Potential use of microbial engineering in single-cell protein production.

Single-cell proteins (SCPs) have been widely used in human food and animal feed applications, still, there are challenges in their production and commercialization. Recently, advances in microbial synthetic biology, genomic engineering, and biofoundry technologies have offered capabilities to effectively and rapidly engineer microorganisms for improving the productivity, nutritional, and functional quality of SCPs. In this review, we discuss various synthetic biology, genomic engineering, and biofoundry tools that can be harnessed for SCP production and genetic modification.

Metabolic engineering of Escherichia coli for acetaldehyde overproduction using pyruvate decarboxylase from Zymomonas mobilis.

For the sustainable production of acetaldehyde, a key raw-material for a large number of chemical products, microbial production is a promising alternative. We have engineered an Escherichia coli strain for acetaldehyde production from glucose by introducing the pyruvate decarboxylase (Pdc) from Zymomonas mobilis and NADH oxidase (Nox) from Lactococcus lactis. Acetaldehyde production was systematically improved by knocking out the competing metabolic pathways.

In silico design of anaerobic growth-coupled product formation in Escherichia coli: experimental validation using a simple polyol, glycerol.

Integrated approaches using in silico model-based design and advanced genetic tools have enabled efficient production of fuels, chemicals and functional ingredients using microbial cell factories. In this study, using a recently developed genome-scale metabolic model for Escherichia coli iJO1366, a mutant strain has been designed in silico for the anaerobic growth-coupled production of a simple polyol, glycerol. Computational complexity was significantly reduced by systematically reducing the target reactions used for knockout simulations.

Transcriptomic Analysis of 3-Hydroxypropanoic Acid Stress in Escherichia coli.

The stress response of Escherichia coli to 3-hydroxypropanoic acid (3-HP) was elucidated through global transcriptomic analysis. Around 375 genes showed difference of more than 2-fold in 3-HP-treated samples. Further analysis revealed that the toxicity effect of 3-HP was due to the cation and anion components of this acid and some effects-specific to 3-HP.

Size of gene specific inverted repeat--dependent gene deletion In Saccharomyces cerevisiae.

We describe here an approach for rapidly producing scar-free and precise gene deletions in S. cerevisiae with high efficiency. Preparation of the disruption gene cassette in this approach was simply performed by overlap extension-PCR of an invert repeat of a partial or complete sequence of the targeted gene with URA3.

An extremely simple and effective colony PCR procedure for bacteria, yeasts, and microalgae.

An extremely simple and effective colony PCR procedure is established for both gram-negative and gram-positive bacteria, yeasts, and microalgae. Among the four lysis buffers examined, Y-PER is observed to be more effective than Tris/EDTA, 0.2 % SDS, and 10 mM EDTA in the extraction of PCR-quality genomic DNA from those microorganisms.

Reconstruction and analysis of a genome-scale metabolic model for Scheffersomyces stipitis.

Background: Fermentation of xylose, the major component in hemicellulose, is essential for economic conversion of lignocellulosic biomass to fuels and chemicals. The yeast Scheffersomyces stipitis (formerly known as Pichia stipitis) has the highest known native capacity for xylose fermentation and possesses several genes for lignocellulose bioconversion in its genome. Understanding the metabolism of this yeast at a global scale, by reconstructing the genome scale metabolic model, is essential for manipulating its metabolic capabilities and for successful transfer of its capabilities to other industrial microbes.

Theoretical and experimental investigation of chaperone effects on soluble recombinant proteins in Escherichia coli: effect of free DnaK level on temperature-induced recombinant streptokinase production.

Modeling and analysis of genetic networks have become increasingly important in the investigation of cellular processes. The genetic networks involved in cellular stress response can have a critical effect on the productivity of recombinant proteins. In this work, it was found that the temperature-inducible expression system for the production of soluble recombinant streptokinase in Escherichia coli resulted in a lower productivity compared to the chemically-induced system.