Structural insights into diversity and n-alkane biodegradation mechanisms of alkane hydroxylases

Abstract

Environmental microbes utilize four degradation pathways for the oxidation of n-alkanes. Although the enzymes degrading n-alkanes in different microbes may vary, enzymes functioning in the first step in the aerobic degradation of alkanes all belong to the alkane hydroxylases. Alkane hydroxylases are a class of enzymes that insert oxygen atoms derived from molecular oxygen into different sites of the alkane terminus (or termini) depending on the type of enzymes. In this review, we summarize the different types of alkane hydroxylases, their degrading steps, and compare typical enzymes from various classes with regard to their three-dimensional structures, in order to provide insights into how the enzymes mediate their different roles in the degradation of n-alkanes and what determines their different substrate ranges. Through the above analyzes, the degrading mechanisms of enzymes can be elucidated and molecular biological methods can be utilized to expand their catalytic roles in the petrochemical industry or in bioremediation of oil-contaminated environments.

Enzyme-mediated biodegradation of long-chain n-alkanes (C32 and C40) by thermophilic bacteria

“…The membrane-bound AHy were measured in all pure isolates and also measured in other nalkane-degrading strains (Liu et al 2009). Alkane hydroxylase initiates the aerobic degradation of alkanes by inserting oxygen atoms at the different sites of alkane terminus (Jauhari et al 2014;Ji et al 2013). Such structures are exemplified by microbodies in alkane-grown bacteria (Watkinson and Morgan 1990).…”

OPTIMASI PERTUMBUHAN BAKTERI LAUTSalinicola peritrichatus LBF-1-0025 DALAM SENYAWA ALKANA

“…Kemampuan ini mengindikasikan isolat ini memiliki beberapa enzim pendegradasi alkana yaitu metana monoksigenase, enzim P450 sitokrom, dan long chain alkane monooksigenase. Beberapa laporan menyebutkan bahwa enzim metanapropana monoksigenease merupakan enzim yang mendegradasi alkana rantai pendek (C1-C4), enzim P450 sitokrom merupakan enzim yang mendegradasi alkana rantai medium (C6-C11), dan long chain alkane monooksigenase (LadA) merupakan enzim yang mendegradasi alkana rantai panjang (C15-C36) (Ji, Mao, Wang, & Bartlam, 2013, Liu & Shao, 2005van Beilen, Li, Duetz, Smits, & Witholt, 2003). Namun dugaan ini haruslah diuji secara mendetail dalam tahap berikutnya dengan fokus identifikasi dan uji aktivitas enzim-enzim tersebut dalam senyawa alkana.…”

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

“…Short-chain carboxylates or complete mineralization are ultimately obtained through the consecutive metabolism of longchain alkylcarboxylates or alcohols. Several oxidative enzymes, including cytochrome P450 (CYP) were reported from bacteria (Ji et al, 2013). Compared to bacteria, a limited number of yeast and fungi have been documented as efficient petroleum alkanedegraders (Atlas, 1981;Leahy and Colwell, 1990;Adekunle and Oluyode, 2005).…”