دانلود رایگان مقاله لاتین باکتری گرمادوست از سایت الزویر
عنوان فارسی مقاله:
بررسی تولید اگزوپلی ساکارید توسط باکتری دو سویه گرمادوست رودوترموس مارینوس
عنوان انگلیسی مقاله:
Evaluation of the production of exopolysaccharides by two strains of the thermophilic bacterium Rhodothermus marinus
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
Extracellular polysaccharides (exopolysaccharides, EPSs) are the major part of extracellular polymeric substances produced by microorganisms (Jindal, Singh, & Khattar, 2011). They exist in two main forms; as a capsule associated with the cell surface or secreted out of the cell, either to the surroundings or remain loosely attached to the cell surface (Tallon, Bressollier, & Urdaci, 2003). Exopolysaccharides have important ecological and physiological functions and play special roles in protecting the microorganisms that produce them. EPSs are believed to protect cells against antimicrobial substances, desiccation, bacteriophages, osmotic stress, and antibodies (Mata et al., 2006; Tallon et al., 2003). EPSs can be found as homopolysaccharides or heteropolysaccharides and can be decorated with other residues such as phosphates, sulfates, N-acetyl-aminosugars, and acetyl groups (Laws, Gu, & Marshall, 2001). The properties of the EPSs areinfluenced by their composition which is affected by nutrient availability as well as by other factors such as their molecular mass and the location of functional groups. The unique and complex chemical structures of EPSs, which are natural polymers with different functional properties, make them interesting for various industrial applications in food, pharmaceutical, petroleum and other industries (Castellane, Lemos, & deMacedo Lemos, 2014), for example by affecting the fluidity of active compounds. Both prokaryotes (Gram-positive and Gram-negative bacteria) and eukaryotes (fungi, some algea, and phytoplankton) are known to produce EPSs and new species are currently being targeted in the search for EPSs with novel properties. As a result of these screening efforts, marine bacteria are now widely accepted as the source of EPSs with unique properties that can be exploited for novel biotechnological processes (Chi & Fang, 2005). Rhodothermus marinus is a thermophilic, reddish colored aerobic, and Gram-negative bacterium that was first isolated from shallow marine hot springs in Iceland (Alfredsson, Kristjansson, Hjörleifsdotter, & Stetter, 1988). The bacterium grows heterotrophically and is known to produce highly thermostable enzymes (Nordberg Karlsson, Bartonek-Roxå, & Holst, 1998; Blücher, Nordberg Karlsson, & Holst, 2000). It is of interest as representing the deepest lineage in the phylum Bacteroidetes (Nolan, Tindall, Pomrenke, Lapidus, & Copeland, 2009). The complete genome sequence is available for the type strain and tools have been developed for genetic manipulation of a second strain, MAT493 (Bjornsdottir, Fridjonsson, Hreggvidsson, & Eggertsson, 2011; Bjornsdottir, Thorbjarnardottir, & Eggertsson, 2005). The cells of R. marinus have been shown to form a distinct capsule when grown on carbohydrate-rich medium (Alfredsson et al., 1988). To our knowledge,however,no informationis available ontheproduction of EPSs by R.marinus, or on their physico-chemical properties. The aim of this study was the evaluation of EPS production by the R.marinus type strain (DSM 4252T) as well as by a strain that is amenable to engineering (MAT 493). The work involved the examination of the kinetics of EPS production in batch cultures using shake flasks under varied nutritional conditions. Also, the isolation and characterization of novel EPS from the two R.marinus strains has opened possibilities for applying EPSs from R.marinus for industrial purposes.
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کلمات کلیدی:
The Prokaryotes: Vol. 7: Proteobacteria: Delta and Epsilon ... https://books.google.com/books?isbn=0387254978 Stanley Falkow, Eugene Rosenberg, Karl-Heinz Schleifer - 2006 - Science Carotenoids of thermophilic bacteria: Rhodothermus marinus from submarine ... Isolation and characterization of Rhodothermus strains from S. Miguel, Azores. Thermophilic Bacteria - Page 66 - Google Books Result https://books.google.com/books?isbn=0849352398 Jakob K. Kristjansson - 1991 - Science It has a rather high optimum temperature for a bacterium and has also a rather alkaline pH optimum. ... all strains but lysine or ornithine was also found in some strains. ... of Rhodothermus marinus CM, cytoplasmic 66 Thermophilic Bacteria. Extremophiles in Deep-Sea Environments https://books.google.com/books?isbn=4431679251 K. Horikoshi, K. Tsujii - 2012 - Science Our results demonstrate that Vibrio vulnificus-related bacteria also exist in the ... to the 16S rBNA of thermophilic bacterium Rhodothermus marinus in the Cytophaga group. A number of Rhodothermus marinus strains have been isolated from ... [PDF]Compatible Solutes in the Thermophilic Bacteria Rhodothermus ... pubmedcentralcanada.ca/pmcc/articles/PMC1388471/pdf/hw2351.pdf by OC Nunes - 1995 - Cited by 86 - Related articles Two strains of Rhodothermus marinus and four strains of ''Thermus thermophilus'' grown in ... Many thermophilic archaea and bacteria are also halotoler-. Rhodothermus - Bergey's Manual of Systematics of Archaea and ... onlinelibrary.wiley.com › ... › Abstract Sep 14, 2015 - Red colonies are formed by most strains of Rhodothermus marinus, but two .... (1996) isolated a thermophilic bacterium from a shallow marine ... Rhodothermus - Wiley Online Library onlinelibrary.wiley.com/doi/10.1002/9781118960608.gbm00282/pdf Aero- bic. Thermophilic, growing at 54–77. ∘ .... Rhodothermus marinus strains were isolated at different geo- .... (1996) isolated a thermophilic bacterium from. [PDF]Evaluation of the production of exopolysaccharides by two strains of ... iranarze.ir/wp-content/uploads/2016/11/E2692.pdf Aug 21, 2016 - Evaluation of the production of exopolysaccharides by two strains of the thermophilic bacterium Rhodothermus marinus. Roya R.R. Sardaria,∗, ...
