Journal of Integrative Agriculture · 2015 · 19 citations · 27 references
AgricultureMicrobiologySoil SciencesSoil BiologySoil MicrobiologySoil ScienceArsenic ToxicologyContaminated Soil CharacterizationContaminated Soil RemediationSoil PollutionSoil ToxicologyArsenic BioaccumulationArsenic RemediationArsenic Resistance MechanismsContaminated SoilEnvironmental Arsenic ContaminationInoculationInoculation Biology
Fungi capable of arsenic (As) accumulation and volatilization are hoped to tackle As-contaminated environment in the future. However, little data is available regarding their performances in field soils. In this study, the chlamydospores of Trichoderma asperellum SM-12F1 capable of As resistance, accumulation, and volatilization were inoculated into As-contaminated Chen-zhou (CZ) and Shimen (SM) soils, and subsequently As volatilization and availability were assessed. The results indicated that T. asperellum SM-12F1 could reproduce well in As-contaminated soils. After cultivated for 42 days, the colony forming units (cfu) of T. asperellum SM-12F1 in CZ and SM soils reached 1010−1011 cfu g−1 fresh soil when inoculated at a rate of 5.0%. Inoculation with chlamydospores of T. asperellum SM-12F1 could significantly accelerate As volatilization from soils. The contents of volatilized As from CZ and SM soils after being inoculated with chlamydospores at a rate of 5.0% for 42 days were 2.0 and 0.6 μg kg−1, respectively, which were about 27.5 and 2.5 times higher than their corresponding controls of no inoculation (CZ, 0.1 μg kg−1; SM, 0.3 μg kg−1). Furthermore, the available As content in SM soils was decreased by 23.7%, and that in CZ soils increased by 3.3% compared with their corresponding controls. Further studies showed that soil pH values significantly decreased as a function of cultivation time or the inoculation level of chlamydospores. The pH values in CZ and SM soils after being inoculated with 5.0% of chlamydospores for 42 days were 6.04 and 6.02, respectively, which were lowered by 0.34 and 1.21 compared with their corresponding controls (CZ, 6.38; SM, 7.23). The changes in soil pH and As-binding fractions after inoculation might be responsible for the changes in As availability. These observations could shed light on the future remediation of As-contaminated soils using fungi.
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