GB/T 4789.16-2003Microbiological examination of food hygiene -- Identification of common mycotoxin-producing fungi (English PDF)

6.1 Aspergillus (Aspergillus)

Toxigenic fungi of the genus include Aspergillus flavus, Aspergillus parasiticus, Aspergillus versicolor, Aspergillus nidulans, Aspergillus ochraceus, Aspergillus niger, Aspergillus and black curved rod Mold and so on. These fungi may produce secondary metabolites of Aspergillus flavus toxin, ochratoxin, fumonisin, patulin and so on.

Aspergillus mycelium colorless, transparent or in bright colors, but not dirt color was dark; fertile conidia stalks in a generally perpendicular direction from Specialized foot thick-walled cells give birth, smooth or rough, usually without diaphragm; forming a top top inflated balloon, with different shapes, formed from the surface of the bottle Stems, or to produce stem base, and then forming a bottle stems from the stem base, and finally produce spores stems from the bottle. Conidia unicellular, with a variety of different shapes and Color, smooth or ornamented, connected unbranched chains. From the top of the capsule to conidia chains of different shapes conidia head, revealing different Colour. Some species can form a thick shell cell shape varies by species; some species can be formed sclerotia or sclerotia class structure; there are species produce Sexual stage, to form a closed capsule shell containing asci and ascospores, mostly transparent or with different colors, shapes and ornamentation.

6.1.1 Flavus (A.flavus)

Colonies grew rapidly in Czapek agar, 25 °C 7d diameter 35mm ~ 40mm (~ 70mm), 12d ~ 14d of 55mm ~ 70mm; velvet-like texture is mainly dense, sometimes a little now or a central portion of fluff were flocculent, or are flat to irregular radial grooves; points Endospores more structure, the color is yellow-green to green grass, early lighter, slightly darker, mostly in shallow water near the green after Qin old (LightCressGreen -> CressGreen, R.XXXI), there was a green Osmanthus (MignonetteGreen, R.XXXI), dark green grass (Kronberg'sGreen, R.XXXI) or emerald green (JadeGreen, R.XXXI) were initially some strains are now yellow, nearly strontium yellow (StrontiumYelow, R.

XVI), then green; generally no exudate; some strains formed small or large sclerotia, a lot of time, affecting the appearance of the colony accompanied by exudate, Colorless to light brown, colony reverse colorless to pale brown, sclerotia-producing strain in the back at the sclerotia appear dark brown spots. Meristem First spores spherical head, after radiate, (80 ~) 200 ~ 500 (~ 800) µm, or breaks into a few loose columnar body, there are a few were short column Like those; conidiophores mostly students from the matrix, spore stalks (200 ~) 400 ~ 800 (~ 3000) µm × (4 ~) 9.6 ~ 16 (~ 20) µm, wall Thick, colorless, rough to very rough; top to the flask-shaped capsule nearly spherical diameter (9 ~) 23 ~ 50 (~ 65) µm, most fertile surfaces, only the upper part of the small Fertile; sporulation bilayer structure. terrier group 6.2 ~ 13.2 (19 ~) × 3.2µm × 6µm, bottles Terrier 6.2 ~ 12µm × 2.4 ~ 4µm, some small top Bottle capsule had only stems; conidia mostly spherical or near spherical (2.4 ~) 3.6 ~ 4.8 (~ 6.4) µm, few oval 3.2 ~ 5.2µm × 2.7 ~ 4.2µm, slightly rough to the wall with small spines; some strains produce sclerotia, white at the beginning, after the old brownish black, spherical or near spherical shape, size or Number of different, generally (280 ~) 420 ~ 980µm, shown in Figure 2.

Some strains of Aspergillus flavus produces aflatoxin (Aflatoxins).

