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Biotechnology
Detection of Catabacter hongkongensis in polluted European water samples
Francesc CODONY, Bárbara ADRADOS, Leonardo Martín PÉREZ, Mariana FITTIPALDI, Jordi MORATÓ
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 867-869.   https://doi.org/10.1631/jzus.B0920218
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The Catabacteriaceae is a new bacterial family with a unique member: Catabacter hongkongensis is a strictly anaerobic, non-sporulating, Gram-positive coccobacillus that is phylogenetically related to some clostridial clusters. Little is known of its epidemiology and environmental distribution, but the inclusion of its 16S rRNA gene sequence in GenBank has allowed it to be detected qualitatively. As a first approach for prospective surveys, a real-time polymerase chain reaction (PCR) procedure to identify C. hongkongensis has been developed. The presence of Catabacteriaceae in 29 water bodies subjected to possible human or animal impact has been investigated. Four of them were positive. The results confirm that highly polluted water can contain C. hongkongensis.
Optimization of soybean (Glycine max (L.) Merrill) in planta ovary transformation using a linear minimal gus gene cassette
Ming LIU, Jun YANG, Yun-qing CHENG, Li-jia AN
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 870-876.   https://doi.org/10.1631/jzus.B0920204
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Soybean transformation by ovary-drip was improved by optimizing the length of the transformation pathway by cutting the styles. These modifications facilitated soybean transformation manipulation and improved transformation reproducibility and efficiency. Using a linear minimal gus gene cassette as the foreign DNA, a maximum transformation frequency of 11% was obtained in flowers of the soybean cultivar ‘Liaodou 14’ with their styles mostly removed, whereas removal of only the stigma, partial style cutting and partial ovary cutting gave transformation frequencies of 0%, 1%, and 2%, respectively. An average transformation frequency of 8.2% was obtained when 619 flowers from three soybean cultivars (‘Liaodou 14’, ‘Liaodou 13’, and ‘Tiefeng 29’) were transformed by this optimized method. Southern blotting analysis showed that the gus reporter gene (encoding β-glucuronidase) was stably inherited with a simple pattern. Reverse transcription-polymerase chain reaction (RT-PCR) and GUS staining confirmed the expression of the gus gene in transgenic plants.
Determination of benzalkonium chloride in viscous ophthalmic drops of azithromycin by high-performance liquid chromatography
Yan SHEN, Sheng-jie XU, Shi-chun WANG, Jia-sheng TU
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 877-882.   https://doi.org/10.1631/jzus.B0920229
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A high-performance liquid chromatography (HPLC) system was used in the reversed phase mode for the determination of benzalkonium chloride (BKC) in azithromycin viscous ophthalmic drops. A Venusil-XBP(L)-C18 (150 mm×4.6 mm, 5 μm) column was used at 50 °C. The mobile phase consisted of a mixture of methanol-potassium phosphate (16:5, v/v). Two sample preparation methods were compared. The results suggested that, compared with an extraction procedure, a deproteinization procedure was much quicker and more convenient. Using the deproteinization procedure for sample preparation, calibration curves were linear in the range 5.0~50 μg/ml. The within-day and inter-day coefficients of variation were less than 10%. The average recoveries were determined as 96.70%, 98.52%, and 97.96% at concentrations of 10.0, 30.0, and 50.0 μg/ml, respectively. Variability in precision did not exceed 5%. In conclusion, this HPLC method using a simple sample treatment procedure appears suitable for monitoring BKC content in azithromycin viscous ophthalmic drops.
