Improvement of Arsenic Tolerance and Removal Ability of Multi-stress-tolerant Pichia kudriavzevii A16 by Salt Preincubation.

Arsenic (As) exists widely in the environment and its strong toxicity endangers human health, causing widespread concern. Microbial adsorption technology plays an important role in As removal due to its advantages of high safety, low pollution, and low cost. The removal of As by active microorganisms requires not only good accumulation characteristics but also high As tolerance. The effect of salt preincubation on arsenate [As(V)] tolerance and bioaccumulation of Pichia kudriavzevii A16 and the possible mechanisms were studied. Salt preincubation improved the As(V) tolerance and bioaccumulation ability of the yeast. After NaPO preincubation, the proportion of dead cells and cells with high reactive oxygen species (ROS) accumulation decreased from 50.88% and 16.54% to 14.60% and 5.24%, respectively. In addition, the As removal rate significantly increased from 26.20% to 57.98%. The preincubated cells showed stronger As(V) tolerance and removal ability. The potential of use in complex environment to remove As(V) as well as the mechanisms involved in As(V) tolerance by yeast will be discussed.