Figure 2 Aspergillus flavus spore structures and conidia

6.1.2 Aspergillus parasiticus (A.parasiticus)

Colonies on Czapek agar 25 °C 7d diameter 35mm, 12d ~ 14d50mm ~ 60mm; velvet-like texture, occasional floc bacteria Silk, margin white; spores more structure, the color is dark green, near Cedar Green (CedarGreen, R.VI), after nearly darken old ivy Green (IvyGreen, R.XXXI); there are radial grooves, no effusion, negative colonies pale brown, nearly grayish brown (LightDrab, R.

VLVI). First conidia spherical head, after radiate diameter of 84µm ~ 210µm; Conidiophore born from the matrix, spore stalks 140 ~ 420 (~ 800) µm × 6 ~ 12µm, wall rough now, there are nearly smooth; top sac pestle-shaped or flask-shaped, diameter (13.8 ~) 17 ~ 31µm, most fertile surface; sporulation structure monolayer bottles Terrier 6.2 ~ 10.6µm × 2.4 ~ 4µm, occasionally observed is longer reachable 15µm, with a middle wall; spores spherical or near spherical, (3.6 ~) 4.2 ~ 5.5 (~ 6.4) µm, the wall is slightly rough, with crude sulfur small spines; not See sclerotia, shown in Figure 3.

Aspergillus parasiticus strains can produce aflatoxin.

Figure 3 Aspergillus parasiticus spores and spore structures

6.1.3 Aspergillus versicolor (A.versicolor)

Limitations colonies grown on Czapek agar, 25 °C 7d diameter 15mm ~ 17mm, 10d ~ 12d of 24mm ~ 30mm; texture A velvet-like or flocculent, or coexist with each other or both texture mosaic; colonies uneven, thicker central part of the uplift or depression, or in varying degrees Warping; color vary widely, early white, later showed different degrees of green, close to the green beans, green flower Fu (PoisGreen, Asphodel Green, R.XLI) deep green grapes (DeepGrapeGreen, R.XLI), some strains were malachite green (MalachiteGreen, R.XXX II), olive green (OliveGreen, R.IV) or dark olive-brown (DarkOliveBuff, R.XL), sometimes there are those who are not green, depending on points How many students spore structures; mycelium lanes brown, pink, light brown close to pink (BuffyPink, R.XXLIII) or pale pink cinnamon (PalePinkishCinnamrn, R.XXIX), because different strains varies; sometimes forming spores structure slow; there are radial grooves; infiltration with or without a liquid, nearly colorless or light brown to purple to form droplets or gather into large drops; no smell or slightly musty; colony reverse Yen Color varies, nearly colorless to pale brown, pink, purple or purple-brown rose, the spread of pigment in the matrix; some strains of cells to form a shell, the old culture Yang was visible clumps together into a pale yellow. Conidial head is small, spherical beginning after radiate in diameter (25 ~) 75 ~ 125µm; points Spore stalk stem directly from the matrix by students (45 ~) 150 ~ 300 (~ 500) µm × 4 ~ 8µm, born from aerial hyphae were mostly very short, colorless or slightly with yellow, thick-walled, smooth; vesicle hemispherical, slightly longer or slightly oval, diameter 9 ~ 20µm, about 3/4 of the fertile surface, only a small vesicle Top conidia stalks slightly inflated without significantly; sporulation bilayer structure. terrier group generally 5 ~ 8µm × 2 ~ 3µm, bottle Terrier 6 ~ 8µm × 1.5 ~ 2.5µm; spores spherical or near spherical, green, diameter (2 ~) 2.5 ~ 3.5 (~ 4) µm, rough walls, with small spines; or near-spherical shell cell Spherical diameter of 11µm ~ 20µm, formed together into a large number of yellow clumps Figure 4.

Certain strains of Aspergillus versicolor can produce sterigmatocystin (sterigmatocystin).

Explanation.

1,4 --- sporulation structures;

2 --- incomplete sporulation structures;

3,5 --- conidia;

6 --- shell cells.