Firmness measurement of peach by impact force response
Yong-wei WANG, Jun WANG, Chong YAO, Qiu-jun LU
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 883-889.   https://doi.org/10.1631/jzus.B0920108
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The impact force response of a peach impacting on a metal flat-surface was considered as nondestructive determination of firmness. The objectives were to analyze the effect of firmness, drop height, fruit mass, and impact orientation on the impact force parameters, and to establish a relationship between the impact force parameter and firmness. The effect of fruit firmness, drop height and fruit mass on the impact force parameters (coefficient of restitution, percentage of energy absorbed, and coefficient of force-time) was evaluated. The study found that the coefficient of restitution, percentage of energy absorbed, and force-time impact coefficient were significantly affected by fruit ripeness, but not affected by drop height, impact position (fruit cheek), and mass. The percentage of absorbed energy increased with ripeness, while the force-time impact coefficient and coefficient of restitution decreased with ripeness. Relationships were obtained between the three impact characteristic parameters (force-time impact coefficient, coefficient of restitution, and percentage of energy absorbed) and peach firmness using a polynomial model (R2=0.932), S model (R2=0.910), and exponential model (R2=0.941), respectively.
Bacterial and archaeal communities in the surface sediment from the northern slope of the South China Sea
Li LIAO, Xue-wei XU, Chun-sheng WANG, Dong-sheng ZHANG, Min WU
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 890-901.   https://doi.org/10.1631/jzus.B0920181
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Microbial diversity of sediments from the northern slope of the South China Sea was studied by constructing bacterial and archaeal 16S rRNA gene clone libraries. Fourteen bacterial phylogenetic groups were detected, including Gammaproteobacteria, Deltaproteobacteria, Planctomycetes, Alphaproteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Chloroflexi, Acidobacteria, Betaproteobacteria, Nitrospirae, candidate divisions OP8 and OP11, and an unknown group. Gammaproteobacteria was the predominant group in bacterial libraries with the percentage ranging from 31.8% to 63.2%. However, archaeal libraries had relatively lower diversity, with most clones belonging to marine archaeal group І uncultured Crenarchaeota. In addition, two novel euryarchaeal clones were detected not to match any culture-dependent or -independent isolates. Compared with other gas hydrate-rich ecosystems and different areas of the South China Sea, a distinct microbial community was revealed in this study.
Population growth, trophic level, and reproductive biology of two congeneric archer fishes (Toxotes chatareus, Hamilton 1822 and Toxotes jaculatrix, Pallas 1767) inhabiting Malaysian coastal waters
K. D. SIMON, Y. BAKAR, A. SAMAT, C. C. ZAIDI, A. AZIZ, A. G. MAZLAN
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 902-911.   https://doi.org/10.1631/jzus.B0920173
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Population growth, trophic level, and some aspects of reproductive biology of two congeneric archer fish species, Toxotes chatareus and Toxotes jaculatrix, collected from Johor coastal waters, Malaysia, were studied. Growth pattern by length-weight relationship (W=aLb) for the sexes differed, and exhibited positive allometric growth (male, female and combined sexes of T. chatareus; female and combined sexes of T. jaculatrix) and isometric growth (male samples of T. jaculatrix only). Trophic levels of both species were analyzed based on 128 specimens. The results show that, in both species, crustaceans and insects were the most abundant prey items, and among crustaceans the red clawed crab Sesarma bidens and Formicidae family insects were the most represented taxa. The estimated mean trophic levels for T. chatareus and T. jaculatrix were 3.422±0.009 and 3.420±0.020, respectively, indicating that they are largely carnivores. Fecundity of T. chatareus ranged from 38 354 to 147 185 eggs for females with total length ranging from 14.5 to 22.5 cm and total body weight from 48.7 to 270.2 g, and T. jaculatrix 25 251 to 150 456 eggs for females with total length ranging from 12.2 to 23.0 cm and total body weight from 25.7 to 275.0 g. Differences in values of gonadosomatic and hepatosomatic indexes calculated for both species in this study may have resulted from uneven sample size ranges.
