Overview
ISO/TS 10832:2009 specifies a standardized spore germination bioassay to assess the effects of pollutants on the arbuscular mycorrhizal fungus Glomus mosseae. The method is an acute, direct toxicity test designed to evaluate how chemical substances, contaminated soils, wastes, soil–waste mixtures and sludges affect spore germination - an early and ecologically relevant step in mycorrhizal symbiosis that supports plant nutrition and sustainable agriculture.
Key topics and technical requirements
- Test organism: Glomus mosseae (mature spores; BEG 12). Spores/sporocarps are stored in distilled water at 4 °C (sporocarps used within 1 week, spores within 2 days).
- Test principle: Spores are placed between two nitrocellulose membranes (a “sandwich”) and exposed to test mixtures; germination is scored after 14 days.
- Controlled conditions: Incubation in the dark at (24 ± 2) °C.
- Control and substrates: Use inert control substrate (sand or artificial soil per ISO 11268-1). Control germination must exceed 75% for validity.
- Endpoints and calculations: Percent germinated spores and inhibition concentrations (ICx); IC50 (50% spore-germination inhibition) is the primary reporting metric. Example ring-test results for cadmium nitrate (reference substance) gave IC50 values in sand between 0.15 and 1.7 mg·kg−1.
- Reagents and staining: Trypan blue staining is used to visualize fungal structures (recipe specified in the TS).
- Apparatus: 9 cm sterile Petri dishes, slide frames (24 × 36 mm), binocular microscope (~32×).
- Reporting and validity: Test setup, concentrations, culture conditions, raw counts, calculations (ICx), and conformity to validity criteria are required.
Applications and users
Practical uses of ISO/TS 10832:2009 include:
- Environmental risk assessment of contaminated soils, sludges and wastes.
- Ecotoxicology labs evaluating pollutant impacts on beneficial soil microbes.
- Regulatory bodies and environmental consultants assessing sludge reuse and land application safety.
- Agricultural researchers and soil microbiologists studying pollutant effects on plant–fungus symbioses and sustainable agriculture practices.
This test complements plant-based assays by targeting a key microbial bioindicator - mycorrhizal fungi - that influence crop health, nutrient uptake and resistance to stress.
Related standards
Normative and complementary references cited in the TS include:
Keywords: ISO/TS 10832:2009, soil quality, mycorrhizal fungi, Glomus mosseae, spore germination test, IC50, ecotoxicology, contaminated soils, sewage sludge, sustainable agriculture.