Abstract. ‘Aini K, Elfita, Widyajanti H, Setiawan A, Kurniawati AR. 2021. Antibacterial activity of endophytic fungi isolated from the stem bark of jambu mawar (Syzygium jambos). Biodiversitas 23: 521-532. Syzygium jambos (jambu mawar) is widely used in South Sumatra as a traditional medicine to treat various diseases, including pathogenic bacterial infections. Literature studies report that parts of S. jambos have been used worldwide for treating diarrhea accompanied by fever, dysentery, sore throat, diabetes, and other infectious diseases. Endophytic fungi isolated from medicinal plants have high diversity, and the biological activity of their secondary metabolites is associated with their host. Therefore, this study aimed to determine the diversity of endophytic fungi from the stem bark of S. jambos and the antibacterial activity of secondary metabolites of endophytic fungi. Fungal isolates with high antibacterial activity were identified to obtain fungal species, and the structure of their compounds was determined. The disc diffusion method carried the antibacterial activity test against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Salmonella typhi) bacteria. Characteristics of endophytic fungi were identified microscopically and macroscopically. Active endophytic fungi were identified by molecular analysis of the internal transcribed region (ITS) of the ribosomal DNA. Isolation of antibacterial compounds using chromatographic techniques and determination of chemical structures using spectroscopy was performed. Eight endophytic fungi were obtained from the stem bark of S. jambos, namely SJ1–SJ8. The endophytic fungus SJ6 showed the highest activity and base on phylogenetic analysis, was identified as Fusarium verticillioides. Pure compounds isolated as yellowish-white solids showed good antibacterial activity against S. aureus and S. typhi with minimum inhibitory concentration values of 64 g/mL each. Based on 1D and 2D nuclear magnetic resonance spectroscopic analysis, compound 1 was identified as 3-hydroxy-4-(hydroxy(4-hydroxyphenyl)methyl)dihydrofuran-2-on.

Abstract. ‘Aini K, Elfita, Widjajanti H, Setiawan A. 2022. Diversity and antibacterial activity of endophytic fungi isolated from the medicinal plant of Syzygium jambos. Biodiversitas 23: 2981-2989. Currently, antimicrobial resistance is one of the most important threats to global public health. This is due to the various mechanisms of antimicrobial resistance. Thus, the need for new sources of bioactive compounds outside conventional antibiotics is a top priority. This investigation evaluated the diversity and antibacterial activities of endophytic fungi isolated from the leaves and root bark of jambu mawar (Syzygium jambos (L.) Alston). The endophytic fungi were grown on PDA media, and their antibacterial activities were tested using the Kirby-Bauer method on two Gram-positive and two Gram-negative bacteria. A total of 10 (SJD1-SJD10) and 11 isolates (SJA1-SJA11) of endophytic fungi were identified from the leaves and root bark of S. jambos, respectively. Among them, SJA8 isolate exhibited strong antibacterial activity. Based on morphological characterization and phylogenetic tree analysis, SJA8 was identified as Pleiocarpon livistonae. Isolation and identification of pure compounds from the fungi may reveal potential candidates for new antibiotic substances.

Abstract. Widjajanti H, Elfita, Sari MT, Hidayati N, Hariani PL, Setiawan A. 2023. Diversity and antioxidant activity of endophytic fungi isolated from salam (Syzygium polyanthum). Biodiversitas 24: 3051-3062. Salam (Syzygium polyanthum (Wight) Walp.) is a medicinal plant from the family Myrtaceae. The leaves are used as a spice and treat diseases such as diabetes mellitus, hypertension, ulcers, diarrhea, gastritis, and skin. This study aimed to determine endophytic fungi's diversity and antioxidant activity in the S. polyanthum plant. In addition, the distribution of endophytic fungi found on S. polyanthum was compared to that of previously reported endophytic fungi on other species of Syzygium. The distribution pattern of these endophytic fungi is needed to determine the presence of potential endophytic fungi that can live in host plants of the same genus. The endophytic fungi were isolated from fresh root bark, stem bark, and leaf tissues of S. polyanthum. The endophytic fungi were identified morphologically to determine their level of diversity; their extract was then tested for their antioxidant activity using the DPPH method. The extract that showed the highest antioxidant activity was identified molecularly. A total of 18 endophytic fungi were obtained from S. polyanthum, including seven isolates from root bark (HSA1–HSA7), four isolates from stem bark (HSB1–HSB4), and seven isolates from leaves (HSD1–HSD7). The morphological identification showed seven genera scattered in all investigated parts: Trichoderma, Penicillium, Aspergillus, Pythium, Papulaspora, Pythiogeton, and Clonostachys. The HSD5 isolate showed the best antioxidant activity, and the molecular identification confirmed this isolate as Clonostachys rosea. The comparison of the distribution of endophytic fungi isolated from S. polyanthum to endophytic fungi isolated from the host genus Syzygium showed that endophytic fungi of three genera, namely Clonostachys, Papulaspora, and Pythiogeton, are specifically found on S. polyanthum. In addition, those of four other genera, namely Trichoderma, Aspergillus, Penicillium, and Pythium, are found on other species of Syzygium.