A thermostable maltose‐tolerant α‐amylase from <i>Aspergillus tamarii</i>

Moreira, Fabiana Guillen; Lenartovicz, Veridiana; Peralta, Rosane Marina

doi:10.1002/jobm.200310302

Cited by 31 publications

(22 citation statements)

References 20 publications

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“…de Azevedo et al [11] showed that α-amylase of T. harzianum degraded the starch, glycogen and amylopectin but not cellobiose, α-cyclodextrin or β-cyclodextrin. The starch and amylopectin were the substrates preferentially hydrolyzed by A. tamarii α-amylase [24]. In a decreasing order, A. sporosulcatum α-amylase catalyzed the degradation of starch > glycogen > dextrin [25].…”

Section: Resultsmentioning

confidence: 99%

Purification and characterization of α-amylase from Trichoderma pseudokoningii

Abdulaal

2018

BMC Biochem

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BackgroundPrevious studies have demonstrated that members of Trichoderma are able to generate appreciable amount of extracellular amylase and glucoamylase on soluble potato starch. In this study the α-amylase was purified and characterized from Trichoderma pseudokoningii grown on orange peel under solid state fermentation (SSF).ResultsFive α-amylases A1-A5 from Trichodrma pseudokoningii were separated on DEAE-Sepharose column. The homogeneity of α-amylase A4 was detected after chromatography on Sephacryl S-200. α-Amylase A4 had molecular weight of 30 kDa by Sephacryl S-200 and SDS-PAGE. The enzyme had a broad pH optimum ranged from 4.5 to 8.5. The optimum temperature of A4 was 50 °C with high retention of its activity from 30 to 80 °C. The thermal stability of A4 was detected up to 50 °C and the enzyme was highly stable till 80 °C after 1 h incubation. All substrate analogues tested had amylase activity toward A4 ranged from 12 to 100% of its initial activity. The Km and Vmax values of A4 were 4 mg starch/ml and 0.74 μmol reducing sugar, respectively. The most of metals tested caused moderate inhibitory effect, except of Ca2+ and Mg2+ enhanced the activity. Hg2+ and Cd+ 2 strongly inhibited the activity of A4. EDTA as metal chelator caused strong inhibitory effect.ConclusionsThe properties of the purified α-amylase A4 from T. pseudokoningii meet the prerequisites needed for several applications.

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Section: Resultsmentioning

confidence: 99%

Purification and characterization of α-amylase from Trichoderma pseudokoningii

Abdulaal

2018

BMC Biochem

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“…Khoo et al, 1994;Moreira et al, 2004;Dey et al, 2002). There are several possible explanations for this low activity of AmyD.…”

Section: Discussionmentioning

confidence: 99%

“…Steyn et al, 1995;Matsuura et al, 1984;Moreira et al, 2004;Boel et al, 1990). In all cases, these enzymes are secreted into the extracellular environment, where they are involved in degradation of starch and glycogen into small oligosaccharides, which can be imported into the cells to serve as energy and carbon sources.…”

Section: Introductionmentioning

confidence: 99%

Phylogenetic and biochemical characterization of a novel cluster of intracellular fungal α-amylase enzymes

et al. 2007

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Currently known fungal a-amylases are well-characterized extracellular enzymes that are classified into glycoside hydrolase subfamily GH13_1. This study describes the identification, and phylogenetic and biochemical analysis of novel intracellular fungal a-amylases. The phylogenetic analysis shows that they cluster in the recently identified subfamily GH13_5 and display very low similarity to fungal a-amylases of family GH13_1. Homologues of these intracellular enzymes are present in the genome sequences of all filamentous fungi studied, including ascomycetes and basidiomycetes. One of the enzymes belonging to this new group, Amy1p from Histoplasma capsulatum, has recently been functionally linked to the formation of cell wall a-glucan. To study the biochemical characteristics of this novel cluster of a-amylases, we overexpressed and purified a homologue from Aspergillus niger, AmyD, and studied its activity product profile with starch and related substrates. AmyD has a relatively low hydrolysing activity on starch (2.2 U mg "1 ), producing mainly maltotriose. A possible function of these enzymes in relation to cell wall a-glucan synthesis is discussed. INTRODUCTIONa-Amylases are widely occurring enzymes which hydrolyse the a-(1,4)-glycosidic bonds in starch and glycogen, producing short maltooligosaccharides and maltose. Based on sequence similarity, most a-amylases (EC 3.2.1.1) are classified in glycoside hydrolase (GH) family 13, although some a-amylases originating from extremophilic organisms belong to family GH57 (Henrissat, 1991;Henrissat & Bairoch, 1996) (see also the CAZy website, http://www.cazy.org). Based on a phylogenetic analysis of 1691 different members of the GH13 family, the family has recently been divided into 35 subfamilies, all acting on aglycosidic bonds (Stam et al., 2006). Several of these subfamilies display a-amylase specificity, but many other enzyme reaction specificities are also represented. The tertiary structure of these enzymes is characterized by a (b/a) 8 barrel containing four highly conserved amino acid regions that form the active site (MacGregor et al., 2001), but the overall sequence similarity can be as low as 10 % and only a catalytic triad of amino acids is conserved invariantly (Machovic & Janecek, 2003). The shared (b/a) 8 barrel structure and catalytic mechanism within GH13 enzymes are believed to represent a common evolutionary origin (Kuriki & Imanaka, 1999;Janecek, 1997). The presence of the four conserved regions and a common secondary and tertiary structure allow construction of alignments and phylogenetic studies within the family. The phylogeny of a-amylases is generally in agreement with their origin, e.g. all fungal a-amylases are more related to each other than to the a-amylases originating from plants or animals. a-Amylases from bacteria, however, are scattered over several clusters, which group with animal, plant or fungal a-amylases, or form a separate branch (Janecek, 1994).Several a-amylases from yeasts and fungi have been studied previously (see e.g....

