Dewa Ngurah Suprapta
Laboratory of Biopesticide, Faculty of Agriculture, Universitas Udayana. Jl. PB. Sudirman, Denpasar 80238, Bali, Indonesia

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Identification Michelia alba barks extract using Gas Chromatography-Mass Spectrometry (GC-MS) and its antifungal properties to inhibit microbial growth I Made Dira Swantara; I Gusti Agung Gede Bawa; Dewa Ngurah Suprapta; Kadek Karang Agustina; I Gede Rai Maya Temaja
Biodiversitas Journal of Biological Diversity Vol. 21 No. 4 (2020)
Publisher : Society for Indonesian Biodiversity

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/biodiv/d210435

Abstract

Abstract. Swantara IMD, Bawa IGAG, Suprapta DN, Agustina KK, Temaja IGRM. 2020. Identification Michelia alba barks extract using Gas Chromatography-Mass Spectrometry (GC-MS) and its antifungal properties to inhibit microbial growth. Biodiversitas 21: 1541-1550. Fungicides are substances that inhibit the growth or kill the pathogenic fungi. A substance can be categorized as a fungicide if it shows antifungal activity. This activity is resulting from bioactive compounds derived from the secondary metabolites. Michelia alba bark’s extract could inhibit the growth of Curvularia verruculosa, the cause of leaf spot disease on rice. The purpose of this study was to analyze chemical compounds of bark extract which inhibit the growth of C. verruculosa. The extraction of bark metabolites of M. alba was done using methanol as the solvent. The inhibitory test of the extract was carried out by the diffusion well method on Potato Dextrose Agar (PDA) medium. Analysis of chemical compounds of the M. alba extract was carried out in Gas chromatography-mass spectroscopy. The results of inhibitory test found that the M alba bark extract inhibits the C. verruculosa with the inhibition zone as wide as 36 mm in diameter. The majority of chemical compounds identified from the M. alba extract consisted of 10 compounds, namely: Hexadecanoic acid, methyl ester; 4H-tomentosine; 4H-tomentosine (compound isomer 2); 3-hydroxy pregn-4-ene-20-one; Tomentosine; 2-hydroxy tomentosine; Tert-butyl-2-aminophenylcarbamol; 2H-cyclohepta [b] furan-2-one, 3,3a, 4,7,8,8a-hexahydro-7-methyl-3-methylene-6-(2-formil-3-oxobutyl)-; Isoxanthanol and Xanthanol. To conclude, this extract is useful to treat C. verruculosa that causes leaf spot disease on rice.
Potential antagonistic rhizobacteria to control Colletotrichum scovillei, the cause of anthracnose disease in chili pepper Dewa Ngurah Suprapta; Anak Agung Ketut Darmadi; Khamdan Khalimi
Biodiversitas Journal of Biological Diversity Vol. 21 No. 6 (2020)
Publisher : Society for Indonesian Biodiversity

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.13057/biodiv/d210648

Abstract

Abstract. Darmadi AAK, Suprapta DN, Khalimi K. 2020. Potential antagonistic rhizobacteria to control Colletotrichum scovillei, the cause of anthracnose disease in chili pepper. Biodiversitas 21: 2727-2734. Six species of Colletotrichum were identified as the cause of anthracnose disease on Bali Island, Indonesia in 2018. These species were C. scovillei, C. acutatum, C. nymphaeae, C. gloesporioides, C. truncatum, and C. fructicola. Among them, C. scovillei was the most prevalent at 55% of all samples tested. This study was conducted to find potential antagonistic rhizobacteria isolated from various rhizospheres of plants grown in Bali. A total of 1,040 rhizobacteria isolates were tested for their antagonistic activity against the growth of C. scovillei on potato dextrose agar. Results showed that 10 isolates inhibited the growth of C. scovillei by more than 80%. Among these isolates C1 and C7B possessed inhibitory activity at 94.9% and 94.3%, respectively. Molecular identification based on analysis of 16S rRNA gene showed that isolate C1 belonged to the species Paenibacillus polymyxa, whereas isolate C7B was identified as Bacillus siamensis. According to scanning electron serious damage on mycelia of C. scovillei was observed. Wrinkles were observed on mycelia of C. scovillei grown jointly with rhizobacterial isolate C1, whereas no wrinkle was observed on C. scovillei grown solely. Three compounds were detected in the hexane phase of cell-free filtrate P. polymyxa C1, namely, 3-hydroxy-2-butanone and 2,3-butanediol. These compounds may be responsible for antifungal activity against C. scovillei.