Biosynthesis of raw starch degradingβ-cyclodextrin glycosyltransferase by immobilized cells of Bacillus licheniformis using potato wastewater  

作　　者：YASSER S.MOSTAFA SAAD A.ALAMRI SULIMAN A.ALRUMMAN TAREK H.TAHA MOHAMED HASHEM MAHMOUD MOUSTAFA LAMIAA I.FAHMY 

机构地区：[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,Egypta

出　　处：《BIOCELL》2021年第6期1661-1672,共12页生物细胞（英文）

基　　金：Deanship of Scientific Research at King Khalid University through research groups program,Grant No.R.G.P.1/241/41.

摘　　要：The study was sought to enhance the synthesis of thermal stableβ-cyclodextrin glycosyltransferase(β-CGTase)using potato wastewater as a low-cost medium and assess the degree to which it is efficient for industrial production ofβ-cyclodextrin(β-CD)from raw potato starch.Thermophilic bacteria producingβ-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 ofβ-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 ofβ-CGTase production for 252 h.The optimal conditions forβ-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 87.71μmoL/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 ofβ-CGTase having distinctive properties forβ-CD production with ecofriendly utilization of potato wastewater.

关 键 词：Potato wastewater Bacillus licheniformis β-CGTase 16S rDNA gene Semi-continuous fermentation Β-CYCLODEXTRIN 

分 类 号：TQ9[化学工程]