scholarly journals Dynamic Aspects of Alcoholic Fermentation of Rice Seedlings in Response to Anaerobiosis and to Complete Submergence: Relationship to Submergence Tolerance

2003 ◽  
Vol 91 (2) ◽  
pp. 279-290 ◽  
Author(s):  
E. I. BOAMFA
Keyword(s):  
Alcoholic Fermentation ◽  
Submergence Tolerance ◽  
Rice Seedlings

Metabolic changes in rice seedlings with different submergence tolerance after desubmergence

2002 ◽  
Vol 47 (3) ◽  
pp. 195-203 ◽  
Author(s):  
Naoyoshi Kawano ◽  
Evangelina Ella ◽  
Osamu Ito ◽  
Yasuo Yamauchi ◽  
Kiyoshi Tanaka
Keyword(s):  
Metabolic Changes ◽  
Submergence Tolerance ◽  
Rice Seedlings

Alcoholic Fermentation and Malate Metabolism in Rice Germinating at Low Oxygen Concentrations

1978 ◽  
Vol 5 (1) ◽  
pp. 15 ◽  
Author(s):  
PN Avadhani ◽  
H Greenway ◽  
R Lefroy ◽  
L Prior
Keyword(s):  
Alcoholic Fermentation ◽  
Rice Seedlings ◽  
Low Oxygen ◽  
Ethanol Formation ◽  
N2 Atmosphere ◽  
High K ◽  
Dark Fixation ◽  
Co2 Dark Fixation ◽  
K Concentration ◽  
Malate Metabolism

Germinating rice was exposed, in the dark, to low or zero O2 concentrations for 4-5 days by: (1) submergence under 4-5 cm of stagnant solution (3 ppm O2); (2) exposure to a N2 atmosphere; or (3) submergence under solutions flushed with N2. These treatments completely inhibited root growth. Elongation of coleoptiles was stimulated in the stagnant solutions, but not in the N2 treatments. In most experiments, low O2 concentrations resulted in twofold to eightfold increases of malate concentrations in the shoots. Absence of O2 during exposure to H14CO3-, for 30-60 min, inhibited CO2 dark fixation. This inhibition was considerably smaller when seedlings had been raised in N2 rather than in air. Under aerobic conditions during fixation, excised shoots from seedlings raised in N2 fixed more CO2 than shoots from seedlings raised in air. Malate always contained 70% or more of the total fixed 14C, irrespective of the O2 regime during germination and during 14CO2 fixation. Ethanol in stagnant solutions was shown to be formed by the rice seedlings, rather than by bacteria. Ethanol formation during one single day was 20-30-fold greater than the highest recorded amounts of malate in the seedlings. Alcoholic fermentation also responded quickly to changes in aeration regimes, indicating it was an important adaptive factor. Another likely adaptive feature was the high K+ concentration in shoots, even of seedlings grown in the complete absence of O2. It is suggested that these high K+ concentrations have a function in maintaining turgor required for the rapid extension growth of the coleoptiles under low O2 concentrations.

Distribution of phenolic compounds in rice seedlings under Cr ex- posure

2017 ◽  
Vol 2 (2) ◽  
pp. 29-36
Author(s):  
Xiao-Zhang Yu ◽  
◽  
Fei-Fei Zhang ◽  
Keyword(s):  
Phenolic Compounds ◽  
Rice Seedlings

FERMENTATIVE HYDROLYTIC PREPARATION METHODS OF CEREAL WORT FOR ALCOHOL FERMENTATION

1970 ◽  
pp. 52-56
Author(s):  
Е. M. Serba ◽  
М. B. Overchenko ◽  
L. V. Rimareva ◽  
N. I. Ignatova ◽  
А. E. Orekhova ◽  
...  
Keyword(s):  
Alcoholic Fermentation ◽  
Raw Materials ◽  
Alcohol Concentration ◽  
Activity Level ◽  
Optimal Dosage ◽  
Main Role ◽  
Alcohol Fermentation ◽  
Ph Optimum ◽  
Amylolytic Enzyme ◽  
Enzyme Preparations

In the production of alcohol in the preparation of grain raw materials for fermentation, the main role is given to enzyme preparations of amylolytic action, which are key enzymes that catalyze the hydrolysis of starch. Amylolytic enzyme preparations with a different composition of enzymes and their level of activity, a mechanism of biocatalytic effect on starch, and a range of thermal and pH optimum are widely represented on the Russian market. The development of optimal conditions for the preparation of grain wort, the rational selection and dosage of concentrated enzyme preparations, the properties of which correspond to the parameters of the technological process, will ensure the effective preparation of starch for fermentation, and increase the profitability of alcohol production. The aim of this work was to study the influence of enzyme preparations of amylolytic action and the conditions of their use on the efficiency of the process of alcoholic fermentation and the yield of the final product, ethanol. The effect of various dosages of enzyme preparations of glucoamylase action, with a different ratio of the main enzyme glucoamylase and minor enzyme α-amylase, as well as methods for preparing wheat wort on the process of alcoholic fermentation, was studied. It was found that the enzyme preparation, the source of glucoamylase, in which α-amylase was present in a ratio of 15: 1 (in terms of activity level), turned out to be more effective in fermenting prepared wheat wort: its optimal dosage was 8 units. GLS / g starch. The presence of a sufficient amount of α-amylase in this preparation compensated for the dosage of thermostable α-amylase. The alcohol concentration in the mash was 10.2% vol., The alcohol yield was 67.9 cm3 / 100 g of starch. When glucoamylase with a lower ratio of the main and minor enzyme (75: 1) was used at the saccharification stage, an increase in the wort fermentation depth was observed with an increase in the concentration of glucoamylase to 9-10 units of GLS / g and α-amylase to 0.5 units. AC / g. It was also found that an increase in the duration of enzymatic-hydrolytic preparation of the wort had a positive effect on the fermentation process, the alcohol concentration in the mash increased to 10.2 vol.%. It was shown that the introduction of proteases into the wort helps to reduce the viscosity of grain wort, enriching it with assimilable yeast amino acids, which leads to an increase in the yield of alcohol. It has been confirmed that the synergy of the action of enzymes of amylolytic and proteolytic effects on polymers of grain raw materials allows to increase the efficiency of their conversion to ethanol. The conditions of enzymatic-hydrolytic processing of grain raw materials for fermentation are developed. The use of the digestion stage did not significantly affect the fermentation results of wheat wort.

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