Dictyoglomus thermophilum: Difference between revisions
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==Genome structure== | ==Genome structure== | ||
The complete genome for D. thermophilum has yet to be fully sequenced. Since the year 2006, geneticists at The Institute for Genomic Research (TIGR), have been conducting “random” shotgun sequencing in an attempt to construct the organism’s entire genome. The lack of information has made it difficult for microbiologists to isolate numerous proteins and enzymes synthesized by this organism [10, 14]. | |||
The G+C content of D. thermophilum is around 29 mol% [6]. Thirteen nucleotide regions, which code for a total of 17 proteins have been sequenced from Dictyoglomus thermophilus’s genome [10]. These numbers are miniscule when compared to the thousands of coding regions that have been identified from genomes in other organisms. Of the 17 discovered coding regions, many of them code for amylase proteins, xylanse enzymes, DNA polymerase, multiple unnamed proteins, and various kinase and transferase proteins. | |||
A total of three DNA sequences have been identified encoding three different Alpha-amylase enzymes (amyA, amyB, and amyC). Each of the sequences are 2649, 2496, and 2226 base pairs long. These enzymes are primarily involved in starch breakdown, providing the microbe with nutrients [6, 7, 9]. A 2639 base pair sequence was found to encode for DNA polymerase I [13]. Another internal 1507-bp fragment was sequenced and shown to code for a small, 352 amino acid long xylanase protein (XynA) [6]. This enzyme is involved in the degradation of heteropolymer, xylan. Another xylanase, xynB, is also coded in the genome of D. thermophilum. XynB also is involved in the breakdown of xylan, however, it is of greater interest than xynA because of its ability to bleach paper. Various nucleotide sequences such as these have been isolated and found to encode proteins primarily involved in hydrolysis of organic molecules. | |||
The exact positioning of these genes on the chromosome is not yet known. Once the complete genome has been constructed, a lot more can be inferred about its genomic structure. | |||
==Cell structure and metabolism== | ==Cell structure and metabolism== | ||
Revision as of 06:47, 29 August 2007
A Microbial Biorealm page on the genus Dictyoglomus thermophilum
Classification
Higher order taxa
Bacteria; Dictyoglomi; Dictyoglomi; Dictyoglomales; Dictyoglomaceae
Species
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NCBI: Taxonomy |
Dictyoglomus thermophilum
Description and significance
Dictyoglomus thermophilum is light grey, anaerobic, extremely thermophilic, rod-shaped bacterium first isolated from a slightly alkaline hot spring (pH 7.2, 100% N2) in Japan, 1985. Since then, the organism has been found in hot spring beds located in New Zealand and Russia as well. Like other thermophiles, D. thermophilum, thrives in environments of high temperature (between 50 and 80˚C, with an optimal value of 78˚C) [7, 10, 12].
This bacterium is unique in that it is the only member of the phylum entitled Dictyoglomi. The properties of this strain do not fit those of any previously described genus, warranting its very own phylum. D. thermophilum only lives in aquatic environments and is not known to have any form of motility [10]. It is a chemoorganotorph, meaning it derives energy by metabolizing organic molecules. This mysterious and elusive bacterium has generated interest because it has the ability to express xylanase, an enzyme involved in the digestion of xylan (a heteropolymer of the pentose sugar xylose). By treating wood pulp with this enzyme, manufacturers can give paper its characteristic “whiteness” without the use of chlorine bleach [4, 8]. Scientists have attempted to sequence and study the genes which encode this unusual protein and many others, with the intention of understanding how this organism is able to thrive under such extreme conditions.
Dictyoglomus thermophilum is a fairly young organism, only discovered in the year 1985 by Saiki et al. in a tsuetate hot spring of Japan [3, 12].
Genome structure
The complete genome for D. thermophilum has yet to be fully sequenced. Since the year 2006, geneticists at The Institute for Genomic Research (TIGR), have been conducting “random” shotgun sequencing in an attempt to construct the organism’s entire genome. The lack of information has made it difficult for microbiologists to isolate numerous proteins and enzymes synthesized by this organism [10, 14].
The G+C content of D. thermophilum is around 29 mol% [6]. Thirteen nucleotide regions, which code for a total of 17 proteins have been sequenced from Dictyoglomus thermophilus’s genome [10]. These numbers are miniscule when compared to the thousands of coding regions that have been identified from genomes in other organisms. Of the 17 discovered coding regions, many of them code for amylase proteins, xylanse enzymes, DNA polymerase, multiple unnamed proteins, and various kinase and transferase proteins.
A total of three DNA sequences have been identified encoding three different Alpha-amylase enzymes (amyA, amyB, and amyC). Each of the sequences are 2649, 2496, and 2226 base pairs long. These enzymes are primarily involved in starch breakdown, providing the microbe with nutrients [6, 7, 9]. A 2639 base pair sequence was found to encode for DNA polymerase I [13]. Another internal 1507-bp fragment was sequenced and shown to code for a small, 352 amino acid long xylanase protein (XynA) [6]. This enzyme is involved in the degradation of heteropolymer, xylan. Another xylanase, xynB, is also coded in the genome of D. thermophilum. XynB also is involved in the breakdown of xylan, however, it is of greater interest than xynA because of its ability to bleach paper. Various nucleotide sequences such as these have been isolated and found to encode proteins primarily involved in hydrolysis of organic molecules.
The exact positioning of these genes on the chromosome is not yet known. Once the complete genome has been constructed, a lot more can be inferred about its genomic structure.
Cell structure and metabolism
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
Ecology
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
Enter summaries of the most recent research here--at least three required
References
Edited by student of Rachel Larsen
