Yeasts in an industrial malting ecosystem.

Area of Science:

• Microbiology
• Food Science
• Industrial Biotechnology

Background:

• The malting ecosystem involves cereal grains and microbial communities, with yeasts and yeast-like fungi playing a significant but understudied role.
• Understanding the composition and function of these fungi is crucial for optimizing malting processes and malt quality.

Purpose of the Study:

• To survey the diversity of yeasts and yeast-like fungi throughout industrial malting processes.
• To identify these fungi and assess their potential enzyme production relevant to malting.

Main Methods:

• Collected 136 samples from four industrial malting processes.
• Isolated and characterized over 700 yeast colonies using PCR-fingerprinting (M13 primer) and 26S rRNA gene sequencing (D1/D2 domain).
• Screened identified yeasts for extracellular enzyme production (alpha-amylase, beta-glucanase, cellulase, xylanase).

Main Results:

• Detected a numerous and diverse yeast community, including ascomycetous (e.g., Candida, Saccharomyces) and basidiomycetous (e.g., Cryptococcus, Rhodotorula) species.
• Commonly identified yeast-like fungi belonged to Aureobasidium and Exophiala.
• Isolated yeasts produced extracellular hydrolytic enzymes, potentially contributing positively to the malt enzyme spectrum.

Conclusions:

• The malting process harbors a rich diversity of yeasts and yeast-like fungi.
• These fungi possess enzymatic capabilities that could benefit malt production.
• This microbial diversity knowledge aids in managing microflora and understanding their role in cereal germination.