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

Abstract

Removal of long-chain hydrocarbons and nalkanes from oil-contaminated environments are mere important to reduce the ecological damages, while bioaugmentation is a very promising technology that requires highly efficient microbes. In present study, the efficiency of pure isolates, i.e., Geobacillus thermoparaffinivorans IR2, Geobacillus stearothermophillus IR4 and Bacillus licheniformis MN6 and mixed consortium on degradation of long-chain n-alkanes C 32 and C 40 was investigated by batch cultivation test. Biodegradation efficiencies were found high for C 32 by mixed consortium (90%) than pure strains, while the pure strains were better in degradation of C 40 than mixed consortium (87%). In contrast, the maximum alkane hydroxylase activities (161 lmol mg -1 protein) were recorded in mixed consortium system that had supplied with C 40 as sole carbon source. Also, the alcohol dehydrogenase (71 lmol mg -1 protein) and lipase activity (57 lmol mg -1 protein) were found high. Along with the enzyme activities, the hydrophobicity natures of the bacterial strains were found to determine the degradation efficiency of the hydrocarbons. Thus, the study suggested that the hydrophobicity of the bacteria is a critical parameter to understand the biodegradation of n-alkanes.

Microbial Biodegradation of Paraffin Wax in Malaysian Crude Oil Mediated by Degradative Enzymes

“…The accumulation of these products resulted in the induction of the activity of these degradative enzymes. Previous studies also showed that less lipase enzyme was induced during the early incubation period, followed by a rapid increase in enzyme production when the hydrocarbon content decreased (Margesin et al, 2000;Elumalai et al, 2017).…”

“…Biodegradative enzymes present a significant role in microbial degradation of petroleum hydrocarbons (Yong and Zhong, 2010;Wasoh et al, 2019). The hydrocarbon removal efficiency depends on the bacteria used and their enzymatic oxidation characteristics (Elumalai et al, 2017). In the alkane degradation pathway, the degradation of n-alkane is usually initiated by alkane hydroxylase enzymes that transform alkane into alkanols by targeting different ranges of hydrocarbon (van Beilen et al, 1994;Singh et al, 2012).…”

Bacterial succession and co‐occurrence patterns of an enriched marine microbial community during light crude oil degradation in a batch reactor

“…Although short‐chain alkanes, naphthalene and 1‐methylnaphthalene were degraded in the first 6 days, an increase in their concentration was observed after 21 days. Since the biodegradation of complex compounds generates less complex intermediates (Elumalai et al ; Hou et al ), we hypothesized that this increase in concentration could be due to the accumulation of intermediates from the degradation of more complex aliphatic and aromatic compounds.…”

Bioremediation of Diesel Contaminated Marine Water by Bacteria: A Review and Bibliometric Analysis

“…For n-alkanes (C 8 -C 40 ), the aerobic degradation is divided into three oxidation modes [124]. These modes are known as terminal oxidation [125], subterminal oxidation [126], and biterminal oxidation [127]. The oxidation modes take place at different carbon positions and form various end products.…”