Increased Production of Food-Grade d-Tagatose from d-Galactose by Permeabilized and Immobilized Cells of Corynebacterium glutamicum, a GRAS Host, Expressing d-Galactose Isomerase from Geobacillus thermodenitrificans

Abstract

The generally recognized as safe microorganism Corynebacterium glutamicum expressing Geobacillus thermodenitrificans d-galactose isomerase (d-GaI) was an efficient host for the production of d-tagatose, a functional sweetener. The d-tagatose production at 500 g/L d-galactose by the host was 1.4-fold higher than that by Escherichia coli expressing d-GaI. The d-tagatose-producing activity of permeabilized C. glutamicum (PCG) cells treated with 1% (w/v) Triton X-100 was 2.1-fold higher than that of untreated cells. Permeabilized and immobilized C. glutamicum (PICG) cells in 3% (w/v) alginate showed a 3.1-fold longer half-life at 50 °C and 3.1-fold higher total d-tagatose concentration in repeated batch reactions than PCG cells. PICG cells, which produced 165 g/L d-tagatose after 3 h, with a conversion of 55% (w/w) and a productivity of 55 g/L/h, showed significantly higher d-tagatose productivity than that reported for other cells. Thus, d-tagatose production by PICG cells may be an economical process to produce food-grade d-tagatose.

Development of food‐grade expression system for d‐allulose 3‐epimerase preparation with tandem isoenzyme genes in Corynebacterium glutamicum and its application in conversion of cane molasses to D‐allulose

“…However, immobilized cells for D ‐allulose production have not been reported yet. Previous study reported the research on D ‐tagatose production using immobilized cells of recombinant C. glutamicum expressing D ‐galactose isomerase (Shin, Sim, Seo, & Oh, ). In this study, we attempted to prepare immobilized cells of DAE16 and INV1 using alginate as carrier and measure their catalytic efficiency in conversion of fructose and sucrose.…”

Recombinant Protein Expression System in Corynebacterium glutamicum and Its Application

“…In addition, cytosolic protein expression in C. glutamicum has contributed to the production of biochemicals such as polyhydroxyalkanoate (PHA) (Matsumoto et al, 2011 ), ethanol (Jojima et al, 2015 ), and γ-aminobutyric acid (GABA) (Choi et al, 2015 ). The industrial techniques for the production of rare saccharides such as D-tagatose (Shin et al, 2016 ), D-sorbose and D-psicose (Yang et al, 2015 ), D-allose ( https://patents.google.com/patent/WO2017111339A1/en ), and GDP-L-fucose (Chin et al, 2013 ) are also the methods of nutraceutical production that involve cytosolic protein overexpression in C. glutamicum .…”

Efficient gene editing in Corynebacterium glutamicum using the CRISPR/Cas9 system

“…Corynebacterium glutamicum , a gram-positive bacterium with a high G+C content, has been used for the industrial production of various amino acids for more than 50 years. Moreover, it has recently demonstrated strong potential for use as a protein expression system [ 1 , 2 ] because of its excellent culture characteristics and also because it is non-pathogenic, does not produce endotoxins, and is generally recognized as safe [ 3 , 4 ]. Furthermore, C. glutamicum produces minimal protease activity in the culture supernatant and has the ability to secrete properly folded proteins, which can improve subsequent purification efficiency.…”