I read this book the same weekend that the Packers took on the Rams, and the experience of the latter event, obviously, colored my judgment. Although I abhor anything that smacks of being a handbook (like, \"How to Earn a Merit Badge in Neurosurgery\") because too many volumes in biomedical science already evince a boyscout-like approach, I must confess that parts of this volume are fast, scholarly, and significant, with certain reservations. I like parts of this well-illustrated book because Dr. Sj6strand, without so stating, develops certain subjects on technique in relation to the acquisition of judgment and sophistication. And this is important! So, given that the author (like all of us) is somewhat deficient in some areas, and biased in others, the book is still valuable if the uninitiated reader swallows it in a general fashion, realizing full well that what will be required from the reader is a modulation to fit his vision, propreception, adaptation and response, and the kind of problem he is undertaking. A major deficiency of this book is revealed by comparison of its use of physics and of chemistry to provide understanding and background for the application of high resolution electron microscopy to problems in biology. Since the volume is keyed to high resolution electron microscopy, which is a sophisticated form of structural analysis, but really morphology in a modern guise, the physical and mechanical background of The instrument and its ancillary tools are simply and well presented. The potential use of chemical or cytochemical information as it relates to biological fine structure , however, is quite deficient. I wonder when even sophisticated morphol-ogists will consider fixation a reaction and not a technique; only then will the fundamentals become self-evident and predictable and this sine qua flon will become less mystical. Staining reactions (the most inadequate chapter) ought to be something more than a technique to selectively enhance contrast of morphological elements; it ought to give the structural addresses of some of the chemical residents of cell components. Is it pertinent that auto-radiography gets singled out for more complete coverage than other significant aspects of cytochemistry by a high resolution microscopist, when it has a built-in minimal error of 1,000 A in standard practice? I don't mean to blind-side (in strict football terminology) Dr. Sj6strand's efforts for what is \"routinely used in our laboratory\"; what is done is usually well done. It's just that …

Methods in Enzymology.

Microbial conversion of d-xylose to xylitol

Processes for fermentative production of xylitol - a sugar substitute

Biotechnological production of xylitol. Part 1: Interest of xylitol and fundamentals of its biosynthesis

The aerobic microorganism Corynebacterium glutamicum was metabolically engineered to broaden its substrate utilization range to include the pentose sugar xylose, which is commonly found in agricultural residues and other lignocellulosic biomass. We demonstrated the functionality of the corynebacterial xylB gene encoding xylulokinase and constructed two recombinant C. glutamicum strains capable of utilizing xylose by cloning the Escherichia coli gene xylA encoding xylose isomerase, either alone (strain CRX1) or in combination with the E. coli gene xylB (strain CRX2). These genes were provided on a high-copy-number plasmid and were under the control of the constitutive promoter trc derived from plasmid pTrc99A. Both recombinant strains were able to grow in mineral medium containing xylose as the sole carbon source, but strain CRX2 grew faster on xylose than strain CRX1. We previously reported the use of oxygen deprivation conditions to arrest cell replication in C. glutamicum and divert carbon source utilization towards product production rather than towards vegetative functions (M. Inui, S. Murakami, S. Okino, H. Kawaguchi, A. A. Vertes, and H. Yukawa, J. Mol. Microbiol. Biotechnol. 7:182-196, 2004). Under these conditions, strain CRX2 efficiently consumed xylose and produced predominantly lactic and succinic acids without growth. Moreover, in mineral medium containing a sugar mixture of 5% glucose and 2.5% xylose, oxygen-deprived strain CRX2 cells simultaneously consumed both sugars, demonstrating the absence of diauxic phenomena relative to the new xylA-xylB construct, albeit glucose-mediated regulation still exerted a measurable influence on xylose consumption kinetics.

