title: Yeast-Yeast Interactions in Guava and Tomato Fruits.
abstract: The host specificity of yeast-yeast interactions was investigated for two yeast types, represented by six pairs of Pichia membranifaciens clade yeasts (Pichia membranifaciens or Issatchenkia occidentalis) with apiculate yeasts (Kloeckera apis, Kloeckera africana, or Saccharomycodes ludwigii), commonly found in fruits. Competitive interactions between the two types were detected in both ripe tomato and guava fruit pulp. The differences in growth rates and carrying capacities depended on fruit type (host) and culture conditions (monocultures versus bicultures). These differences were probably due to nutrient composition of each fruit. Pichia membranifaciens did not show host dependent responses, but the apiculate yeasts and Issatchenkia occidentalis did. Depending on yeast strain and culture conditions (i.e., monoculture or biculture), carbon, nitrogen, and vitamins were investigated as potential limiting growth factors in guava fruit. Both singular and multiple limiting nutrients were implicated.
authors.affiliation: Instituto de Microbiologia Prof. Paulo de Góes, CCS, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590, Brazil.
authors.forename: J.
authors.initials: J
authors.lastname: Abranches
authors.forename: W.T.
authors.initials: WT
authors.lastname: Starmer
authors.forename: A.N.
authors.initials: AN
authors.lastname: Hagler