Microbial Cell Factories

https://microbialcellfactories.biomedcentral.com

List of Papers (Total 1,642)

Key sub-community dynamics of medium-chain carboxylate production

The carboxylate platform is a promising technology for substituting petrochemicals in the provision of specific platform chemicals and liquid fuels. It includes the chain elongation process that exploits reverse β–oxidation to elongate short-chain fatty acids and forms the more valuable medium-chain variants. The pH value influences this process through multiple mechanisms and is...

An efficient expression tag library based on self-assembling amphipathic peptides

Self-assembling amphipathic peptides (SAPs) may improve protein production or induce the formation of inclusion bodies by fusing them to the N-terminus of proteins. However, they do not function uniformly well with all target enzymes and systematic research on how the composition of SAPs influence the production of fusion protein is still limited. To improve the efficiency of...

In vivo continuous evolution of metabolic pathways for chemical production

Microorganisms have long been used as chemical plant to convert simple substrates into complex molecules. Various metabolic pathways have been optimised over the past few decades, but the progresses were limited due to our finite knowledge on metabolism. Evolution is a knowledge-free genetic randomisation approach, employed to improve the chemical production in microbial cell...

OhsR acts as an organic peroxide-sensing transcriptional activator using an S -mycothiolation mechanism in Corynebacterium glutamicum

Corynebacterium glutamicum is a well-known producer of various l-amino acids in industry. During the fermenting process, C. glutamicum unavoidably encounters oxidative stress due to a specific reactive oxygen species (ROS) produced by consistent adverse conditions. To combat the ROS, C. glutamicum has developed many common disulfide bond-based regulatory devices to control a...

Tuning recombinant protein expression to match secretion capacity

The secretion of recombinant disulfide-bond containing proteins into the periplasm of Gram-negative bacterial hosts, such as E. coli, has many advantages that can facilitate product isolation, quality and activity. However, the secretion machinery of E. coli has a limited capacity and can become overloaded, leading to cytoplasmic retention of product; which can negatively impact...

Comparative analysis of deep sequenced methanogenic communities: identification of microorganisms responsible for methane production

Although interactions between microorganisms involved in biogas production are largely uncharted, it is commonly accepted that methanogenic Archaea are essential for the process. Methanogens thrive in various environments, but the most extensively studied communities come from biogas plants. In this study, we employed a metagenomic analysis of deeply sequenced methanogenic...

Developing Gram-negative bacteria for the secretion of heterologous proteins

Gram-negative bacteria are attractive hosts for recombinant protein production because they are fast growing, easy to manipulate, and genetically stable in large cultures. However, the utility of these microbes would expand if they also could secrete the product at commercial scales. Secretion of biotechnologically relevant proteins into the extracellular medium increases product...

Saccharomyces cerevisiae morphological changes and cytokinesis arrest elicited by hypoxia during scale-up for production of therapeutic recombinant proteins

Scaling up of bioprocesses represents a crucial step in the industrial production of biologicals. However, our knowledge about the impact of scale-up on the organism’s physiology and function is still incomplete. Our previous studies have suggested the existence of morphological changes during the scale-up of a yeast (Saccharomyces cerevisiae) fermentation process as inferred...

Production efficiency of the bacterial non-ribosomal peptide indigoidine relies on the respiratory metabolic state in S. cerevisiae

Beyond pathway engineering, the metabolic state of the production host is critical in maintaining the efficiency of cellular production. The biotechnologically important yeast Saccharomyces cerevisiae adjusts its energy metabolism based on the availability of oxygen and carbon sources. This transition between respiratory and non-respiratory metabolic state is accompanied by...

A strategy to identify a ketoreductase that preferentially synthesizes pharmaceutically relevant ( S )-alcohols using whole-cell biotransformation

Chemical industries are constantly in search of an expeditious and environmentally benign method for producing chiral synthons. Ketoreductases have been used as catalysts for enantioselective conversion of desired prochiral ketones to their corresponding alcohol. We chose reported promiscuous ketoreductases belonging to different protein families and expressed them in E. coli to...

One-step affinity purification of fusion proteins with optimal monodispersity and biological activity: application to aggregation-prone HPV E6 proteins

Bacterial expression and purification of recombinant proteins under homogeneous active form is often challenging. Fusion to highly soluble carrier proteins such as Maltose Binding Protein (MBP) often improves their folding and solubility, but self-association may still occur. For instance, HPV E6 oncoproteins, when produced as MBP-E6 fusions, are expressed as mixtures of...

