Zhou et al. 2023 — Arsenic and elemental profile in new toxic Inosperma mushroom species from tropical China
This study described a new toxic mushroom species, Inosperma wuzhishanense, from tropical China (Hainan Province), characterized by ICP-MS elemental profiling across 24 elements. The primary purpose is taxonomic description and muscarine toxicity assessment, but the paper reports high arsenic concentration in the mushroom: total arsenic was 36.76 ± 0.43 mg/kg (dry weight), the highest toxicity-concern element among the heavy metals detected. This makes the paper relevant to the wiki as a food-safety data point for wild mushrooms as a food source, given that Inosperma species are consumed in some communities despite their toxicity.
Key numbers
- Arsenic in Inosperma wuzhishanense: 36.76 ± 0.43 mg/kg DW (highest heavy metal concentration detected)
- Total elements profiled by ICP-MS: 24
- Muscarine content: 4,359.79–7,114.03 mg/kg in stipe; 2,748.37–4,491.35 mg/kg in pileus; 2,301.36–2,775.90 mg/kg in lamellae
Species context: Inosperma (Inocybaceae) is a genus of approximately 86 species; Old World tropical clade 2 species are mainly distributed in tropical Asia, known to cause muscarine-poisoning incidents.
Methods (brief)
Dried basidiomata collected from Wuzhishan City, Hainan Province, tropical China. ICP-MS for elemental analysis (24 elements; specific instrument and sample digestion protocol described in full text Section 2.3). UPLC-MS/MS (Waters ACQUITY UPLC I-Class Plus/Xevo TQ-XS) for muscarine quantification. Morphological and multi-locus phylogenetic identification (ITS, nrLSU, RPB2). All element concentrations reported as dry weight.
Implications
Certification: Wild mushrooms are a known hyperaccumulator of arsenic and other heavy metals (especially in contaminated soils); 36.76 mg/kg DW in this tropical species is high even for mushrooms. For HMT&C purposes, wild-harvested mushroom ingredients warrant separate risk-assessment from cultivated mushrooms.
Courses: Useful example of hyperaccumulation in fungi; the distinction between organic arsenic (less toxic, typical of seafood) and inorganic arsenic (more toxic) is relevant here — the paper reports total As without speciation.
App: Wild mushroom ingredient flag: elevated total As is documented in Inosperma and related genera; speciation data are not available for this species.