Taxonomic identification, phenol biodegradation and soil remediation of the strain Rhodococcus sacchari sp. nov. Z13T.

Phenols are highly toxic chemicals that are extensively used in industry and produce large amounts of emissions. Notably, phenols released into the soil are highly persistent, causing long-term harm to human health and the environment. In this study, a gram-positive, aerobic, and rod-shaped bacterial strain, Z13T, with efficient phenol degradation ability, was isolated from the soil of sugarcane fields. Based on the physiological properties and genomic features, strain Z13T is considered as a novel species of the genus Rhodococcus, for which the name Rhodococcus sacchari sp. nov. is proposed. The type strain is Z13T (= CCTCC AB 2022327T = JCM 35797T). This strain can use phenol as its sole carbon source. Z13T was able to completely degrade 1200 mg/L phenol within 20 h; the maximum specific growth rate was µmax = 0.93174 h-1, and the maximum specific degradation rate was qmax = 0.47405 h-1. Based on whole-genome sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, strain Z13T contains a series of phenol degradation genes, including dmpP, CatA, dmpB, pcaG, and pcaH, and can metabolize aromatic compounds. Moreover, the potential of strain Z13T for soil remediation was investigated by introducing Z13T into simulated phenol-contaminated soil, and the soil microbial diversity was analyzed. The results showed that 100% of the phenol in the soil was removed within 7.5 d. Furthermore, microbial diversity analysis revealed an increase in the relative species richness of Oceanobacillus, Chungangia, and Bacillus.

Investigations on the Band-Gap Characteristics of Variable Cross-Section Periodic Structure Support Made of Acrylonitrile-Butadiene-Styrene.

Based on the band gap theory of periodic structure, this article proposes a new variable cross-section periodic structure support made of acrylonitrile-butadiene-styrene. The band gap characteristics of the periodic structure support were studied experimentally. According to the basic theory of band gap calculation, two kinds of supports with the same installation size were designed, and they were manufactured by 3D printer. Then, the displacement-load curve and the vibration characteristic curves of the periodic structure support were obtained through simulation analysis. The band gap range of the two supports was measured by hammer excitation, and the accuracy of the finite element model was verified by comparison with the experiment results. Finally, the response curve of the periodic structure support with variable cross-section every 100 Hz was obtained by excitation of the shaker, which verified the vibration isolation effect of the measured band gap. The results show a band gap in the support of the variable cross-section periodic structure, compared with the support of the non-periodic structure. If the vibration frequency is within the band gap frequency, the vibration will be significantly attenuated.

Biodesulfurization of diesel oil in oil-water two phase reaction system by Gordonia sp. SC-10.

OBJECTIVES: Different sulfur contents of diesel oils were used for biodesulfurization to study the desulfurization capacity of Gordonia sp. SC-10 in oil-water two-phase reaction system. RESULTS: Gordonia sp. SC-10 showed great properties in desulfurizing diesel oil with different sulfur contents. This bacterium could decrease sulfur contents in different diesel oils from 194.7 ± 3.7 to 30.4 ± 0.5 mg/l and from 3035.3 ± 23.8 to 1792.8 ± 48.9 mg/l, respectively. Furthermore, this bacterium could desulfurize broad range of organosulfur compounds and had strong desulfurization activity against alkylated DBTs. For low-sulfur diesel oil, sulfur could be removed from 10.2 ± 0.1 to 5.0 ± 0.1 mg/l. CONCLUSIONS: The newly isolated bacteria Gordonia sp. SC-10 showed a good performance in desulfurizing diesel oils, and it might be a useful desulfurizing biocatalyst to enable the industrialized application of biodesulfurization process.

Thermophilic biodesulfurization and its application in oil desulfurization.

To reduce the harm caused to the environment by fuel combustion and meet the increasingly stringent emission standards, the sulfur content of fuels should be reduced. Dibenzothiophene, benzothiophene, and their derivatives are sulfur-containing components of fuels that are difficult to desulfurize and can therefore cause great environmental damage. Biodesulfurization is a desulfurization method that has the advantage of being able to remove dibenzothiophene and its derivatives removed easily under conditions that are relatively mild when compared with hydrodesulfurization. This paper introduces the advantages of thermophilic biodesulfurization compared with mesophilic biodesulfurization; analyzes the desulfurization mechanism, including the desulfurization pathways and enzymic systems of desulfurization bacteria; and discusses the application of biodesulfurization in oil desulfurization. The main problems existing in biodesulfurization and possible solutions are also analyzed in this paper. Biological desulfurization is a promising method for desulfurization; accordingly, more studies investigating biodesulfurization of actual oil are needed to enable the industrialized application of biodesulfurization.

