## 3 Discussion  
This study is the first report on volatile organic compounds (VOCs) produced by _Malassezia globosa_, _Malassezia restricta_, and _Malassezia sympadiis_ in the exponential and stationary growth phases. Headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) identified 54 compounds released by all three species, and multivariate analysis provided evidence that both the species and growth phase influence the emission of VOCs. The growth stage of microorganisms determines their metabolic processes, which are influenced by environmental factors, such as nutrient availability, temperature, CO\({}_{2}\) levels, and humidity. Additionally, the growth phase explains how microbes adapt to a niche [36; 37]. These findings indicate that VOCs produced by the _Malassezia_ species are differentially emitted at different developmental stages. They demonstrate the metabolic diversity of _Malassezia_ spp. since the volatile profiles of the different species strongly differ. _M. globosa_ produces more compounds than others; for example, octan-3-one is produced by this species in both phases but with a higher peak area in the exponential phase. Likewise, only in the stationary phase is the VOC octan-3-ol produced. These findings may be similar to what occurs in mushrooms, where it has been suggested that reduction of octan-3-one through the activity of an alcohol dehydrogenase produces octan-3-ol [38], so the yeast could be producing a compound at an early stage of growth and metabolizing it at another, demonstrating the importance of the growth phase in the production of VOCs. This alcoholic compound (octan-3-ol) was also identified in the fungus _Trantes versicolor_ in a study to determine the electrophysiological responses of Coleoptera to VOCs [39], as well as in _Tuber_ species, where this compound shows phytotoxic activity [40]. It is known that _M. globosa_ exhibits a longer stationary phase than the other species evaluated in this study, so this feature could influence VOC production. Other compounds that are differentially expressed in _M. globosa_ at the stationary phase are hept-2-en-1-ol and 2-ethyllexan-1-ol, both belonging to fatty alcohols, indicating that they are possibly produced during the degradation of the fatty acid pathway. These profiles also support the metabolic diversity of _Malassezia_: despite all the species being lipid-dependent, they assimilate the fatty acids from the host differentially [3]. It has been demonstrated that _Malassezia_ presents differences in the assimilation profile of lipids, such as palmitic acid, by _M. globosa_ and _M. sympodialis_, which show defects in its assimilation [6]. In addition, the lipidome of the species tested shows differences in the presence of some lipids, such as triacylglycerlecrools, where the content in _M. globosa_ is lower than that in _M. restricta_ and _M. sympodialis_, and cholesterol, which is more abundant in _M. globosa_ than in the other two species [41]. Despite no information about the implication of lipid metabolism in VOC production, there could be a relationship since the assimilation of lipids differs between species. According to the growth phase, it is possible to establish some similarities between species in the stationary phase; for instance, 2-phenylethanol and non-3-en-1-ol are released by all species only in the stationary phase. Likewise, 2-phenylethanol is a common volatile released by several microorganisms, such as _Saccharomyces cerevisiae_, _Klebsiella pneumoniae_, and other bacteria and fungi [11; 42; 43; 44]. Moreover, this compound has been associated with interaction processes related to insect attraction and repulsion [11; 44]. Curiously, _M. restricta_ and _M. sympodialis_ have more \begin{table}
\begin{tabular}{l l l} \hline
**Variable** & **R\({}^{2}\)** & **_p Value_** \\ \hline Species & 0.20 & \textless{}0.001 \\ Phase & 0.20 & \textless{}0.001 \\ Species/phase & 0.56 & \textless{}0.001 \\ \hline \end{tabular}
\end{table}