Glucose Production from Treated Sago Starch Granules by Raw Starch Digesting Amylase from Penicillium brunneum

Several microorganisms have been found to produce raw starch digesting amylase. We have isolated Penicillium brunneum from sago palm tree at a sago processing site, which was used as a source of starch digesting amylase. All the raw starch digesting enzymes were effective for cereal starches, but root starches and sago starch were resistant to the enzyme reaction. Treatment of sago starch by heating to temperature below gelatinization temperature at lower pHs resulted in an increase in the ability of enzyme to digest sago starch granules. Heating to 60°C at pH 2.0 resulted in a conversion rate of sago starch granules to glucose near to the conversion rate of raw corn starch to glucose. At higher concentration, the degree of hydrolysis of treated sago starch granules was about 275% as compared to that of untreated sago starch granules. Addition of the enzyme in large amount or small portion at various time intervals was found effective in the hydrolysis of treated sago starch granules.     

Effect of Cellulase Addition on Hydrolysis of Sago Starch Granules by Raw Starch Digesting Amylase from Penicillium brunneum No. 24

Raw sago starch digesting amylase was obtained from Penicillium brunneum No. 24. with strong ability to digest sago starch granules. The crude enzyme from this strain contains CMC-ase and avicelase. The specific activity of the enzyme did not increase proportionally with purification. We tried combination of our purified enzyme with other hydrolytic enzymes as a means of improving the hydrolysis of sago starch granules. Addition of cellulase at the initial stage of the hydrolyzation process resulted in an increase in the ability of raw starch digesting amylase to digest sago starch granules. Adding 10 unit/g starch of cellulase. followed of our purified raw starch digesting amylase in small portion at various time intervals was found effective in the hydrolysis of untreated sago starch granules. The treatment resulted in a convertion rate of untreated sago starch granules to glucose near to complete after 120h enzymes reaction, and was also effective in reducing the reaction time of hydrolysis of treated sago starch granules. This process showed that mainly glucose was produced.     

Purification and Properties of the Raw Starch Digesting Amylase from Penicillium brunneum No. 24

Raw sago starch digesting amylase was obtained from Penicillium brunneum No. 24. The crude enzyme from this strain contains carboxymethylcellulase (CMC-ase), avicelase, α-amylase and α-glucosidase. Affinity chromatography (α-cyclodextrin-Sepharose 6B) of the enzyme after ammonium sulfate fractionation, Toyopearl HW-55F gel filtration, DEAE-Sephadex A-50 and DEAE-cellulose chromatographies fractionation steps, resulted in a homogeneous glucoamylase. SDS-polyacrylamide gel electrophoresis of purified enzyme showed a single band, and a molecular weight of 80,000 for the native glucoamylase from Penicillium brunneum No. 24 was observed. After modification of the native glucoamylase with subtilisin, the molecular weight was reduced to 76,000. It lost the ability to digest and adsorb onto raw starches. However, its ability to digest gelatinized starches was preserved.     

Penicillium sp.X-1液态发酵生产生淀粉酶的优化

通过摇瓶发酵,研究了培养基成分对Penicillium sp.X-1液态发酵产生淀粉酶的影响。结果表明：碳源、氮源及MgCl2对产酶有较大的影响,经响应面优化得到的培养基组成为：玉米粉42 g/L,豆饼粉30 g/L,MgCl216 mmol/L,在最优条件下酶活达到239 U/mL,与采用基本培养基的相比,酶活提高了7.5倍.     

Crystallinity of Raw Rice Starch Granules as Indexed by Corrosion with Hydrochloric Acid and Amylase

After 15 d in 2.2N HCl at 35°C, residual starch of 34 granular rice starches differing in apparent amylose content (AC) and final gelatinization temperature (GT) ranged from 1.3 to 20.8% and was verified to correlate significantly with GT (r = 0.69**) and AC (r = 0.44**). Residual starch after 5 h corrosion with crude Chalara paradoxa amylase ranged from 0 to 29.4% and also correlated significantly with GT (r = 0.45**) and AC (r = 0.70**). The amounts of residual starch after Lintnerization and after C. paradoxa amylase digestion were significantly correlated (r = 0.72**).     

淀粉酶分解马铃薯淀粉的因素研究

研究α-淀粉酶与β-淀粉酶对马铃薯淀粉的分解效果。在控制一定温度和时间的条件下,采用正交设计、因素分析、优化处理、均衡试验。实验结果表明,α-淀粉酶添加量0.15%(4000U),淀粉量20%,处理温度80.0℃,时间13min,液化效果达到最佳;β-淀粉酶量0.15%(50000U)、温度60℃、时间46h、pH5.4,糖化效果最佳。     

Some Enzyme Properties of Raw Starch Digesting Amylases from Streptomyces sp. No. 4

