Effect of temperature upon growth rate and solvent production in batch cultures ofClostridium acetobutylicum

1985 ◽  
Vol 7 (7) ◽  
pp. 499-502 ◽  
Author(s):  
B McNeil ◽  
B Kristiahsen
PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3743 ◽  
Author(s):  
Lars Fredrik Skau ◽  
Tom Andersen ◽  
Jan-Erik Thrane ◽  
Dag Olav Hessen

Temperature and nutrients are key factors affecting the growth, cell size, and physiology of marine phytoplankton. In the ocean, temperature and nutrient availability often co-vary because temperature drives vertical stratification, which further controls nutrient upwelling. This makes it difficult to disentangle the effects of temperature and nutrients on phytoplankton purely from observational studies. In this study, we carried out a factorial experiment crossing two temperatures (13°and 19°C) with two growth regimes (P-limited, semi-continuous batch cultures [“−P”] and nutrient replete batch cultures in turbidostat mode [“+P”]) for three species of common marine haptophytes (Emiliania huxleyi, Chrysochromulina rotalis and Prymnesium polylepis) to address the effects of temperature and nutrient limitation on elemental content and stoichiometry (C:N:P), total RNA, cell size, and growth rate. We found that the main gradient in elemental content and RNA largely was related to nutrient regime and the resulting differences in growth rate and degree of P-limitation, and observed reduced cell volume-specific content of P and RNA (but also N and C in most cases) and higher N:P and C:P in the slow growing −P cultures compared to the fast growing +P cultures. P-limited cells also tended to be larger than nutrient replete cells. Contrary to other recent studies, we found lower N:P and C:P ratios at high temperature. Overall, elemental content and RNA increased with temperature, especially in the nutrient replete cultures. Notably, however, temperature had a weaker–and in some cases a negative–effect on elemental content and RNA under P-limitation. This interaction indicates that the effect of temperature on cellular composition may differ between nutrient replete and nutrient limited conditions, where cellular uptake and storage of excess nutrients may overshadow changes in resource allocation among the non-storage fractions of biomass (e.g. P-rich ribosomes and N-rich proteins). Cell size decreased at high temperature, which is in accordance with general observations.


1990 ◽  
Vol 55 (7) ◽  
pp. 1691-1707 ◽  
Author(s):  
Miloslav Karel ◽  
Jiří Hostomský ◽  
Jaroslav Nývlt ◽  
Axel König

Crystal growth rates of copper sulphate pentahydrate (CuSO4.5 H2O) determined by different authors and methods are compared. The methods included in this comparison are: (i) Measurement on a fixed crystal suspended in a streaming solution, (ii) measurement on a rotating disc, (iii) measurement in a fluidized bed, (iv) measurement in an agitated suspension. The comparison involves critical estimation of the supersaturation used in measurements, of shape factors used for data treatment and a correction for the effect of temperature. Conclusions are drawn for the choice of values to be specified when data of crystal growth rate measurements are published.


2007 ◽  
Vol 73 (11) ◽  
pp. 3637-3644 ◽  
Author(s):  
Alberto Amaretti ◽  
Tatiana Bernardi ◽  
Elena Tamburini ◽  
Simona Zanoni ◽  
Mariella Lomma ◽  
...  

