The molecular genetics and biotechnological application of enzymes from extremely thermophilic eubacteria

Bergquist, Peter L.; Morgan, Hugh W.; Herbert, R. A.; Sharp, Richard

doi:10.1007/978-94-011-2274-0_2

Cited by 19 publications

(13 citation statements)

References 113 publications

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“…Most of these processes are carried out at high temperatures, so that thermostable enzymes would give an advantage (Sonnleitner & Fiechter 1983). Over the past decade, there has been a considerable increase in the interest in thermophilic endospore-forming bacteria of the genus Bacillus, both because of their possible contamination of heated food products and because of their biotechnological importance as sources of thermostable enzymes and other products attracting the industrial interest (Bergquist & Morgan 1992). Therefore, thermophilic organisms are of special inter-est as a source of novel thermostable enzymes (Becker et al 1997;Lee et al 1999;Beg et al 2000;Touzel et al 2000).…”

Section: Introductionmentioning

confidence: 99%

Characterization of a xylanase from a thermophilic strain of Anoxybacillus pushchinoensis A8

et al. 2008

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A facultatively anaerobic, thermophilic, xylanolytic bacterium was isolated from a sample collected from the Diyadin Hot Springs, Turkey. According to morphological, biochemical and molecular identification, this new strain was suggested to be representative of the Anoxybacillus pushchinoensis and it was designated as Anoxybacillus pushchinoensis strain A8. It exhibited 97% similarity to 16S rRNA gene sequence of A. pushchinoensis and 77% DNA homology by DNA-DNA hybridization studies. Q-sepharose and CM-sepharose chromatography was used to purify an extracellular xylanase to >90% purity from this species. The enzyme had a molecular mass of approximately 83 kDa. The enzyme showed optimum activity at pH 6.5 and it was 96% stable over a broad pH range of 6.5-11 for 24 hours. The enzyme had optimum activity at 55• C and it was 100% stable at temperature between 50-60• C up to 24 hours. Kinetic characterization of the enzyme was performed at temperature optima (55 • C) and Vmax and Km were found to be 59.88 U/mg protein and 0.909 mg/mL, respectively. Oat spelt xylan but not xylooligosaccharides was degraded by the enzyme and xylose was the only product detected from oat xylan degradation. This suggested that the enzyme was an exo-acting xylanase.

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Section: Introductionmentioning

confidence: 99%

Characterization of a xylanase from a thermophilic strain of Anoxybacillus pushchinoensis A8

et al. 2008

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“…Thermophilic and extremely thermophilic microorganisms have gained a great deal of attention recently (3). Enzymes from these micro-organisms are of special interest since they are not usually denatured by high temperatures and are even active at elevated temperatures (3,35).…”

Section: Introductionmentioning

confidence: 99%

“…Enzymes from these micro-organisms are of special interest since they are not usually denatured by high temperatures and are even active at elevated temperatures (3,35). Furthermore, members of the thermoanaerobic saccharolytic group may be commercially useful for producing chemicals and fuels such as ethanol and lactate from plant biomass (15).…”

Section: Introductionmentioning

confidence: 99%

Caldicellulosiruptor owensensis sp. nov., an anaerobic, extremely thermophilic, xylanolytic bacterium

Huang

Patel

Mah

et al. 1998

International Journal of Systematic Bacteriology

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An anaerobic, extremely thermophilic, xylanolytic, non-spore-forming bacterium was isolated from a sediment sample taken from Owens Lake, California, and designated strain OLT (T = type strain). Strain OLT had a Gramnegative reaction and occurred as short rods which sometimes formed long chains containing a f e w coccoid cells. It grew a t 50-80 "C, with an optimum a t 75 "C. The pH range for growth was 55-900 with an optimum a t about pH 7.5. When grown on glucose a t optimal conditions, its doubling time was 7-3 h. In addition to glucose, the isolate utilized sucrose, xylose, fructose, ribose, xylan, starch, pectin and cellulose. Yeast extract stimulated growth on carbohydrates but was not obligately required. The end products from glucose fermentation were lactate, acetate, ethanol, H, and CO, . The G+C content of strain OLT was 36.6 mol%. The 165 rDNA sequence analysis indicated that strain OLT was a member of the subdivision containing Gram-positive bacteria with DNA G+C content of less than 55 mol% and clustered with members of the genus Caldicellulosiru~ tor. Because s tra i n OLT is p h y log ene t ica I I y and p he no typ ica I I y different from other members of this genus, it is proposed to designate this isolate Caldicellulosiruptor owensensis sp. nov. Strain OLT is the type strain (= ATCC 7001673.

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“…Although a great deal is known about the physiology and biochemistry of thermophiles, very little is known about their chromosome structure or their genetics. Few genetic studies have been done so far because of a lack of tools for gene transfer in these organisms, although a number of genes have been cloned in Escherichia coli (3).…”

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confidence: 99%

“…To locate genes cloned from various Thermus strains on the T. thennophilus HB8 map, probe plasmids (50 to 100 ng) linearized with an appropriate restriction endonuclease were either DIG labelled according to the instructions of the manufacturer or radiolabelled with 30 ,uCi of [a-32P]dCTP (3,000 Ci/mmol) with the Gigaprime DNA labelling kit from Bresatec Limited (Adelaide, Australia). These Thermus probes were generously supplied by the researchers indicated in Table 4.…”

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confidence: 99%

Genomic restriction map of the extremely thermophilic bacterium Thermus thermophilus HB8

Borges

Bergquist

1993

J Bacteriol

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A physical map of the chromosome of the extremely thermophilic eubacterium Thermus thermophilus HB8 has been constructed by using pulsed-field gel electrophoresis techniques. A total of 26 cleavage sites for the rarely cutting restriction endonucleases HpaI, MunI, and NdeI were located on the genome. On the basis of the sizes of the restriction fragments generated, the genome size was estimated to be 1. Thermus thermophilus HB8 is a gram-negative, obligatory aerobic eubacterium that can grow at temperatures of up to 850C (32). Previous work has shown that this organism possesses two cryptic plasmids, p1T8 (11) and pVV8 (41), but no studies on the genome and its size have been reported. In this study, a pulsed-field gel electrophoresis (PFGE) examination of the genome of T. thermophilus HB8 was initiated to facilitate analysis of the genetics and chromosome structure of thermophilic eubacteria. Three restriction endonucleases which cleave the genome infrequently were identified, restriction fragment separation was optimized, and the fragments were ordered to generate a physical map of the genome. Sixteen genes cloned from several Thennus strains were also located on the chromosomal map.MATERIALS AND METHODS Preparation of DNA gel plugs. T. thennophilus HB8 (ATCC 27634) cells were grown at 70'C in 162 salts medium supplemented with 0.3% tryptone and 0.3% yeast extract (9) to a cell density of approximately 4 x 108/ml. Cells (10 ml) were washed with 10 ml of wash buffer (10 mM Tris-HCl [pH 7.6], 1 M NaCl), resuspended in 1.

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The molecular genetics and biotechnological application of enzymes from extremely thermophilic eubacteria

Cited by 19 publications

References 113 publications

Characterization of a xylanase from a thermophilic strain of Anoxybacillus pushchinoensis A8

Characterization of a xylanase from a thermophilic strain of Anoxybacillus pushchinoensis A8

Caldicellulosiruptor owensensis sp. nov., an anaerobic, extremely thermophilic, xylanolytic bacterium

Genomic restriction map of the extremely thermophilic bacterium Thermus thermophilus HB8

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