Aerobic biodegradation of hopanes and norhopanes in Venezuelan crude oils

a b s t r a c tA bacterial strain, CN-3, was isolated from petroleum-contaminated sediment in Bohai Bay, China. Morphological, physiological and phylogenetic analyses indicated that the strain belonged to the genus Dietzia. It was capable of utilizing a wide range of alkanes (C 14 eC 31 ), aromatic compounds and crude oil as the sole carbon and energy sources. The bacterium showed high degradation rate (>80%) of the saturated hydrocarbons of crude oil in the pH range of 6e9. The degradation rate was hardly affected at a NaCl concentration up to 85 g L À1 , indicating that the strain can tolerate high salinities. The real-time quantitative Polymerase Chain Reaction (PCR) results showed that the CYP153 genes could be significantly induced by C 14 , C 15 , C 16 , C 26 and pristane, whereas the transcription level of alkB gene was increased moderately with C 14 , C 15 , C 16 , C 26 and pristane induction condition. A high degradation extent, wide substrate range and facile conditions enhanced the potential for this bacterial strain to be used in the bioremediation of crude oil pollution.

Section: Crude Oil Degradation By Strain Cn-3mentioning

confidence: 99%

High efficiency degradation of alkanes and crude oil by a salt-tolerant bacterium Dietzia species CN-3

Chen

Sun

et al. 2017

“…The residual oil was extracted from the cultures with 10 mL n-hexane for three times. The extracts were collected and dried in anhydrous sodium sulfate (Bost et al, 2001). After being concentrated with vacuum rotary evaporation, the extracts were fractionated by column chromatography.…”

Section: Crude Oil Extraction and Components Analysismentioning

confidence: 99%

Use of bacteria-immobilized cotton fibers to absorb and degrade crude oil

Meng

Liu

Chen

et al. 2014

a b s t r a c tUsing enrichment culture technique, two isolates that brought a significant degradation and dispersion of crude oil were obtained from contaminated sediments of the Bohai Bay, China. 16S rRNA gene sequencing and phylogenetic analysis indicated that the two bacterial strains affiliated with the genera Vibrio and Acinetobacter. Subsequently, the bacterial cells were immobilized on the surface of cotton fibers. Cotton fibers were used as crude oil sorbent as well as a biocarrier for bacteria immobilization. Among the two isolates, the marine bacteria Acinetobacter sp. HC8-3S showed a strong binding to the cotton fibers, possibly enhanced through extracellular dispersant excreted by Acinetobacter sp. HC8-3S. Both planktonic and immobilized bacteria showed relatively high biodegradation (>60%) of saturated hydrocarbons fraction of crude oil, in the pH range of 5.6e8.6. The degradation activities of planktonic and immobilized bacteria were not affected significantly when the NaCl concentration reached 70 g/L. The immobilized bacterial cells exhibited an enhanced biodegradation of crude oil. The efficiency of saturated hydrocarbons degradation by the immobilized bacterial cells increased about 30% compared to the planktonic bacterial cells.

“…Then the extract was combined and dried with anhydrous sodium sulfate (Bost et al, 2001). After concentration by vacuum rotary evaporation, the constant volume of the extract was 25 ml.…”

Section: Crude Oil Extraction and Analysismentioning

confidence: 99%

Industrial-scale culturing of the crude oil-degrading marine Acinetobacter sp. strain HC8-3S

Liu

Liu³

2016

a b s t r a c tThe marine bacterium Acinetobacter sp. strain HC8-3S, capable of degrading petroleum hydrocarbons, was previously shown to be applicable for bioremediation. Here, we evaluated the performance of the strain during industrial-scale fermentation, long-term storage, and biodegradation processes. Fermentation parameters were optimized for industrial-scale culturing using lower salinity and fewer inorganic salts in the culture medium. The shelf-life of the fermentation broth was evaluated in different storage conditions. Biodegradation efficiency of the strain was evaluated using gas chromatography. Results indicated that the optimum conditions for one-ton scale fermentation were 30 C, pH 7.4e7.8, and rotation speed 90 rpm; the cell density reached 3.6 ± 1.9 Â 10 10 CFU ml À1 after 12 h. The low temperature can preserved fermentation broth for longer time. When the storage temperature was down to 4 C from room temperature, half-life of strain HC8-3S extended from 9 days to 34 days. The biodegradation rate of the saturated hydrocarbon fraction of crude oil was 94% after treatment with the strain for 5 days. The results indicate that Acinetobacter sp. strain HC8-3S can be enriched efficiently on a large scale, making it a potentially useful industrial strain. This crude oil degradative capability of the strain HC8-3S provides possible application for the clean-up of crude oil-contaminated environment.