Fusarium oxysporum LBKURCC41 is an endophytic isolated from Dahlia variabilis tubers from Padang Luar, West Sumatra. The strain was fermented using modified Huangs’ media, ie using corn as a carbon source for 15 days. The purpose of this study is to isolate secondary metabolites from LBKURCC41 strains. The filtrate from the liquid fermentation media was extracted using EtOAc:MeOH at a ratio of 95:5 to 50:50. Purification using fast chromatography was performed with a mixture of BAW (5:1:4). The structure was elucidated by, FTIR and 1H NMR spectroscopy. The isolate was identified as a sesquiterpenoid, with weak antimicrobial activity against E.coli and S. aureus with 2.1 mm clear zone and concentration of 10 ppm.

Endophytic fungus LBKURCC40 isolated from dahlia tubers (Dahlia variabilis) was morphologically and molecularly identified. Molecular identification was carried out using ITS4 and ITS5 primers, furthermore, the homology level of LBKURCC40 isolates was checked using BLAST program and the suitability of BLAST results was tested with the TrichOKEY program. The results of showed that LBKURCC40 isolates were identified as Trichoderma asperellum with a homology level of 99%. Phylogenetic analysis was carried out with N-J tree bootstrap test with 10,000 repetitions, and LBKURCC40 isolate was obtained to have the closest kinship to Trichoderma asperellum strain Tr266B.

Abstract. Saryono, Novianty R, Suraya N, Piska F, Devi S, Pratiwi NW, Ardhi A. 2022. Molecular identification of cellulase-producing thermophilic fungi isolated from Sungai Pinang hot spring, Riau Province, Indonesia. Biodiversitas 23: 1457-1465. Thermostable cellulolytic enzymes have become a subject of interest in industrial processes due to their ability to degrade cellulosic polysaccharides at elevated temperatures produced by microorganisms such as fungi and bacteria. In the present study, cellulase-producing thermophilic fungi were isolated and identified from Sungai Pinang hot spring, Riau Province, Indonesia. Morphological identification was carried out by macroscopic and microscopic observations. The ability of the thermophilic fungi to produce cellulase was determined using the clear zone test on carboxymethyl cellulose medium with a congo red staining. Isolate with the highest activity was identified molecularly using universal primers ITS1F and ITS4R. The results showed 19 isolates were morphologically identified as Aspergillus sp. and Penicillium sp. Based on qualitative testing, 3 of the19 isolates showed cellulase activity. The isolate performing the most considerable cellulase was LBKURCC293, which was identified as Aspergillus fumigatus with a cellulase activity of 2.6 x 10-2 IU/mL and a specific cellulase activity 8.0 x 10-3 IU/mg protein after 96 days of incubation.

Abstract. Ginting CN, Piska F, Harmileni, Fachrial E. 2023. Molecular identification of thermophilic bacteria with antimicrobial activity isolated from hot springs in North Sumatra, Indonesia. Biodiversitas 24: 752-758. Microorganisms such as thermophilic bacteria are promising sources of antimicrobial compounds due to their abundance, which has yet to be widely investigated. Therefore, this study aims to identify thermophilic bacteria isolated from natural hot springs, Sidebuk Debuk, in North Sumatra, Indonesia. The bacteria were isolated from sediments and hot springs water. Isolated 10 bacteria were characterized and identified based on their morphological and biochemical properties, which included gelatinase activity, motility, citrate utilization, triple sugar iron agar test, catalase test, cell shape, color, and Gram staining. Antimicrobial activity was tested using the disc diffusion method against Escherichia coli and Staphylococcus aureus. The most potential isolates were identified molecularly by amplification of 16S rRNA genes using universal primers. The sequences result were trimmed and assembled using BioEdit and submitted to BLAST to determine the homology of the bacteria. The isolate ITU9 was identified as Bacillus megaterium and exhibited the best antimicrobial activity with an inhibition zone of 9.5 mm against S. aureus during 72 h of incubation. This research showed that the thermophilic B. megaterium strain ITU9 was successfully isolated from Sidebuk Debuk hot springs and had stable antimicrobial activity for 72 h against E. coli and S. aureus.

Abstract. Nasution SA, Fachrial E, Ginting CN, Liena, Piska F. 2023. Bacteriocin-producing Pediococcus acidilactici BAMA 15 isolated from "naniura" traditional foods in North Sumatra, Indonesia. Biodiversitas 24: 2830-2835. Lactic Acid Bacteria (LAB) have beneficial properties for their hosts, potentially promoting health and balancing the normal gut flora. Meanwhile, bacteriocin is a bacteriostatic polypeptide used as a food preservative. LAB are generally produced from fermented products, such as dengke naniura, a typical Toba Batak food. Therefore, it is estimated that the LAB present in this food has the potential as a probiotic and produces bacteriocin, an antimicrobial polypeptide compound. The purpose of this study was to identify the LAB species found in dengke naniura and to characterize the bacteriocin generated by them. The first study stages included the isolation and biochemical and morphological characterization of LAB. Nine LAB isolates (BAMA 10-11, BAMA 15-20, and BAMA 25) were isolated from the samples. The best strain for use as a probiotic was Pediococcus acidilactici BAMA 15 because its antimicrobial activity against E. coli and S. aureus was 6.44 and 7.53 mm, respectively. The bacteriocin produced has a molecular weight estimated to be ?12 kDa.