Antagonistic Interactions and Killer Yeasts

The ecology of killer yeasts: Interference competition in natural habitats

“…Since the mid‐20th century, yeast biologists have understood that some yeasts secrete killer toxins, which target and kill sensitive yeasts (Bevan & Makower, ; Makower & Bevan, ). Killer toxins (also sometimes called “mycocins,” “zymocins,” and “zymocides”) are generally secreted proteins or glycoproteins that interact with receptors on the surfaces of sensitive cells; toxin‐secreting cells are usually immune to their own toxins (Klassen et al, ; Magliani, Conti, Gerloni, Bertolotti, & Polonelli, ). Killer toxins can target yeasts of the same species as the secreting yeast, other species, or both (Chang, Leu, & Chang, ; Vadkertiova & Slavikova, ).…”

“…Updated names according to speciesfungorum.org are shown. See also Klassen et al () for further examples.…”

“…Other killer toxins are coded by cytoplasmic linear DNA plasmids (also called "virus-like elements") or chromosomal genes (Goto et al, 1990;Gunge, Tamaru, Ozawa, & Sakaguchi, 1981;Satwika, Klassen, & Meinhardt, 2012;Starmer et al, 1992). This diversity in killer toxins and toxin coding-even within the same species (Magliani et al, 1997;Starmer et al, 1992)suggests that the killer phenotype evolved repeatedly multiple times throughout the Fungal tree of life (Klassen et al, 2017).…”

“…Although there is strong evidence that killer toxins are effective at killing sensitive yeasts, killer toxins may have alternative benefits unrelated to interference competition. Some potential alternative benefits include predation, protection of hosts from pathogens, help colonizing new habitats, and intercellular communication (Klassen, Schaffrath, Buzzini, & Ganter, 2017;Rodrigues, Cable, Mueller, Bacci, & Pagnocca, 2009;Romero, Traxler, Lopez, & Kolter, 2011;Wloch-Salamon, Gerla, Hoekstra, & de Visser, 2008). Direct observations and experiments under natural conditions are needed to investigate these potential benefits.…”

“…However, the killer phenomenon has been a model system for yeast cell biology for decades, and there are a variety of reviews on killer yeasts in the literature for interested readers. These include reviews focusing on mechanisms of toxin production and activity (Magliani et al, 1997;Marquina, Santos, & Peinado, 2002;Schmitt & Breinig, 2006;Stark, Boyd, Mileham, & Romanos, 1990), the diversity and biology of yeast cytoplasmic elements and toxins (Klassen et al, 2017;Rowley, 2017;Wickner, 1996), and the role of killers in applied biotechnology (El-Banna, Malak, & Shehata, 2011).…”