THE EFFECT OF OXYGEN TENSION ON GROWTH, CONIDIATION, AND ALCOHOL PRODUCTION OF NEUROSPORA CRASSA

1967 ◽  
Vol 13 (7) ◽  
pp. 805-809 ◽  
Author(s):  
M. J. Kobr ◽  
D. E. Bianchi ◽  
N. Oulevey ◽  
G. Turian
Keyword(s):  
Growth Rate ◽  
Neurospora Crassa ◽  
Nitrogen Source ◽  
Oxygen Tension ◽  
Growth Rates ◽  
Dry Weight ◽  
Alcohol Production ◽  
Conidial Formation ◽  
Oxygen Tensions ◽  
Effect Of Oxygen

Cultures of Neurospora crassa that are shaken are capable of producing conidia on an [Formula: see text] medium which does not support conidial formation under standing conditions. A decrease in oxygen tension from 160 mm Hg causes a regular decrease in growth rate, a promotion in alcohol production, and a delay in conidia formation. In a medium with [Formula: see text] as the nitrogen source, oxygen tensions from 160 to 60 mm Hg do not greatly alter the growth rates, alcohol production is increased, and conidiation is delayed. Oxygen tensions below 60 mm Hg further delay conidiation, sharply decrease dry weight, and accelerate the production of alcohol 20 to 30% over amounts produced in the [Formula: see text] medium.

POLYHYDRIC ALCOHOL PRODUCTION BY OSMOPHILIC YEASTS: EFFECT OF OXYGEN TENSION AND INORGANIC PHOSPHATE CONCENTRATION

1957 ◽  
Vol 3 (4) ◽  
pp. 559-567 ◽  
Author(s):  
J. F. T. Spencer ◽  
Ping Shu
Keyword(s):  
Oxygen Tension ◽  
Inorganic Phosphate ◽  
Opposite Effect ◽  
Ethanol Yield ◽  
Phosphate Concentration ◽  
Alcohol Production ◽  
Lower Oxygen ◽  
Oxygen Tensions ◽  
Effect Of Oxygen ◽  
Very High

A study was made of the effects of oxygen tension and inorganic phosphate concentration on the production of glycerol, arabitol, and ethanol by a strain of osmophilic yeast. Increasing the oxygen tension increased the yields of glycerol and arabitol and decreased the yield of ethanol, while increasing the concentration of inorganic phosphate had the opposite effect.The changes in yields of products with increasing phosphate concentration were most pronounced at a partial pressure of oxygen of 280 mm. of mercury. At lower oxygen tensions the yields of polyols were low and the yield of ethanol was high at all concentrations of phosphate, while at very high oxygen tensions the opposite effect was observed. When the ethanol yield was high, the respiratory quotient was also high. These results are discussed in relation to the oxidative phosphate-lack theory of the Pasteur effect.

Relationships Between RNA–DNA Ratio, Prey Density, and Growth Rate in Atlantic Cod (Gadus morhua) Larvae

1979 ◽  
Vol 36 (12) ◽  
pp. 1497-1502 ◽  
Author(s):  
L. J. Buckley
Keyword(s):  
Growth Rate ◽  
Nutritional Status ◽  
Growth Rates ◽  
Prey Density ◽  
Gadus Morhua ◽  
Slow Growth ◽  
Atlantic Cod ◽  
Larval Fish ◽  
Dry Weight ◽  
Dna And Rna

The protein, DNA, and RNA content of larvae maintained at 1.0 plankter/mL increased at the rates of 9.3, 9.9, and 9.8% per day, respectively, for the 5 wk after hatching. Protein reserves of larvae held at 0 or 0.2 plankters/mL were depleted by 45 and 35%, respectively, prior to death 12–13 d after hatching. Starved larvae had similar protein concentrations (percent of dry weight), lower RNA concentrations, and higher DNA concentrations than fed larvae. Larvae held at higher plankton densities had higher RNA–DNA ratios and faster growth rates than larvae held at lower plankton densities. The RNA–DNA ratio was significantly correlated (P < 0.01) with the protein growth rate. The RNA–DNA ratio appears to be a useful index of nutritional status in larval Atlantic cod (Gadus morhua) and may be useful for determining if cod larvae were in a period of rapid or slow growth at the time of capture. Key words: RNA–DNA ratio, starvation, protein, nucleic acids, growth, larval fish, Atlantic cod

COMPARATIVE STUDIES OF NORTH AMERICAN AND EUROPEAN CULTURES OF THE ROOT ROT FUNGUS, FOMES ANNOSUS (FR.) COOKE

1955 ◽  
Vol 33 (5) ◽  
pp. 416-428 ◽  
Author(s):  
D. E. Etheridge
Keyword(s):  
Growth Rate ◽  
North American ◽  
Growth Rates ◽  
Root Rot ◽  
Linear Growth ◽  
Morphological Characteristics ◽  
Dry Weight ◽  
Cellulolytic Activity ◽  
Ph Optimum ◽  
Two Cultures

