotrophic yeast Pichia pastoris [14] (syn.…”