34
Modern Food Microbiology
kefir grains and can be isolated from a wide range of foods, such as dry-cured salami and numerous
fruits. S. cerevisiae rarely causes spoilage.
Schizosaccharomyces. These ascosporogenous yeasts divide by lateral fission of cross-wall formation
and may produce true hyphae and arthrospores. Asci contain from four to eight bean-shaped spores,
and no buds are produced. They are regarded as being only distantly related to the true yeasts. S. pombe
is the most prevalent species; it is osmophilic and resistant to some chemical preservatives.
Torulaspora. Multilateral budding is the method of reproduction with spherical spores in asci. Three
haploid species formerly in the genus Saccharomyces are now in this genus. They are strong fermenters
of sugars, and contain coenzyme Q-6. T. delbrueckii is the most prevalent species.
Trichosporon. These nonascospore-forming oxidative yeasts multiply by budding and by arthroconidia formation. They produce a true mycelium, and sugar fermentation is absent or weak. They are
involved in cacao bean and idli fermentations and have been recovered from fresh shrimp, ground
beef, poultry, frozen lamb, and other foods. T. pullulans is the most prevalent species, and it produces
lipase.
Yarrowia. Formerly Saccharomycopsis, these yeasts belong to the order Endomycetales and they are
common on fruits, vegetables, meats, and poultry. Candida lipolytica is the anamorph, and Y. lipolytica
is the teleomorphic (perfect) stage.
Zygosaccharomyces. Multilateral budding is the method of reproduction, and the bean-shaped ascospores formed are generally free in asci. Most are haploid and they are strong fermenters of sugars.
Z. rouxii is the most prevalent species, and it can grow at an a w of 0.62, second only to Xeromyces
bisporus in its ability to grow at a low a w .
37 Some are involved in shoyu and miso fermentations, and
some are common spoilers of mayonnaise and salad dressing, especially Z. bailii, which can grow at
a pH of 1.8.
37
REFERENCES
1. Ajithkumar, B., V.P. Ajithkumar, R. Iriye, Y. Doi, and T. Sakai. 2003. Spore-forming Serratia marcescens subsp. sakuensis
subsp. nov., isolated from a domestic wastewater treatment tank. Int. J. System. Evol. Microbiol. 53:253–258.
2. Ash, C., F.G. Priest, and M.D. Collins. 1993. Molecular identification of rRNA group 3 bacilli (Ash, Farrow, Wallbanks
and Collins) using a PCR probe test. Antonie van Leeuwenhoek 64:253–260.
3. Beneke, E.S., and K.E. Stevenson. 1987. Classification of food and beverage fungi. In Food and Beverage Mycology, 2d
ed., ed. L.R. Beuchat, 1–50. New York: Kluwer Academic Publishing.
4. Beuchat, L.R., ed. 1987. Food and Beverage Mycology, 2d ed. New York: Van Nostrand Reinhold.
5. Berkeley, R.C.A., and N. Ali. 1994. Classification and identification of endospore-forming bacteria. J. Appl. Bacteriol.
(Symp. Suppl.) 76:1S–8S.
6. Champomier, M.-C., M.-C. Montel, and R. Talon. 1989. Nucleic acid relatedness studies on the genus Carnobacterium
and related taxa. J. Gen. Microbiol. 135:1391–1394.
7. Coenye, T., E. Falsen, B. Hoste, M. Ohl´ en, J. Goris, J.R.W. Govan, M. Gillis, and P. Vandamme. 2000. Description of
Pandoraea gen. nov. with Pandoraea apista sp. nov., Pandoraea pulmonicola sp. nov., Pandoraea pnomenusa sp. nov.,
Pandoraea sputorum sp. nov. and Pandoraea norimbergensis comb. nov. Int. J. System. Evol. Microbiol. 50:887–899.
8. Collins, M.D., P.A. Lawson, A. Willems, J.J. Cordoba, J. Fernandez-Garayzabal, P. Garcia, J. Cai, H. Hippe, and J.A.E.
Farrow. 1994. The phylogeny of the genus Clostridium: Proposal of five new genera and eleven new species combinations.
Int. J. Syst. Bacteriol. 44:812–826.
