Carbon sources effects on conidiation in Penicillium camemberti: a transcriptomic analysis

Area of Science:

• Mycology
• Fungal Biotechnology
• Industrial Microbiology

Background:

• The asexual reproduction of Penicillium camemberti, a filamentous fungus, is crucial for cheese ripening and industrial conidia production.
• Mycelium macromorphology's impact on conidia production during submerged fermentation is not well understood.
• Conidia are vital for inoculating fungi onto French soft cheeses and are produced industrially.

Purpose of the Study:

• To investigate the relationship between Penicillium camemberti mycelium morphology and conidia production under varying carbohydrate conditions.
• To analyze gene expression profiles during submerged fermentation to understand the conidiation pathway.
• To identify potential regulatory factors influencing conidia formation.

Main Methods:

• Laboratory-scale studies on the physiological effects of different carbohydrate sources and concentrations on fungal morphology and conidia production.
• RNA-sequencing (RNA-seq) transcriptomic analyses of P. camemberti during liquid cultures with varying glucose, sucrose, and fructose conditions.
• Comparative analysis of gene expression profiles to understand the conidiation pathway and identify regulatory elements.

Main Results:

• Different carbohydrate sources and concentrations induced distinct mycelial morphologies in P. camemberti, affecting conidia production efficiency.
• A dispersed morphology did not consistently correlate with higher conidia production.
• Transcriptomic analysis confirmed the involvement of the known conidiation pathway in P. camemberti and identified a potential conidiation-inhibiting transcription factor specific to Eurotiales.

Conclusions:

• Fungal morphology significantly influences conidia yield in P. camemberti submerged fermentation.
• A novel, potentially inhibitory transcription factor was identified, offering a new target for regulating asexual reproduction in fungi.
• Further functional studies in Aspergillus nidulans are needed to validate the role of the identified transcription factor in the asexual cycle.