Optimum temperature for the growth performance of juvenile orange-spotted grouper (Epinephelus coioides H.)

Effects of water temperature (17, 21, 25, 30 and 35 degrees C) and body size (14.75-281.41 g initial body weight) on food consumption, growth, feed conversion, and dry matter content in orange-spotted grouper fed to satiation were investigated. The combined effect of temperature (T, degrees C) and body weight (W, g) on maximum food consumption (C-max, g/day) was described as: InCmax= -7.411+0.828 lnW+0.317T-0.004 7T(2), and the optimum feeding temperature was 33.9 degrees C. The combined effect of temperature and body weight on growth (G) was described as: InG= -4.461-0.208lnW+0.394T-0.006 3T(2). The optimum growth temperature was 31.4 degrees C, whereas overall growth rates were high at 25, 30 and 35 degrees C. Feed conversion efficiencies (FCE, %), increasing first and then decreasing with increasing temperature, averaged from 1.8 to 2.1 in terms of dry weight of food fish. The optimum temperature for FCE tended to be lower than that for growth or feeding. Dry matter content increased with both increasing water temperature (17, 25, 30 and 35 degrees C) and body weight, and the combined effect of temperature and body weight on dry matter content (DM, %) was described as: lnDM =3.232+0.01 4 lnW-0.004 4T+0.001 2TlnW.

The optimum temperature for long-season cropping in the everbearing strawberry 'Everest'

The prolonged season of everbearing strawberries causes vegetative growth and fruiting to coincide, so the influence of the environment on the balance of assimilate partitioning between vegetative and reproductive growth is important for optimised long-season production. Fruiting patterns were evaluated over three seasons for the everbearing strawberry 'Everest'. A range of temperatures (15-27 degrees C) was studied in the first season to establish a temperature response curve. Detailed transfer treatments in the second and third seasons gave insight into heat-induced cropping troughs ('thermo-dormancy'). The detrimental effect on yield of thermo-dormancy was prevented by cool night-time temperature during the periods of heat stress, a treatment that resulted in the largest total fruit fresh weight and overall yield. The highest yields were recorded for plants grown between 18 and 23 degrees C. At higher temperatures fruit number increased, but fruit weight decreased. The importance of night-time temperature in optimising long-season fruit production has significance for commercial production, in which protected cropping tends to increase average temperature through the season.

The optimum temperature for the operation of a non-scaling multi-stage flash evaporator plant,

On cover: Saline water conversion research.

Correlation of temperature induced conformation change with optimum catalytic activity in the recombinant G/11 xylanase A from Bacillus subtilis strain 168 (1A1)

The 1.7 angstrom resolution crystal structure of recombinant family G/11 beta-1,4-xylanase (rXynA) from Bacillus subtilis 1A1 shows a jellyroll fold in which two curved P-sheets form the active-site and substrate-binding cleft. The onset of thermal denaturation of rXynA occurs at 328 K, in excellent agreement with the optimum catalytic temperature. Molecular dynamics simulations at temperatures of 298-328 K demonstrate that below the optimum temperature the thumb loop and palm domain adopt a closed conformation. However, at 328 K these two domains separate facilitating substrate access to the active-site pocket, thereby accounting for the optimum catalytic temperature of the rXynA. (c) 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Genetic variability in high temperature effects on seed-set in sorghum

Sorghum (Sorghum bicolor (L.) Moench) is grown as a dryland crop in semiarid subtropical and tropical environments where it is often exposed to high temperatures around flowering. Projected climate change is likely to increase the incidence of exposure to high temperature, with potential adverse effects on growth, development and grain yield. The objectives of this study were to explore genetic variability for the effects of high temperature on crop growth and development, in vitro pollen germination and seed-set. Eighteen diverse sorghum genotypes were grown at day : night temperatures of 32 : 21 degrees C (optimum temperature, OT) and 38 : 21 degrees C (high temperature, HT during the middle of the day) in controlled environment chambers. HT significantly accelerated development, and reduced plant height and individual leaf size. However, there was no consistent effect on leaf area per plant. HT significantly reduced pollen germination and seed-set percentage of all genotypes; under HT, genotypes differed significantly in pollen viability percentage (17-63%) and seed-set percentage (7-65%). The two traits were strongly and positively associated (R-2 = 0.93, n = 36, P < 0.001), suggesting a causal association. The observed genetic variation in pollen and seed-set traits should be able to be exploited through breeding to develop heat-tolerant varieties for future climates.

