[Identification and degradation capability of three pyrene-degrading Gordonia sp. strains].

Three pyrene-degrading bacterial strains named D44, D82S and D82Q were isolated from PAHs-contaminated soil in Shenfu Irrigation Area of Shenyang, Northeast China. The strains were identified as Gordonia sp., based on the morphological observation, physiological and biochemical identification, and phylogenetical analysis of 16S rDNA sequences. For all the three stains, their optimal pH was 7, and their growth was obviously inhibited when the pH was lower than 5 or higher than 9. The three strains were capable of utilizing pyrene, benzo[a] pyrene, anthracene, naphthalene, phenanthrene, and fluoranthene as the sole source of carbon and energy. After seven days incubation, the three strains could degrade more than 65% of pyrene with an initial concentration 100 mg x L(-1), and the D44, D82S, and D82Q could degrade 79.6%, 91.3%, and 62.8% of benzo[a] pyrene with an initial concentration 50 mg x L(-1), respectively. PCR amplification indicated that the strains D82Q and D82S possessed alkane monooxygenase gene alkB.

[Isolation and identification of a highly efficient pyrene-degrading Mycobacterium sp. strain N12].

By using selective enrichment method, a highly efficient pyrene-degrading bacterium strain N12 was isolated from an oil-contaminated soil collected from Shenfu irrigation area of Shenyang. Based on the physiological and biochemical characteristics and the phylogenetic similarity of 16S rDNA gene sequence, the strain N12 was identified as Mycobacterium sp. , which could utilize phenanthrene, acenaphthene, fluorine, and pyrene, but not anthracene, naphthalene, and benzo (a)pyrene as the sole carbon and energy source. However, when the strain N12 was cultured with pyrene and phenanthrene, 79.0% of benzo(a)pyrene could be co-metabolized within 9 days. The degradation rate of 100 mg x L(-1) of pyrene by the strain N12 was 94.4% within 7 days and 100% after 14 days, and that of 600 mg x L(-1) of pyrene was 56.1% within 7 days and 95.5% within 14 days. The addition of glucose promoted the degradation of pyrene. It was suggested that the strain N12 was an efficient PAHs-degrading bacterium, being a potential candidate for the bioremediation of PAHs-contaminated soils.

[Optimum of polysaccharide distillation on scrap Cordyceps militaris medium].

A mass of scrap Cordyceps militaris solid culture medium could not be utilized better. In this test, using orthogonal design the optimal technique parmeter of extracting polysaccharide was 80 degrees C, two times, in twenty times of water, and 120 minutes each time. Temperature was the most important factor. The referenced data could be provided to depurative production of Cordyceps militaris and resource utilization.

[Study on the immunogenicity of major leptospiral genus-specific protein antigens and the distribution of antigens in different serogroups of Leptospira interrogans].

OBJECTIVE: The determination of antigenicity and immunogenicity of Leptospira interrogans genus-specific outer envelope proteins (OEPs) will offer evidence for developing universal leptospiral genetic engineering vaccine and detection kit. METHODS: In this study, Ni-NTA affinity chromatography is used to purify the recombinant products rLipL21, rOmpL1/1, rOmpL1/2, rLipL32/1, rLipL32/2, rLipL41/1 and rLipL41/2 expressed by the major genotypes of four leptospiral OEPs of 15 serogroups. SDS-PAGE is applied to examine the expression and purity of the recombinant proteins. Rabbits are intracutaneously immunized with the recombinant proteins to obtain antisera. Microscope agglutination test (MAT) is used to measure the cross inmmunoagglutination titers of antisera. The OMPs of the reference standard strains belonging to 15 serogroups of L. interrogans in China and L. biflexa strain Patoc I are prepared using salt-denature method. By each of the antisera as the first antibody, Western blot assay is established to detect the natural expressions and immunoreactivity of the four OEPs. RESULTS: The outputs of rLipL21, rLipL32/1, rLipL32/2, rLipL41/1l, rLipL41/2, rOmpL1/1 and rOmpL1/2 are 10%, 40%, 35%, 15%, 10%, 30% and 15%, respectively. Each the purified recombinant proteins shows a single fragment after SDS-PAGE. Each the rabbit antisera displays extensive cross immunoreactivity between the products expressed by different genotypes of the same gene and the MAT titers ranging from 1:2-1:128. All the four OEPs can be detectable in the OEPs preparations. However, LipL21 is found to exist only in L. interrrogans. CONCLUSION: The results of this study indicate that all the four OEPs are superficial genus-specific antigens of Leptospira which can be used as the candidate antigens of leptospiral universal vaccine and detection kit.