Development and large-scale production of human milk fat analog by fermentation of microalgae.

Background: Human milk contains a complex mixture of triacylglycerols (TAG), making it challenging to recreate using common ingredients.

Objective: The study aimed to develop an innovative fermentation technique to produce essential human milk TAG, effectively tackling a significant hurdle in infant nutrition.

Method: An in-depth analysis of the literature has been conducted to identify the specific TAG to be targeted.

Expanding Extender Substrate Selection for Unnatural Polyketide Biosynthesis by Acyltransferase Domain Exchange within a Modular Polyketide Synthase.

Modular polyketide synthases (PKSs) are polymerases that employ α-carboxyacyl-CoAs as extender substrates. This enzyme family contains several catalytic modules, where each module is responsible for a single round of polyketide chain extension. Although PKS modules typically use malonyl-CoA or methylmalonyl-CoA for chain elongation, many other malonyl-CoA analogues are used to diversify polyketide structures in nature.

Transport coefficients of isotopic mixtures of noble gases based on potentials.

The transport coefficients such as viscosity, thermal conductivity, diffusion and thermal diffusion of neon, argon, krypton, and xenon are computed for a wide range of temperatures taking into consideration their real isotopic compositions. A new concept of isotopic thermal diffusion factor is introduced and calculated. The Chapman-Enskog method based on the 10th order approximation with respect to the Sonine polynomial expansion is applied.

Accuracy of the functional, flow cytometer-based Emo-Test HIT Confirm® for the diagnosis of heparin-induced thrombocytopenia.

Introduction: Rapid functional assays have been proposed to overcome the limitations of washed platelet assays in the work-up of patients with suspected heparin-induced thrombocytopenia (HIT). Data on the diagnostic accuracy are, however, scarce and conflicting. We aimed to study the diagnostic accuracy of a rapid, flow cytometer-based assay and to explore sources of variability.

Further engineering of R. toruloides for the production of terpenes from lignocellulosic biomass.

Background: Mitigation of climate change requires that new routes for the production of fuels and chemicals be as oil-independent as possible. The microbial conversion of lignocellulosic feedstocks into terpene-based biofuels and bioproducts represents one such route. This work builds upon previous demonstrations that the single-celled carotenogenic basidiomycete, Rhodosporidium toruloides, is a promising host for the production of terpenes from lignocellulosic hydrolysates.

Reprogramming sphingolipid glycosylation is required for endosymbiont persistence in Medicago truncatula.

Plant endosymbiosis relies on the development of specialized membranes that encapsulate the endosymbiont and facilitate nutrient exchange. However, the identity and function of lipids within these membrane interfaces is largely unknown. Here, we identify GLUCOSAMINE INOSITOL PHOSPHORYLCERAMIDE TRANSFERASE1 (GINT1) as a sphingolipid glycosyltransferase highly expressed in Medicago truncatula root nodules and roots colonized by arbuscular mycorrhizal (AM) fungi and further demonstrate that this enzyme functions in the synthesis of N-acetyl-glucosamine-decorated glycosyl inositol phosphoryl ceramides (GIPCs) in planta.

Expression of a bacterial 3-dehydroshikimate dehydratase (QsuB) reduces lignin and improves biomass saccharification efficiency in switchgrass (Panicum virgatum L.).

Background: Lignin deposited in plant cell walls negatively affects biomass conversion into advanced bioproducts. There is therefore a strong interest in developing bioenergy crops with reduced lignin content or altered lignin structures. Another desired trait for bioenergy crops is the ability to accumulate novel bioproducts, which would enhance the development of economically sustainable biorefineries.

Spinal fractures in patients with ankylosing spondylitis: A case report and literature review.

Background: Severe ankylosing spondylitis (AS) affects the entire spine, increasing the risk of vertebral fractures. There are several fusion procedures used (e.g.

A bimodular PKS platform that expands the biological design space.

