Subject(s)
Humans , Acupuncture , Acupuncture Points , Acupuncture Therapy , Meridians , Moxibustion , SpasmABSTRACT
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. coli FMJ144 which was lactate dehydrogenase and pyruvate-formate lyase double defective mutant. The nucleotide sequence of the ldhL gene predicted a protein of 316 amino acid starting with ATG. The putative molecular weight of the L-LDH amino acid sequence was 33.84kD. A putative typical promoter (-35 and -10 boxes) had been observed in the 5' noncoding region. An rho-independent transcriptional terminator has been observed in the 3' noncoding region. Three highly conserved regions (Gly13 approximately Asp50, Asp73 approximately Ileul00 and Asn123 approximately Arg154) with several conserved residues had been identified. Gly13 approximately Asp50 was NADH-binding site domain. Asp73 approximately Ileu100 and Asn123 approximately Arg154 were reported to be the active site domains. The ldhL and the L-LDH of Lactobacillus sp. MD-1 showed the low identity and similarity with other Lactobacilli, and the highest percentage were 61.9% and 68.9% respectively. All the above indicated this gene is a novel ldhL.
Subject(s)
Amino Acid Sequence , Base Sequence , Cloning, Molecular , L-Lactate Dehydrogenase , Chemistry , Genetics , Physiology , Lactobacillus , Genetics , Molecular Sequence DataABSTRACT
A low-temperature hydrocarbon-degrading strain T7-2, isolated from sea-mud of Bohai polluted area and identified as Rhodococcus erythropolis, was found to produce an extracellular, nondialyzable emul- sifying agent (referred to as bioemulsifier) when grew with hexadecane as carbon source. The results showed that, this bioemulsifier which could remarkably emulsify hydrocarbons such as diesel oil, is consisted of three parts-carbohydrates, lipids and proteins, the proportion of which was 55.43:31.24:12.65. The mono- saccharide compositions were identified as mannose and rhamnose; the lipid compositions included de- canoic acid, lauric acid, hexadecanoic acid and stearic acid, and the protein constituents were composed of sixteen amino acids. Besides, according to the study of the physic-chemical properties of the bioemulsifier, it possesses the obvious advantages of character stability, high function efficiency and wide adaptation range, therefore this bioemulsifier is believed to have extensive application values for bioremediation of marine oil pollution, petroleum exploitation and etc.
ABSTRACT
Nowadays,oil-pollution of seawater in the world has severely threatened the security of sea entironment.Bioremediation offers one available option for an oil spill response.The aspects as follows are introduced some evolvement of microbial ecology,including new method of survey of microbial diversity without cultivation,new isolated method and the properties of main hydrocarbon degradated strain.But we have little or no understanding of the vast majority of marine bacteria that remain uncultured,and more efforts should be made to improve current methods for isolating oil-degrading or oil-emulsifying bacteria,not only for assessing the fate and effects of the spilled oil,but also for isolating novel bacteria that would be useful for the petroleum industry.
ABSTRACT
Based on reservoir condition and fluid characteristics, the oil-degrading bacterial strain NX-2 was screened from Ma-2 fault block of Huabei oil field. Bacterial metabolism and the capability of improving oil property were evaluated on oxygen-deficient condition. At 87℃ which reservoir temperature is, artificial homogeneous core displacement experiment indicated the enhanced oil recovery of microbe was 7.1% higher than that of waterflooding. In experiment on individual well Ma-410, additional oil production of 669 tons was gained, and decreased water production of this trial well reached more than 3000 tons. These results demonstrated NX-2 could adapt to stratum conditions, enhance oil recovery and improve oil property as well.
ABSTRACT
The optimum medium for Lactobacillus M7 was systematically studied with SAS system. Firstly, the prime factors affecting lactic acid yield were selected by means of Plackett-Burman design; secondly, the pnme facias were optimized by response rurface analysis. Under the optimum level determined, the yield is increased by 15%.
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Two Pseudomonas strains, K80 - B and K80 - A, can use hydrocarbon as carbon source by two different mechanisms. Different effects can be observed when they are applied to 69-8 oil of Dagan Oil Field. The strain K80-B producing both hydrocarbon pseudosolubilizing factor and hydrocarbon emulsifying factor can decrease the viscosity and solidifying point of the 69-8 oil 51.6% and 2℃ respectively. Whereas the other can only decrease 43.5% and 3℃ respectively. When the two strains are mixed, synergistic effect on crude oil is obvious.
ABSTRACT
A mixed bacteria culture F6 isolated from oil field wastewater can degrade petroleum hydrocarbons efficiently. The bacteria were suitable to treat oil-polluted wastewater of oil field. Simulated result treating oil-polluted wastewater in laboratory showed that after "XingyiLian" wastewater of Liaohe Oil Field was treated by fluidized-bed bioreactor system with the vehicle of activated carbon , the amount of oil and CODcr of the flow out water were decreased from 45mg/L to 4. 1mg/L and 470mg/L to 42mg/L separately , according with first class standards of Chinese Wastewater Discharge Regulation.
ABSTRACT
we first find that the protoplast of Xanthomonas campestris can synthesize and secret Xanthan in the high permeable nutrition containing sucrose as substrate.