110 research outputs found
Bio : A Mulrimodal biometric authentication system for person identification and verification
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Automatic validation of glycan sequences in distributed databases
The creation and maintenance of glycan databases is critically important for the development of the field of glycobiology. As part of the process to build up the database, any deposited sequences need to be validated to ensure the correctness of the database. This thesis details the design and implementation of a semi-automatic system to validate new sequences with respect to the context that the sequences appear in
Nutrition induced pleomorphism and budding mode of reproduction in Deinococcus radiodurans
<p>Abstract</p> <p>Background</p> <p>Morphological adaptation is an important biological function of a microorganism to cope with its environment. Pleomorphism (to exist in a number of morphological forms) took centre stage in many discussions wherein a bacterium exhibits morphological transition and altered mode of reproduction in response to an environmental condition.</p> <p>Findings</p> <p>To strengthen the concept on pleomorphism in bacteria, we report here different cell morphologies of <it>Deinococcus radiodurans </it>in response to variation in nutrient concentration. From our studies we attempt primary evidence towards the presence of significant population of monomer cells of <it>D. radiodurans </it>in specific culture condition. In this report we also illustrate with scanning electron micrographs an unusual budding mode of reproduction in <it>D. radiodurans </it>which was not reported till date for this group of bacteria.</p> <p>Conclusion</p> <p>In a holistic view the study reflects on bacterial shape (morphotypes) and the physiological adaptation to a particular nutrient environment. The discovery of budding mode of reproduction in <it>Deinococcus </it>will be of interest to microbiologists. It can serve as a model system to understand the mechanism of budding process at molecular level.</p
Mossbauer Spectroscopic and Magnetic Studies of the Gel-Grown Iron (II) Tartrate Dihydrate Crystals
Competition Triggers Plasmid-Mediated Enhancement of Substrate Utilisation in Pseudomonas putida
Competition between species plays a central role in the activity and structure of communities. Stable co-existence of diverse organisms in communities is thought to be fostered by individual tradeoffs and optimization of competitive strategies along resource gradients. Outside the laboratory, microbes exist as multispecies consortia, continuously interacting with one another and the environment. Survival and proliferation of a particular species is governed by its competitive fitness. Therefore, bacteria must be able to continuously sense their immediate environs for presence of competitors and prevailing conditions. Here we present results of our investigations on a novel competition sensing mechanism in the rhizosphere-inhabiting Pseudomonas putida KT2440, harbouring gfpmut3b-modified KanR TOL plasmid. We monitored benzyl alcohol (BA) degradation rate, along with GFP expression profiling in mono species and dual species cultures. Interestingly, enhanced plasmid expression (monitored using GFP expression) and consequent BA degradation were observed in dual species consortia, irrespective of whether the competitor was a BA degrader (Pseudomonas aeruginosa) or a non-degrader (E. coli). Attempts at elucidation of the mechanistic aspects of induction indicated the role of physical interaction, but not of any diffusible compounds emanating from the competitors. This contention is supported by the observation that greater induction took place in presence of increasing number of competitors. Inert microspheres mimicking competitor cell size and concentration did not elicit any significant induction, further suggesting the role of physical cell-cell interaction. Furthermore, it was also established that cell wall compromised competitor had minimal induction capability. We conclude that P. putida harbouring pWW0 experience a competitive stress when grown as dual-species consortium, irrespective of the counterpart being BA degrader or not. The immediate effect of this stress is a marked increase in expression of TOL, leading to rapid utilization of the available carbon source and massive increase in its population density. The plausible mechanisms behind the phenomenon are hypothesised and practical implications are indicated and discussed
Sharing of worldwide distributed carbohydrate-related digital resources: online connection of the Bacterial Carbohydrate Structure DataBase and GLYCOSCIENCES.de
Functional glycomics, the scientific attempt to identify and assign functions to all glycan molecules synthesized by an organism, is an emerging field of science. In recent years, several databases have been started, all aiming to support deciphering the biological function of carbohydrates. However, diverse encoding and storage schemes are in use amongst these databases, significantly hampering the interchange of data. The mutual online access between the Bacterial Carbohydrate Structure DataBase (BCSDB) and the GLYCOSCIENCES.de portal, as a first reported attempt of a structure-based direct interconnection of two glyco-related databases is described. In this approach, users have to learn only one interface, will always have access to the latest data of both services, and will have the results of both searches presented in a consistent way. The establishment of this connection helped to find shortcomings and inconsistencies in the database design and functionality related to underlying data concepts and structural representations. For the maintenance of the databases, duplication of work can be easily avoided, and will hopefully lead to a better worldwide acceptance of both services within the community of glycoscienists. BCSDB is available at and the GLYCOSCIENCES.de portal a
An Integrative Approach to the Identification of Arabidopsis and Rice Genes Involved in Xylan and Secondary Wall Development
Xylans constitute the major non-cellulosic component of plant biomass. Xylan biosynthesis is particularly pronounced in cells with secondary walls, implying that the synthesis network consists of a set of highly expressed genes in such cells. To improve the understanding of xylan biosynthesis, we performed a comparative analysis of co-expression networks between Arabidopsis and rice as reference species with different wall types. Many co-expressed genes were represented by orthologs in both species, which implies common biological features, while some gene families were only found in one of the species, and therefore likely to be related to differences in their cell walls. To predict the subcellular location of the identified proteins, we developed a new method, PFANTOM (plant protein family information-based predictor for endomembrane), which was shown to perform better for proteins in the endomembrane system than other available prediction methods. Based on the combined approach of co-expression and predicted cellular localization, we propose a model for Arabidopsis and rice xylan synthesis in the Golgi apparatus and signaling from plasma membrane to nucleus for secondary cell wall differentiation. As an experimental validation of the model, we show that an Arabidopsis mutant in the PGSIP1 gene encoding one of the Golgi localized candidate proteins has a highly decreased content of glucuronic acid in secondary cell walls and substantially reduced xylan glucuronosyltransferase activity
GlycoViewer: a tool for visual summary and comparative analysis of the glycome
The GlycoViewer (http://www.systemsbiology.org.au/glycoviewer) is a web-based tool that can visualize, summarize and compare sets of glycan structures. Its input is a group of glycan structures; these can be entered as a list in IUPAC format or via a sugar structure builder. Its output is a detailed graphic, which summarizes all salient features of the glycans according to the shapes of the core structures, the nature and length of any chains, and the types of terminal epitopes. The tool can summarize up to hundreds of structures in a single figure. This allows unique, high-level views to be generated of glycans from one protein, from a cell, a tissue or a whole organism. Use of the tool is illustrated in the analysis of normal and disease-associated glycans from the human glycoproteome
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