Optimal growth temperature

Further investigations revealed additional advantages conferred by the association of the partners in the T. thermophilus transamidosome. The kinetics of the hydrolysis of the aa-tRNAs in free form or bound in the complex show that the transamidosome stabilizes the ester bond of the Asp-tRNA intermediate by increasing its half-life about twofold (half-lives 315 and 204 min) and that of the end product Asn-tRNA fourfold (half-lives 18 and 66 min). Finally, measurements of the thermostability of the protein partners reveal a significant increase in the stability of GatCAB and the ND-AspRS at 85 °C, the optimal growth temperature of T. thermophilus, when associated in the transamidosome. 

Subgenus, Optimal Growth Temperature, and Origin for 12 Penicillium Strains Investigated... 

Fig. 1. Optimal growth temperatures for mesophilic and extremophilic organisms.

The sublimation sandwich method (SSM) is similar to the sublimation method, except for the small distance between source powder and substrate, 2-5 mm [10-12], Ga or GaN was used as a source and the substrate was sapphire or 6H-SiC. The optimal growth temperature was around 1200°C as temperatures lower than 1150°C caused the formation of structural defects such as voids and micropipes. Polycrystalline GaN was grown under 1050°C. At higher temperatures, GaN was thermally decomposed. The growth rate is much higher, up to 300 pm/hr [10] or 0.2 - 1.1 mm/hr [12], and crystalline GaN with the maximum thickness of 500 pm could be obtained. 

Insect cells will grow reasonably well at any temperature from room temperature to 30°C and they do not require C02. An optimal growth temperature is 27°C. In order to maintain consistency of cell growth and virus infection, cells should be used within 20-30 passages. After that, a culture should be replaced by retrieving a fresh batch of cells from liquid nitrogen. 

Abbreviations RvG act., reverse-gyrase activity +, detection of ATP-dependent positive supercoiling in crude extract ND, not detected (see also Fig. 7) e, euryarchaeota c, crenarchaeota Topt, optimal growth temperature. 

The results summarized in Table 3 show that there is no simple relationship between optimal growth temperature and the G+C content of the genomic DNA. Although... 

Pd. occultum, with the highest optimal growth temperature (>100°C), exhibits the highest G-i-C content (62%), for the next group of organisms, growing at 95-100 C, the G-i-C contents lie in the range of 38-46%. Thus, one can infer that factors other than nucleotide composition of the DNA determine its thermal stability. Examples of... 

Comparison of optimal growth temperatures and genomic G-C contents... 

Organism Optimal growth temperature (°C) Genomic G-C content (%) Reference... 

For the open reading frames, the nucleotide compositions were also correlated with the optimal growth temperatures. No direct relationship was observed between G-t-C content and temperature. However, as illustrated in Fig. 2, the G+C content of the protein-coding... 

Fig. 1. Dependence of the nucleotide compositions of the large rRNAs on the optimal growth temperature of the organisms listed in Table 3. The bacterial rRNAs from Eschericia coli, Bacillus stearothermophilus and Fervidobacterium nodosum were used to cover the lower temperature range.

No direct relationship exists between the optimal growth temperature of the archaeal thermophiles and their genomic G+C content. However, for the large rRNAs, the G+C content increases directly with optimal growth temperature and, at the highest temperatures, the C content increases relatively more than the G content, which suggests that G-U pairs may be converted to G-C pairs. 

For the open reading frames the G+C content is directly proportional to the genomic G+C content but shows no direct relationship to the optimal growth temperature at high growth temperatures the C content of the open reading frames increases more rapidly than the G content. 

The numerical calculations are performed for the optimal growth temperature range, found in [6] to be 440-470 °C, and for incident fluxes of active species used practically. The results are presented in Figs. 1 and 2. 

Around the hydrothermal vents in the deep sea, extremely thermophilic bacteria reside which have the optimal growth temperature at 100°C which participate in the reduction of several metals. For example, Pyrobaculum islandicum (Kashefi... 

On the basis of the 16S/18S rRNA sequence comparisons, the hyperthermophilic bacteria (optimal growth temperature higher than 80°C) are located nearer to origins of life in the phylogenetic tree (Stetter, 1994). Therefore, many researchers think that life might have originated at temperatures as high as 100°C, before the surface of the Earth had cooled to around 30° K)°C. 

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