Abstract
β-glucosidases can produce gentiooligosaccharides that are lucrative and promising for the prebiotic and alternative food industries. However, the commercial production of gentiooligosaccharides using β-glucosidase is challenging, as this process is limited by the need for high thermal energy and increasing demand for the enzyme. Here, a putative β-glucosidase gene, selected from the coral microbial metagenome, was expressed in Escherichia coli. Reverse hydrolysis of glucose by Blg163 at pH 7.0 and 40 °C achieved a gentiooligosaccharide yield of 43.02 ± 3.20 g·L−1 at a conversion rate of 5.38 ± 0.40%. Transglycosylation of mixed substrates, glucose and cellobiose, by Blg163 consumed 21.6 U/0.5 g glucose/g cellobiose, achieving a gentiooligosaccharide yield of 70.34 ± 2.20 g·L−1 at a conversion rate of 15.63%, which is close to the highest yield reported in previous findings. Blg163-mediated synthesis of gentiooligosaccharides is the mildest reaction and the lowest β-glucosidase consumption reported to date.
Highlights
IntroductionGentiooligosaccharides can promote the growth of Bifidobacteria and Lactobacillus as probiotics, enhance vitamin synthesis, improve metabolism, inhibit the proliferation of harmful bacteria and tumors, and promote host immune response and nutrient absorption [3,4,5]
264 different β-glucosidase-producing strains were obtained from coral, and their metagenome sequencing and annotation were carried out
The amino acid residues from Met1 to Ser447 of the Blg163 protein resembled the catalytic domain of the glycosyl hydrolase family 1 (GH1) proteins
Summary
Gentiooligosaccharides can promote the growth of Bifidobacteria and Lactobacillus as probiotics, enhance vitamin synthesis, improve metabolism, inhibit the proliferation of harmful bacteria and tumors, and promote host immune response and nutrient absorption [3,4,5]. One of the characteristic features of gentiooligosaccharides is hygroscopicity, which helps in maintaining moisture in food, preventing its aging, and increasing its shelf life [5]. They improve the sensory properties of food by imparting a bitter but soft and refreshing taste; they are useful as an additive and preservative in the food industry. Gentiooligosaccharides have been employed widely in coffee, spices, chocolate, ice cream, baking products, and dairy beverages [6]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
