Optimization of nutrient component for diesel oil degradation by Acinetobacter beijerinckii ZRS.

A new bacterial strain that is capable of using diesel as the sole carbon source was isolated from the petroleum-contaminated soil of Xinjiang oil field, Northwest China. This bacterium was identified on the basis of its morphological and physiological characteristics and 16S rRNA gene sequence analysis, and it showed the greatest similarity with Acinetobacter beijerinckii 302-PWB-OH1 (99.86%).

Sphingomonas sanxanigenens sp. nov., isolated from soil.

Strain NX02(T), a Gram-negative, non-spore-forming, rod-shaped bacterium, was isolated from soil, and its taxonomic position was investigated using a polyphasic approach. Chemotaxonomic analysis revealed that strain NX02(T) possessed Q-10 as the predominant ubiquinone, sym-homospermidine as the major polyamine and C(18 : 1)omega7c, C(16 : 0) and C(14 : 0) 2-OH as the major fatty acids. The main polar lipids were sphingoglycolipid, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine and an unidentified glycolipid.

[Characterization of a thermophilic Geobacillus strain DM-2 degrading hydrocarbons].

A thermophilic Geobacillus strain DM-2 from a deep-subsurface oil reservoir was investigated on its capability of degrading crude oil under various conditions as well as its characters on degrading hydrocarbons in optimal conditions. The results showed that Geobacillus strain DM-2 was able to degrade crude oil under anoxic wide-range conditions with pH ranging from 4.0 to 10.

[Functional correlation of dibenzothiophene and benzothiophene desulfurization enzymes].

Gordonia sp. C-6 can desulfurize benzothiophene (BT) as the pathway similar to the "4S" pathway of dibenzothiophene (DBT)-desulfurizing, but the strain can not grow with DBT as the sole sulfur source. At current, there were not related reports on BT-desulfurizing genes at home or abroad.

Optimization of nutrient component for diesel oil degradation by Rhodococcus erythropolis.

A novel bacterium T7-2 was isolated from the oil-polluted sea-bed mud of Bohai Sea, northern China, which can degrade diesel oil at 15 degrees C. This bacterium was identified as a strain of Rhodococcus erythropolis according to its 16S rDNA gene. In order to enhance degradation efficiency, a five-level, three-factor central composite design was employed to optimize the nutrition supplied to artificial seawater.

[Isolation of functional bacteria guided by PCR-DGGE technology from high temperature petroleum reservoirs].

It is a brand-new method to isolate functional bacteria from high temperature petroleum reservoirs according to the sequence information obtained from PCR-DGGE patterns. Three-set primers of 16S rDNA high variable region, V3, V8, V9, were compared. The results showed that more microbial diversity information could be obtained from the PCR product of V9 region.

Improved biodesulfurization of hydrodesulfurized diesel oil using Rhodococcus erythropolis and Gordonia sp.

Substituted benzothiophenes (BTs) and dibenzothiophenes (DBTs) remain in diesel oil following conventional desulfurization by hydrodesulfurization. A mixture of washed cells (13.6 g dry cell wt l(-1)) of Rhodococcus erythropolis DS-3 and Gordonia sp.

Genetic rearrangement strategy for optimizing the dibenzothiophene biodesulfurization pathway in Rhodococcus erythropolis.

Dibenzothiophene (DBT) and its derivatives can be microbially desulfurized by enzymes DszC, DszA, and DszB, which are encoded by the operon dszABC and contribute to the conversion in tandem. We investigated the expression characteristics of the dsz operon. Our results revealed that the levels of transcription and translation of dszA, dszB, and dszC decreased according to the positions of the genes in the dsz operon.

[Isolation and identification of a low temperature hydrocarbon-degrading strain and its degradation characteristics].

A low-temperature hydrocarbon-degrading strain T7-2 was isolated from sea-mud of Bohai polluted area and identified as Rhodococcus erythropolis, which could use diesel oil as carbon source. The optimal temperature and pH for the strain utilizing ethanol was 15 degrees C and 7.8, and the optimal concentration of ethanol and the seed culture was 0.

Improvement of dibenzothiophene desulfurization activity by removing the gene overlap in the dsz operon.

Dibenzothiophene (DBT) and its derivatives can be microbially desulfurized by Dsz enzymes. We investigated the expressional characteristics of the dsz operon. The result revealed that the ratio of mRNA quantity of dszA, dszB, and dszC was 11:3.

[Microbial denitrogenation of fuel oil].

The amount of organic nitrides contained in fuel oil is smaller than the one of organic sulfur compounds, but the existence of them is enough to affect the invariability of oil product greatly , and has a big effect on the color of oil. They also contribute to catalyst poisoning during the refining of crude oil, thus reducing the catalyzing rate of the catalyst and increasing process costs. Further more, some nitrogen organic compounds possess mutagenic and toxic activities.

[Performance of demulsification by Rhodococcus sp. PR-1].

Rhodococcus sp. PR-1 with high capability of demulsification on a surfactant-stabilized kerosene-water model emulsion was isolated from sewage of Dagang oil field. It could demulsify the model emulsion completely in 8 hours at 55 degrees C and had better demulsifying capability than chemical demulsifier DGF-01.

[Isolation and characterization of a benzothiophene-desulfurizing bacterium].

A benzothiophene-desulfurizing strain was isolated and identified as Gordonia sp. C-6, which could degrade benzothiophene (BT) in a way analogous to the 4S pathway. It was found strain C-6 had the ability to grow in KT-BT medium whose sole source of sulfur was BT or its derivatives, whereas it couldn't grow well in a medium with DBT and its derivatives as the sole source of sulfur, the desulfurized product was identified as 2-(2'-hydroxyphenyl) ethan-1-al or its isomer benzofuran by GC-MS analysis.

Isolation and characterization of a novel thermophilic Bacillus strain degrading long-chain n-alkanes.

A thermophilic Bacillus strain NG80-2 growing within the temperature range of 45-73 degrees C (optimum at 65 degrees C) was isolated from a deep subterranean oil-reservoir in northern China. The strain was able to utilize crude oil and liquid paraffin as the sole carbon sources for growth, and the growth with crude oil was accompanied by the production of an unknown emulsifying agent. Further examination showed that NG80-2 degraded and utilized only long-chain (C15-C36) n-alkanes, but not short-chain (C8-C14) n-alkanes and those longer than C40.

[Screening, identification of the strain Fds-1 for microbial desulfurization specially and its use in diesel oil desulfurization].

A strain Fds-1, which can specially break the C-S bond of dibenzothiophene (DBT) and convert DBT into 2-hydrobenzophene (2-HBP), was screened out from soil soaked with crude oil and identified as Bacillus subtilis. Both Gibb's reaction and GC-MS analysis proved that this bacterium could remove sulfur of DBT by "4S" pathway. The optimal temperature of desulfurization is 30 degrees C.

[Cloning and function analysis of L-lactate dehydrogenase gene from Lactobacillus sp. MD-1].

It was constructed that a genomic DNA library from Lactobacillus sp. MD-1 yielding D, L-lactic acid. The gene encoding L-lactate dehydrogenase (L-LDH) was cloned from the genomic library of strain MD-1 by complementation in E.

[Selectively desulfurizing organic sulfur of diesel oil by resting cells].

Rhodococcus sp. FS-1 ,which can specially break the C[single bond]S bond of dibenzothiophene (DBT) and convert DBT into 2-hydrobenzophene by "4S" pathway, is used to decrease the sulfur content in diesel oil. This research focuses on the diesel oil desulfurization using resting cells of Rhodococcus sp.