Modern Food Microbiology
kefir grains and can be isolated from a wide range of foods, such as dry-cured salami and numerous
fruits. S. cerevisiae rarely causes spoilage.
Schizosaccharomyces. These ascosporogenous yeasts divide by lateral fission of cross-wall formation
and may produce true hyphae and arthrospores. Asci contain from four to eight bean-shaped spores,
and no buds are produced. They are regarded as being only distantly related to the true yeasts. S. pombe
is the most prevalent species; it is osmophilic and resistant to some chemical preservatives.
Torulaspora. Multilateral budding is the method of reproduction with spherical spores in asci. Three
haploid species formerly in the genus Saccharomyces are now in this genus. They are strong fermenters
of sugars, and contain coenzyme Q-6. T. delbrueckii is the most prevalent species.
Trichosporon. These nonascospore-forming oxidative yeasts multiply by budding and by arthroconidia formation. They produce a true mycelium, and sugar fermentation is absent or weak. They are
involved in cacao bean and idli fermentations and have been recovered from fresh shrimp, ground
beef, poultry, frozen lamb, and other foods. T. pullulans is the most prevalent species, and it produces
lipase.
Yarrowia. Formerly Saccharomycopsis, these yeasts belong to the order Endomycetales and they are
common on fruits, vegetables, meats, and poultry. Candida lipolytica is the anamorph, and Y. lipolytica
is the teleomorphic (perfect) stage.
Zygosaccharomyces. Multilateral budding is the method of reproduction, and the bean-shaped ascospores formed are generally free in asci. Most are haploid and they are strong fermenters of sugars.
Z. rouxii is the most prevalent species, and it can grow at an a w of 0.62, second only to Xeromyces
bisporus in its ability to grow at a low a w .
37 Some are involved in shoyu and miso fermentations, and
some are common spoilers of mayonnaise and salad dressing, especially Z. bailii, which can grow at
a pH of 1.8.
37
REFERENCES
1. Ajithkumar, B., V.P. Ajithkumar, R. Iriye, Y. Doi, and T. Sakai. 2003. Spore-forming Serratia marcescens subsp. sakuensis
subsp. nov., isolated from a domestic wastewater treatment tank. Int. J. System. Evol. Microbiol. 53:253–258.
2. Ash, C., F.G. Priest, and M.D. Collins. 1993. Molecular identification of rRNA group 3 bacilli (Ash, Farrow, Wallbanks
and Collins) using a PCR probe test. Antonie van Leeuwenhoek 64:253–260.
3. Beneke, E.S., and K.E. Stevenson. 1987. Classification of food and beverage fungi. In Food and Beverage Mycology, 2d
ed., ed. L.R. Beuchat, 1–50. New York: Kluwer Academic Publishing.
4. Beuchat, L.R., ed. 1987. Food and Beverage Mycology, 2d ed. New York: Van Nostrand Reinhold.
5. Berkeley, R.C.A., and N. Ali. 1994. Classification and identification of endospore-forming bacteria. J. Appl. Bacteriol.
(Symp. Suppl.) 76:1S–8S.
6. Champomier, M.-C., M.-C. Montel, and R. Talon. 1989. Nucleic acid relatedness studies on the genus Carnobacterium
and related taxa. J. Gen. Microbiol. 135:1391–1394.
7. Coenye, T., E. Falsen, B. Hoste, M. Ohl´ en, J. Goris, J.R.W. Govan, M. Gillis, and P. Vandamme. 2000. Description of
Pandoraea gen. nov. with Pandoraea apista sp. nov., Pandoraea pulmonicola sp. nov., Pandoraea pnomenusa sp. nov.,
Pandoraea sputorum sp. nov. and Pandoraea norimbergensis comb. nov. Int. J. System. Evol. Microbiol. 50:887–899.
8. Collins, M.D., P.A. Lawson, A. Willems, J.J. Cordoba, J. Fernandez-Garayzabal, P. Garcia, J. Cai, H. Hippe, and J.A.E.
Farrow. 1994. The phylogeny of the genus Clostridium: Proposal of five new genera and eleven new species combinations.
Int. J. Syst. Bacteriol. 44:812–826.