Cultures of Fames annosus originating in Europe could not be distinguished from those originating in North America either by colony appearance, growth rate, pH optimum, or cellulolytic activity. Three growth rate types on 2.5% malt agar were recognized and these are ascribed to individual variation rather than to host or geographical influences. Successive subculturing produced variants that fell into three growth classes. Half of the isolates displayed spontaneous, but reversible, changes in growth rate and colony appearance during subculturing and this is discussed from the standpoint of genetical and environmental influences. Cultures displaying different morphological characteristics and linear-growth rates differed little metabolically; each had a similar pH optimum ranging from 4.6 to 5.5, and each proved capable of altering the initial acidity of the medium to a reaction which was more suitable for growth. Two cultures were characterized by double pH optima at 4.6 and 5.5. Cultures having different linear-growth rates produced about the same dry-weight of mycelium on a cellulose substrate in a semisynthetic nutrient solution. On the basis of a statistical analysis of cellulose utilization by representative isolates it was impossible to distinguish between North American and European cultures.

The development of barley grain: comparisons between cultivars for growth rate and α-amylase activity

1976 ◽  
Vol 86 (3) ◽  
pp. 603-608 ◽  
Author(s):  
T. J. Riggs ◽  
P. G. Gothard
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Growth Rates ◽  
Amylase Activity ◽  
Spring Barley ◽  
Dry Weight ◽  
Barley Grain ◽  
Absolute Level ◽  
Barley Cultivars ◽  
Days After Anthesis

SummaryGrains from ears of known anthesis time in seven spring barley cultivars were measured for dry weight and α-amylase activity at regular intervals during grain maturation. During the period 10–31 days after anthesis, dry weight increase of the grain was found to be substantially linear in all the cultivars. Comparisons between linear slopes fitted for this phase of growth were found to provide an objective means of comparing grain growth rates in different cultivars.α-Amylase activity per grain reached a peak in all except one cultivar at between 10 and 16 days after anthesis but declined rapidly during the linear phase of grain growth. α-Amylase activity per gram grain dry weight decreased exponentially during this period and transformation of the data to logarithms allowed a substantially linear fit to be made. Slopes for each of the cultivars were compared.Differences were found between cultivars in grain growth rates, total α-amylase activity and rates of fall of α-amylase activity per gram for the period 10–31 days after anthesis. No relationship could be found between grain growth rate and either the absolute level of α-amylase activity achieved in the grain or the rate of fall in activity during development.

The Respiratory Physiology of the Marine Nematodes Enoplus Brevis (Bastian) and E. Communis (Bastian)

1973 ◽  
Vol 59 (1) ◽  
pp. 255-266
Author(s):  
H. J. ATKINSON
Keyword(s):  
Oxygen Consumption ◽  
Body Size ◽  
Oxygen Tension ◽  
Dry Weight ◽  
Respiratory Physiology ◽  
Rate Of Oxygen Consumption ◽  
Oxygen Tensions ◽  
The Difference ◽  
Relationship Of ◽  
The Relationship

1. The rate of oxygen consumption of individual males of Enoplus brevis and E. communis was measured at 15 °C and at each of four oxygen tensions, 135, 75, 35, and 12 Torr, after at least 12 h experience of these conditions. 2. It was clearly demonstrated that the level of oxygen consumption of both species was reduced by each lowering of the imposed oxygen tension. 3. In all cases the oxygen consumption of each species fell with increasing body size. On a unit dry-weight basis the oxygen consumption of E. brevis is greater than that of the larger E. communis, but after allowing for the difference of body size the two species have more or less similar oxygen uptakes at all oxygen tensions. 4. In E. brevis oxygen tension influenced the relationship of body size and metabolism, the slope relating oxygen consumption and body weight becomes steeper with decreasing oxygen tension. This effect was not shown by E. communis. 5. Some general factors influencing the availability of oxygen to nematodes are considered.

In Vitro Studies of Erythropoiesis

Blood ◽  
1955 ◽  
Vol 10 (6) ◽  
pp. 612-615 ◽  
Author(s):  
E. D. THOMAS
Keyword(s):  
Bone Marrow ◽  
Oxygen Tension ◽  
In Vitro Studies ◽  
Cent Oxygen ◽  
In Vitro Synthesis ◽  
Heme Synthesis ◽  
Rabbit Bone ◽  
Oxygen Tensions ◽  
Effect Of Oxygen

Abstract The effect of various oxygen tensions on the in vitro synthesis of heme by rabbit bone marrow was measured. At levels above 4 per cent oxygen there was no effect of oxygen tension on heme synthesis. Total anoxia stopped heme synthesis completely. No level of oxygen tension was found to stimulate heme synthesis.

scholarly journals Soybean (Glycine max) seed growth characteristics in response to light enrichment and shading

