scholarly journals Efficient hydrolysis of raw starch and ethanol fermentation: a novel raw starch-digesting glucoamylase from Penicillium oxalicum

2016 ◽  
Vol 9 (1) ◽  
Author(s):  
Qiang-Sheng Xu ◽  
Yu-Si Yan ◽  
Jia-Xun Feng
Keyword(s):  
Ethanol Fermentation ◽  
Penicillium Oxalicum ◽  
Raw Starch ◽  
Hydrolysis Of

Autolysis of Penicillium oxalicum with special reference to its cell walls

1982 ◽  
Vol 28 (12) ◽  
pp. 1289-1295 ◽  
Author(s):  
M. I. Perez-Leblic ◽  
Fuensanta Reyes ◽  
R. Lahoz ◽  
S. A. Archer
Keyword(s):  
Cell Walls ◽  
Schizophyllum Commune ◽  
Dry Weight ◽  
Penicillium Oxalicum ◽  
Lytic Enzyme ◽  
Enzyme Complex ◽  
Fungal Cell ◽  
Rapid Hydrolysis ◽  
And Storage ◽  
Hydrolysis Of

Cultures of Penicillium oxalicum growing on a denned medium supplemented with yeast extract reached the onset of autolysis after 3 days at 25 °C. Thenceforth, autolysis was progressive and eventual reductions in dry weight of 96% were recorded by day 47. The pH of the medium fluctuated between 4.0 during the exponential phase of growth and 9.0 during autolysis. Electron microscopy of autolyzing cultures revealed a progressive loss of cytoplasmic ultrastructure. Digestion of the cell walls, with a rapid hydrolysis of the three external layers and a low hydrolysis of the two inner layers, was accompanied by deep pitting and by loss of the distinct five-layered structure. A lytic enzyme complex was obtained from the filtrates of extensively autolyzed cultures. It was rich in (1 → 3)-β-glucanase and other enzymes active against a range of fungal cell wall and storage polysaccharides. This enzyme complex degraded extensively isolated cell walls of P. oxalicum and three other Ascomycetes but had less effect on walls isolated from Mucor mucedo or Schizophyllum commune. In the case of P. oxalicum, cell walls harvested from young cultures were more readily digested than were the walls from older cultures.

Raw starch degrading α-amylases: an unsolved riddle

Amylase ◽  
2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Nataša Božić ◽  
Nikola Lončar ◽  
Marinela Šokarda Slavić ◽  
Zoran Vujčić
Keyword(s):  
Glycoside Hydrolase Family ◽  
Food Ingredient ◽  
Raw Starch ◽  
Functional Studies ◽  
Structures And Properties ◽  
Structural Peculiarities ◽  
To Come ◽  
Starch Conversion ◽  
Maltose Syrup ◽  
Hydrolysis Of

AbstractStarch is an important food ingredient and a substrate for the production of many industrial products. Biological and industrial processes involve hydrolysis of raw starch, such as digestion by humans and animals, starch metabolism in plants, and industrial starch conversion for obtaining glucose, fructose and maltose syrup or bioethanol. Raw starch degrading α-amylases (RSDA) can directly degrade raw starch below the gelatinization temperature of starch. Knowledge of the structures and properties of starch and RSDA has increased significantly in recent years. Understanding the relationships between structural peculiarities and properties of RSDA is a prerequisite for efficient application in different aspects of human benefit from health to the industry. This review summarizes recent advances on RSDA research with emphasizes on representatives of glycoside hydrolase family GH13. Definite understanding of raw starch digesting ability is yet to come with accumulating structural and functional studies of RSDA.

DORMANCY STUDIES IN SEED OF AVENA FATUA: 3. A RELATIONSHIP BETWEEN MALTASE, AMYLASES, AND GIBBERELLIN

1962 ◽  
Vol 40 (12) ◽  
pp. 1659-1673 ◽  
Author(s):  
G. M. Simpson ◽  
J. M. Naylor
Keyword(s):  
Energy Source ◽  
Gibberellic Acid ◽  
Avena Fatua ◽  
Starch Granules ◽  
Raw Starch ◽  
Endosperm Starch ◽  
Hydrolysis Of ◽  
Exogenous Sugar ◽  
Excised Embryos

Initiation of germination in excised embryos requires an exogenous energy source. Normally this is obtained from the endosperm. In dormant seeds the hydrolysis of starch is blocked despite the fact that dormant and non-dormant seeds contain similar amounts of α- and β-amylases. Alone or in combination the amylases are unable to break down raw endosperm starch granules to simple sugars in vitro. Exogenous maltase in combination with α-amylase hydrolyzes raw starch to glucose. Exogenous maltase eliminates the requirement for exogenous sugar. Examination of the maltase content of imbibed dormant and non-dormant seeds showed a marked increase in non-dormant seeds during the first 40 hours. This does not occur in dormant seeds unless they are treated with gibberellic acid. The results lead to the conclusion that an important effect of gibberellic acid is to induce the synthesis of maltase or in some way activate the preformed enzyme.

scholarly journals A thin layer chromatographic comparison of raw and soluble starch hydrolysis patterns of some α-amylases from Bacillus sp. isolated in Serbia

2014 ◽  
Vol 79 (4) ◽  
pp. 411-420 ◽  
Author(s):  
Nikola Gligorijevic ◽  
Nikola Stevanovic ◽  
Nikola Loncar ◽  
Rada Baosic ◽  
Zoran Vujcic ◽  
...  
Keyword(s):  
Corn Starch ◽  
Soluble Starch ◽  
Starch Hydrolysis ◽  
Bacillus Sp ◽  
Raw Starch ◽  
Raw Starch Hydrolysis ◽  
Different Temperatures ◽  
Natural Isolates ◽  
Tlc Analysis ◽  
Hydrolysis Of

Several natural isolates of Bacillus strains namely 5B, 12B, 16B, 18 and 24B were grown on two different temperatures in submerged fermentation for the raw-starch-digesting a-amylases production. All strains except Bacillus sp. 18 produced more ?-amylase on 37?C. The hydrolysis of raw corn starch followed same pattern. Efficient hydrolysis was obtained with ?-amylases from Bacillus sp. 5B, 12B, 16B and 24B grown on 37?C and Bacillus sp. 18 grown on 50?C. Zymography after isoelectric focusing shown that ?-amylases were produced in multiple forms, from 2 to 6, depending on the strain when they were growing at 37 ?C, while growing at 50?C induced only 1 or 2 isoforms. TLC analysis of hydrolysis products of raw corn and soluble starch by ?-amylases revealed production of various mixtures of oligosaccharides. In most cases G3 was the most dominant product from soluble starch while G2, G3 and G5 were the main products of raw starch hydrolysis. This indicates that obtained a-amylases can be used for starch liquefying or short-chain-oligosaccharide forming, depending on what type of starch (raw or soluble) was used for the hydrolysis.

Sign in / Sign up

Export Citation Format

Share Document