Epsilon Archive for Student Projects

Abstract

There are several fungal species including Aspergillus niger that are responsible for food
spoilage. The conidia of Aspergillus niger contain mannitol and trehalose and these
compounds act as stress protectants and keep the cells viable. In my experiments, I
observed the survival after stress in trehalose and mannitol deficient mutants of
Aspergillus niger and compared with wild type strains. I applied different treatments like
heat shock, freeze-drying and different energy sources on mutants and wild types spores
at different ages. The results indicate that 1-month-old spores of mutant of ΔtppB and
ΔmpdA are more vulnerable at high and low temperatures. These experiments indicate
that the trehalose deficient mutant ΔtppB and the mannitol deficient mutant ΔmpdA are
more sensitive compared to wild type and most probably due to their lower mannitol and
trehalose levels.