Department of Biology, Faculty of Basic Sciences, Azarbaijan Shahid Madani University, Tabriz, Iran.
Department of Chemistry, Faculty of Basic Sciences, Azarbaijan Shahid Madani University, Tabriz, Iran.
Sci Rep. 2024 Mar 25;14(1):6810. doi: 10.1038/s41598-024-57222-8.
Endophytic fungi are microorganisms that are considered as a potential source of natural compounds, and can be applied in various industries. The aims of this research were molecular identification of endophytic fungi isolated from the Gundelia tournefortii stems, and investigation their biological activities as well as phenolic and fatty acid profile. Surface sterilized stems of G. tournefortii were placed on potato dextrose agar (PDA) to isolate the fungal endophytes. Genomic DNA was extracted by CTAB method, and PCR amplification was performed by ITS 1 and ITS 4 as primers. The enzyme production of endophytic fungi was determined based on the formation of a clear zone that appeared around the colonies of fungus. The anti-oxidant activity was evaluated by measuring the amount of free radicals DPPH. Also, the total phenol and flavonoid contents were measured obtained by Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. Moreover, the separation and identification of phenolic acids and fatty acids were done by HPLC and GC, respectively. Phylogenetic analysis was done based on the Internal Transcribed Spacer (ITS) region, and five isolates were identified as following: Aspergillus niger, Penicillium glabrum, Alternaria alternata, A. tenuissima, and Mucor circinelloides. Evaluation of the enzymatic properties showed that P. gabrum (31 ± 1.9 mm), and A. niger (23 ± 1.7) had more ability for producing pectinase and cellulase. The anti-oxidant activity of isolates showed that A. alternata extract (IC = 471 ± 29 µg/mL) had the highest anti-oxidant properties, followed by A. tenuissima extract (IC = 512 ± 19 µg/mL). Also, the extract of A. alternata had the greatest amount of total phenols and flavonoids contents (8.2 ± 0.4 mg GAL/g and 2.3 ± 0.3 mg QE/g, respectively). The quantification analysis of phenolic acid showed that rosmarinic acid, para-coumaric acid, and meta-coumaric acid (42.02 ± 1.31, 7.53 ± 0.19, 5.41 ± 0.21 mg/g, respectively) were the main phenolic acids in the studied fungi. The analysis of fatty acids confirmed that, in all fungi, the main fatty acids were stearic acid (27.9-35.2%), oleic acid (11.3-17.3%), palmitic acid (16.9-23.2%), linoleic acid (5.8-11.6%), and caprylic acid (6.3-10.9%). Our finding showed that endophytic fungi are a source of bioactive compounds, which could be used in various industries. This is the first report of endophytic fungi associated with G. tournefortii, which provides knowledge on their future use on biotechnological processes.
内生真菌被认为是天然化合物的潜在来源，可应用于各个行业。本研究的目的是从一枝黄花茎中分离内生真菌并对其进行分子鉴定，同时研究其生物活性以及酚类和脂肪酸组成。采用表面消毒法从一枝黄花茎中分离内生真菌，用 CTAB 法提取基因组 DNA，用 ITS1 和 ITS4 作为引物进行 PCR 扩增。根据真菌菌落周围形成的清晰区域来确定内生真菌的产酶能力。采用 DPPH 法测定抗氧化活性，通过福林-氯仿比色法和三氯化铝比色法分别测定总酚和总黄酮含量。此外，采用高效液相色谱法（HPLC）和气相色谱法（GC）分别对酚酸和脂肪酸进行分离和鉴定。基于内转录间隔区（ITS）进行系统发育分析，鉴定出 5 株内生真菌，分别为：黑曲霉、青霉、链格孢菌、细极链格孢和少根根霉。对酶特性的评价表明，青霉（31±1.9mm）和黑曲霉（23±1.7）具有更强的果胶酶和纤维素酶产生能力。内生真菌提取物的抗氧化活性表明，链格孢提取物（IC=471±29μg/mL）具有最强的抗氧化活性，其次是细极链格孢提取物（IC=512±19μg/mL）。此外，链格孢提取物的总酚和总黄酮含量最高（分别为 8.2±0.4mgGAE/g 和 2.3±0.3mgQE/g）。酚酸定量分析表明，迷迭香酸、对香豆酸和间香豆酸（42.02±1.31、7.53±0.19、5.41±0.21mg/g）是研究真菌中的主要酚酸。脂肪酸分析证实，所有真菌中的主要脂肪酸均为硬脂酸（27.9-35.2%）、油酸（11.3-17.3%）、棕榈酸（16.9-23.2%）、亚油酸（5.8-11.6%）和辛酸（6.3-10.9%）。本研究表明内生真菌是生物活性化合物的来源，可应用于各个行业。这是首次报道与一枝黄花相关的内生真菌，为其在生物技术过程中的未来应用提供了知识。
