Refined methodology for quantifying virulence using .

Larvae of (the greater wax moth) are being increasingly used as a model to study microbial pathogenesis. In this model, bacterial virulence is typically measured by determining the 50% lethal dose (LD) of a bacterial strain or mutant. The use of to study pathogenesis, however, is challenging because of the extreme sensitivity of larvae to this bacterium.

Taxonomic characterization of sp. nov., a novel species discovered from a commercially purchased antibiotic.

In an attempt to identify novel bacterial species, microbiologists have examined a wide range of environmental niches. We describe the serendipitous discovery of a novel gram-negative bacterial species from a different type of extreme niche: a purchased vial of antibiotic. The vial of antibiotic hygromycin B was found to be factory contaminated with a bacterial species, which we designate sp.

Glucose assimilation rate determines the partition of flux at pyruvate between lactic acid and ethanol in Saccharomyces cerevisiae.

Engineered Saccharomyces cerevisiae expressing a lactic acid dehydrogenase can metabolize pyruvate into lactic acid. However, three pyruvate decarboxylase (PDC) isozymes drive most carbon flux toward ethanol rather than lactic acid. Deletion of endogenous PDCs will eliminate ethanol production, but the resulting strain suffers from C auxotrophy and struggles to complete a fermentation.

Trends in valorization of highly-toxic lignocellulosic biomass derived-compounds via engineered microbes.

Lignocellulosic biomass-derived fuels, chemicals, and materials are promising sustainable solutions to replace the current petroleum-based production. The direct microbial conversion of thermos-chemically pretreated lignocellulosic biomass is hampered by the presence of highly toxic chemical compounds. Also, thermo-catalytic upgrading of lignocellulosic biomass generates wastewater that contains heterogeneous toxic chemicals, a mixture of unutilized carbon.

First report of cultured from the lungs of a patient with pneumonia.

A man in his 50s with neutropenic fever and multifocal lung opacities was diagnosed with a viral pneumonia. A small number of bacteria grown from bronchoalveolar lavage fluid collected during a repeat bronchoscopy were initially identified as by VITEK-2 and mass spectrometry platforms. Whole-genome sequencing, however, subsequently demonstrated that the bacteria were , representing the first known case of cultured from human lungs.

An extra copy of the β-glucosidase gene improved the cellobiose fermentation capability of an engineered strain.

In a previously engineered recombinant, the cellobiose fermentation rate was significantly lower than the glucose fermentation rate. Thus, we implemented a genome-wide perturbation library to find gene targets for improving the cellobiose fermentation capability of the yeast strain. Unexpectedly, we discovered a transformant that contained an additional β-glucosidase gene (-), possibly through homologous recombination between the plasmids.

Deletion of JEN1 and ADY2 reduces lactic acid yield from an engineered Saccharomyces cerevisiae, in xylose medium, expressing a heterologous lactate dehydrogenase.

Microorganisms have evolved to produce specific end products for many reasons, including maintaining redox balance between NAD+ and NADH. The yeast Saccharomyces cerevisiae, for example, produces ethanol as a primary end product from glucose for the regeneration of NAD+. Engineered S.

Expression of Gre2p improves tolerance of engineered xylose-fermenting Saccharomyces cerevisiae to glycolaldehyde under xylose metabolism.

Engineered S. cerevisiae employing the xylose reductase pathway enables efficient xylose valorization to fuels and chemicals. However, toxicity of thermochemically pretreated biomass hydrolysate on S.

Direct conversion of cellulose into ethanol and ethyl-β-d-glucoside via engineered Saccharomyces cerevisiae.

Simultaneous saccharification and fermentation (SSF) of cellulose via engineered Saccharomyces cerevisiae is a sustainable solution to valorize cellulose into fuels and chemicals. In this study, we demonstrate the feasibility of direct conversion of cellulose into ethanol and a biodegradable surfactant, ethyl-β-d-glucoside, via an engineered yeast strain (i.e.

Phenotypic evaluation and characterization of 21 industrial Saccharomyces cerevisiae yeast strains.

Microorganisms have been studied and used extensively to produce value-added fuels and chemicals. Yeasts, specifically Saccharomyces cerevisiae, receive industrial attention because of their well-known ability to ferment glucose and produce ethanol. Thousands of natural or genetically modified S.

Complete genome sequence of Leuconostoc garlicum KCCM 43211 producing exopolysaccharide.

Leuconostoc garlicum KCCM 43211 isolated from traditional Korean fermented food is an intensive producer of exopolysaccharide (EPS). Here we report the first complete genome sequence of L. garlicum KCCM 43211.

Enhanced xylose fermentation by engineered yeast expressing NADH oxidase through high cell density inoculums.

Accumulation of reduced byproducts such as glycerol and xylitol during xylose fermentation by engineered Saccharomyces cerevisiae hampers the economic production of biofuels and chemicals from cellulosic hydrolysates. In particular, engineered S. cerevisiae expressing NADPH-linked xylose reductase (XR) and NAD-linked xylitol dehydrogenase (XDH) produces substantial amounts of the reduced byproducts under anaerobic conditions due to the cofactor difference of XR and XDH.

Engineering and Evolution of Saccharomyces cerevisiae to Produce Biofuels and Chemicals.

To mitigate global climate change caused partly by the use of fossil fuels, the production of fuels and chemicals from renewable biomass has been attempted. The conversion of various sugars from renewable biomass into biofuels by engineered baker's yeast (Saccharomyces cerevisiae) is one major direction which has grown dramatically in recent years. As well as shifting away from fossil fuels, the production of commodity chemicals by engineered S.

Short communication: Conversion of lactose and whey into lactic acid by engineered yeast.