/pdf/engineering-of-a-xylose-metabolic-pathway-in-corynebacterium-2x4di0f8ic.pdf

Engineering of a Xylose Metabolic Pathway in Corynebacterium glutamicum

An extract of cells of D-xylose-utilizing Enterobacter liquefaciens No. 553 grown in a D-xylose medium showed NADPH-dependent D-xylose reductase, glucose 6-phosphate dehydrogenase, phosphogluconate dehydrogenase and isocitrate dehydrogenase activities. D-Xylose isomerase, D-xylulokinase, transketolase and phosphoglucose isomerase activities were also found in the cell-free extract. These enzymes were fractionated by Sephadex G-100 gel filtration and DEAE-cellulose column chromatography, and some of their properties were examined. The reduction of D-xylose to xylitol was confirmed by the coupling of the fractionated D-xylose reductase and the glucose 6-phosphate dehydrogenase, phosphogluconate dehydrogenase or isocitrate dehydrogenase with NADP as a cofactor. The presence of NADPH in the cells accelerated the conversion of D-xylose into xylitol and repressed the isomerization of n-xylose into D-xylulose. The level of NAD-dependent xylitol dehydrogenase in the cells and the rate of reverse reaction by the D-xylose reductase dropped under the conditions favoring the production of xylitol.

Xylitol Production by Enterobacter liquefaciens

A gluconate-utilizing strain of Corynebacterium was found to be capable of utilizing aldopentoses and producing corresponding pentitols when pentoses were added to the medium containing gluconate as a carbon source during the cultivation of the organism.Pentitols produced from d-xylose, l-arabinose, and d-ribose were isolated from the cultured medium and identified as xylitol, l-arabitol, and ribitol, respectively.The pentitol production was significantly influenced by the concentration of gluconate in the initial medium and that of pentose added to the medium during the cultivation.The amount of xylitol, l-arabitol, and ribitol reached 69 mg/ml, 60 mg/ml, and 32 mg/ml, respectively, after 14 days of incubation when pentoses were added to the medium containing 9.6% potassium gluconate to give a final concentration of 150 mg/ml.

Production of Polyalcohol by a Corynebacterium sp:Part I. Production of Pentitol from Aldopentose

Production of Polyalcohol by a Corynebacterium sp

(1) 土壌中より分離されたD-キシロース資化性菌No. 17株の菌学的性質を検討した結果, Entevobacter cloacaeと同定された. (2) 本菌はD-キシロースより酸性物質を生成し,この酸性物質はD-キシロン酸と同定された. (3) D-キシロン酸の生成条件を検討した結果, D-キシロース20%, (NH4)2SO4 0.2%, KH2PO4 0.1%, MgSO4・7H2Ｏ O.05%, C. S. L. 0.2%, CaCO3 8.0%, (pH6.5)の培地組成で30°Cで5日間振盪培養すると,培地中に180～190mg/mlのD-キシロン酸が生成された. (4) 本菌によるD-キシロース以外の糖から酸性物質の生成の有無を検討した結果, L-アラビノース, D-グルコース, D-ガラクトース, D-マンノース,ラクトース,およびマルトースから酸性物質が検出された. (5) 本菌は30% D-グルコースより90%以上の収率で, D-グルコン酸を生成することが認められた.

D-Xylonic Acid Production by Enterobacter cloacae

A thiamine-requiring strain of Corynebacterium was found to accumulate a ketopentose extracellularly from gluconate. The ketopentose was isolated from the culture medium and identified as d-ribulose. The accumulation of d-ribulose was significantly influenced by the concentration of thiamine in the medium. The maximum yield of d-ribulose was obtained at a thiamine concentration of 10 μg per liter, whereas good growth was favored at thiamine concentrations greater than 50 μg per liter. The accumulation of d-ribulose reached the concentration of 9.5 mg per ml after cessation of cell growth in shake culture at 30°C in a medium containing 6% potassium gluconate as a carbon source.

Gluconate Metabolism by a Thiamine-requiring Species of Corynebacterium :Part IV. Accumulation of D-Ribulose

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Mutsuo Shimamura

Author Tools

Chat about Author