Effects of temperature and irradiance on early development of Chondrus ocellatus Holm (Gigartinaceae, Rhodophyta)

Chondrus is a type of commercially produced red seaweed that widely used for food and carrageen extraction. Although the natural life history of the alga had been well understood, the factors influencing development of the tetraspore and carpospore remain poorly understood. In the perspective of seedling resources, the regulation of early development is crucial for the seedling nursing; therefore, it is necessary to understand the physiological influences during its early development. In this study, we studied the effects of temperature and irradiance on the early development of Chondrus ocellatus Holm under laboratory conditions. The released tetraspores and carpospores were cultivated at different temperatures (10-28 degrees C) and irradiances ( 10, 60 mu mol photons m(-2)s(-1)) with a photoperiod of 12L:12D. The results indicate that both tetraspores and carpospores are tolerant to temperatures of 10-25 degrees C, and have the highest relative growth rate at 20 degrees C. Irradiance variances influenced the growth of the discoid crusts, and the influence was more significant with increasing temperature; 60 mu mol photons m(-2)s(-1) was more suitable than 10 mu mol photons m(-2)s(-1). The optimum temperature and irradiance for the development of seedlings was 20 degrees C and 60 mu mol photons m(-2)s(-1), respectively.

Effects of temperature on CO2 exchange between the atmosphere and an alpine meadow

The alpine meadow ecosystem on the Qinghai-Tibetan Plateau is characterized by low temperatures because of its high elevation. The low-temperature environment may limit both ecosystem photosynthetic CO2 uptake and ecosystem respiration, and thus affect the net ecosystem CO2 exchange (NEE). We clarified the low-temperature constraint on photosynthesis and respiration in an alpine meadow ecosystem on the northern edge of the plateau using flux measurements obtained by the eddy covariance technique in two growing seasons. When we compared NEE during the two periods, during which the leaf area index and other environmental parameters were similar but the mean temperature differed, we found that NEE from 9 August to 10 September 2001, when the average temperature was low, was greater than that during the same period in 2002, when the average temperature was high, but the ecosystem gross primary production was similar during the two periods. Further analysis showed that ecosystem respiration was significantly higher in 2002 than in 2001 during the study period, as estimated from the relationship between temperature and nighttime ecosystem respiration. The results suggest that low temperature controlled the NEE mainly through its influence on ecosystem respiration. The annual NEE, estimated from 15 January 2002 to 14 January 2003, was about 290 g CO2 m(-2) year(-1). The optimum temperature for ecosystem NEE under light-saturated conditions was estimated to be around 15 degrees C.

A two-stage process with temperature-shift for enhanced anthocyanin production in strawberry cell suspension cultures

A two-stage process with temperature-shift has been developed to enhance the anthocyanin yield in suspension cultures of strawberry cells. The effect of the temperature-shift interval and the shift-time point was investigated for the optimization of this strategy. In this process, strawberry cells were grown at 30 degrees C (the optimum temperature for cell growth) for a certain period as the first stage, with the temperature shifted to a lower temperature for the second stage. In response to the temperature shift-down, anthocyanin synthesis was stimulated and a higher content could be achieved than that at both boundary temperatures but cell growth was suppressed. When the lower boundary temperature was decreased, cell growth was lowered and a delayed, sustained maximum anthocyanin content was achieved. Anthocyanin synthesis was strongly influenced by the shift-time point but cell growth was not. Consequently, the maximum anthocyanin content of 2.7 mg.g-fresh cell(-1) was obtained on day 9 by a temperature-shift from 30 degrees C, after 3-d culture, to 15 degrees C. The highest anthocyanin yield of 318 mg.L-1 on day 12 was achieved when the temperature was shifted from 30 degrees C, after 5-d culture, to 20 degrees C. For a global optimization of both the yield and productivity, the optimum anthocyanin yield and productivity of 272 mg.L-1 and 30.2 mg.L-1.d(-1) on day 9 were achieved by a two-stage culture with a temperature-shift from 30 degrees C after 3 d to 20 degrees C.

