# Dependence of the Staphylococcal Volatilome Composition on Microbial Nutrition
## 1 Introduction
Additionally, acids, aldehydes, ketones, and alcohols are formed by amino acid degradation via deamination, followed by decarboxylation and reduction [32; 33; 34]. Catabolism of glucose to pyruvate and acetyl-CoA leads to the synthesis of short-chain fatty acids and esters, which can be reduced to aldehydes, alcohols, and saturated and unsaturated hydrocarbons [32; 33; 34]. Extrapolating these observations to predict effects on the volatilome of staph is challenging, though two comparative analyses of bacterial volatiles in rich media have been performed and inform our hypotheses. [PERSON] and colleagues [35] analyzed the volatilomes of ten isolates each of _S. aureus, Pseudomonas aeruginosa, Stenotrophomas malophilia_, and _Burkholderia cepacia_ complex in BHI, MHB, and nutrient broth (NB), which like LB contains yeast extract and no added sugars or starches. _S. aureus_ produced the highest proportion of acids when grown in BHI, the medium with readily accessible sugars, and when grown in the no-sugar medium, NB, it produced the highest proportion of hydrocarbons. [PERSON] and colleagues [36] characterized the volatilomes of _Klebsiella pneumoniae_ clinical isolates cultivated in BHI, LB, MHB, and TSB. When comparing the four media by the numbers of compounds produced in each, similar chemical compositions of the _K. pneumoniae_ volatilomes were observed. However, when clustering the volatilomes using the relative abundances of the volatiles, they observed significant media-dependent differences in the volatilomes, which clustered by high-glucose media (BHI and TSB) versus low-glucose media (LB and MHB). The primary goal of this study was to determine how the chemical compositions of the volatilomes of _S. aureus_ and _S. epidermidis_ are affected by the nutrients of the growth medium. Because glucose is the preferred carbon source of staphylococci, we expected that media with high concentrations of glucose would support the highest overall abundances of volatiles. We also hypothesized that high-glucose media would activate catabolite repression control, and thus a narrower range of metabolic pathways will be engaged, which will result in the production of a lower diversity of volatile chemical classes. Additionally, we expected to observe a higher relative abundance of aldehydes, acids and esters,ketones and alcohols in high-glucose media versus low-glucose media. Conversely, media without glucose will not induce catabolite repression control and will, therefore, have a higher relative abundance of volatiles derived from amino acid catabolism, e.g., nitrogen and sulfur compounds. To test our hypotheses, we cultured _S. aureus_ and _S. epidermidis_ in BHI, LB, MHB, and TSB and analyzed the volatilomes using headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography - time-of-flight mass spectrometry (HS-SPME-GC\(\times\)GC-TOFMS). We compared the volatilomes by the number and relative abundance of volatiles in each chemical class. Additionally, we compared the analyzed volatilomes to the literature on _S. aureus_ and _S. epidermidis_ volatiles and added several compounds to the volatilomes of both species by reporting them here for the first time.