Important Mold/Yeast Genera in Foods

Question 1

+ Septate hyphae; conidia in chains
+ Many are xerophilic
+ Production of mycotoxins

Answer 1

Aspergillus

Question 2

+ Septate hyphae
+ Large ovate or club-shaped conidia in chains
+ Causes brown and black rot of fruits

Answer 2

Alternaria

Question 3

+ Rectangular arthrospores
+ Hyphae dichotomously branched
+ Grows on food-contact equipment and dairy products

Answer 3

Geotrichum

Question 4

+ Spoilage of fruits, vegetables, grains, bread and meat
+ Used in production of special cheeses

Answer 4

Penicillium

Question 5

+ Branched conidiophore
+ Ovate conidia, 2-celled when mature
+ Spoilage of butter and margarine

Answer 5

Cladosporium

Question 6

+ Long stiff conidiophores (branched at ends)
+ Small ovate conidia in grape-like bunches
+Gray rot of apples, grapes, pears, citrus, raspberries, etc.

Answer 6

Botyritis

Question 7

+ Non-septate hyphae
+ Cottony mycelium (loose growth)
+ Brown rot of citrus fruits, pineapple, potatoes

Answer 7

Fusarium

Question 8

+ Non-septate hyphae with rhizoids and stolons
+ Sporangia
+ Sporangiophores in clusters
+ Watery soft rot of apples, pears, grapes, figs

Answer 8

Rhizopus

Question 9

+ Non-septate hyphae
+ No stolons or rhizoids
+ Common on saccharine and starchy foods
+ “Whiskers” on stored meats

Answer 9

Mucor

Question 10

+ Non-septate hyphae
+ Small sporangia on branched structures
+ Grows on refrigerated beef hind quarters

Answer 10

Thamnidium

Question 11

+ Yeast-like mold
+ Produce clusters of acsi
+Uniquely associated with fruit spoil
+ Spoilage of high acid canned foods, canned and bottled fruit, fruit juices, and drinks

Answer 11

Byssochlamys

Question 12

+ Generally unicellular
+ Can grow over a wide range of pH, alcohol, and sugar concentration
+ Some produce ascospores or arthrospores

Answer 12

Yeasts