Bacillus lehensis—an alkali-tolerant bacterium isolated from cassava starch wastewater: optimization of parameters for cyclodextrin glycosyltransferase production

Abstract

A Gram-positive, endospore-forming, alkalitolerant bacterial strain, designated CGII, was isolated from the wastewater of a cassava flour mill in the state of São Paulo, Brazil and submitted to phylogenetic studies and biochemical tests. The 16S rRNA gene sequence indicated the highest degree of genomic similarity with MLB2 strains of Bacillus lehensis (100%). A two-level central composite rotatable design was then employed to optimize the medium composition and culture conditions for the production of the enzyme cyclodextrin glycosyltransferase (CGTase) in shake-flask and bioreactors. CCTase activity was measured under different production conditions, such as culture medium, agitation and aeration. Highest enzyme production by B. lehensis was achieved in 72 h with a maximal activity of 134.05 U mL −1 . The response surface method demonstrated that the proposed model achieved a good level of agreement with experimental data, with a correlation coefficient of 0.910, thereby confirming the adequate reliability of the model.

Bovine Bone Charcoal as Support Material for Immobilization of <em>Bacillus firmus</em> Strain 37 and Production of Cyclomaltodextrin Glucanotransferase by Batch Fermentation in a Fluidized Bed

“…Blanco [38] reported that lower values of dissolved oxygen and rate of agitation may limit the uptake of nutrients by the microorganisms (such as the nitrogen source and starch), decreasing the synthesis of CGTase. Advances in Chemical Engineering and Science activity, approximately 0.5 U/mL, was obtained at 400 rpm and 1 vvm.…”

Cyclodextrin production by Bacillus lehensis isolated from cassava starch: Characterisation of a novel enzyme

“…Bacillus lehensis CGII was isolated from wastewater samples from a cassava flour mill in Brazil. This bacterium is filed under the accession number HQ399547 (Blanco et al 2012). The B. lehensis CGII strain was inoculated in an Erlenmeyer flask containing 100 ml of optimised growth medium (Blanco et al 2012) and incubated at 35 ± 1°C for 72 h on a rotary shaker (New Brunswick Scientific Co, Edison, USA) at 150 rpm with an initial pH of 9.2.…”

“…Moreover, novel CGTase-producing strains have been identified for this purpose (Blanco et al 2012). The purification degree of commercial enzymes depends on the application (Wolfgang 2007).…”

“…However, the commercial use of CGTase is only possible after the definition of the purification method and enzyme characterisation. The microorganism Bacillus lehensis CGII, isolated from the wastewater of cassava flour mills and identified by Blanco et al (2012) (GenBank accession number HQ399547), exhibits high levels of CGTase production whose features, however, remain unknown.…”

Reuse of Cyclodextrin Glycosyltransferase through Immobilization on Magnetic Carriers

“…CD production involves starch catalysis by the enzyme cyclodextrin glycosyltransferase (CGTase), produced by bacteria of the genera Bacillus [4], Paenibacillus [5], Klebsiella [6] and Thermoanaerobacterium [7]. Enzyme stability during catalytic activity and the separation of the product from the reaction medium are important factors to address, when using CGTase for CD production.…”