Yeasts are eukaryotic microorganisms classified in the kingdom Fungi, with about 1,500 species currently described.
• What are differences between yeasts and molds?
• What are differences between yeasts and bacteria?
• Pseudomycellium or pseudohyphae?
• “Pseudohyphae” are distinguished from true hyphae by their method of growth, relative frailty and lack of cytoplasmic connection between the cells.
• Yeast can form pseudohyphae. They are the result of a sort of incomplete budding where the cells remain attached after division.
• True yeast?
• Wild yeast?
• The cellular morphology of the yeast can vary from ovoid to long “sausage” shaped cells.
• The yeast produces large amounts of acetic acid when grown on glucose rich media (Asidogenic).
• They multiply by budding.
• They can use sugars as oxidative or fermentative.
• The most important species is B. intermedius.
– It can grow at as low as 1,8 pH.
– It can cause spoilage of beer, wine, non-alcoholic beverages and pickles.
• Candida genus was first described in 1923.
• Cells do not contain carotenoid pigment.
• Candida means “clear and bright white”
• Some species of this genus play role in fermentation of kefir, cacao, beer, ale and fruit juices.
• Some Candida spp. are commonly found in ground meat and poultry meats.
• While usually living as commensals, some Candida species have the potential to cause disease (aphthae).
• Many of them form films and can spoil foods high in acid and salt.
• Lypolytic Candida lypolytica can spoil butter and oleomargarine.