Figure 4 Aspergillus versicolor sporulation structures housing cells and spores

6.1.4 Nidulans Emericella (Emericellanidulans)

Anamorph. nidulans (A.nidulans) Colonies on Czapek agar 25 °C 7d diameter of about 25mm, 12d ~ 14d45mm ~ 65mm; velvet-like texture or flocculent, flat Tan or with obscure radiation groove; a large number of spores structure or less, showed different degrees of green, close to the emerald green to green cress (Jade Green -> CressGreen, R.XXXI) or Lincoln green to green flower Fu (LincolnGreen -> AsphodelGreen, R.XLI) and even Pale yellow olive (LightYelowishOlive, R.XXX); some cleistothecia scattered in the meantime, some strains produce large amounts of cleistothecia by Shell surrounded by cells, so that the surface appears yellow or floc particles agglomerate structure, the colonies with brown, nearly deer brown, light brown or bronze (FawnColor, BuffyBrown, R.XL; IsabelaColor, R.XXX); exudate more, or no less, pale reddish brown to purple-brown; no Odor; colony reverse purple brown to purple-brown, brown deer near wine (VinaceousFawn, R.XL), slightly diffused in the matrix. Closed capsule Shell spherical, dark purple, diameter of 100 ~ 250 (~ 300) µm, outside and showed yellow cells surrounded by a shell; ASCUS nearly spherical, 8 ~ 12µm, generally mature in two weeks, while others are immature; ascospores lenticular-shaped, 3.5 ~ 5µm × 3.2 ~ 4µm, with two complete Equatorial crown, with pleats, width of 0.5 ~ 1µm, purple, smooth convex surface. Conidia early to head for the radial spherical diameter of 30 ~ 70µm, old After the short form dense cylindrical, 50 ~ 100µm × 30 ~ 40µm; Conidiophore born from the matrix or aerial hyphae, spore stalks are mostly short (~ 20) 50 ~ 150 (~ 300) µm × 3.5 ~ 6.5µm, slightly curved, with dark brown, smooth wall; hemispherical top bag, the same color and spore stalk stem diameter (5.5 ~) 8 ~ 16µm, the upper half of the surface of fertility; sporulation bilayer structure. terrier group 4 ~ 8µm × 2.5 ~ 3µm, some abnormal strain on the top of the capsule Hypertrophy formed nearly spherical terrier group, bottle Terrier 5 ~ 8µm × 2 ~ 2.5µm; spores spherical (2.5 ~) 3 ~ 4 (~ 4.5) µm, rough, Occasionally nearly smooth; cells mostly spherical shell diameter of 11µm ~ 25µm, few longish or oval 18 ~ 40µm × 12 ~ 24µm, See Figure 5.

Some strains of A. nidulans can generate sterigmatocystin.

Explanation.

1 --- sporulation structures;

2 --- conidia;

3 --- ascospores;

4 --- shell cells.

Sporulation Chart 5 nidulans of Emericella

6.1.5 OTA (A.ochraceus)

Colonies on Czapek agar 25 °C 7d diameter 25mm ~ 35mm, 10d ~ 12d of 35mm ~ 55mm; velvet-like texture or Now a little fluff, flat or with inconspicuous radial grooves; conidia structure dense or sparse, light brown, buckskin color to near cinnamon (Chamois, R.XXX -> Cinnamon, R.XXIX) or yellow ocher (Yelow Ocher, R.XV), there are nearly in bronze (Isabela, R.XXX) who mycelium white; sometimes forming colorless to brown exudate; slightly musty; some strains can form sclerotia, single Alone or in groups; reverse colorless colonies showed different degrees of green or brown to purple-brown. First conidial head is spherical 75µm ~ 200µm, old After up to 500µm, often split into several diverging dense columnar body; conidia stems mostly students from the matrix, spore stalks generally 500 ~ 1500µm × (6 ~) 10 ~ 15µm, a small number of the elderly up to 200µm or more, mostly brown, wall thickness 0.7 ~ 1.5µm, rough; spherical vesicle or nearly spherical, (20 ~) 30 ~ 45 (~ 55) µm, the entire surface of fertile, with occasional small vesicle exists, only the top fertile; sporulation bilayer structure. terrier group (7 ~) 10 ~ 25µm × (2.5 ~) 3 ~ 6µm, bottles Terrier 7 ~ 13µm × 1.5 ~ 3µm; spores are mostly spherical or near spherical diameter (2 ~) 2.5 ~ 3.5 (~ 4) µm, few broadly elliptic, 3 ~ 3.5µm × 2.5 ~ 3µm, wall nearly smooth or rough fine. If the sclerotia Spherical, oval or slightly longer, 500µm ~ 1000µm, early white, later purple-brown, shown in Figure 6.

