Bioprocessing and Biodetection Laboratory, Department of Food Science and Engineering, University of Tehran, Karaj 31587-77871, Iran.
Bioprocessing and Biodetection Laboratory, Department of Food Science and Engineering, University of Tehran, Karaj 31587-77871, Iran.
Int J Biol Macromol. 2020 Jun 1;152:305-313. doi: 10.1016/j.ijbiomac.2020.02.226. Epub 2020 Feb 20.
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 (M) of 2.07 × 10 g.mol based on gel permeation chromatography results. The decomposition temperature (T) of the produced pullulan was ~300 °C and also, the resulting pullulan had a Newtonian flow behavior in a wide range of concentrations.
在这项研究中，从树叶中分离出一种疑似为出芽短梗霉的新菌株。分子特征分析和生成的系统发育树表明，分离出的菌株为出芽短梗霉。此外，甲基化分析、单糖组成、FTIR、NMR 和 XRD 的结果证实，从所述菌株获得的胞外多糖为普鲁兰。利用中心复合设计（CCD）对普鲁兰生产进行优化，结果表明在最佳条件（pH 值为 6.5、蔗糖浓度为 5.5%（w/v）和酵母提取物浓度为 0.1%（w/v））下可获得最大产量为 51.4±0.50g/L。根据凝胶渗透色谱结果，所产生的普鲁兰的平均分子量（M）为 2.07×10g.mol。所产生的普鲁兰的分解温度（T）约为 300°C，并且在较宽的浓度范围内，所得普鲁兰具有牛顿流动行为。
