Fuqiang Fan

Microbial degradation of four crude oil by biosurfactant producing strain Rhodococcus sp.

Rhodococcus erythropolis M-25, one of the representative biosurfactant producers, performed effectively during the biodegradation of four crude oil. The microbial degradation efficiency is positively relevant to the API of the crude oil. The chemical dispersant Corexit 9500A did not enhance the biodegradation of the petroleum hydrocarbons during the experimental period. 70.7% of the N-4 oil was degraded after 30days, while in the Corexit 9500A plus sample the biodegradation removal was 42.8%. The Corexit-derived compounds were metabolized by M-25 at the same time of the petroleum hydrocarbons biodegrading. Neither biodegradation nor chemical dispersion process has almost no effect on the biomarker (m/z=231). The saturated methyl-branched fatty acids increased from 37.3%, to 49.4%, when M-25 was exposed with the N-4 crude oil. Similarly, the saturated methyl-branched fatty acids in the membrane of N3-2P increased from 20.25% to 44.1%, when exposed it with the N-4 crude oil.

Anaerobic biodegradation of benzo(a)pyrene by a novel Cellulosimicrobium cellulans CWS2 isolated from polycyclic aromatic hydrocarbon-contaminated soil

Cellulosimicrobium cellulans CWS2, a novel strain capable of utilizing benzo(a)pyrene (BaP) as the sole carbon and energy source under nitrate-reducing conditions, was isolated from PAH-contaminated soil. Temperature and pH significantly affected BaP biodegradation, and the strain exhibited enhanced biodegradation ability at temperatures above 30 °C and between pH 7 and 10. The highest BaP removal rate (78.8%) was observed in 13 days when the initial BaP concentration was 10 mg/L, and the strain degraded BaP at constant rate even at a higher concentration (50 mg/L). Metal exposure experimental results illustrated that Cd(II) was the only metal ion that significantly inhibited biodegradation of BaP. The addition of 0.5 and 1.0 g/L glucose enhanced BaP biodegradation, while the addition of low-molecular-weight organic acids with stronger acidity reduced BaP removal rates during co-metabolic biodegradation. The addition of phenanthrene and pyrene, which were degraded to some extent by the strain, showed no distinct effect on BaP biodegradation. Gas chromatography–mass spectrometry (GC-MS) analysis revealed that the five rings of BaP opened, producing compounds with one to four rings which were more bioavailable. Thus, the strain exhibited strong BaP degradation capability and has great potential in the remediation of BaP-/PAH-contaminated environments.

Phospholipid fatty acid (PLFA) analysis for profiling microbial communities in offshore produced water

A method based on phospholipid fatty acid (PLFA) analysis for profiling microbial communities in offshore produced water was optimized. The operation parameters affecting final PLFA profiling performance from the solid phase extraction (SPE) purification and fatty acid methyl esters (FAMEs) yielding process were investigated. Under the selected conditions, 92.9%, 96.3% and 92.8% of the spiked phospholipid standards C16:1 (cis-9) PC, C18:1 (cis-9) PC, and C19:0 PC were recovered, respectively, using 10mL methanol as elution solvent on a non-commercial SPE column. Over 90% of spiked C19:0 PC was recovered before sample transesterification. Four parameters including alkaline reagent, volume of acid for neutralization, time and temperature for FAMEs derivatization were examined. Gas Chromatography-Mass Spectrometry (GC-MS) was used to analyze FAMEs and the method linearities, recoveries of 29 FAMEs during transesterification, detection limits, relative standard deviations were presented. The results provided valuable information for biological reservoir souring control.

Isolation and Performance for Two Strains of Benzo[a]pyrene Degradation

This is the report describing the biodegradation of benzo[a]pyrene （BaP） by strains isolated from the soil of the PAH contaminated sites. Achromobacter sp and Alcaligenes sp were found with the capability of degrading Bap as sole carbon source, their biodegradation performance of BaP was evaluated when the initial BaP concentrations was approximately 0.25mg/L, 0.40mg/L and 0.90mg/L. The results demonstrated Alcaligenes sp could degrade Bap completely within two weeks when the initial Bap concentration was 0.40mg/L. Alcaligenes sp showed higher removal efficiency than Achromobacter sp.

Determination of Two Organophosphorus Pesticides Using Electrochemical Sensor in Water Samples

A detection method for organophosphorus pesticides using electrochemical sensor based on enzyme inhibition has been developed. Acetylcholine esterase (AChE) was selected to quantify the pesticides concentration in water samples due to its activity was non-competitively inhibited in the presence of pesticides. To detect parathion and dichlorvos, optimized analytical conditions were that the substrate concentration was 3mmol/L, enzyme solution concentration was 18g/L and reaction time was 20min. Under the optimized detection conditons, a detection limit of 1.2ng/mL and 0.004ng/mL for parathion and dichlorvos was obtained, respectively. The approach was rapid, simple, accurate and of high sensitivity when compared with immunoassays or chromatographic methods.

Biodegradation of Indeno (1,2,3-cd) Pyrene by a Pure Bacterial Culture of Pandoraea sp.

Three new isolated bacterial cultures of Pandoraea sp., Stenotrophomonas sp., and T Pseudoxanthomonas mexicana that could efficiently degraded Indeno (1,2,3-cd) pyrene (Inp) were reported in this paper. The biodegradation performance of Inp by Pandoraea sp was studied under different pH conditions. Under the conditions of pH=8, the removal efficiency of Inp fluctuated sharply among 8% and 40%. The optimal condition for InP removal was pH=7, and removal efficiency was nearly 60% after the incubation of 25days.

Optimal Conditions for Biodegradation of Indeno (1,2,3-cd) Pyrene in Soil Slurry Reactors

Soil slurry reactor technology is one of the effective methods for treating PAHs contaminated soil. In this paper, removal of high molecular weight PAHs, Indeno (1,2,3-cd) pyrene (Inp), was studied in soil slurry reactors with isolated bacteria from PAHs contaminated soil. The factors affecting Inp biodegradation and the optimal conditions were investigated using orthogonal experimental design (L9(34)). The highest degradation efficiency of Inp was 50.71% after the incubation of 12 days. The most significant influencing factors were aeration rate, water to soil ratio and salinity, while pH was less significant. The optimal conditions for Inp degradation in soil slurry reactor was: aeration rate 120L/h, water to soil ratio 2:1, salinity 10%, pH=6.