Thermostable -Amylase and Glucoamylase from Thermomyces lanuginosus F1

Abstract

An α-amylase and a glucoamylase produced by Thermomyces lanuginosus F 1 were separated by ionexchange chromatography on Q-Sepharose fast flow. The enzymes were further purified to electrophoretic homogeneity by chromatography on Sephadex G-100 and Phenyl-Sepharose CL-4B. The molecular weights and isoelectric points of the enzymes were 55,000 Da and pH i 4.0 for α-amylase and 70,000 Da and pH i 4.0 for glucoamylase, respectively. The optimum pH and temperatures for the enzymes were found to be 5.0 and 60°C for α-amylase, and 6.0 and 70°C for glucoamylase, respectively. Both enzymes were maximally stable at pH 4.0 and retained over 80% of their activity between pH 5.0 and 6.0 for 24 h. After incubation at 90°C (1 h), the α-amylase and glucoamylase retained only 6% and 16% of their activity, respectively. The enzymes readily hydrolyzed soluble starch, amylose, amylopectin and glycogen but hydrolyzed pullulan very slowly. Glucoamylase and α-amylase had highest affinity for soluble starch with K M values of 0.80 mg/ml and 0.67 mg/ml, respectively. The α-amylase hydrolyzed raw starch granules with a predominant production of glucose and maltose. The activities of α-amylase and glucoamylase increased in the presence of Mn 2+ , Co 2+ , Ca 2+ , Zn 2+ and Fe 2+ , but were inhibited by guanidine-HCl, urea and disodium EDTA. Both enzymes possess pH and thermal stability characteristics that may be of technological significance.

Partial purification and some physicochemical properties of Aspergillus flavus -amylase isolated from decomposing cassava peels

“…such as A. oryzae, Aspergillus ficuum and A. niger were found to give significant yields of α-amylase at pH 5.0 to 6.0 in submerged fermentations (Moller et al, 2004); Knox et al, 2004). Therefore, the pH optimum 5.0 obtained in this work compares well with the works of Ali and AbdelMoneim (1989); Sudo et al (1994) and Odibo and Ulbrich-Hofmann (2001) who reported optimum pH of 5.0 for alpha-amylase from A. flavus var. columnaris, Aspergillus kawachi IFO 4308 and T. lanuginosus respectively which indicated that the organism prefer acidic condition for better enzyme production.…”

Chitinase from Thermomyces lanuginosus SSBP and its biotechnological applications

“…Some of them are thermostable and very suitable for the industrial applications. T. lanuginosus secretes many enzymes (Fischer et al 1995;Chaudhuri and Maheshwari 1996;Li et al 1997;Bharadwaj and Maheshwari 1999;Singh et al 2000a;Odibo and Ulbrich-Hofmann 2001;Gulati et al 2007;Rezessy-Szabo et al 2007;Khucharoenphaisan and Sinma 2010;Fang et al 2014) that are listed in Table 1. Table 1 suggests that thermophilic microorganisms like T. lanuginosus produces thermostable enzymes that are able to survive at high temperatures as well as extremes of pH conditions (Haki and Rakshit 2003).…”

Immobilization of starch-converting enzymes on surface-modified carriers using single and co-immobilized systems: properties and application to starch hydrolysis

“…4, single glucoamylase produced 7.89 mg/ml of glucose, whereas single ␣-amylase produced 1.95 mg/ml of glucose. Since ␣-amylase breaks ␣-1,4-glycosidic bonds in the inner part of starch (liquefaction of starch) [10], ␣-amylase-catalyzed liquefaction mainly produces oligosaccharides with the small amount of glucose as end products [11]. On the other hand, glucoamylase, an exoamylase, cleaves both ␣-1,4-and ␣-1,6-glycosidic bonds [12].…”