PubMed Central (PMC3 - NLM DTD)
Archive of life sciences journal literature at the U.S. National Institutes of Health (NIH), developed and managed by NIH's National Center for Biotechnology Information (NCBI) in the National Library of Medicine (NLM).
Development of bio-based fine chemical production through synthetic bioengineering - Hara, Kiyotaka Y; Araki, Michihiro; Okai, Naoko; Wakai, Satoshi; Hasunuma, Tomohisa; Kondo, Akihiko
Fine chemicals that are physiologically active, such as pharmaceuticals, cosmetics, nutritional supplements, flavoring agents as well as additives for foods, feed, and fertilizer are produced by enzymatically or through microbial fermentation. The identification of enzymes that catalyze the target reaction makes possible the enzymatic synthesis of the desired fine chemical. The genes encoding these enzymes are then introduced into suitable microbial hosts that are cultured with inexpensive, naturally abundant carbon sources, and other nutrients. Metabolic engineering create efficient microbial cell factories for producing chemicals at higher yields. Molecular genetic techniques are then used to optimize metabolic pathways of genetically and...
Genome engineering for improved recombinant protein expression in Escherichia coli - Mahalik, Shubhashree; Sharma, Ashish K; Mukherjee, Krishna J
A metabolic engineering perspective which views recombinant protein expression as a multistep pathway allows us to move beyond vector design and identify the downstream rate limiting steps in expression. In E.coli these are typically at the translational level and the supply of precursors in the form of energy, amino acids and nucleotides. Further recombinant protein production triggers a global cellular stress response which feedback inhibits both growth and product formation. Countering this requires a system level analysis followed by a rational host cell engineering to sustain expression for longer time periods. Another strategy to increase protein yields could be to...
Quality assessment and optimization of purified protein samples: why and how? - Raynal, Bertrand; Lenormand, Pascal; Baron, Bruno; Hoos, Sylviane; England, Patrick
Purified protein quality control is the final and critical check-point of any protein production process. Unfortunately, it is too often overlooked and performed hastily, resulting in irreproducible and misleading observations in downstream applications. In this review, we aim at proposing a simple-to-follow workflow based on an ensemble of widely available physico-chemical technologies, to assess sequentially the essential properties of any protein sample: purity and integrity, homogeneity and activity. Approaches are then suggested to optimize the homogeneity, time-stability and storage conditions of purified protein preparations, as well as methods to rapidly evaluate their reproducibility and lot-to-lot consistency.
Fourier transform infrared spectroscopy for the prediction of fatty acid profiles in Mucor fungi grown in media with different carbon sources - Shapaval, Volha; Afseth, Nils Kristian; Vogt, Gjermund; Kohler, Achim
Fungal production of polyunsaturated fatty acids (PUFAs) is a highly potential approach in biotechnology. Currently the main focus is directed towards screening of hundreds strains in order to select of few potential ones. Thus, a reliable method for screening a high number of strains within a short period of time is needed. Here, we present a novel method for screening of PUFA-producing fungi by high-throughput microcultivation and FTIR spectroscopy. In the study selected Mucor fungi were grown in media with different carbon sources and fatty acid profiles were predicted on the basis of the obtained spectral data. FTIR spectra were...
Effect of elevated oxygen concentration on bacteria, yeasts, and cells propagated for production of biological compounds - Baez, Antonino; Shiloach, Joseph
The response of bacteria, yeast, and mammalian and insects cells to oxidative stress is a topic that has been studied for many years. However, in most the reported studies, the oxidative stress was caused by challenging the organisms with H2O2 and redox-cycling drugs, but not by subjecting the cells to high concentrations of molecular oxygen. In this review we summarize available information about the effect of elevated oxygen concentrations on the physiology of microorganisms and cells at various culture conditions. In general, increased oxygen concentrations promote higher leakage of reactive oxygen species (superoxide and H2O2) from the respiratory chain affecting...
Metabolic engineering of microorganisms for the production of L-arginine and its derivatives - Shin, Jae Ho; Lee, Sang Yup
L-arginine (ARG) is an important amino acid for both medicinal and industrial applications. For almost six decades, the research has been going on for its improved industrial level production using different microorganisms. While the initial approaches involved random mutagenesis for increased tolerance to ARG and consequently higher ARG titer, it is laborious and often leads to unwanted phenotypes, such as retarded growth. Discovery of L-glutamate (GLU) overproducing strains and using them as base strains for ARG production led to improved ARG production titer. Continued effort to unveil molecular mechanisms led to the accumulation of detailed knowledge on amino acid metabolism,...