Stress situations induce cyanide-resistant respiration in spoilage yeasts

Abstract

Aims: To investigate the conditions that promote the expression of cyanide-resistant respiration (CRR) in the spoilage yeasts Pichia membranifaciens and Debaryomyces hansenii. Methods and Results: CRR was detected by sensitivity of oxygen consumption to salicylhydroxamic acid. It was absent in both yeasts in the early exponential phase, but was triggered by several stress situations. Starvation under aerobic conditions, decreasing pH or incubation of the culture in a narrow temperature range below the maximum temperature for growth promoted the emergence of CRR in both yeasts. In D. hansenii, CRR was also induced by 1AE5-2 mol l )1 NaCl. Although the presence of H 2 O 2 and menadione induced CRR, radical scavengers had no effect on the emergence of CRR. Also, the level of reactive oxygen species did not vary with the CRR activity.Conclusions: Under aerobic conditions, a respiratory pathway alternative to the cytochrome chain is triggered by stress conditions in P. membranifaciens and D. hansenii. Significance and Impact of the Study: The relationship between stress situations and CRR must be taken into account in studies on the performance of spoilage yeasts in the food processing environments where several forms of stress are common.

Pichia pastoris ‘just in time’ alternative respiration

“…Furthermore, the differences occurred at a later stage of growth than those observed in the X-33 PpAOD strain. As the literature links alternative oxidase activity to stress response (Gonzalez-Meler et al, 1999;Kirimura et al, 1996;Ordog et al, 2002;Simons et al, 1999;Vanlerberghe et al, 2002;Veiga et al, 2003b) and therefore to cellular viability we consider increased cell death phenomena as a possible explanation for this discrepancy.…”

“…For example, osmotic stress, chilling (Gonzalez-Meler et al, 1999;Veiga et al, 2003b), wounding, pathogen attack (Simons et al, 1999), and treatment with H 2 O 2 or inhibitors of the main respiratory chain, such as cyanide and antimycin A (Kirimura et al, 1996), have been reported to induce alternative respiration. There is substantial experimental support for the role of alternative oxidases as protecting the cell from reactive oxygen species or providing some metabolic flexibility (Joseph-Horne et al, 2001).…”

Oxidative stress in fungal fermentation processes: the roles of alternative respiration

“…In M. grisea, for example, active oxygen species are thought to be signal mediators to activate transcription of the AOX gene (Yukioka et al 1998), and the superoxide anion ( O 2 •-) is involved in the induction of cyanide-resistant-respiration (CRR) in the yeast H. anomala (Minagawa et al 1992). The presence of H 2 O 2 and menadione induces CRR in Pichia membranifaciens and Debaryomyces hansenii (Veiga et al 2003). Karrafa et al (2001) reported a negative correlation between CRR and intracellular peroxide levels in A. chrysogenum, supporting the protective role of alternative respiration against oxidative damage in cells.…”

Alternative respiration of fungus Phycomyces blakesleeanus

“…While animals posses only cytochrome respiratory pathway (cyanide-sensitive respiration, CSR), performed by the single terminal CytC oxidase (COX), most fungi, apart of classical cytochrome respiratory pathway, just like plants, also posses alternative respiration (cyanide-resistant respiration, CRR) sensitive to SHAM, and performed by alternative oxidase (AOX) which is located in the inner mitochondrial membrane (JosephHorne et al 2001). Unlike plants, where CRR is found in all species investigated to date, it is absent in fungi capable of aerobic fermentation (Veiga et al 2000). In the rest of fungi the AOX expression and activity are very complex and highly diverse among different species.…”

“…While the increasing body of evidence shows that AOX in plants plays a role in lowering mitochondrial reactive oxygen species (ROS) formation (Maxwell et al 1999;Yip and Vanlerberghe 2001), in fungi this function could not be confirmed (Veiga et al 2003a). Even more, in Podospora anserina mutant overexpression of AOX considerably increased ROS production (Lorin et al 2001).…”