Characterization of Dietzia cercidiphylli C-1 isolated from extra-heavy oil contaminated soil

High-efficiency bioremediation technology for heavy oil pollution has been a popular research topic in recent years. Laccase is very promising for the remediation of heavy oil pollution because it can not only convert bio-refractory hydrocarbons into less toxic or completely harmless compounds, but also accelerate the biodegradation efficiency of heavy oil. However, there are few reports on the use of laccase to enhance the biodegradation of heavy oil. In this study, we investigated the effect of laccase on the bacterial consortia degradation of heavy oil. The degradation efficiencies of bacterial consortia and the laccase-bacterial consortia were 60.6 ± 0.1% and 68.2 ± 0.6%, respectively, and the corresponding heavy oil degradation rate constants were 0.112 day−1 and 0.198 day−1, respectively. The addition of laccase increased the heavy oil biodegradation efficiency (p < 0.05) and biodegradation rate of the bacterial consortia. Moreover, gas chromatography–mass spectrometry analysis showed that the biodegradation efficiencies of the laccase-bacterial consortia for saturated hydrocarbons and aromatic hydrocarbons were 82.5 ± 0.7% and 76.2 ± 0.9%, respectively, which were 16.0 ± 0.3% and 13.0 ± 1.8% higher than those of the bacterial consortia, respectively. In addition, the degradation rate constants of the laccase-bacterial consortia for saturated hydrocarbons and aromatic hydrocarbons were 0.267 day−1 and 0.226 day−1, respectively, which were 1.07 and 1.15 times higher than those of the bacterial consortia, respectively. The degradation of C15 to C35 n-alkanes and 2 to 5-ring polycyclic aromatic hydrocarbons by laccase-bacterial consortia was higher than individual bacterial consortia. It is further seen that the addition of laccase significantly improved the biodegradation of long-chain n-alkanes of C22–C35 (p < 0.05). Overall, this study shows that the combination of laccase and bacterial consortia is an effective remediation technology for heavy oil pollution. Adding laccase can significantly improve the heavy oil biodegradation efficiency and biodegradation rate of the bacterial consortia.

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“…The microbial degradation of heavy oil is typically expressed using first-order kinetics [24,25], as given in Equation ( 2):…”

Section: Heavy Oil Degradation Efficiency and Degradation Kineticsmentioning

confidence: 99%

Effects of Adding Laccase to Bacterial Consortia Degrading Heavy Oil

Dai

Wei

et al. 2021

Processes

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“…The microbial degradation of heavy oil is usually expressed by first-order kinetics [21,22] as given in Equation 2:…”

Section: Heavy Oil Degradation Kinetics Of Bacterial Consortiummentioning

confidence: 99%

Heavy Oil Biodegradation by Mixed Bacterial Consortium of Biosurfactant-Producing and Heavy Oil-Degrading Bacteria

Dai¹,

Lv²,

Wei³

2020

Pol. J. Environ. Stud.

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Heavy oil has been widely used to meet the escalating energy demand all over the world due to the decrease in conventional oil and gas resources. Compared with conventional crude oil, heavy oil contains more refractory resins, asphaltenes, polycyclic aromatic hydrocarbons (PAHs), heterocyclic compounds, and heavy metals [1, 2]. Many of these components are biorefractory and toxic, therefore, heavy oil can cause more serious and lasting damage to the biological environment [3, 4]. Thus, an efficient remediation technology for heavy oil contamination is urgently needed.

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