Background
Methods
Chemicals and reagents
Samples collection
Name of Samples | No. of samples | Fungal speciesa
| |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
A. flavus
|
A. versicolor
|
A. aculeatus
| Other Asper-gillus spp. |
Euro-tium spp. |
Penic-illium spp. |
Clados-porium spp |
Fusa-rium spp. | Others | Total | ||
Bulbus Fritillariae cirrhosae
| 3 | -b
| – | – | – | 1 | 2 | – | – | 1 | 4 |
Cortex Eucommiae
| 3 | – | – | – | – | – | 2 | – | – | 1 | 3 |
Cortex Magnoliae officinalis
| 3 | – | – | – | 0 | 1 | – | – | – | 1 | 2 |
Flos Carthami
| 3 | 2 | – | – | 2 | 1 | 2 | – | – | 6 | 13 |
Flos Lonicerae japonicae
| 3 | – | – | – | – | 1 | 2 | – | – | 0 | 3 |
Fructus Lycii
| 3 | 1 | 1 | – | 1 | – | – | – | – | 4 | 7 |
Herba Andrographis
| 3 | – | 1 | – | 3 | 4 | 5 | 2 | – | 3 | 18 |
Radix Angelicae sinensis
| 3 | – | – | 1 | 1 | 1 | 3 | – | 1 | – | 7 |
Radix Astragali
| 3 | – | – | – | 3 | – | 2 | 3 | – | 4 | 12 |
Radix Codcnopsitis Pilosulas
| 3 | – | – | 1 | – | – | 5 | – | 1 | 1 | 8 |
Radix et Rhizoma Glycyrrhizae
| 3 | – | 2 | 1 | 2 | – | 2 | 1 | 1 | 6 | 15 |
Radix Notoginseng
| 3 | – | 1 | – | 1 | – | 2 | – | – | 2 | 6 |
Radix Panacis quinquefolii
| 3 | – | – | – | – | – | 3 | 2 | – | 6 | 11 |
Radix Pseudostellariae
| 3 | – | 1 | – | – | – | 3 | 1 | – | – | 5 |
Semen Armeniacae amarae
| 3 | – | 2 | – | 2 | 5 | 2 | 1 | – | – | 12 |
Total | 45 | 3 | 8 | 3 | 14 | 14 | 35 | 10 | 3 | 36 | 126 |
Isolation of the fungi
Morphological observation
Molecular identification by ITS primers
Primer name | Primer sequence | Amplification product (bp) | Annotation | Gene targeted |
---|---|---|---|---|
Wen1-F | 5′–TCCAACCTCCCACCCGTGTTTA–3′ | 400 | This study | ITS1-5.8S-ITS2 |
Wen1-R | 5′–AAGCCCCTACGCTCGAGGA–3′ | |||
ITS1 | 5′–TCCGTAGGTGAACCTGCG–3′ | 500 ~ 700 | [32] | |
ITS4 | 5′–TCCTCCGCTTATTGATATGC–3′ |
Mycotoxin-producing potential analysis
Mycotoxin | RT (min) | Precursor ion (m/z) | Product ions (m/z) | Collision energy (eV) | LOD (ng/L) |
---|---|---|---|---|---|
Aflatoxin B1
| 10.20 | 313 [M + H]+
| 285/241 | 23/37 | 5.20 |
Aflatoxin B2
| 9.82 | 315 [M + H]+
| 287/259 | 27/31 | 6.30 |
Aflatoxin G1
| 9.41 | 329 [M + H]+
| 243/200 | 27/45 | 10.60 |
Aflatoxin G2
| 8.96 | 331 [M + H]+
| 313/245 | 26/30 | 5.80 |
Ochratoxin A | 13.22 | 404 [M + H]+
| 239/358 | 25/15 | 25.00 |
Sterigmatocystin | 13.44 | 325 [M + H]+
| 281/310 | 36/25 | 1.56 |
Statistical analysis
Results and discussion
Fungal contamination
Mycotoxigenic potentials of the fungal isolates
Fungi | Source | No. of strains isolated | No. of positive strains | Toxin productiona
|
---|---|---|---|---|
A. flavus
| Flos Carthami
| 2 | 0 | –b
|
A. flavus
| Fructus Lycii
| 1 | 1 | AFB1, AFB2
|
A. versicolor
| Radix et Rhizoma Glycyrrhizae
| 2 | 2 | ST |
A. versicolor
| Semen Armeniacae amarae
| 2 | 1 | ST |
A. versicolor
| Herba Andrographis
| 1 | 1 | ST |
A. versicolor
| Radix Pseudostellariae
| 1 | 1 | ST |
A. versicolor
| Fructus Lycii
| 1 | 1 | ST |
A. versicolor
| Radix Notoginseng
| 1 | 0 | – |
A. aculeatus
| Radix et Rhizoma Glycyrrhizae
| 1 | 1 | OTA |
A. aculeatus
| Radix Codcnopsitis pilosulas
| 1 | 1 | OTA |
A. aculeatus
| Radix Angelicae sinensis
| 1 | 1 | OTA |