[Regulatory Role of Nitric Oxide in Development and Hatching of Mouse Blastocysts].

OBJECTIVE: To determine the regulatory role and mechanism of nitric oxide (NO) in the development and hatching of mouse blastocysts. METHODS: The Kunming female mice were superovulated and then mated with mature male mice. On the day 2.5 of their pregnancy, morulae were flushed from their uterine horns with culture media. Morulae were cultured in different concentrations of N-nitro-L arginine methyl ester (L-NAME), sodium nitroprusside (SNP), or the combination of L-NAME and SNP in culture media for 48 hours. The development and hatching of blastocysts were examined on day 4 and day 5 and the total numbers of blastocyst cells and cysteinyl aspartate specific proteinase 3 (caspase 3) were observed under confocal laser scanning microscope. RESULTS: With the increase of the concentration of L-NAME or SNP, the hatching rate of blastocysts and the total number of blastocyst cells were significantly reduced. The addition of 10 nmol/L SNP in culture media with 5 mmol/L L-NAME significantly increased the development of blastocysts and promoted hatching of blastocysts. However, with increase of SNP concentration in culture media with 5 mmol/L L-NAME, the development and hatching rates of blastocysts were significantly decreased. L-NAME had no obvious effect on the expression of active caspase 3 in blastocyst cells. However,when being above 500 nmol/L,SNP significantly increased the expression of caspase 3 in blastocyst cells. CONCLUSIONS: NO plays an important role in development and hatching of mouse blastocysts. Excessively high or low NO can damage the division of blastomeres, resulting in the failure of the blastocyst development and hatching. Also, excessively high NO can lead to the apoptosis of the blastocyst cells.

Immunological response in H22 transplanted mice undergoing Aconitum coreanum polysaccharide treatment.

In this study, a polysaccharide (ACP-a1), with a molecular weight of 3.2×10(5)Da, was successfully purified and identified from the roots of Aconitum coreanum (Lèvl.) Rapaics. Gas chromatography (GC) analysis indicated that ACP-a1 was mainly composed of ß-d-mannose and ß-d-glucose in a molar ratio of 1.2:3.5. The effects of ACP-a1 on the tumor growth and immune function were assessed in hepatoma H22 bearing mice. Results showed that ACP-a1 significantly inhibited the growth of hepatoma H22 transplanted in mice and prolonged the survival time of H22 tumor-bearing mice. Besides, the body weight, peripheral white blood cells (WBC), thymus index and spleen index of H22 tumor-bearing were also improved after ACP-a1 treatment. Furthermore, ACP-a1 could promote the secretion of serum cytokines in H22 tumor-bearing mice, such as IL-2, TNF-α and IFN-γ. Taken together, our results indicate that ACP-a1 inhibits tumor growth in vivo at least partly via improving immune responses of host organism, and seems to be safe and effective as a novel agent with immunomodulatory activity for the use of anti-tumor therapy.

[Study in the killing effect of Myxoma virus to C6 glioma cell in vitro].

OBJECTIVE: To evaluate the susceptibility of C6 glioma cells to Myxoma virus and the killing effect of Myxoma virus to the C6 glioma cells in vitro. METHODS: C6 glioma cells were infected with myxoma virus, used death virus as the negative control, 5-FU as the positive control, DEMD as blank control. The number of living cells were counted every 24 h, and Western-Blot method, inverted microscope and MTT assay were applicated to observe the cell morphology and survival rate in each group. RESULTS: The cell number were decreased rapidly in virus effected group and 5-FU group, with significant differences to the negative and blank control groups. And cells in virus effected group appeared cytopathic effect. CONCLUSIONS: C6 glioma cells were susceptible to myxoma virus and myxoma virus had killing effect to C6 glioma cells in vitro.

[Comparative study of chemosensitivity and efficacy between pirarubicin and epirubicin in breast cancer].