Some strains can produce ochratoxin (Ochratoxins).

Figure 6 ochratoxin structure of sporulation and conidia

6.1.6 Aspergillus niger (A.niger)

Colonies grew rapidly in Czapek agar, 25 °C 7d diameter is generally 50mm ~ 70mm, a few strains more limited; flat or slightly Centre Projections, regular or irregular radial grooves; or velvet-like texture is slightly flocculent, some strains sometimes infertility overgrowth; conidia A large number of structures, the surface was dark brown to black carbon black; exudate with or without colorless; with or without musty; some strains produce sclerotia, the slant culture Many born when support base; colony reverse colorless or slightly varying degrees of yellow, brown or yellowish green belt. First conidia spherical head to radiation Shot shape, the diameter of 150 ~ 500µm, after the old split into several cylindrical structure, up to 800µm; Conidiophore occurs in the matrix, spore stalks (800) 1500 ~ 3500 (~ 4000) µm × 9 ~ 20µm, wall smooth, with yellow or brown when old; vesicle spherical or near spherical diameter (30 ~) 40 ~ 70 (~ 80) µm, brown when old, the entire surface of fertile; sporulation bilayer structure. Terrier group within a certain time frame with the strain age increase Large increases, (10 ~) 15 ~ 35 (~ 70) µm × (3 ~) 5 ~ 8 (~ 14) µm, when old dark brown; phialides (7 ~) 8 ~ 10 (~ 12) µm × (2-3) after 2.5 ~ 3µm, spores spherical, nearly spherical or old becomes flat transverse diameter of 3 ~ 4.8 (~ 5.4) µm, with sharp or rough wall significantly Warts, irregular ridges or vertical stripes, sometimes a little rough or nearly smooth now are; if sclerotia was spherical or near spherical diameter 700µm ~ 1000µm, or greater, cream to pale yellow, shown in Figure 7.

Certain strains of Aspergillus niger produces fumonisin B group (FumonisinsB).

Figure 7 Aspergillus niger spores and spore structures

6.1.7 Carbon black niger (A.carbonarius)

Colonies grew rapidly in Czapek agar, 25 °C 7d diameter is generally 40mm ~ 60mm, flat; velvet-like texture, and some strains More aerial mycelium; conidia structure a lot, sometimes at the edges or near the edge of the small, pure black spore head; a small amount of a colorless exudate or no; inconspicuous slightly musty; colony reverse pale yellow to brown or yellowish brown to dark brown was central. First conidial head is spherical, Diameter 100 ~ 300 (~ 500) µm, when the old split into several cylindrical structures, with diameters up to 1000µm or larger; Conidiophore occurred in Matrix, spore stalks 2000 ~ 4500 × 20 ~ 30 (~ 40) µm, colorless and transparent, when the old part of the bag near the top with a yellow or light brown, smooth wall; top Spherical or near spherical capsule diameter of 70 ~ 80 (~ 120) µm, old brown belt, the entire surface of fertile; sporulation bilayer structure. Terrier group at a certain time with the range of strain age increases, generally 20 ~ 50µm × (5 ~) 7 ~ 13µm, and the larger up to 80µm, when old brown; bottle Terrier 8 ~ 12 (~ 15) µm × 3 ~ 6 (~ 8) µm; spores spherical, nearly spherical, diameter 6µm ~ 9µm, wall significantly rough, old-peaked after warty or warty, shown in Figure 8. Reported occasionally produce sclerotia.

Some strains can produce carbon black Aspergillus fumonisin and ochratoxin.