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981.
982.
Romeu Cardoso Guimarães 《Origins of life and evolution of the biosphere》2011,41(4):357-371
An investigation of the biosynthesis pathways producing glycine and serine was necessary to clarify an apparent inconsistency
between the self-referential model (SRM) for the formation of the genetic code and the model of coevolution of encodings and
of amino acid biosynthesis routes. According to the SRM proposal, glycine was the first amino acid encoded, followed by serine.
The coevolution model does not state precisely which the first encodings were, only presenting a list of about ten early assignments
including the derivation of glycine from serine—this being derived from the glycolysis intermediate glycerate, which reverses
the order proposed by the self-referential model. Our search identified the glycine-serine pathway of syntheses based on one-carbon
sources, involving activities of the glycine decarboxylase complex and its associated serine hydroxymethyltransferase, which
is consistent with the order proposed by the self-referential model and supports its rationale for the origin of the genetic
code: protein synthesis was developed inside an early metabolic system, serving the function of a sink of amino acids; the
first peptides were glycine-rich and fit for the function of building the early ribonucleoproteins; glycine consumption in
proteins drove the fixation of the glycine-serine pathway. 相似文献
983.
984.
985.
This review focuses on utilization of plant lectins as medical diagnostic reagents and tools. The lectin-related diagnostic
is aimed at detection of several diseases connected to alteration of the glycosylation profiles of cells and at identification
of microbial and viral agents in clinical microbiology. Certain lectins, proposed for or used as diagnostic tools could even
recognize those cellular determinants, which are not detected by available antibodies. Broad information is presented on the
lectinomics field, illustrating that lectin diagnostics might become practical alternative to antibody-based diagnostic products.
In addition, the rising trend of lectin utilization in biomedical diagnostics might initiate a development of innovative methods
based on better analytical technologies. Lectin microarray, a rapid and simple methodology, can be viewed as an example for
such initiative. This technology could provide simple and efficient screening tools for analysis of glycosylation patterns
in biological samples (cellular extracts, tissues and the whole cells), allowing thus personalized detection of changes associated
with carbohydrate-related diseases. 相似文献
986.
987.
Xylose anaerobic conversion by open-mixed cultures 总被引:1,自引:0,他引:1
Margarida F. Temudo Tania Mato Robbert Kleerebezem Mark C. M. van Loosdrecht 《Applied microbiology and biotechnology》2009,82(2):231-239
Xylose is, after glucose, the dominant sugar in agricultural wastes. In anaerobic environments, carbohydrates are converted
into volatile fatty acids and alcohols. These can be used as building blocks in biotechnological or chemical processes, e.g.,
to produce bioplastics. In this study, xylose fermentation by mixed microbial cultures was investigated and compared with
glucose under the same conditions. The product spectrum obtained with both substrates was comparable. It was observed that,
in the case of xylose, a higher fraction of the carbon was converted into catabolic products (butyrate, acetate, and ethanol)
and the biomass yield was approximately 20% lower than on glucose, 0.16 versus 0.21 Cmol X/Cmol S. This lower yield is likely
related to the need of an extra ATP during xylose uptake. When submitted to a pulse of glucose, the population cultivated
on xylose could instantaneously convert the glucose. No substrate preference was observed when glucose and xylose were fed
simultaneously to the continuously operated bioreactor. 相似文献
988.
Two new species of the genus Quadroppia Jacot, 1939, Quadroppia (Coronoquadroppia) squarrosa sp. n. and Quadroppia (Quadroppia) foveolata sp. n. are described and illustrated from Turkey. They were collected from soil and litter under pear trees (Pyrus communis) and moss on rock, respectively. 相似文献
989.
Tayvich Vorapreeda Chinae Thammarongtham Kobkul Laoteng 《World journal of microbiology & biotechnology》2016,32(7):122
Lipid-degrading or lipolytic enzymes have gained enormous attention in academic and industrial sectors. Several efforts are underway to discover new lipase enzymes from a variety of microorganisms with particular catalytic properties to be used for extensive applications. In addition, various tools and strategies have been implemented to unravel the functional relevance of the versatile lipid-degrading enzymes for special purposes. This review highlights the study of microbial lipid-degrading enzymes through an integrative computational approach. The identification of putative lipase genes from microbial genomes and metagenomic libraries using homology-based mining is discussed, with an emphasis on sequence analysis of conserved motifs and enzyme topology. Molecular modelling of three-dimensional structure on the basis of sequence similarity is shown to be a potential approach for exploring the structural and functional relationships of candidate lipase enzymes. The perspectives on a discriminative framework of cutting-edge tools and technologies, including bioinformatics, computational biology, functional genomics and functional proteomics, intended to facilitate rapid progress in understanding lipolysis mechanism and to discover novel lipid-degrading enzymes of microorganisms are discussed. 相似文献
990.