ABSTRACT The kinetics and the metabolism of Bifidobacterium adolescentis MB 239 growing on galactooligosaccharides (GOS), lactose, galactose, and glucose were investigated. An unstructured unsegregated model for growth in batch cultures was developed, and kinetic parameters were calculated with a recursive algorithm. The growth rate and cellular yield were highest on galactose, followed by lactose and GOS, and were lowest on glucose. Lactate, acetate, and ethanol yields allowed the calculation of carbon fluxes toward fermentation products. Distributions between two- and three-carbon products were similar on all the carbohydrates (55 and 45%, respectively), but ethanol yields were different on glucose, GOS, lactose, and galactose, in decreasing order of production. Based on the stoichiometry of the fructose-6-phosphate shunt and on the carbon distribution among the products, the ATP yield was calculated. The highest yield was obtained on galactose, while the yields were 5, 8, and 25% lower on lactose, GOS, and glucose, respectively. Therefore, a correspondence among ethanol production, low ATP yields, and low biomass production was established, demonstrating that carbohydrate preferences may result from different distributions of carbon fluxes through the fermentative pathway. During the fermentation of a GOS mixture, substrate selectivity based on the degree of polymerization was exhibited, since lactose and the trisaccharide were the first to be consumed, while a delay was observed until longer oligosaccharides were utilized. Throughout the growth on both lactose and GOS, galactose accumulated in the cultural broth, suggesting that β(1-4) galactosides can be hydrolyzed before they are taken up.


2005 ◽  
Vol 187 (7) ◽  
pp. 2261-2266 ◽  
Author(s):  
Tali W. Dror ◽  
Adi Rolider ◽  
Edward A. Bayer ◽  
Raphael Lamed ◽  
Yuval Shoham

ABSTRACT The expression of scaffoldin-anchoring genes and one of the major processive endoglucanases (CelS) from the cellulosome of Clostridium thermocellum has been shown to be dependent on the growth rate. For the present work, we studied the gene regulation of selected cellulosomal endoglucanases and a major xylanase in order to examine the previously observed substrate-linked alterations in cellulosome composition. For this purpose, the transcript levels of genes encoding endoglucanases CelB, CelG, and CelD and the family 10 xylanase XynC were determined in batch cultures, grown on either cellobiose or cellulose, and in carbon-limited continuous cultures at different dilution rates. Under all conditions tested, the transcript levels of celB and celG were at least 10-fold higher than that of celD. Like the major processive endoglucanase CelS, the transcript levels of these endoglucanase genes were also dependent on the growth rate. Thus, at a rate of 0.04 h−1, the levels of celB, celG, and celD were threefold higher than those obtained in cultures grown at maximal rates (0.35 h−1) on cellobiose. In contrast, no clear correlation was observed between the transcript level of xynC and the growth rate—the levels remained relatively high, fluctuating between 30 and 50 transcripts per cell. The results suggest that the regulation of C. thermocellum endoglucanases is similar to that of the processive endoglucanase celS but differs from that of a major cellulosomal xylanase in that expression of the latter enzyme is independent of the growth rate.


2004 ◽  
Vol 52 (1) ◽  
pp. 19-28
Author(s):  
A. F. Fieldsend

In field crops of evening primrose (Oenothera spp.) the post-winter growth of rosettes is slow to re-start. The effect of temperature on the growth of rosettes was assessed in a controlled environment experiment. Relative growth rate was positively correlated with temperature, but in apparent contrast to the results from field trials, the rosettes grew at constant temperatures as low as 6.5ºC. However, following transfer to warmer temperatures an increase in relative growth rate did not occur until 7-10 days later, whilst a change to a cooler environment caused an immediate reduction in relative growth rate. Thus, it seems likely that growth is inhibited by intermittent exposure to temperatures of 0°C or below. Partitioning of biomass between root and shoot was independent of temperature, but at 6.5ºC the relative rate of leaf area increase was very low. Consequently, the specific leaf area was lower in rosettes growing at lower temperatures.


2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.


