α-Amylase inactivation during rice starch hydrolysis

Apar, Dilek Kılıç; Özbek, Belma

doi:10.1016/j.procbio.2004.06.006

Cited by 36 publications

(26 citation statements)

References 11 publications

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“…In this figure is observed that increasing in substrate concentration produced a decrease in enzymatic activity on starch hydrolysis. This effect could be due to diffusional constraints during the enzymatic hydrolysis of starch, 16 caused mainly by increasing in viscosity by gelatinized starch. Similar observations have been reported by Baks et al, 28 working with high starch concentrations (650 g of strach L -1 ).…”

Section: Effect Of Substrate Concentrationmentioning

confidence: 99%

“…On the other hand, stirring rate was kept at 390 rpm during all starch hydrolysis process, and it was not detrimental for enzyme stability, 9 allowing god mass transfer and mixing performances for enzymatic starch hydrolysis. 16 …”

Section: Effect Of Substrate Concentrationmentioning

confidence: 99%

“…Among these different conditions are: temperature, pH, reaction time, enzyme concentration, viscosity, mixing rates, ionic strength, calcium concentration, etc. 11,15,16 Moreover, native starch is little soluble in water and resistant to hydrolysis at mild conditions. For this reason, it needs to carry out hydrothermal process for the gelatinization.…”

Section: Introductionmentioning

confidence: 99%

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Enzymatic hydrolysis of cassava starch for production of bioethanol with a colombian wild yeast strain

Ruiz¹,

Sánchez²,

Torrres³

et al. 2011

J. Braz. Chem. Soc.

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A hidrólise enzimática do amido de mandioca para produção de xaropes de glucose foi avaliada usando alfa-amilase de Bacillus licheniformis e glucoamilase de Aspergillus níger. Também, uma mistura enzimática composta de α-amylase de Aspergillus kawachi e glucoamilase de Aspergillus níger foi testada. As condições da enzima para a hidrólise do amido foram otimizadas por um planejamento fatorial experimental (3 3 ×2) usando como variáveis a concentração do substrato, a relação enzima/ substrato e o tempo de reação. As condições ótimas de reação com 100 g de amido per L foram: α-amilase pH 5,0, 80 °C e 130,5 U g -1 de amido; glucoamilase pH 4,5, 70 °C e 81,5 U g -1 de amido. Adicionalmente, as condições ótimas da mistura enzimática foram pH 4,5, 46 °C e 16,4 U g -1 de amido. Finalmente, a produção de álcool usando xaropes de glucose a partir do amido hidrolisado enzimaticamente foi realizada usando uma cepa selvagem de Candida sp isolada do caldo de cana de açúcar, obtendo produtividades em etanol volumétrico em torno de 1,Enzymatic hydrolysis of cassava starch for producing glucose syrups was evaluated using alpha-amylase from Bacillus licheniformis and glucoamylase from Aspergillus niger. Moreover, an enzyme mixture of α-amylase from Aspergillus kawachi and glucoamylase from Aspergillus niger was tested. Enzyme conditions for starch hydrolysis were optimized by a factorial experimental design (3 3 ×2) using as variables substrate concentration, enzyme/substrate ratio and time reaction. Optimal enzyme reactions with 100 g of starch per L were: α-amylase at pH 5.0, 80 °C and enzyme dosage of 130.5 U g -1 of starch; and glucoamylase, pH 4.5, 70 °C and enzyme dosage of 81.5 U g -1 of starch. Additionally, optimal conditions for the enzymatic mixture were pH 4.5, 46 °C, and enzyme dosage of 16.4 U g -1 of starch. Finally, alcohol production using glucose syrups from enzymatically-hydrolyzed starch was carried out with a wild strain of Candida sp isolated from sugar cane juice, obtaining volumetric ethanol productivities around 1.8-3.2 g L -1 h -1 .

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Section: Effect Of Substrate Concentrationmentioning

confidence: 99%

Section: Effect Of Substrate Concentrationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Enzymatic hydrolysis of cassava starch for production of bioethanol with a colombian wild yeast strain

Ruiz¹,

Sánchez²,

Torrres³

et al. 2011

J. Braz. Chem. Soc.

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“…Amylases are used in filling of pores of texture and papers, desizing of starch in woven texture in textile, in removing food and starch stains in dry cleaning, in food biotechnology in the following applications: bakery, liquefying doughs, production of starch hydrolysis products such as glucose and fructose, production of corn and chocolate syrup, production of low-calories beer, in purification of apple and pear juice, malt production, in removing stickiness in paper industry, in detergent industry as well as in medical industry (Gupta et al 2003;Ul-Haq et al 2003;Apar &Özbek 2004).…”

Section: Introductionmentioning

confidence: 99%

Isolation and production of thermostable α-amylase from thermophilic Anoxybacillus sp. KP1 from Diyadin hot spring in Ağri, Turkey

Bekler

Güven

2014

Biologia

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A novel amylolytic enzyme producing thermophilic bacterial strain KP1 from the Diyadin hot spring water in Agri, Turkey, was isolated in the present study. Phylogenetic analysis based on the partial 16S rRNA gene, biochemical and physiological tests revealed that the strain KP1 belongs to the genus Anoxybacillus. The pH and temperature optima for the α-amylase production by Anoxybacillus sp. KP1 were 8.0 and 50• C, respectively, where the maximum growth was obtained at the 28 th hour of incubation and the highest α-amylase activity was obtained at the 40 th hour of incubation (8979.6 U/mL). The optimum pH and temperature for the enzyme activity were 8.0 and 60• C, respectively. The maximum α-amylase production was secreted in the presence of 2% (w/v) soluble starch (10837.7 U/mL). Among the various organic and inorganic nitrogen sources tested, while keeping the beef extract concentration constant, casamino acid (14310.6 U/mL), urea (14126 U/mL), and tryptone (13217.2 U/mL) at a concentration of 2% gave the maximum α-amylase production. The enzyme activity was enhanced in the presence of 1.5 mM Mn 2+ (123%), whereas it was strongly inhibited 1.5 mM by Hg 2+ . Inhibition by 89% was obtained also with sodium dodecyl sulphate (1%). The enzyme was found to be relatively stable at a range of pH and temperature.

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“…Activity assay of α-amylase was performed following to the procedure of Apar and Ozbek (2005) (22). The assay was performed at room temperature, using soluble starch as substrate and iodine solution as a stopper.…”

Section: Enzyme Activity Assaymentioning

confidence: 99%