[Screening and identification of antioxidant endophytes from Lycium barbarum of Ningxia]

In this paper, 29 endophytes were isolated from different organs and tissues of Lycium barbarum of Ningxia by tablet coating method, 18 of them was fungi, and 11 of them was actinomycetes. The endophytes quantity in the different tissues were leaves > flowers > roots >fruits; The hydroxyl radical scavenging activities of 11 endophytes were investigated by Fenton reaction, and total antioxidant capacities of them were examined by a. total antioxidant capacity test kit; culture features and strain-specific sequence analysis were employed to explore the diversity of the 11 endophytes. The result showed that 5 fungi and 6 actinomycetes that having antioxidant activity could be phylogenetically classified into 3 genera, 3 genera and 3 families, respectively. The total antioxidant capacity and hydroxyl radical scavenging activity of the 11 endophytes showed distinct difference. The antioxidant activity of Aspergillus were stronger, among which total antioxidant capacity of fL1 was (188.5 ± 0.549) U · mL⁻¹ and the IC₅₀ was 0.3 mg · L⁻¹; the IC₅₀ of strain fL1 was 0.42 mg · L⁻¹ and the total antioxidant capacity of fL9 was (113.63 ± 1.021) U · mL⁻¹, all of them were stronger than the positive control Vit C. The experimental results indicated that endophytic fungi of L. barbarum of Ningxia have a great developing and application prospect for the development of antioxidant agent.