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ARTICLE
Biosynthesis of raw starch degrading β-cyclodextrin glycosyltransferase by immobilized cells of Bacillus licheniformis using potato wastewater
YASSER S. MOSTAFA1,*, SAAD A. ALAMRI1,2, SULIMAN A. ALRUMMAN1, TAREK H. TAHA3, MOHAMED HASHEM1,4, MAHMOUD MOUSTAFA1,5, LAMIAA I. FAHMY6
1 Department of Biology, College of Science, King Khalid University, Abha, 9004, Saudi Arabia
2 Prince Sultan Bin Abdulaziz Center for Environmental and Tourism Research and Studies, King Khalid University, Abha, 9004, Saudi Arabia
3 Environmental Biotechnology Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research & Technological Applications, New Borg El-Arab City, 21934, Egypt
4 Department of Botany and Microbiology, Faculty of Science, Assiut University, Assiut, 71515, Egypt
5 Department of Botany and Microbiology, Faculty of Science, South Valley University, Qena, 83523, Egypt
6 Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Science and Art, Giza, 12451, Egypt
* Corresponding Author: Yasser S. Mostafa,
BIOCELL 2021, 45(6), 1661-1672. https://doi.org/10.32604/biocell.2021.016193
Received 16 February 2021; Accepted 23 April 2021; Issue published 01 September 2021
Abstract
The study was sought to enhance the synthesis of thermal stable β-cyclodextrin glycosyltransferase (β-CGTase)
using potato wastewater as a low-cost medium and assess the degree to which it is efficient for industrial production of
β-cyclodextrin (β-CD) from raw potato starch. Thermophilic bacteria producing β-CGTase was isolated from Saudi
Arabia and the promising strain was identified as
Bacillus licheniformis using phylogenetic analysis of the 16S rRNA
gene. Alginate-encapsulated cultures exhibited twice-fold of β-CGTase production more than free cells. Scanning
electron microscopy (SEM) of polymeric capsules indicated the potential for a longer shelf-life, which promotes the
restoration of activity in bacterial cells across semi-continuous fermentation of β-CGTase production for 252 h. The
optimal conditions for β-CGTase synthesis using potato wastewater medium were at 36 h, pH of 8.0, and 50°C with
0.4% potato starch and 0.6% yeast extract as carbon and nitrogen sources, respectively. The purified enzyme showed a
specific activity of 63.90 U/mg with a molecular weight of ∼84.6 kDa as determined by SDS-PAGE analysis. The high
enzyme activity was observed up to 60°C, and complete stability was achieved at 75°C. High levels of activity and
stability were shown at pH 8.0, and the pH range from 7.0–10.0, respectively. The enzyme has an appreciable affinity
for raw potato starch with a Km of 5.7 × 10
−6 M and a Vmax of 87.71 µmoL/mL/min. β-CD production was effective
against 25 U/g of raw potato starch. The outcomes demonstrated its feasibility to develop a fermentation process by
integrating the cost-effective production of β-CGTase having distinctive properties for β-CD production with ecofriendly utilization of potato wastewater.
Keywords
Cite This Article
MOSTAFA, Y. S., ALAMRI, S. A., ALRUMMAN, S. A., TAHA, T. H., HASHEM, M. et al. (2021). Biosynthesis of raw starch degrading β-cyclodextrin glycosyltransferase by immobilized cells of
Bacillus licheniformis using potato wastewater.
BIOCELL, 45(6), 1661–1672.