Traditionally engineered to produce novel bioactive molecules, Type I modular polyketide synthases (PKSs) could be engineered as a new biosynthetic platform for the production of de novo fuels, commodity chemicals, and specialty chemicals. Previously, our investigations manipulated the first module of the lipomycin PKS to produce short chain ketones, 3-hydroxy acids, and saturated, branched carboxylic acids. Building upon this work, we have expanded to multi-modular systems by engineering the first two modules of lipomycin to generate unnatural polyketides as potential biofuels and specialty chemicals in Streptomyces albus.

An iron (II) dependent oxygenase performs the last missing step of plant lysine catabolism.

Despite intensive study, plant lysine catabolism beyond the 2-oxoadipate (2OA) intermediate remains unvalidated. Recently we described a missing step in the D-lysine catabolism of Pseudomonas putida in which 2OA is converted to D-2-hydroxyglutarate (2HG) via hydroxyglutarate synthase (HglS), a DUF1338 family protein. Here we solve the structure of HglS to 1.

Chemoinformatic-Guided Engineering of Polyketide Synthases.

Polyketide synthase (PKS) engineering is an attractive method to generate new molecules such as commodity, fine and specialty chemicals. A significant challenge is re-engineering a partially reductive PKS module to produce a saturated β-carbon through a reductive loop (RL) exchange. In this work, we sought to establish that chemoinformatics, a field traditionally used in drug discovery, offers a viable strategy for RL exchanges.

Author Correction: Complete biosynthesis of cannabinoids and their unnatural analogues in yeast.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Response of Pseudomonas putida to Complex, Aromatic-Rich Fractions from Biomass.

There is strong interest in the valorization of lignin to produce valuable products; however, its structural complexity has been a conversion bottleneck. Chemical pretreatment liberates lignin-derived soluble fractions that may be upgraded by bioconversion. Cholinium ionic liquid pretreatment of sorghum produced soluble, aromatic-rich fractions that were converted by Pseudomonas putida (P.

Omics-driven identification and elimination of valerolactam catabolism in KT2440 for increased product titer.

is a promising bacterial chassis for metabolic engineering given its ability to metabolize a wide array of carbon sources, especially aromatic compounds derived from lignin. However, this omnivorous metabolism can also be a hindrance when it can naturally metabolize products produced from engineered pathways. Herein we show that is able to use valerolactam as a sole carbon source, as well as degrade caprolactam.

Optimization of the IPP-bypass mevalonate pathway and fed-batch fermentation for the production of isoprenol in Escherichia coli.

Isoprenol (3-methyl-3-buten-1-ol) is a drop-in biofuel and a precursor for commodity chemicals. Biological production of isoprenol via the mevalonate pathway has been developed and optimized extensively in Escherichia coli, but high ATP requirements and isopentenyl diphosphate (IPP) toxicity have made it difficult to achieve high titer, yield, and large-scale production. To overcome these limitations, an IPP-bypass pathway was previously developed using the promiscuous activity of diphosphomevalonate decarboxylase, and enabled the production of isoprenol at a comparable yield and titer to the original pathway.

A screening method to identify efficient sgRNAs in Arabidopsis, used in conjunction with cell-specific lignin reduction.

Background: Single guide RNA (sgRNA) selection is important for the efficiency of CRISPR/Cas9-mediated genome editing. However, in plants, the rules governing selection are not well established.

Results: We developed a facile transient assay to screen sgRNA efficiency.

Lessons from Two Design-Build-Test-Learn Cycles of Dodecanol Production in Escherichia coli Aided by Machine Learning.

The Design-Build-Test-Learn (DBTL) cycle, facilitated by exponentially improving capabilities in synthetic biology, is an increasingly adopted metabolic engineering framework that represents a more systematic and efficient approach to strain development than historical efforts in biofuels and biobased products. Here, we report on implementation of two DBTL cycles to optimize 1-dodecanol production from glucose using 60 engineered Escherichia coli MG1655 strains. The first DBTL cycle employed a simple strategy to learn efficiently from a relatively small number of strains (36), wherein only the choice of ribosome-binding sites and an acyl-ACP/acyl-CoA reductase were modulated in a single pathway operon including genes encoding a thioesterase (UcFatB1), an acyl-ACP/acyl-CoA reductase (Maqu_2507, Maqu_2220, or Acr1), and an acyl-CoA synthetase (FadD).

