title: Potential bioremediation of mercury-contaminated substrate using filamentous fungi isolated from forest soil.
abstract: The use of filamentous fungi in bioremediation of heavy metal contamination has been developed recently. This research aims to observe the capability of filamentous fungi isolated from forest soil for bioremediation of mercury contamination in a substrate. Six fungal strains were selected based on their capability to grow in 25 mg/L Hg(2+)-contaminated potato dextrose agar plates. Fungal strain KRP1 showed the highest ratio of growth diameter, 0.831, thus was chosen for further observation. Identification based on colony and cell morphology carried out by 18S rRNA analysis gave a 98% match to Aspergillus flavus strain KRP1. The fungal characteristics in mercury(II) contamination such as range of optimum pH, optimum temperature and tolerance level were 5.5-7 and 25-35°C and 100 mg/L respectively. The concentration of mercury in the media affected fungal growth during lag phases. The capability of the fungal strain to remove the mercury(II) contaminant was evaluated in 100 mL sterile 10 mg/L Hg(2+)-contaminated potato dextrose broth media in 250 mL Erlenmeyer flasks inoculated with 10(8) spore/mL fungal spore suspension and incubation at 30°C for 7 days. The mercury(II) utilization was observed for flasks shaken in a 130 r/min orbital shaker (shaken) and non-shaken flasks (static) treatments. Flasks containing contaminated media with no fungal spores were also provided as control. All treatments were done in triplicate. The strain was able to remove 97.50% and 98.73% mercury from shaken and static systems respectively. A. flavus strain KRP1 seems to have potential use in bioremediation of aqueous substrates containing mercury(II) through a biosorption mechanism.
authors: Department of Agricultural Engineering, Brawijaya University, East Java, 65145, Indonesia; Division of Environmental Science and Sustainable Engineering, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 755-0097, Japan. Electronic address: evikurniati@ub.ac.id.
authors: Evi
authors: E
authors: Kurniati
authors: Department of Agrotechnology, Malang Islamic University, East Java 65145, Indonesia.
authors: Novi
authors: N
authors: Arfarita
authors: Division of Environmental Science and Sustainable Engineering, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 755-0097, Japan. Electronic address: imai@yamaguchi-u.ac.jp.
authors: Tsuyoshi
authors: T
authors: Imai
authors: Division of Environmental Science and Sustainable Engineering, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 755-0097, Japan.
authors: Takaya
authors: T
authors: Higuchi
authors: Division of Environmental Science and Sustainable Engineering, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 755-0097, Japan.
authors: Ariyo
authors: A
authors: Kanno
authors: Division of Environmental Science and Sustainable Engineering, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 755-0097, Japan.
authors: Koichi
authors: K
authors: Yamamoto
authors: Division of Environmental Science and Sustainable Engineering, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 755-0097, Japan.
authors: Masahiko
authors: M
authors: Sekine
mesh_terms: D001231:Aspergillus flavus / Q000302:isolation & purification* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D008628:Mercury / Q000378:metabolism*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D008628:Mercury
keywords: Aspergillus flavus strain KRP1; biosorption; mercury contaminant