Topic
Thermus
About: Thermus is a research topic. Over the lifetime, 657 publications have been published within this topic receiving 18859 citations.
Papers published on a yearly basis
Papers
TL;DR: Thermus aquaticus gen. n and sp. n are gram-negative nonsporulating nonmotile rods which frequently form long filaments at supraoptimal temperatures or in the stationary phase as mentioned in this paper.
Abstract: The isolation of a new thermophilic bacterium, Thermus aquaticus gen. n. and sp. n., is described. Successful enrichment requires incubation at 70 to 75 C, and the use of nutrient media relatively dilute with respect to the organic components. Strains of T. aquaticus have been isolated from a variety of thermal springs in Yellowstone National Park and from a thermal spring in California. The organism has also been isolated from man-made thermal habitats, such as hot tap water, in geographical locations quite distant from thermal springs. Isolates of T. aquaticus are gram-negative nonsporulating nonmotile rods which frequently form long filaments at supraoptimal temperatures or in the stationary phase. All isolates form a yellow cellular pigment, probably a carotenoid. A characteristic structure formed by all isolates is a large sphere, considerably larger than a spheroplast. These large spheres, as well as lysozyme-induced spheroplasts, are resistant to osmotic lysis. Deoxyribonucleic acid base compositions of four strains were determined by CsCl density gradient ultracentrifugation and found to be between 65.4 and 67.4 moles per cent guanine plus cytosine. The growth of all isolates tested is inhibited by fairly low concentrations of cycloserine, streptomycin, penicillin, novobiocin, tetracycline, and chloramphenicol. Nutritional studies on one strain showed that it did not require vitamins or amino acids, although growth was considerably faster in enriched than in synthetic medium. Several sugars and organic acids served as carbon sources, and either NH4+ or glutamate could serve as nitrogen source. The organism is an obligate aerobe and has a pH optimum of 7.5 to 7.8. The optimum temperature for growth is 70 C, the maximum 79 C, and the minimum about 40 C. The generation time at the optimum is about 50 min. The possible relationships of this new genus to the myxobacteria, flexibacteria, and flavobacteria are discussed.
745 citations
TL;DR: The properties of an extremely thermophilic bacterium isolated from water at a Japanese hot spring and previously named Flavobacterium thermophilum are described and this microorganism is transferred to the genus Thermus as T. thermophilus (Yoshida and Oshima) comb.
Abstract: The properties of an extremely thermophilic bacterium isolated from water at a Japanese hot spring and previously named Flavobacterium thermophilum are described. The cells are gram-negative, nonsporulating, aerobic rods containing yellow pigment. The optimum temperature for growth is between 65 and 72 C, the maximum being 85 C and the minimum being 47 C. The guanine plus cytosine content of the deoxyribonucleic acid of the thermophile is 69 mol %. This microorganism is sensitive to various antibiotics including those which are known to be rather ineffective against gram-negative bacteria. Spheroplast-like bodies are formed upon treating intact cells with egg-white lysozyme at 60 C. The spheres are osmotically more stable than mesophile protoplasts, and their rupture under hypotonic conditions is not complete unless 0.5% Brij 58 is added to the suspension. Bulk protein extracted from this thermophile is much more stable to heat than mesophile proteins, and only about 10% of the total protein is denatured by heating at 110 C for 5 min. Nevertheless, the amino acid composition of the bulk protein is similar to that of mesophile proteins. As the properties of this organism are similar to those of Thermus aquaticus (Brock and Freeze) and inasmuch as Flavobacterium is a poorly defined genus, this thermophilic microorganism is transferred to the genus Thermus as T. thermophilus (Yoshida and Oshima) comb. nov. The type strain is HB8 (=ATCC 27634).
620 citations
TL;DR: This study suggests that Thermus strains play an important role in organic-matter degradation during the thermogenic phase of the composting process.
Abstract: High numbers (10(7) to 10(10) cells per g [dry weight]) of heterotrophic, gram-negative, rod-shaped, non-sporeforming, aerobic, thermophilic bacteria related to the genus Thermus were isolated from thermogenic composts at temperatures between 65 and 82 degrees C. These bacteria were present in different types of wastes (garden and kitchen wastes and sewage sludge) and in all the industrial composting systems studied (open-air windows, boxes with automated turning and aeration, and closed bioreactors with aeration). Isolates grew fast on a rich complex medium at temperatures between 40 and 80 degrees C, with optimum growth between 65 and 75 degrees C. Nutritional characteristics, total protein profiles, DNA-DNA hybridization (except strain JT4), and restriction fragment length polymorphism profiles of the DNAs coding for the 16S rRNAs (16S rDNAs) showed that Thermus strains isolated from hot composts were closely related to Thermus thermophilus HB8. These newly isolated T. thermophilus strains have probably adapted to the conditions in the hot-compost ecosystem. Heterotrophic, ovalspore-forming, thermophilic bacilli were also isolated from hot composts, but none of the isolates was able to grow at temperatures above 70 degrees C. This is the first report of hot composts as habitats for a high number of thermophilic bacteria related to the genus Thermus. Our study suggests that Thermus strains play an important role in organic-matter degradation during the thermogenic phase (65 to 80 degrees C) of the composting process.
239 citations
TL;DR: In studies on the cause of the extreme stability of the macromolecules of Thermus thermophilus HB8, the leuB gene coding for 3-isopropylmalate dehydrogenase of the leucine synthesis pathway and its flanking regions were cloned and sequenced.
209 citations
TL;DR: A simplified method is described here for isolating the recombinant Taq enzyme after overproduction in Escherichia coli and contains a single, nearly homogeneous protein consistent with the previously established size of the Taq DNA polymerase.
209 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 7 |
| 2024 | 16 |
| 2023 | 10 |
| 2022 | 27 |
| 2021 | 17 |
| 2020 | 10 |