2011 ◽  
Vol 52 (No. 4) ◽  
pp. 178-185 ◽  
Author(s):  
X. Liu ◽  
S.J. Herbert ◽  
K. Baath ◽  
A.M. Hashemi
Keyword(s):  
Growth Rate ◽  
Glycine Max ◽  
Seed Size ◽  
Growth Rates ◽  
Dry Weight ◽  
Cell Number ◽  
Seed Filling ◽  
Light Reduction ◽  
Seed Growth ◽  
Cotyledon Cell

Seeds are the primary sinks for photosynthates during reproductive growth. Variation in light intercepted during and after seed initiation has been found a major environmental determinant of soybean [Glycine max(L.) Merrill] seed size. We investigated the influence of light enrichment and shading on seed growth rate, effective filling, cotyledon cell number, cell volume and endogenousABA concentrations of cotyledons/testas during seed filling of soybean. Evans, an indeterminate Group 0 soybean, was subjected to light reduction and enrichment treatments from the beginning of pod formation until final harvest for two years inMassachusetts. Higher rates of seed growth, greater seed dry weight, and higher cotyledon cell number were all observed with light enrichment. There was a&nbsp;reduction in seed growth rate and cotyledon cell number, along with a significant lowering of endogenousABA levels in testa and cotyledon with shade. The level ofABAin cotyledon during seed development was significantly correlated with seed growth rates only under shade treatments. Both the growth rates and seed filling duration were influenced by variation in light interception by the soybean canopy. The effects of varying light treatment on seed size, within one genotype, were most likely due to the differences in seed growth rate and cotyledon cell number.

Growth and yield of highland maize in Mexico

1974 ◽  
Vol 83 (2) ◽  
pp. 213-221 ◽  
Author(s):  
P. R. Goldsworthy ◽  
M. Colegrove
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Growth Rates ◽  
Dry Weight ◽  
Grain Filling ◽  
Growth And Yield ◽  
Weight Changes ◽  
Highland Maize ◽  
Grain Filling Period ◽  
Tropical Varieties

SUMMARYThe growth and yield of five highland varieties of tropical maize were studied. Grain yields were between 4·7 and 8·8 t/ha. Crop growth rates (C) increased to a maximum of between 25 and 35 g/m2/day at silking and then declined. Grain growth rates (maximum 21 g/m2/day) exceeded current C during most of the grain-filling period.After silking, when C exceeded grain growth rate, dry matter accumulated in the stem and husk, resulting in an increase of from 200 to 600 g/m2. Later, as grain growth rate increased and exceeded current C, some of this accumulated material was incorporated into the grain, and stem weight decreased. A comparison of the dry weight changes after flowering in these varieties with those reported for a hybrid that yielded 12 t grain/ha indicates that the smaller yield of the Mexican varieties was associated with smaller grain growth rates and the incorporation into the grain of a smaller fraction of the dry weight produced after flowering. These results suggest that the capacity of the grain ‘sink’ to utilize assimilates limited yields in the tropical varieties.

scholarly journals Growth rate and haploidization of Aspergillus niger on medium containing p-fluorophenylalanine

1968 ◽  
Vol 12 (3) ◽  
pp. 305-315 ◽  
Author(s):  
Pol Lhoas
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growth Curves ◽  
Dry Weight ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Complete Medium ◽  
Acid Analogue ◽  
Mean Size ◽  
The Mean

1. The comparison of the dry weight of thin layer haploid and diploid colonies of A. niger on complete medium and complete medium supplemented with p-fluoro-phenylalanine led to the conclusion that there is a difference in growth rates of hyphae under these different conditions.2. The growth curves of the same strains on both media were established. On complete medium, haploids and diploid show a growth rate increasing linearly for about 20 h after germination and reaching a maximum which is then maintained. On p-fluorophenylalanine, the haploids show a similar curve, although the maximum growth rate reached and maintained is about half that on complete medium; for the diploid, however, the maximum is less than the corresponding one in the haploid and, once this maximum has been reached, the growth rate goes down linearly to a very low value which is then maintained.3. The cytological study of the hyphal tip cell showed, in the presence of the amino acid analogue, a reduction of the mean size of the diploid nuclei together with an increase of the number of nuclear fragments. This explains the growth rates observed and is accepted as a confirmation that p-fluorophenylalanine, by its action on the mitosis, favours chromosome losses which lead finally to the production of haploid nuclei.

Comparison of copper sulphate pentahydrate growth rates determined by different methods

1990 ◽  
Vol 55 (7) ◽  
pp. 1691-1707 ◽  
Author(s):  
Miloslav Karel ◽  
Jiří Hostomský ◽  
Jaroslav Nývlt ◽  
Axel König
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Fluidized Bed ◽  
Growth Rates ◽  
Copper Sulphate ◽  
Crystal Growth Rate ◽  
Effect Of Temperature ◽  
Rotating Disc ◽  
Shape Factors ◽  
Data Treatment

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.

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