JOURNAL OF DEGRADED AND MINING LANDS MANAGEMENT ISSN: 2339-076X, Volume 1, Number 2 (January 2014): 63-68 Research Article Potential use of soil-born fungi isolated from treated soil in Indonesia to degrade glyphosate herbicide N. Arfarita1*, T. Imai 2, B. Prasetya3 1 Faculty of Agriculture, Malang Islamic University, Jl. M.T. Haryono, Malang 65144, Indonesia 2 Division of Environmental Science and Engineering, Graduate School of Science and Engineering, Yamaguchi University, Yamaguchi 755-8611, Japan 3 Faculty of Agriculture, Brawijaya University, Jl. Veteran, Malang 65145, Indonesia. * Corresponding author: [email protected] Abstract: The glyphosate herbicide is the most common herbicides used in palm-oil plantations and other agricultural in Indonesial. In 2020, Indonesian government to plan the development of oil palm plantations has reached 20 million hectares of which now have reached 6 million hectares. It means that a huge chemicals particularly glyphosate has been poured into the ground and continues to pollute the soil. However, there is no report regarding biodegradation of glyphosate-contaminated soils using fungal strain especially in Indonesia. This study was to observe the usage of Round Up as selection agent for isolation of soil-born fungi capable to grow on glyphosate as a sole source of phosphorus. Five fungal strains were able to grow consistently in the presence of glyphosate as the sole phosphorus source and identified as Aspergillus sp. strain KRP1, Fusarium sp. strain KRP2, Verticillium sp. strain KRP3, Acremoniumsp. strain GRP1 and Scopulariopsis sp. strain GRP2. This indicates as their capability to utilize and degrade this herbicide. We also used standard medium as control and get seventeen fungal strains. The seventeen fungal strains were identified as species of Botrytis, Fusarium, Aspergillus, Penicillium, Verticillium, Trichoderma and Paecilomyces. These results show the reduction in the number of fungal strains on solid medium containing glyphosate. Of the five isolated fungal species, Verticillium sp. strain KRP3 and Scopulariopsis sp. strain GRP2 were selected for further study based on their highest ratio of growth diameter. This study indicates that treatment of soil with glyphosate degrading fungus would be useful in some areas where this herbicide is extensively used. Keywords: biodegradation, glyphosate, Scopulariopsis, Verticillium. Introduction The excessive use and large scale synthesis of glyphosate cause a number of environmental Glyphosate was introduced in 1974 for non- problems as reported by Buffin and Jewell (2001). selective weed control and sales took off in the Glyphosate is toxic to soil organisms and late 1990s, after Monsanto created its brand of beneficial arthropod predators. Penaloza-Vazquez Roundup, frequently sold under the brand name et al. (1995) reported that glyphosate remains Roundup. Roundup is the most common unchanged in the soil for varying lengths of time, herbicides used in palm-oil plantations and other because of its adsorption on clay particles and agricultural. Indonesia is the second producer of organic matter present in the soil. This condition palm oil after Malaysia, together with a total makes this herbicide very persistent in soils and production of 80% of the total world production sediments. Factually, glyphosate herbicide has of palm oil. In 2020, Indonesian government to met a success commercially as an effective plan the development of oil palm plantations has herbicide. This success, also supported by the reached 20 million hectares of which now have statement as environmentally friendly, has reached 6 million hectares. It means that a huge encouraged extensive studies on its chemicals particularly glyphosate has been poured biodegradation by soil microorganisms. into the ground and continues to pollute the soil. www.jdmlm.ub.ac.id 63 Potential use of soil-born fungi isolated from treated soil to degrade glyphosate herbicide Glyphosate’s primary route of decomposition in Chemical) was purchased from a local store in the environment is through microbial degradation. Ube, Yamaguchi, Japan. All other chemicals The herbicide is inactivated and biodegraded by were of the highest purity commercially available. soil microbes at rates of degradation related to Isolation of fungal strains microbial activity in the soil and factors that affect this activity (Eriksson, 1975). The biological Soil samples were processed in an isolation degradation process is carried out under both process using direct inoculation of screened aerobic and anaerobic conditions by soil immersion plate, containing standard Rose Bengal microorganisms. Rates of decomposition depend Agar C (RBAC) which consisted of 5 g of soy on soil and microbial population