High level in vivo mucin-type glycosylation in Escherichia coli

Increasing efforts have been made to assess the potential of Escherichia coli strains for the production of complex recombinant proteins. Since a considerable part of therapeutic proteins are glycoproteins, the lack of the post-translational attachment of sugar moieties in standard E. coli expression strains represents a major caveat, thus limiting the use of E. coli based cell...

An oleaginous yeast platform for renewable 1-butanol synthesis based on a heterologous CoA-dependent pathway and an endogenous pathway

Microbial biofuel production provides a promising sustainable alternative to fossil fuels. 1-Butanol is recognized as an advanced biofuel and is gaining attention as an ideal green replacement for gasoline. In this proof-of-principle study, the oleaginous yeast Yarrowia lipolytica was first engineered with a heterologous CoA-dependent pathway and an endogenous pathway...

In silico model-guided identification of transcriptional regulator targets for efficient strain design

Cellular metabolism is tightly regulated by hard-wired multiple layers of biological processes to achieve robust and homeostatic states given the limited resources. As a result, even the most intuitive enzyme-centric metabolic engineering endeavours through the up-/down-regulation of multiple genes in biochemical pathways often deliver insignificant improvements in the product...

Enhanced trypsin thermostability in Pichia pastoris through truncating the flexible region

High thermostability is required for trypsin to have wider industrial applications. Target mutagenesis at flexible regions has been proved to be an efficient protein engineering method to enhance the protein thermostability. The flexible regions in porcine trypsin were predicted using the methods including molecular dynamic simulation, FlexPred, and FoldUnfold. The amino acids 78...

Efficient production of extracellular pullulanase in Bacillus subtilis ATCC6051 using the host strain construction and promoter optimization expression system

Bacillus subtilis has been widely used as a host for heterologous protein expression in food industry. B. subtilis ATCC6051 is an alternative expression host for the production of industrial enzymes, and exhibits favorable growth properties compared to B. subtilis 168. Extracellular expression of pullulanase from recombinant B. subtilis is still limited due to the issues on...

Biobutanol production from coffee silverskin

Coffee silverskin, a by-product from coffee roasting industries, was evaluated as a feedstock for biobutanol production by acetone–butanol–ethanol fermentation. This lignocellulosic biomass contained approximately 30% total carbohydrates and 30% lignin. Coffee silverskin was subjected to autohydrolysis at 170 °C during 20 min, with a biomass-to-solvent ratio of 20%, and a...

Widespread effect of N -acetyl- d -glucosamine assimilation on the metabolisms of amino acids, purines, and pyrimidines in Scheffersomyces stipitis

Following cellulose, chitin is the most abundant renewable resource and is composed of the monomeric amino sugar N-acetyl-d-glucosamine (GlcNAc). Although many yeasts, including Saccharomyces cerevisiae, have lost their ability to utilize GlcNAc, some yeasts are able to use GlcNAc as a carbon source. However, our understanding of the effects of GlcNAc on the intracellular...

Production of p -amino- l -phenylalanine ( l -PAPA) from glycerol by metabolic grafting of Escherichia coli

The non-proteinogenic aromatic amino acid, p-amino-l-phenylalanine (l-PAPA) is a high-value product with a broad field of applications. In nature, l-PAPA occurs as an intermediate of the chloramphenicol biosynthesis pathway in Streptomyces venezuelae. Here we demonstrate that the model organism Escherichia coli can be transformed with metabolic grafting approaches to result in an...

Evaluation of GFP reporter utility for analysis of transcriptional slippage during gene expression

Epimutations arising from transcriptional slippage seem to have more important role in regulating gene expression than earlier though. Since the level and the fidelity of transcription primarily determine the overall efficiency of gene expression, all factors contributing to their decrease should be identified and optimized. To examine the influence of A/T homopolymeric sequences...

Development of a strictly regulated xylose-induced expression system in Streptomyces

Genetic tools including constitutive and inducible promoters have been developed over the last few decades for strain engineering in Streptomyces. Inducible promoters are useful for controlling gene expression, however only a limited number are applicable to Streptomyces. The aim of this study is to develop a controllable protein expression system based on an inducible promoter...

Role of phosphate limitation and pyruvate decarboxylase in rewiring of the metabolic network for increasing flux towards isoprenoid pathway in a TATA binding protein mutant of Saccharomyces cerevisiae

Production of isoprenoids, a large and diverse class of commercially important chemicals, can be achieved through engineering metabolism in microorganisms. Several attempts have been made to reroute metabolic flux towards isoprenoid pathway in yeast. Most approaches have focused on the core isoprenoid pathway as well as on meeting the increased precursors and cofactor...