Author(s):  
Sheraz Ahmed Qureshi ◽  
Amir Shafeeq ◽  
Aamir Ijaz ◽  
Muhammad Moeen Butt

Algaecides are chemicals that cause serious health problems. Conventional paints contain algaecides to improve the algae resistance on the paint film. Present research has suggested an environmental friendly paint formulation that focuses on developing algae resistance without having algaecides. In this research, Algae growth on newly developed paint is modeled by incorporating dirt resistance of paint and natural phenomena including humidity, temperature and time respectively. The fitted Model revealed explained variation of 59.65% in the average algae growth, of which, Dirt Resistance, Humidity and temperature and some of their interactions play significant role in this variation. Model suggests that the proposed newly developed paint without algaecides is more resilient to algae growth and significantly decreased the average algae growth rate by 0.53% as compared to conventional paints. Keeping the effect of all other factors constant, if dirt resistance of paint (Dc value) increases by one percent, average algae growth decreases by 12.98%; when temperature increases by 1oC, average algae growth decreases by 22.4%; a positive unit change in the joint linear effect dirt resistance, temperature and humidity caused a decrease in average algae growth by 0.0031%. It was also observed that the individual effect of humidity variable was inversely related with average algae growth. However the combination of humidity and temperature, humidity and dirt resistance, humidity and time, and the quadratic effect of humidity were found to increase the average algae growth rate. The cubic effect of temperature variable by one degree centigrade resulted in decrease of average algae growth by 0.000907%.


1935 ◽  
Vol 116 (800) ◽  
pp. 479-493 ◽  

Although temperature and gravity both influence plant life, and although both factors have been studied for many decades, there is surprisingly little literature decades, there is surprisingly little literature dealing with the relation between the two; and none, so far as I can discover, on the effect in any Pteridophyte. Navez (1929) who criticized the work of some investigators on the effect of temperature on the geotropism of a few seedlings, sums up the present position in his remark that the conclusions of workers are very different and often in opposition. The present paper gives the results of 1100 experiments carried out mainly between the years 1922 and 1927, and though it is realized that much remains to be done on the question, it is believed that the results which have been obtained are of some value. For general methods, reference may be made to previous “Studies” in this series. Geotropic sensitivity, as measured by presentation time at different stages in development of the frond, was fully worked out by Waight (1923) for 20°C, and is adopted here as a standard of reference. The growth rate recorded in the tables is that for the particular frond under investigation, or is the average of the fronds examined during the day of the experiment. Nearly all the experiments included in the tables were conducted during the months of April-October, as I have since been able to show that there is an annual rhythm in geotropic irritability. A decrease in sensitivity occurs in winter, and hence experiments performed in November-March are not strictly comparable with those carried out in the summer. The following abbreviations are used:- P.S. = period of stimulation. P.T. = presentation time, i. e ., the minimum period of stimulation in a horizontal position, which, under the given conditions, will cause a movement of approximately 5° in about 80% of the fronds. L.T. = latent time (Prankerd, 1925) in hours. N = “normal time,” i. e ., the P.T. For different stages of the frond at 20°C (see Waight, 1923).


1932 ◽  
Vol 9 (3) ◽  
pp. 271-276
Author(s):  
A. H. WOOD

1. The rate of respiration (as expressed in c.c. O2 per gram embryo per hour) of the embryos of Salmo fario remains constant at any given temperature until the embryo has reached its maximum growth-rate, after this point it declines. It is suggested that the rate of respiration may be proportional to the amount of available yolk. 2. When incubated at 7° C. the time required to complete development after hatching was 58 days and the total oxygen consumed by an average embryo during this period was 20·31 c.c. (N.T.P.). At 12° the time required for the completion of development was reduced to 27 days, but the oxygen consumption remained practically unchanged at 20·71 c.c. At 3° C. the time required for development was 108 days and the oxygen consumption was 26·96 c.c. per embryo. 3. At 7 and 12° C. the efficiency of development was found to be identical with the value given by Gray for 11·5° C., viz. 63 per cent.; at 3°C. the average efficiency over the period considered was only 54 per cent. 4. It is suggested that, between the limits of temperature to which a trout egg is normally exposed, the effect of temperature on respiration is neither greater nor less than its effect on the growth-rate; possibly both processes are dependent on the same controlling factor. Above and below this range of temperature, the relative intensity of the respiratory processes (to those of growth) is increased, and a smaller embryo is the final result of incubation.


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