OBJECTIVE: To compare the chemosensitivity of pirarubicin (THP) and epirubicin (EPI) in primary breast cancer (PBC) cells so as to examine their differential chemosensitivity to THP and EPI by CD-DST (collagen gel droplet embedded culture-drug sensitivity test) system; To detect the differences in the short-term clinical efficacy and side effects between TAC (docetaxel + pirarubicin + cyclophosphamide) and TEC (docetaxel + epirubicin + cyclophosphamide) as the neoadjuvant chemotherapy regimens and the long-term clinical efficacy of CAF (cyclophosphamide + pirarubicin + fluorouracil) and CEF (cyclophosphamide + epirubicin + fluorouracil) as the chemotherapy regimens in breast cancer; To evaluate the feasibility of THP as an adjuvant chemotherapeutic regimen in the treatment of breast cancer. METHODS: From January 2008 to January 2009, a total of 129 fresh breast cancer samples were collected. The differential chemosensitivity of cultured PBC cells to THP and EPI was measured by CD-DST test. And 139 cases of PBC patients inIIb-IIIc phase were randomly divided into two groups: TAC and TEC groups. After 4-6 cycles of neoadjuvant chemotherapy, the primary lesion, axillary lymph nodes and side effects were assessed; The clinical data and survival status of 1241 cases of PBC patients treated at our hospital from 2003 to 2006 were collected and divided into CAF and CEF groups according to their chemotherapeutic regimens. Long-term prognosis was compared between two groups. RESULTS: There was no significant difference of chemosensitivity between THP and EPI in PBC cells (P = 0.743); The overall response rate (RR) of neoadjuvant chemotherapy was 87.8%; the clinical objective responses, pathologic complete remission (pCR), clinical complete remission (cCR), clinical partial remission (cPR) and stable disease (SD) of groups TAC and TEC were 88.7%, 11.3%, 28.2%, 60.6%, 11.3% vs 86.8%, 10.3%, 26.5%, 60.3%, 13.2% respectively. There was no significant difference between two groups (P > 0.05). No significant differences existed between two groups in such side effects as leukopenia, thrombocytopenia, constipation, cardiotoxity and hepatorenal dysfunction (P > 0.05). The gastrointestinal reactions of nausea and vomiting was less frequent in the TAC group than that in the TEC group (46.5% vs 66.2%, P = 0.019); There was no significant difference in 5-year disease-free survival rate (79% vs 78%) and overall survival rate between two groups (85% vs 82%, P > 0.05). CONCLUSION: There were no significant differences in chemosensitivity, clinical efficacy of neoadjuvant chemotherapy, side effects or long-term efficacy between THP and EPI. Both pirarubicin and epirubicin may be used as conventional chemotherapy in breast cancer.

Expression of Inducible Nitric Oxide Synthase Gene in Neuronal Cells Mediated by Retrovirus Vector.

The role of an inducible nitric oxide synthase (iNOS)expression in the mechanisms of opioid tolerance and dependence was investigated. A recombinant retroviral expression vector containing a cDNA fragment of iNOS was transfected into the neuroblastomaxglioma NG108-15 cells by lipofectamine gene transferring technique. G418-resistant clones were selected and were named NG-LNCXiNOS cells. Using Southern blot, PCR amplification for Neo gene, RT-PCR and Western blot analysis, NG-LNCXiNOS cells were confirmed to have an integral exogenous iNOS gene which was being transcribed and translated into protein. NADPH-diaphorase (NADPH-d) histochemical staining and immunohistochemical staining with iNOS-specific antibody demonstrated that high-level expression of iNOS protein was present in the cytoplasm of NG-LNCXiNOS cells. The catalytic activity and NO( )(2) content in supernatant medium were obviously enhanced in iNOS gene-transfected cells. The results show that the biochemical and pharmacological properties of the recombinant enzyme were similar to those of native enzyme. The recombinant enzyme activity was completely dependent on NADPH and failed to be stimulated by the addition of calcium and calmodulin. Chelating agents failed to decrease its activity. NOS inhibitors could markedly reduce NO( )(2) production at a concentration-dependent manner. The expression of iNOS gene was involved in the up-regulation of NO-cGMP signal transduction cascade. Therefore, an iNOS gene-modified neuronal cell line was successfully established, offering an excellent model system for seeking and screening new drugs to treat opioid tolerance and dependence.