Massively Parallel Fitness Profiling Reveals Multiple Novel Enzymes in Lysine Metabolism.

Despite intensive study for 50 years, the biochemical and genetic links between lysine metabolism and central metabolism in remain unresolved. To establish these biochemical links, we leveraged andom arcode rasposon uencing (RB-TnSeq), a genome-wide assay measuring the fitness of thousands of genes in parallel, to identify multiple novel enzymes in both l- and d-lysine metabolism. We first describe three pathway enzymes that catabolize l-2-aminoadipate (l-2AA) to 2-ketoglutarate (2KG), connecting d-lysine to the TCA cycle.

Methyl ketone production by Pseudomonas putida is enhanced by plant-derived amino acids.

Plants are an attractive sourceof renewable carbon for conversion to biofuels and bio-based chemicals. Conversion strategies often use a fraction of the biomass, focusing on sugars from cellulose and hemicellulose. Strategies that use plant components, such as aromatics and amino acids, may improve the efficiency of biomass conversion.

Complete biosynthesis of cannabinoids and their unnatural analogues in yeast.

Cannabis sativa L. has been cultivated and used around the globe for its medicinal properties for millennia. Some cannabinoids, the hallmark constituents of Cannabis, and their analogues have been investigated extensively for their potential medical applications.

Discovery of novel geranylgeranyl reductases and characterization of their substrate promiscuity.

Background: Geranylgeranyl reductase (GGR) is a flavin-containing redox enzyme that hydrogenates a variety of unactivated polyprenyl substrates, which are further processed mostly for lipid biosynthesis in archaea or chlorophyll biosynthesis in plants. To date, only a few GGR genes have been confirmed to reduce polyprenyl substrates in vitro or in vivo.

Results: In this work, we aimed to expand the confirmed GGR activity space by searching for novel genes that function under amenable conditions for microbial mesophilic growth in conventional hosts such as or 31 putative GGRs were selected to test for potential reductase activity in vitro on farnesyl pyrophosphate, geranylgeranyl pyrophosphate, farnesol (FOH), and geranylgeraniol (GGOH).

Model metabolic strategy for heterotrophic bacteria in the cold ocean based on 34H.

34H is a model psychrophilic bacterium found in the cold ocean-polar sediments, sea ice, and the deep sea. Although the genomes of such psychrophiles have been sequenced, their metabolic strategies at low temperature have not been quantified. We measured the metabolic fluxes and gene expression of 34H at 4 °C (the mean global-ocean temperature and a normal-growth temperature for 34H), making comparative analyses at room temperature (above its upper-growth temperature of 18 °C) and with mesophilic When grown at 4 °C, 34H utilized multiple carbon substrates without catabolite repression or overflow byproducts; its anaplerotic pathways increased flux network flexibility and enabled CO fixation.

Liquid Chromatography and Mass Spectrometry Analysis of Isoprenoid Intermediates in Escherichia coli.

Isoprenoids are a highly diverse group of natural products with broad application as high value chemicals and advanced biofuels. They are synthesized using two primary building blocks, namely, isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) that are generated via the mevalonate (MVA) or deoxy-D-xylulose-5-phosphate (DXP) pathways. Isoprenoid biosynthetic pathways are prevalent in eukaryotes, archaea, and bacteria.

Short-chain ketone production by engineered polyketide synthases in Streptomyces albus.

Microbial production of fuels and commodity chemicals has been performed primarily using natural or slightly modified enzymes, which inherently limits the types of molecules that can be produced. Type I modular polyketide synthases (PKSs) are multi-domain enzymes that can produce unique and diverse molecular structures by combining particular types of catalytic domains in a specific order. This catalytic mechanism offers a wealth of engineering opportunities.