Metabolism of alkenes and ketones by Candida maltosa and related yeasts

Abstract

Knowledge is scarce about the degradation of ketones in yeasts. For bacteria a subterminal degradation of alkanes to ketones and their further metabolization has been described which always involved Baeyer-Villiger monooxygenases (BVMOs). In addition, the question has to be clarified whether alkenes are converted to ketones, in particular for the oil degrading yeast Candida maltosa little is known. In this study we show the degradation of the aliphatic ketone dodecane-2-one by Candida maltosa and the related yeasts Candida tropicalis, Candida catenulata and Candida albicans as well as Trichosporon asahii and Yarrowia lipolytica. One pathway is initiated by the formation of decyl acetate, resulting from a Baeyer-Villiger-oxidation of this ketone. Beyond this, an initial reduction to dodecane-2-ol by a keto reductase was clearly shown. In addition, two different ways to metabolize dodec-1-ene were proposed. One involved the formation of dodecane-2-one and the other one a conversion leading to carboxylic and dicarboxylic acids. Furthermore the induction of ketone degrading enzymes by dodecane-2-one and dodec-1-ene was shown. Interestingly, with dodecane no subterminal degradation products were detected and it did not induce any enzymes to convert dodecane-2-one.

Study of the Enzymatic Capacity of <b><i>Kluyveromyces marxianus</i></b> for the Synthesis of Esters

“…BVMOs are enzymes dependent on FAD or NAD that catalyze the degradation of aliphatic ketones for the formation of branched esters, which are hydrolyzed to yield an acid and an alcohol [Beier et al, 2014;Kim et al, 2018]. By means of this mechanism, compounds of industrial interest such as dodecyl acetate (odor of wax) can be obtained.…”

Biodegradation of 1-alkoxy-2,4-dichlorobenzenes by Yarrowia lipolytica KCTC 17618

“…Each substrate solution was prepared in dimethylsulfoxide (DMSO) at 1-alkoxy-2,4,-dichlorobenzene concentrations of 10, 20, 50, or 100 mg ml À1 DMSO. To assess the utilization of alkoxybenzene as the sole carbon source for growth, the inoculum was harvested by centrifugation (16,000 rpm, 1 h) and the pellet was suspended in mineral medium (MM, 100 ml) (Beier et al, 2014) to an optical density (OD 600 ) of 0.3, followed by the addition of 1-alkoxy-2,4-dichlorobenzene solution (1 ml, 10 mg ml À1 in DMSO). After 7 days of incubation, the optical densities and residual 1-alkoxy-2,4-dichlorobenzene were measured.…”

Detection of ALS3 and EAP1 gene expresssion in Candida albicans and Candida maltosa biofilms by FISH

“…C. albicans is one of the most important microorganisms involved in hospital-acquired infections constituting 40% of bloodstream infections and 15% of all sepsis in clinics [12,13,14]. On the other hand, there are several Candida species with non-pathogenic features and their ability to form biofilm are studied in bioremediation processes [15]. For instance, Candida viswanathii TH1 isolated from oil-polluted sediments collected in coastal zones in Vietnam can transform branched aromatic hydrocarbons in biofilm than in planktonic form [16].…”