Biodegradation Of Aliphatic Hydrocarbons Research Articles

Oil-Contaminated Soil Remediation with Biodegradation by Autochthonous Microorganisms and Phytoremediation by Maize (Zea mays).

Biological methods are currently the most commonly used methods for removing hazardous substances from land. This research work focuses on the remediation of oil-contaminated land. The biodegradation of aliphatic hydrocarbons and PAHs as a result of inoculation with biopreparations B1 and B2 was investigated. Biopreparation B1 was developed on the basis of autochthonous bacteria, consisting of strains Dietzia sp. IN118, Gordonia sp. IN101, Mycolicibacterium frederiksbergense IN53, Rhodococcus erythropolis IN119, Rhodococcus globerulus IN113 and Raoultella sp. IN109, whereas biopreparation B2 was enriched with fungi, such as Aspergillus sydowii, Aspergillus versicolor, Candida sp., Cladosporium halotolerans, Penicillium chrysogenum. As a result of biodegradation tests conducted under ex situ conditions for soil inoculated with biopreparation B1, the concentrations of TPH and PAH were reduced by 31.85% and 27.41%, respectively. Soil inoculation with biopreparation B2 turned out to be more effective, as a result of which the concentration of TPH was reduced by 41.67% and PAH by 34.73%. Another issue was the phytoremediation of the pre-treated G6-3B2 soil with the use of Zea mays. The tests were carried out in three systems (system 1-soil G6-3B2 + Zea mays; system 2-soil G6-3B2 + biopreparation B2 + Zea mays; system 3-soil G6-3B2 + biopreparation B2 with γ-PGA + Zea mays) for 6 months. The highest degree of TPH and PAH reduction was obtained in system 3, amounting to 65.35% and 60.80%, respectively. The lowest phytoremediation efficiency was recorded in the non-inoculated system 1, where the concentration of TPH was reduced by 22.80% and PAH by 18.48%. Toxicological tests carried out using PhytotoxkitTM, OstracodtoxkitTM and Microtox® Solid Phase tests confirmed the effectiveness of remediation procedures and showed a correlation between the concentration of petroleum hydrocarbons in the soil and its toxicity. The results obtained during the research indicate the great potential of bioremediation practices with the use of microbial biopreparations and Zea mays in the treatment of soils contaminated with petroleum hydrocarbons.

Evaluation of the Effectiveness of the Biopreparation in Combination with the Polymer γ-PGA for the Biodegradation of Petroleum Contaminants in Soil.

Biodegradation is a method of effectively removing petroleum hydrocarbons from the natural environment. This research focuses on the biodegradation of aliphatic hydrocarbons, monoaromatic hydrocarbons such as benzene, toluene, ethylbenzene, and all three xylene isomers (BTEX) and polycyclic aromatic hydrocarbons (PAHs) as a result of soil inoculation with a biopreparation A1 based on autochthonous microorganisms and a biopreparation A1 with the addition of γ-PGA. The research used biopreparation A1 made of the following strains: Dietzia sp. IN133, Gordonia sp. IN138 Mycolicibacterium frederiksbergense IN53, Rhodococcus erythropolis IN119, Rhodococcus sp. IN136 and Pseudomonas sp. IN132. The experiments were carried out in laboratory conditions (microbiological tests, respirometric tests, and in semi-technical conditions (ex-situ prism method). The biodegradation efficiency was assessed on the basis of respirometric tests, chromatographic analyses and toxicological tests. As a result of inoculation of AB soil with the biopreparation A1 within 6 months, a reduction of total petroleum hydrocarbons (TPH) (66.03%), BTEX (80.08%) and PAHs (38.86%) was achieved and its toxicity was reduced. Inoculation of AB soil with the biopreparation A1 with the addition of γ-PGA reduced the concentration of TPH, BTEX and PAHs by 79.21%, 90.19%, and 51.18%, respectively, and reduced its toxicity. The conducted research has shown that the addition of γ-PGA affects the efficiency of the biodegradation process of petroleum pollutants, increasing the degree of TPH biodegradation by 13.18%, BTEX by 10.11% and PAHs by 12.32% compared to pure biopreparation A1.