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“…The activity of enzymes observed in medium supplemented with corncobs or wheat bran loss 67.7% or 65.5% of a amylase activity, whereas loss 82.7% or 98.1% of b amylase activity also 87.5% or 97.5% of c amylase activity, the significance reduction of enzymes activity may be due to thickness of the fermentation medium for wheat bran leading to decrease culture aeration, which were essential for the growth and amylases activity (Satyanarayana et al, 2004) also, corncobs was not suitable carbon source, it could be due to their content of starch is very poor, to be insufficient for amylases activity (Moreira et al, 2004).…”

Section: Genotypic Characteristics and The Phylogenetic Treementioning

confidence: 94%

Production of amylases from Bacillus amyloliquefaciens under submerged fermentation using some agro-industrial by-products

Abd-Elhalem

El-Sawy

Gamal

et al. 2015

Annals of Agricultural Sciences

117

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Thirty-one bacterial isolates out of 133 isolates, were obtained from rhizosphere of Egyptian clover plants, and had variant capability for starch degradation on starch agar medium. The isolate E109 was the most potent being 72.5 U ml À1 and 2.5 for amylase activity and starch hydrolysis ratio (SHR), respectively, at 50°C. The potent isolate E109 was identified based on phenotypic characteristics, phylogenetic positions based on 16S rRNA gene analysis and base sequences (submitted to NCBI Gen Bank). 16S rRNA gene analysis confirmed that this isolate belonged to the genus Bacillus and it was most closely related to B. amyloliquefaciens (95% similarity). For the production of amylases, nine agro-industrial residues were added as carbon sources to the basal medium. The medium supplemented with potato starchy waste as the sole carbon source enhanced the enzyme activity more than soluble starch as control for a, b and c amylases activity, as it increased by B. amyloliquefaciens about 1.26 & 4 and 8-fold, respectively after 48 h at 50°C using rotary shaker at 150 rpm. B. amyloliquefaciens gave the maximum values of a, b and c amylases activity on medium supplemented with 2% potato starchy waste after 30, 30 & 36 h of fermentation periods at 50°C using shake flasks technique as a batch culture. These values were 155.2 U ml À1 (R 2 = 0.93), 1.0 U ml À1 (R 2 = 0.94) and 2.4 U ml À1 (R 2 = 0.95), respectively. It could be stated that productive medium supplemented with 2% potato starchy waste as a low price substrate could be more favorable than basal medium containing 1% starch for amylases production in submerged fermentation, as it increased a, b and c amylase activity by 1.98, 7.69 and 12-fold than that produced in basal medium (control), respectively. ª 2015 Production and hosting by Elsevier B.V. on behalf of Faculty of Agriculture, Ain Shams University.

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A thermostable maltose‐tolerant α‐amylase from Aspergillus tamarii

Cited by 31 publications

References 20 publications

Purification and characterization of α-amylase from Trichoderma pseudokoningii

Purification and characterization of α-amylase from Trichoderma pseudokoningii

Phylogenetic and biochemical characterization of a novel cluster of intracellular fungal α-amylase enzymes

Production of amylases from Bacillus amyloliquefaciens under submerged fermentation using some agro-industrial by-products

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