types. peptone, 10 g of glucose, 1 g of KH2PO4, 0.5 g of Studies of glyphosate degrading microbia MgSO4.7H2O, 0.05 g of Rose Bengal, 15 g of agar have involved selection and isolation of pure and 0.1 g of chloramphenicol at pH 5.7. Modified microbial culture strains with enhanced or novel RBAC was prepared same as description on detoxification capabilities for potential uses in standard RBAC however KH2PO4 was replaced biodegradation of polluted soil and water. The by glyphosate herbicide (RoundUp) on equivalent available reference on the microbial degradation concentration to the field application rate (7.2 of glyphosate is wide spread among bacteria. mg/ml). The plates were incubated for 5 days at However, the study on biodegradation of 25ºC. Individual strains were isolated based on the glyphosate by fungal species is lacking. Only the distinct of the colony morphology. Young active degradation process by Penicillium (Bujacz et al., of fungal mycelia from each strain was purified 1995; Pothuluri et al., 1998; Klimek et al., 2001) using single spore technique. The above steps and Fusarium (Sudol and Krzyśko-Lupicka, were repeated by re-isolation of fungal mycelia on 2005) have been extensively characterized. modified Rose Bengal Agar C. The selected Interestingly, all of the above isolates were able to fungal strains that consistently grew on modified utilize glyphosate as sole source of phosphorus. RBAC were re-streaked on Potato Dextrose Agar In this study we report the use of glyphosate (PDA). herbicide as screening agent of the sole phosphorus source for isolation of soil-born fungi Taxonomic Identification from treated soil in Indonesia. We also observed the growth response of the fungi in broth medium Individual strains isolated from modified RBAC containing glyphosate as their characteristics of were then cultivated on Malt Extract Agar, PDA glyphosate degradation process. and Czapek Agar for their taxonomic Isolation of fungal strains had been investigation based on their morphology of colony previously obtained from other soil samples and cell. Identifications were conducted using which had been previously exposed by glyphosate identification keys and methods following (Krzyśko-Lupicka and Orlik, 1997) and also from Domsch et al. (1993). industrial activated sludge (Hallas et al., 1988). However, there is no report regarding to soil-born Ratio of growth diameter fungi from treated soil in Indonesia. Ratio of growth diameter was observed to find out two strains which have the highest capability of Materials and Methods growth on modified RBAC containing glyphosate as the sole source of phosphorus as described in Soil “isolation of fungal strains”. The ratio of growth Soil samples were obtained from two areas of diameter was determined based on colony fruit and vegetable plantations at Malang, East diameter on PDA as control plate. The Java, Indonesia. This area has been exposed by measurement of mycelial growth was performed glyphosate for more than 10 years with twice a according to the method described by Shim et al. year in application. They were collected from (2005). A 5 mm diameter plug of 5 days old depths of 0-15 cm from four sites, placed in sterile cultures of fungal strain from PDA culture was polyethylene bag and mixed well. All samples cut with cork borer and then placed in the center were transported immediately to the laboratory of each agar plate at pH 6, incubated for 7 days at and stored at 4ºC in refrigerator. 27ºC in three replicate. The ratio of growth diameter = [M/S], where Chemicals M is growth diameter on treatment (modified RBAC), and S is growth diameter on control Glyphosate known as Roundup® (containing 480 (PDA) g active ingredient/L of glyphosate, Nissan Journal of Degraded and Mining Lands Management 64 Potential use of soil-born fungi isolated from treated soil to degrade glyphosate herbicide Growth profile able to grow consistently on modified RBA-C, however on standard medium resulted seventeen The observation of growth profile was examined fungal strains (Table 1). These results show the in 250 ml Erlenmeyer flask containing 100 ml reduction in the number of fungal strains on solid Czapek broth medium, which was inoculated with medium containing glyphosate. Five fungal spore suspension (2 x 107 spores/mL), and pH of strains isolated from solid medium containing the medium was maintained at 5.6-6. Each liter of glyphosate were then identified as Aspergillus sp. Czapek broth medium consisted of 30 g of strain KRP1, Fusarium sp. strain KRP2, sucrose, 3 g of NaNO , 1g of K HPO ,0.25 g of 3 2 4 Verticillium sp. strain KRP3, Acremonium sp. MgSO .7H O, 0.5 g of KCl and 10 mg of FeSO . 4 2 4 strain GRP1 and Scopulariopsis sp. strain GRP2. The same medium was removed in K HPO as