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The effect of paraquat dichloride and carbosulfan on soil conditions and population dynamic of soil microbes in a cornfield: a case study in Sumedang, West Java Taufikurahman, Taufik; Aryantha, I Nyoman P; Purwasena, Isty Adhitya; Zahra, Muhandinni; Stefania, Marchia; Fitriyani, Azizah Nur Fitriyani
Current Research on Biosciences and Biotechnology Vol. 5 No. 2 (2024)
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/crbb.2024.5.2/BQCGURSN

Abstract

Paraquat dichloride (PC) is one of the herbicides active ingredients that is widely used by farmers to control various types of weeds, while carbosulfan (CS) is one of the insecticide’s active ingredients that is widely used to control various types of insect pests. The objective of this study is to analyze the impact of pesticides for PC and CS on the chemical and physical conditions of the soil and the dynamics of fungi and soil bacteria population in a corn field in Sumedang district, West Java. The experiment took place between August and October, during the dry season, concluding just as the rainy season began. The PC concentrations used were 0 mL/L, 3.33 mL/L, 4 mL/L, 4.66 mL/L and 5.33 mL/L, while the CS concentrations used were 0 mL/L, 0.5 mL/L, 1 mL/L, 1.5 mL/L and 2 mL/L. Soil sampling was conducted before and after the application of pesticides. The total abundance of fungi and bacteria was analyzed using the total plate count (TPC) method. The application of PC to the cornfield slightly decreased soil bulk density from 1.354 g/cm3 to 0.816 g/cm3, while the application of CS slightly increased soil bulk density. A decrease in bulk density is considered positive for the physical conditions of the soil for plant cultivation. In general, the result indicated that the application of PC and CS did not show a significant effect on the chemical characteristics of the soil, and also it did not affect the population of fungi and bacteria. Weather conditions, i.e. dry season (June-September) and rainy season (started from October) seem to affect more on soil conditions as well soil microbial population than the application of the pesticides.
Antibacterial activity of mycelial extract from a local fungus, Sclerotium rolfsii Zahra, Muhandinni; Aryantha, I Nyoman Pugeg; Sukrasno, Sukrasno; Suhardi, Veronica Sri Harjati
Indonesian Journal of Biotechnology Vol 30, No 3 (2025)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijbiotech.108408

Abstract

Mycelium‐to‐sclerotium differentiation in fungi involves not only morphological but also biochemical changes throughout the process, which may contribute to their persistence and be a possible source of bioactive compounds. This study aims to evaluate the antibacterial activity and identify the bioactive compound in the local isolate Sclerotium rolfsii. Fungal culture was grown in media containing potato extract (20 g/L), dextrose (20 g/L), and peptone (5 g/L) for 27 days under static conditions at room temperature. Mycelium, sclerotium and filtrate were collected every three days and extracted with methanol, followed by evaporation and antibacterial screening. Significant activity was observed in day three of mycelial extract, which showed morphology of initial sclerotium formation (MIC 0.39 mg/mL) against B. subtilis and E. coli. An improved extraction method (sequential extraction) was employed for mycelial sample on the third day. N‐hexane and ethyl acetate extracts exhibited stronger activities (0.20 mg/mL). Ergosterol was identified after TLC‐bioautography, radial chromatography, and NMR elucidation analysis. S. rolfsii mycelium (third day‐sclerotial initiation) was found to contain ergosterol, demonstrating strong defense against bacteria, and possibly related to sclerotium‐differentiation metabolites. These findings may pave the way for more extensive studies of sclerotium differentiation as an interesting phenomenon of fungal development and bioactive compound origins.