A Wickerhamomyces anomalus killer strain in the malaria vector Anopheles stephensi

Area of Science:

• Microbiology
• Biotechnology
• Vector Biology

Background:

• Wickerhamomyces anomalus yeast shows significant biotechnological potential, particularly in food applications.
• Its antimicrobial activity is linked to the production of Killer Toxins (KTs).
• W. anomalus strains have been found in diverse environments, including insects like the malaria mosquito Anopheles stephensi.

Purpose of the Study:

• To investigate the killer yeast properties of W. anomalus strain WaF17.12 isolated from An. stephensi.
• To determine if WaF17.12 produces functional Killer Toxins (KTs) in vitro and in vivo.
• To assess the potential of WaF17.12 for symbiotic control of malaria.

Main Methods:

• Isolation and identification of W. anomalus strain WaF17.12 from An. stephensi.
• Culturing yeast in cell-free medium and stimulating toxin secretion.
• Reintroduction of activated yeast into mosquitoes via diet for in vivo analysis.
• In vitro testing of antimicrobial activity against sensitive microbes.

Main Results:

• Strain WaF17.12 was confirmed as a killer yeast capable of producing Killer Toxins (KTs).
• Consistent WaF17.12-KT production was observed over time after stimulation and reintroduction into mosquitoes.
• The produced WaF17.12-KT demonstrated significant antimicrobial activity against sensitive microbes in vitro.
• Functional toxin release was confirmed for the mosquito-associated yeast strain.

Conclusions:

• The mosquito-associated W. anomalus strain WaF17.12 produces a functional Killer Toxin (KT).
• This yeast exhibits antimicrobial activity both in vitro and in vivo within the mosquito.
• WaF17.12 warrants further investigation as a potential agent for symbiotic malaria control.