Biotechnology, physiology and genetics of the yeast Pichia anomala.

The ascomycetous yeast Pichia anomala is frequently associated with food and feed products, either as a production organism or as a spoilage yeast. It belongs to the nonSaccharomyces wine yeasts and contributes to the wine aroma by the production of volatile compounds. The ability to grow in preserved food and feed environments is due to its capacity to grow under low pH, high osmotic pressure and low oxygen tension. A new application of P. anomala is its use as a biocontrol agent, which is based on the potential to inhibit a variety of moulds in different environments. Although classified as a biosafety class-1 organism, cases of P. anomala infections have been reported in immunocompromised patients. On the other hand, P. anomala killer toxins have a potential as antimicrobial agents. The yeast can use a broad range of nitrogen and phosphor sources, which makes it a potential agent to decrease environmental pollution by organic residues from agriculture. However, present knowledge of the physiological basis of its performance is limited. Recently, the first studies have been published dealing with the global regulation of the metabolism of P. anomala under different conditions of oxygenation.