Streptomyces sp. No. 4 produce two forms of amylase that attack raw cassava starch. Both forms, amylase‐1 and amylase‐2, were purified by starch adsorption, affinity chromatography, and ion exchange chromatography. The molecular weights of amylase‐1 and amylase‐2 as determined by SDS‐PAGE were 56 kD and 77 kD, respectively. Optimal enzyme activities occurred at pH 5.5 and at 50°C for amylase‐1 and at 45°C for amylase‐2. The activation energy of amylase‐1 and amylase‐2 were 67 and 42 kJ/mol, respectively. Hg²⁺ and pCMB inhibited both enzymes, whereas 2‐mercaptoethanol activated only amylase‐2. EDTA inhibited amylase‐1 but activated amylase‐2. The main product of hydrolysis of raw cassava starch by amylase‐1 was maltose, followed by maltotriose, maltotetraose and dextrin. Amylase‐2 cleaved raw cassava starch to produce glucose and maltose as main products. Both amylase‐1 and amylase‐2 are α‐amylases, as shown by the fast disappearance of iodine staining, the corresponding reaction products and the ability of both enzymes to hydrolyze crosslinked blue starch.     

Semi-continuous Hydrolysis of Sweet Potato Raw Starch by Chalara paradoxa Glucoamylase

Effect of preservatives was investigated on semi-continuous digestion of sweet potato raw starch by Chalara paradoxa glucoamylase which digests both raw and gelatinized starch. Potassium metabisulfite strongly inhibited raw starch digesting activity (RDA) although gelatinized starch digesting activity was only slightly inhibited. Potassium sorbate, among the preservatives examined, showed the weakest inhibition (below 10%) on RDA. In the presence of potassium sorbate, semi-continuous digestion of sweet potato raw starch in a 20L scale hollow fiber UF membrane pilot reactor proceeded efficiently at 30% (w/v) initial concentration of raw starch at pH 5.0 and 40°C. Glucose production was 5.7 to 6.0 g/hr/L.     

Amylolytic Hydrolysis of Native Starch Granules Affected by Granule Surface Area

ABSTRACT: Initial stage of hydrolysis of native starch granules with various amylolytic enzymes, α‐amylase from Bacillus subtilis, glucoamylase I (GA‐I) and II (GA‐II) from Aspergillus niger, and β‐amylase from sweet potato showed that the reaction was apparently affected by a specific surface area of the starch granules. The ratios of the reciprocal of initial velocity of each amylolytic hydrolysis for native potato and maize starch to that for rice with the amylolytic enzymes were nearly equivalent to the ratio of surface area per mass of the 2 starch granules to that of rice, that is, 6.94 and 2.25, respectively. Thus, the reciprocal of initial velocity of each enzymatic hydrolysis as expressed in a Lineweaver–Burk plot was a linear function of the reciprocal of surface area for each starch granule. As a result, it is concluded that amylolytic hydrolysis of native starch granules is governed by the specific surface area, not by the mass concentration, of each granule.     

酶解对氧化淀粉粘度的影响

对轻度氧化淀粉采用α-淀粉酶部分水解处理 ,结果表明 :轻度氧化淀粉酶解后的粘度性质与中度或高度氧化淀粉的粘度具有相似的性质 ;热粘度稳定性随氧化程度和酶解程度的增大而降低     

淀粉颗粒结构特性对酶解影响的研究进展

不同品种淀粉颗粒的聚态集结构、表面特征和组成成分存在差异,这些差异对淀粉的酶解特性产生很大的影响.阐述了淀粉颗粒的大小、形状、结晶结构、直链淀粉含量以及淀粉颗粒中非淀粉物质等因素对淀粉的酶解影响,并指出目前存在的问题和研究的方向.     

Characterisation of Dextrins Solubilised by α‐Amylase from Barley Starch Granules

Large granules from barley starch were packed into a column and hydrolysed with α‐amylase by pumping a diluted enzyme solution through the starch bed. The enzyme was then trapped onto an ion‐exchanger and the dextrins that solubilised from the granules were collected and characterised. The size‐distribution of the solubilished dextrins ranged from degree of polymerisation (DP) 2—500. The linear and branched products originated from both the amylose and the amylopectin components. The rate of solubilisation and the composition of the solubilised dextrins from barley starch were very similar to those found for large wheat starch granules.     

Hydrolysis of Native Wheat and Corn Starch Granules by Glucoamylases from Aspergillus Niger and Rhizopus Niveus

The action of glucoamylase I and II (α-1,4-glucan glucohydrolase, E.C. 3.2.1.3) from Aspergillus niger and the glucoamylase from Rhizopus niveus on native wheat and corn starch granules was followed by using scanning electron microscopy (SEM) and by measuring the glucose released by enzymatic attack. Two distinct patterns of attack were observed. Glucoamylase I and the glucoamylase from R. niveus attacked the granule surface relatively uniformly, resulting in large disclike depressions. Glucoamylase II, while showing some disc-like depressions, produced small grooves (furrows) in the surface of the granule. Similar patterns were observed for both corn and wheat starch granules, except that attack by glucoamylase I and the glucoamylase from R. niveus on wheat starch granules also developed along the equatorial groove (not easily seen until the granules were exposed to enzyme solutions). Measuring glucose released indicated that hydrolysis by glucoamylase I and by the glucoamylase from R. niveus were nearly equal in extent and were about twice that by glucoamylase II.     