Lactose is often considered an unwanted and wasted byproduct, particularly lactose trapped in acid whey from yogurt production. But using specialized microbial fermentation, the surplus wasted acid whey could be converted into value-added chemicals. The baker's yeast Saccharomyces cerevisiae, which is commonly used for industrial fermentation, cannot natively ferment lactose.

Optimization of an acetate reduction pathway for producing cellulosic ethanol by engineered yeast.

Xylose fermentation by engineered Saccharomyces cerevisiae expressing NADPH-linked xylose reductase (XR) and NAD -linked xylitol dehydrogenase (XDH) suffers from redox imbalance due to cofactor difference between XR and XDH, especially under anaerobic conditions. We have demonstrated that coupling of an NADH-dependent acetate reduction pathway with surplus NADH producing xylose metabolism enabled not only efficient xylose fermentation, but also in situ detoxification of acetate in cellulosic hydrolysate through simultaneous co-utilization of xylose and acetate. In this study, we report the highest ethanol yield from xylose (0.

CAR1 deletion by CRISPR/Cas9 reduces formation of ethyl carbamate from ethanol fermentation by Saccharomyces cerevisiae.

Enormous advances in genome editing technology have been achieved in recent decades. Among newly born genome editing technologies, CRISPR/Cas9 is considered revolutionary because it is easy to use and highly precise for editing genes in target organisms. CRISPR/Cas9 technology has also been applied for removing unfavorable target genes.

Lactose fermentation by engineered Saccharomyces cerevisiae capable of fermenting cellobiose.

Lactose is an inevitable byproduct of the dairy industry. In addition to cheese manufacturing, the growing Greek yogurt industry generates excess acid whey, which contains lactose. Therefore, rapid and efficient conversion of lactose to fuels and chemicals would be useful for recycling the otherwise harmful acid whey.

Gene Amplification on Demand Accelerates Cellobiose Utilization in Engineered Saccharomyces cerevisiae.

Unlabelled: Efficient microbial utilization of cellulosic sugars is essential for the economic production of biofuels and chemicals. Although the yeast Saccharomyces cerevisiae is a robust microbial platform widely used in ethanol plants using sugar cane and corn starch in large-scale operations, glucose repression is one of the significant barriers to the efficient fermentation of cellulosic sugar mixtures. A recent study demonstrated that intracellular utilization of cellobiose by engineered yeast expressing a cellobiose transporter (encoded by cdt-1) and an intracellular β-glucosidase (encoded by gh1-1) can alleviate glucose repression, resulting in the simultaneous cofermentation of cellobiose and nonglucose sugars.

Lactic acid production from cellobiose and xylose by engineered Saccharomyces cerevisiae.

Efficient and rapid production of value-added chemicals from lignocellulosic biomass is an important step toward a sustainable society. Lactic acid, used for synthesizing the bioplastic polylactide, has been produced by microbial fermentation using primarily glucose. Lignocellulosic hydrolysates contain high concentrations of cellobiose and xylose.

Modal content of living human cone photoreceptors.

Decades of experimental and theoretical investigations have established that photoreceptors capture light based on the principles of optical waveguiding. Yet considerable uncertainty remains, even for the most basic prediction as to whether photoreceptors support more than a single waveguide mode. To test for modal behavior in human cone photoreceptors in the near infrared, we took advantage of adaptive-optics optical coherence tomography (AO-OCT, λc = 785 nm) to noninvasively image in three dimensions the reflectance profile of cones.

Lactic acid production from xylose by engineered Saccharomyces cerevisiae without PDC or ADH deletion.

Production of lactic acid from renewable sugars has received growing attention as lactic acid can be used for making renewable and bio-based plastics. However, most prior studies have focused on production of lactic acid from glucose despite that cellulosic hydrolysates contain xylose as well as glucose. Microbial strains capable of fermenting both glucose and xylose into lactic acid are needed for sustainable and economic lactic acid production.

Adaptive optics optical coherence tomography at 1 MHz.

Image acquisition speed of optical coherence tomography (OCT) remains a fundamental barrier that limits its scientific and clinical utility. Here we demonstrate a novel multi-camera adaptive optics (AO-)OCT system for ophthalmologic use that operates at 1 million A-lines/s at a wavelength of 790 nm with 5.3 μm axial resolution in retinal tissue.

Adaptive-optics optical coherence tomography processing using a graphics processing unit.

Graphics processing units are increasingly being used for scientific computing for their powerful parallel processing abilities, and moderate price compared to super computers and computing grids. In this paper we have used a general purpose graphics processing unit to process adaptive-optics optical coherence tomography (AOOCT) images in real time. Increasing the processing speed of AOOCT is an essential step in moving the super high resolution technology closer to clinical viability.

Pyrosequencing analysis of microbiota reveals that lactic acid bacteria are dominant in Korean flat fish fermented food, gajami-sikhae.

The gajami-sikhae, traditional Korean cuisine fermented with flat fish, samples were collected from eight different manufacturers (GS1-GS8). We employed pyrosequencing method to analyze the bacterial communities of the gajami-sikhae samples. Family- and genus-level analyses indicated that the bacterial community compositions of GS3 and GS6 were distinct from those of the rest.

Yeast synthetic biology toolbox and applications for biofuel production.

Yeasts are efficient biofuel producers with numerous advantages outcompeting bacterial counterparts. While most synthetic biology tools have been developed and customized for bacteria especially for Escherichia coli, yeast synthetic biological tools have been exploited for improving yeast to produce fuels and chemicals from renewable biomass. Here we review the current status of synthetic biological tools and their applications for biofuel production, focusing on the model strain Saccharomyces cerevisiae We describe assembly techniques that have been developed for constructing genes, pathways, and genomes in yeast.