Glucosyltransferase production by Klebsiella sp. K18 and conversion of sucrose to palatinose using immobilized cells

Abstract

The strain Klebsiella sp. K18 produces the enzyme glucosyltransferase and catalyses the conversion of sucrose to palatinose, an alternative sugar that presents low cariogenicity. Response Surface Methodology was successfully employed to determine the optimal concentration of culture medium components. Maximum glucosyltransferase production (21.78 U mL ), after 8 hours of fermentation at 28ºC. The conversion of sucrose to palatinose was studied utilizing immobilized cells in calcium alginate. The effects of the alginate concentration (2-4%), cell mass concentration (20-40%) and substrate concentration (25-45%) were evaluated and the yield of palatinose was approximately 62.5%.

Efficient and economical biosynthesis of high-purity isomaltulose from sugar industrial waste molasses using an engineered Corynebacterium glutamicum strain

“…Many studies have demonstrated that strain growth and enzyme activity are restrained at high substrate concentrations. 29,[42][43][44] In our case, this is probably because high CM concentrations (exceeding 400 g L −1 ) increase the viscosity of the bioreaction system, which likely reduces SIasesucrose interactions. We further investigated the effect of the concentration of steep liquor, which is often used in microbial fermentation as a cheap nitrogen source, on the catalytic performance of IS7.…”

Isomaltulose production using free and immobilized Serratia plymuthica cells

“…(Kawaguti and Sato, 2010;Korneeva et al, 2008;Mundra et al, 2007), Serratia plymuthica (Krastanov and Yoshida, 2003) and Klebsiella sp. (Orsi et al, 2009;Zhang et al, 2003) are known to produce the intracellular enzyme -glucosyltransferase (EC 5.4.99.11), also called sucrose isomerase, responsible for sucrose conversion into isomaltulose. In a recent work, Goulter et al (2012) showed by molecular analyses that the most widely used bacterial strain for industrial production of isomaltulose referred to as Protaminobacter rubrum CBS 574.77 was genetically identified as S. plymuthica.…”

“…Isomaltulose production is documented in literature using free enzymes (Korneeva et al, 2008), free cells (Kawaguti et al, 2007) and immobilized cells (Kawaguti and Sato, 2010;Oliva-Neto and Menão, 2009;Krastanov and Yoshida, 2003;Orsi et al, 2009). The industrial use of free enzymes for isomaltulose production is complicated, because glucosyltransferase is an intracellular enzyme.…”

Immobilization of glucosyltransferase from Erwinia sp. using two different techniques

“…D12 , Serratia plymuthica , Klebsiella sp. k18 (Orsi et al, 2009). For industrial purposes, the immobilization of the biocatalyst (enzyme and/or cells) offers several advantages, including reusability, easy product separation, enhancement of enzyme stability and continuous operation (Oliveira et al, 1997).…”