Yeast strains antagonistic

Nonproteinohenic proline derivatives 9 and 10 have been detected in the cyclic peptide scytonemin A, a metabolite of the cultured cyanophyte Scytonema sp. which possesses potent calcium antagonistic properties. (2S,47 )-4-Hydroxyproline (8) and (25, 35, 45 )-3-hydroxy-4-methylproline (11) were found in echinocandin B, C and D, which were isolated from a strain of Aspergillus ruglosus and Aspergillus nidulans and characterized by their high antifungal and anti-yeast activities. 

When the yeast starter is added, it is important to avoid antagonism with other strains naturally present in the must. Antagonistic reactions may reduce the fermentation rate and contribute to causing stuck fermentation (Section 3.8.1). For inoculation with DAY to be successful, the yeast starter must be more abundaut aud more active than the indigenous yeasts, which must be inhibited by proper hygiene, sufficiently low temperatures, and appropriate use of sulfite. 

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