西米交联淀粉的理化性质

以三偏磷酸钠为交联剂,采用水分散法制备西米交联淀粉,利用扫描电镜、聚焦光束发射测量仪、Bra-bender快速黏度计和紫外分光光度计对其性质进行测定和分析,并与西米原淀粉进行比较。结果表明:西米交联淀粉发生了中等程度的交联;西米交联淀粉保持了西米原淀粉绝大多数颗粒完整、呈椭圆形、存在断切面和断切面处有凹坑的形貌特征,但其表面比较粗糙,有凹痕,且断切面处凹坑更加明显;西米交联淀粉颗粒粒径分布图呈单峰,在水相中的平均粒径为30.1μm,比西米原淀粉颗粒小;西米交联淀粉比西米原淀粉难于糊化,其热稳定性和冷糊稳定性均优于西米原淀粉,有很高的最终黏度;西米交联淀粉的透光率为5.1%,小于西米原淀粉,其透明度较差。     

Changes in Some Properties of Starch Granules of Maize Having Amylose-extender Gene by Amylase Attack

Properties of residual starch by glucoamylase attack were investigated in starch granules of maize (Zea mays L.) of amylose-extender (ae) type (commercial “High Amylose-7”; HA-7). As increasing extent of hydrolysis, the amylose and amylopectin fractions decreased and low-molecular-weight materials were accumulated. Decrease in absorption intensity and sift to a range of shorter wavelength in γmax. of absorption spectra of iodine-starch complexes were observed. The minified fractions had a peak of about 22 average glucose-units and were nearly linear chains. It was suggested that the minified materials consisted of portion resisted to amylases in starch granules according to hydrolysis curves by glucoamylase. The fractions concerned to crystalline area of ae starch were suggested from X-ray diffraction patterns.     

酶解和发酵对氧化淀粉应用性质的影响

轻度氧化淀粉采用α -淀粉酶水解和乳酸菌发酵处理后通过正交试验得出 :羧基含量和酶解程度对淀粉的粘度影响显著 ,而发酵温度的影响不显著 ;发酵后的耐酸性有了很大改善。     

淀粉酶对大米淀粉回生影响机理的研究

利用Avram i方程研究了淀粉酶对大米淀粉回生的影响机理,研究结果表明:对于籼米淀粉而言,β-淀粉酶的处理虽没有影响其重结晶的成核,但降低了重结晶的增长速率,因此回生受到抑制;对于糯米淀粉而言,β-淀粉酶的处理使其重结晶成核速度和增长速率都降低,回生受到有效抑制。对于籼米淀粉和糯米淀粉体系而言,普鲁兰酶的处理使两种淀粉重结晶的成核和结晶速率都增加,淀粉体系的回生被加速。     

无蒸煮酿造麦曲黄酒中生淀粉水解机理及发酵特点

酶系广泛、酶量充足、且α-淀粉酶和葡萄糖淀粉酶组合恰当是促成生大米中生淀粉水解的首要条件.生淀粉的物理性质,决定了免蒸煮麦曲黄酒酿造前酵水解偏缓,酵母菌发酵产酒精和热量偏低的发酵特征.生大米中的蛋白质,因未受湿热作用而变性或胶凝化,决定了免蒸煮麦曲黄酒氨基酸态氮丰富的产品营养特征.     

酸解-球磨法制备小颗粒淀粉及形成机理研究

传统微细化小颗粒淀粉的制备采用原淀粉直接球磨的方法,耗时长,能耗高,产物易糊化。采用先酸解再球磨的新工艺制备了微细化小颗粒淀粉,并与玉米原淀粉、酸处理淀粉的物化性质进行了比较。结果表明,玉米原淀粉的表面积平均粒径为12.9μm,酸处理后淀粉的表面积平均粒径没有明显变化,而微细化淀粉的表面积平均粒径有显著降低;酸处理淀粉的结晶度较原淀粉有所增加,而酸水解后球磨淀粉结晶结构减弱,部分偏光十字消失,双折射强度减弱。     

酵母菌发酵生淀粉提高马铃薯淀粉回生率机理研究

以马铃薯淀粉为原料,淀粉回生率为考察指标,研究酵母菌发酵对马铃薯淀粉回生率的影响。通过对比发酵前后马铃薯回生淀粉的可见和红外吸收曲线,分析了酵母菌发酵提高马铃薯淀粉回生率的机理。结果表明,纤细酵母菌发酵马铃薯淀粉可使马铃薯淀粉回生率由12%提高到39.4%,提高了2.28倍。发酵后马铃薯回生淀粉中直链淀粉的最大可见吸收波长为587.8 nm,大于发酵前的569.6 nm。酵母菌发酵马铃薯淀粉提高其回生率的原因有两方面:一是发酵过程产生的酶使马铃薯支链淀粉脱支生成直链淀粉,增加了参与回生直链淀粉的量;二是发酵过程使马铃薯淀粉中醛基部分转变为伯醇基,进而生成糖苷键,增加直链淀粉链长,有利于淀粉回生过程晶体长大。