Pichia anomala facts for kids

Pichia anomala is a tiny living thing, a type of fungus that belongs to a group called ascomycetes. These fungi are often called yeasts. P. anomala can act as a natural protector, helping to stop other unwanted fungi or molds from growing. This is known as biocontrol.

However, if there's too much of it, P. anomala can also cause food to spoil. People use this yeast in many ways. It helps in making wine and keeps grain safe when stored in airtight containers. It can even protect apples and grapevines from harmful molds. Scientists have recently given P. anomala a new name: Wickerhamomyces anomalus.

What Makes Pichia anomala Special?

Pichia anomala is different from some other types of Pichia yeast. It can handle very high amounts of sugar or salt. This ability is called high osmotolerance. It also has special ways of using sugar.

How It Uses Sugar

P. anomala can ferment sucrose, which is common table sugar. It can also use raffinose, another type of sugar.

This yeast does not show the "Crabtree effect." This means it keeps breathing oxygen even when there's a lot of sugar around. Instead, it shows the "Pasteur effect." This means it uses less sugar when oxygen is available.

Products Made by P. anomala

Pichia anomala can create several interesting substances depending on its environment.

Products Without Oxygen

When there is no oxygen, a process called anaerobiosis happens. In this situation, P. anomala mainly produces ethanol. Ethanol is a type of alcohol.

Products With Oxygen

When oxygen is present, or when oxygen is limited, P. anomala can make other things:

• Acetate: This is a type of acid. It's made when the yeast is breathing or when it's doing both breathing and fermenting.
• Ethyl acetate: This substance has a fruity smell. P. anomala makes it from glucose when there isn't much oxygen.
• Other Volatiles: It can also produce other small, smelly compounds. These include ethyl propanoate, phenyl ethanol, and 2-phenylethyl acetate.

Products Under Stress

When P. anomala is under stress, like having too much sugar or salt (osmotic stress) or not enough oxygen, it can produce:

• Glycerol: A sweet-tasting liquid.
• Arabinitol: Another type of sugar alcohol.
• Trehalose: A sugar that helps protect cells from stress.