A novel cyclomaltodextrin glucanotransferase from Bacillus firmus that degrades raw starch

Abstract

An alkalophilicBacilhuJirmus secreting the enzyme cyclomaltodextrin glucanotransferase was isolated from soil. The enzyme attacked raw starch to produce cyclodextrins. Maximum cyclodextrins were produced from tapioca starch followed by potato and corn starch. About 49 % of tapioca starch (at 10 and 50 g/l) was converted to cyclodextrins. The main reaction products were p and y-cyclodextrins with 40 % and 8 % yield respectively. On prolonged incubation small amount of cr-cyclodextrin was also produced. The ratio of cyclodextrins was dependent on the initial substrate concentration as well as reaction time.

Production of Cyclodextrins by CGTase from Bacillus clausii Using Different Starches as Substrates

“…In the presence of maltodextrin, the CD production was of three types, α-, β-, and γ-CD, while in soluble starch, there was production of only two types of CDs, β-and γ-CD, and no α-CD was observed. Many other CGTase studies have shown similar results, with the production of the β-CD prevailing (9,12,13,15,16,27,28,29). The better conversions were observed on 1.0% soluble starch, which showed a major conversion (80%) or in 2.5% maltodextrin (41%; Table 1).…”

“…9605 (10) were used. However, the CGTases from B. firmus (12,29,34) and B. clausii E16 produced only β-and γ-CD from different starches. The formation of only two types of CDs during hydrolysis processes is important in the separation process because it is easier to separate the CDs produced, which is interesting for industrial application.…”

“…On the other hand, addition of selective complexant agents and organic solvents to the reaction mixture has also shown to significantly influence the ratios of α-, β-, and γ-CDs and their yields. Many works have shown that different substrates can determine the kind of product obtained from enzymatic reaction CDs (9)(10)(11)(12)(13)(14)(15)(16).…”

Initial Screening of Fermentation Variables for the Production of Cyclomaltodextrin Glucanotransferase (CGTase) from Local Isolated Bacillus stearothermophillus HR1

“…CGTase producers can be found in various places such as soil, waste, plantation, hot springs, and even deep-sea mud [ 11. Bacillus coagulans [2], Bacillus circulans [3], Bacillusfirmus [4], Bacillus stearothennophilus [5], Bacillus macerans Little information is available on the effects of fermentation conditions on CGTase production. Therefore, in this study, a preliminary screening process was carried out using Response Surface Methodology (RSM).…”

“…Cyclodextrins (CDs), also known as Schardinger dextrins, are oligosaccharide rings comprising a-1, 4-linked glucopyranose residues. The most common types of CDs are a-, p-and y-cyclodextrins, which are made up of 6,7 or 8 molecules, respectively.…”