In this study, a new strain suspected to be Aureobasidium pullulans was isolated from trees leaves. The molecular characterization and the resulting phylogenetic tree showed that the isolated strain was A. pullulans. Also, the results of methylation analysis, monosaccharide composition, FTIR, NMR and XRD confirmed that the obtained exo-polysaccharide from the mentioned strain was pullulan. The pullulan production optimization by central composite design (CCD) indicated that the maximum yield obtained under optimum conditions (pH of 6.5, sucrose concentration of 5.5% (w/v) and yeast extract concentration of 0.1% (w/v)) was 51.4 ± 0.50 g/L. The produced pullulan had an average molecular weight (Mw) of 207000 g/mol based on gel permeation chromatography results. The decomposition temperature (Td) of the produced pullulan was ~300 °C and also, the resulting pullulan had a Newtonian flow behavior in a wide range of concentrations.
NCBI PubMed ID: 32088229Publication DOI: 10.1016/j.ijbiomac.2020.02.226Journal NLM ID: 7909578Publisher: Butterworth-Heinemann
Correspondence: khodaiyan
ut.ac.ir
Institutions: Bioprocessing and Biodetection Laboratory, Department of Food Science and Engineering, University of Tehran, Karaj, Iran, Chembiotech Laboratories, Advanced Science and Technology Institute, Bromsgrove, UK, Department of Food Science, Engineering and Technology, University of Tehran, Karaj, Iran, Shahrood University of Technology, School of Agricultural Engineering, Department of Food Science and Technology, Shahrood, Iran
Methods: 13C NMR, 1H NMR, methylation, gel filtration, IR, DNA sequencing, GC-MS, X-ray, acid hydrolysis, HPLC, GPC, viscosity measurement, microscopy, acetylation, methylation analysis, reduction, CC, cell growth, DNA extraction, precipitation, Sevag method, centrifugation, thermogravimetric analysis
Found