Ambient pH regulates secretion of lipases in Malassezia furfur

Area of Science:

• Microbiology
• Dermatology
• Medical Mycology

Background:

• Malassezia yeasts are lipophilic commensals found on skin, associated with skin disorders, and can cause bloodstream infections.
• Ambient pH is a critical environmental factor influencing microbial physiology and metabolism.
• The specific impact of pH on Malassezia physiology, particularly lipase activity and gene expression, remains largely uncharacterized.

Purpose of the Study:

• To investigate the effect of ambient pH on the physiology of Malassezia furfur.
• To determine the impact of pH on lipase expression and activity in M. furfur.
• To assess the influence of pH on M. furfur morphology and gene transcription.

Main Methods:

• Culturing Malassezia furfur across a range of pH conditions (pH 4-10).
• Measuring extracellular and intracellular lipase activity.
• Utilizing quantitative PCR (qPCR) to analyze the expression of lipase genes (LIP3-6).

Main Results:

• Malassezia furfur demonstrated growth without morphological changes between pH 4 and 10.
• Increased pH significantly enhanced extracellular lipase activity but reduced intracellular lipase activity.
• Functional lipase genes (LIP3-6) exhibited constitutive expression irrespective of pH or exposure duration.

Conclusions:

• External pH plays a significant role in promoting lipase secretion in Malassezia furfur.
• Lipase gene transcription and yeast morphology are minimally affected by ambient pH.
• These findings provide insights into Malassezia's adaptation to varying pH environments and its lipase regulation.