Biodegradation of Aliphatic Hydrocarbons by Bacteria Isolated from Khor Al-Zubair Channel, Southern Iraq

Four bacterial strains capable of using crude oil as the sole carbon source were isolated from Khor Al-Zubair channel, southern Iraq. The isolates were identified as Vibrio vulnificus ; Brevundimonas diminuta/vesicularis ; Ochrobactrum anthropic and Sphingomonas paucimobilis by the Vitek II system. The bacteria grew aerobically in liquid culture containing four concentrations (0.25%, 0.5%, 1% and 2% v/v) of crude oil at 30ᵒC for a seven day period. The components of crude oil degraded by the isFolates were determined by capillary gas chromatography. Vibrio vulnificus was the most effective bacteria to degrade crude oil, especially in concentration 2% (93.05%). Meanwhile, Ochrobactrum anthropi was the lowest (9.63%) in concentration 0.25%.

Biodegradation of aliphatic hydrocarbons in the presence of hydroxy cucurbit[6]uril

Aliphatic hydrocarbons are one of the major environmental pollutants with reduced bioavailability. The present study focuses on the effect of hydroxy cucurbit[6]uril on the bioavailability of hydrocarbons. A bacterial consortium was used for biodegradation studies under saline and non-saline conditions. Based on denaturing gradient gel electrophoresis results it was found that the consortium under saline conditions had two different strains. The experiment was conducted in microcosms with tetradecane, hexadecane, octadecane and mixture of the mentioned hydrocarbons as the sole carbon source. The residual hydrocarbon was quantified using gas chromatography every 24h. It was found that biodegradation of tetradecane and hexadecane, as individual carbon source increased in the presence of hydroxy CB[6], probably due to the increase in their bioavailability. In case of octadecane this did not happen. Bioavailability of all three aliphatic hydrocarbons was increased when provided as a mixture to the consortium under saline conditions.

Influence of Zeolites On The Degradation of Arabian Light Crude Oil

ABSTRACT The authors have studied the biodegradation of an Arabian Light crude oil in sterile marine water by the CUES229 marine bacteria and the BIOLEN IG30 biologic activator, both in the presence and the absence of zeolites. Two different types of zeolites, a natural one (NZ) and an artificial one (Zestek56), were used to degrade the crude in the first experiment, arising a 20% increment in the degradation in the presence of natural zeolite when compared with a similar sample without zeolites, and a 9% in the artificial zeolite. Next set of experiment were made using reactors filled with 250 g of sea water and 0.02 g of zeolite and injecting CUES 229 bacteria up to 108 cells/ml. Samples were introduced in a shaker at 110 rpm and with regulated temperature at 30-C. Time evolution of the biodegradation was deduced from gas chromatography at the time intervals 1; 7 and 15 days. Later, a similar experiment, but with BIOLEN IG30, was also made. Biodegradation of aliphatic hydrocarbons was observed –after 15 days- until the C14 fractions, using zeolites plus Biolen IG30, and until the C18 fractions, using zeolite plus CUES 229 bacteria.

Bioconversion and biodegradation of aliphatic hydrocarbons

Aliphatic hydrocarbons represent a substantial energy reserve but also constitute a useful feedstock for the biotechnological production of various alkane-derived commodity chemicals. In addition, the biodegradation of aliphatic hydrocarbons continues to pose problems for fuel stocks with associated corrosion and eventual motor filter blocking. A relatively high number of yeasts and filamentous fungi have been described that degrade n-alkanes, but relatively few have received thorough investigation. Early work exploiting hydrocarbons as a potential substrate for unicellular protein production, though never commercially successful, enabled high-performance fermentation strategies to be developed that overcame many of the inherent problems caused by the use of high energy content insoluble liquid substrates. The biochemical pathways and physiological characteristics have been sufficiently established, as have the subcellular localization of the alkane-specific pathways, though many of the regulatory phenomena remain obscure. Currently, interest lies in the exploitation of such species, or their enzymes, in bioconversion processes and the unicellular yeasts, whose amenability to rational genetic engineering strategies exceeds that of filamentous species, are currently attracting renewed research interest. In view of this, the existing knowledge and potential for alkane-based biotechnology will be reviewed. Key words: alkane metabolism, bioconversion, biotechnology, aliphatic hydrocarbons, yeasts, filamentous fungi.