Resolution prediction and optimization of temperature programme in comprehensive two-dimensional gas chromatography

A model is developed for predicting the resolution of interested component pair and calculating the optimum temperature programming condition in the comprehensive two-dimensional gas chromatography (GC x GC). Based on at least three isothermal runs, retention times and the peak widths at half-height on both dimensions are predicted for any kind of linear temperature-programmed run on the first dimension and isothermal runs on the second dimension. The calculation of the optimum temperature programming condition is based on the prediction of the resolution of "difficult-to-separate components" in a given mixture. The resolution of all the neighboring peaks on the first dimension is obtained by the predicted retention time and peak width on the first dimension, the resolution on the second dimension is calculated only for the adjacent components with un-enough resolution on the first dimension and eluted within a same modulation period on the second dimension. The optimum temperature programming condition is acquired when the resolutions of all components of interest by GC x GC separation meet the analytical requirement and the analysis time is the shortest. The validity of the model has been proven by using it to predict and optimize GC x GC temperature programming condition of an alkylpyridine mixture. (c) 2005 Elsevier B.V. All rights reserved.

Analysis of shade and temperature effects on assimilate partitioning in the everbearing strawberry 'Everest' as the basis for optimised long-season fruit production

Growth patterns and cropping were evaluated over the season for the everbearing strawberry 'Everest' at a range of temperatures (15-27degreesC) in two light environments (ambient and 50% shade). The highest yield was recorded for unshaded plants grown at 23degreesC, but the optimum temperature for vegetative growth was 15degreesC. With increasing temperature fruit number increased, but fruit weight decreased. Fruit weight was also significantly reduced by shade, and although 'Everest' showed a degree of shade tolerance in vegetative growth, yield was consistently reduced by shade. Shade also reduced the number of crowns developed by the plants over the course of the season, emphasising that crown number was ultimately the limiting factor for yield potential. We conclude that, in contrast to Junebearers which partition more assimilates to fruit at temperatures around 15degreesC (Le Miere et al., 1998), optimised cropping in the everbearer 'Everest' is achieved at the significantly higher temperature of 23degreesC. These findings have significance for commercial production, in which protection tends to reduce light levels but increase average temperature throughout the season.

Temperature effect on dextransucrase production by Leuconostoc mesenteroides FT 045 B isolated from Alcohol and Sugar Mill Plant

Temperature (23 to 31 degrees C) and sucrose concentration ( 3 and 4%) effects on dextransucrase production by Leuconostoc mesenteroides NRRL B 512 ( F) and Leuconostoc mesenteroides FT 045 B were studied. The conditions in all fermentations were: total reaction volume 2 L, 132 rev. min-1, 0.5 vvm and pH 6.0. The optimum temperature for enzyme yield for strain NRRL B 512 ( F) was 23 degrees C, where at 8-h fermentation was possible to achieve 49.3 DSU/mL. When FT 045 B strain was utilized, 3.2 DSU/mL was obtained at temperature 23 to 25 degrees C.

The Use of Response Surface Methodology in Optimization of Lactic Acid Production: Focus on Medium Supplementation, Temperature and pH Control

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Aspirin increases tolerance to high temperature in seeds of Raphanus sativus L. cvar Early Scarlet Globe

The incubation of seeds of Raphanus sativus L. cvar Early Scarlet Globe with 10 mu M aspirin resulted in increase in the temperature range for germination. The analysis of percentage germination and germination rates indicated the increase in the optimum temperature from 21.4 to 26 degrees C although at 32.6 degrees C 80.8% of seeds germinated with aspirin and no germination in the control. The analysis of the kinetics of seed germination indicated that aspirin treatment resulted in germination by decreasing the enthalpy of activation of the process. The aspirin treatment also resulted in the synchronization of seed germination. on the base of our results we propose aspirin application in practice to increase the tolerance to high temperature and to synchronize seed germination at least in Raphanus sativus L. cvar early scarlet globe.

Interaction of temperature and light on seed germination in Tecoma stans L. Juss. ex Kunth (Bignoniaceae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Phytochrome and temperature control of seed germination in Muntingia calabura L. (Elaeocarpaceae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)