Bioprocessing and Biodetection Laboratory, Department of Food Science and Engineering, University of Tehran, Karaj 31587-77871, Iran.
Chembiotech Laboratories, Advanced Science and Technology Institute, 5 The Croft, Buntsford Drive, Stoke Heath, Bromsgrove, Worcs B60 4JE, UK.
Int J Biol Macromol. 2019 Oct 1;138:725-735. doi: 10.1016/j.ijbiomac.2019.07.123. Epub 2019 Jul 21.
In this study, a new yeast-like fungal was obtained from leaf surfaces collected from Kheyroodkenar forest, Mazandaran, Iran. The properties of this strain, such as morphology, DNA molecular, and product showed that it is related to Aureobasidium pullulans family and named A. pullulans MG271838. The pullulan production conditions by this strain were optimized using a Box-Behnken design. The results showed that the optimum production yield (37.55 ± 0.45 g/l) was obtained in pH of 6.76, sucrose concentration of 6%w/v and yeast extract concentration of 0.2%w/v. The pullulan had a concentration-dependent flow behavior, amorphous structure based on XRD pattern and high thermal stability (decomposition temperature of 300 °C). Also, the chemical structure of pullulan was confirmed by FTIR spectroscopy. In addition, there was a direct relationship between pullulan yield and the gene expression of fks, pgm and ugp as the most important genes in pullulan production.
在这项研究中，从伊朗马赞达兰省 Kheyroodkenar 森林采集的叶片表面获得了一种新型酵母样真菌。该菌株的形态、DNA 分子和产物等特性表明，它与出芽短梗霉属家族有关，并被命名为 A. pullulans MG271838。使用 Box-Behnken 设计对该菌株的普鲁兰生产条件进行了优化。结果表明，在 pH 值为 6.76、蔗糖浓度为 6%w/v 和酵母提取物浓度为 0.2%w/v 的条件下，产量达到最佳（37.55±0.45g/l）。普鲁兰具有浓度依赖性的流动行为、基于 XRD 图谱的无定形结构和高热稳定性（分解温度为 300°C）。此外，通过傅里叶变换红外光谱法（FTIR）确认了普鲁兰的化学结构。此外，普鲁兰的产量与 fks、pgm 和 ugp 等在普鲁兰生产中最重要的基因的基因表达之间存在直接关系。