Enhancing polyphenol extraction from unripe apples by carbohydrate-hydrolyzing enzymes
Hu-zhe ZHENG, In-Wook HWANG, Shin-Kyo CHUNG
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 912-919.   https://doi.org/10.1631/jzus.B0920186
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The effects of process variables such as enzyme types, enzyme ratio, reaction temperature, pH, time, and ethanol concentration on the extraction of unripe apple polyphenol were investigated. The results indicated that Viscozyme L had the strongest effect on polyphenols extraction and was selected to study the polyphenol composition. The ratio of enzyme (Viscozyme L) to substrate (2 fungal beta-glucanase units (FBG)) at 0.02, reaction at pH 3.7, 50 °C for 12 h, and ethanol concentration of 70% were chosen as the most favorable extraction condition. Total phenolic content (TPC), reducing sugar content (RSC), and extraction yield increased by about 3, 1.5, and 2 times, respectively, compared with control. The contents of p-coumaric acid, ferulic acid, and caffeic acid increased to 8, 4, and 32 times, respectively. The enzyme-aided polyphenol extraction process from unripe apples might be applied to food industry for enhancing bioactive compound production.
Biomedicine
Interleukin-6 polymorphisms modify the risk of periodontitis: a systematic review and meta-analysis
Mei-ying SHAO, Ping HUANG, Ran CHENG, Tao HU
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 920-927.   https://doi.org/10.1631/jzus.B0920279
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Objective: To clarify the association of IL-6 polymorphisms and periodontitis, a meta-analysis of case-control studies and a systemic review were conducted. Material and methods: We performed a literature search using PubMed and Medline database to May 2009, with no restrictions. We also reviewed references from all retrieved articles. Six case-control studies involving 1 093 periodontitis cases and 574 controls were selected for meta-analysis to assess the purported associations between IL-6 polymorphisms and the risk of periodontitis. IL-6 −174 G/C and −572 C/G polymorphisms were included in the present meta-analysis, and the association between IL-6 −6331 T/C polymorphism and the risk of periodontitis was adequately reviewed as well. Results and conclusion: The present meta-analysis indicates that the IL-6 −174 G allele could not modify the risk of chronic periodontitis, but increased the risk of aggressive periodontitis. And −572 C/G polymorphism is associated with the pathogenesis of periodontitis, including chronic periodontitis or aggressive periodontitis.
Magnetic cell sorting and flow cytometry sorting methods for the isolation and function analysis of mouse CD4+ CD25+ Treg cells
Hang YAN, Chen-guang DING, Pu-xun TIAN, Guan-qun GE, Zhan-kui JIN, Li-ning JIA, Xiao-ming DING, Xiao-ming PAN, Wu-jun XUE
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 928-932.   https://doi.org/10.1631/jzus.B0920205
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Objective: In this paper we compared the two methods of cell sorting (magnetic cell sorting and flow cytometry sorting) for the isolation and function analysis of mouse CD4+ CD25+ regulatory T (Treg) cells, in order to inform further studies in Treg cell function. Methods: We separately used magnetic cell sorting and flow cytometry sorting to identify CD4+ CD25+ Treg cells. After magnetic cell separation, we further used flow cytometry to analyze the purity of CD4+ CD25+ Treg cells, trypan blue staining to detect cell viability, and propidium iodide (PI) staining to assess the cell viability. We detected the immune inhibition of CD4+ CD25+ Treg cells in the in vitro proliferation experiments. Results: The results showed that compared to flow cytometry sorting, magnetic cell sorting took more time and effort, but fewer live cells were obtained than with flow cytometry sorting. The CD4+ CD25+ Treg cells, however, obtained with both methods have similar immunosuppressive capacities. Conclusion: The result suggests that both methods can be used in isolating CD4+ CD25+ Treg cells, and one can select the best method according to specific needs and availability of the methodologies.
Bacteremia due to Rhodococcus equi: a case report and review of the literature
Xi-yuan CHEN, Feng XU, Jing-yan XIA, Yu-sheng CHENG, Yan YANG
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2009, 10(12): 933-936.   https://doi.org/10.1631/jzus.B0920214
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Rhodococcus equi, previously known as Corynebacterium equi, is one of the most important causes of zoonotic infections in grazing animals. Increased cases of human infection with R. equi have been reported, especially in immunocompromised patients, within recent years. We present a case of R. equi bacteremia in a 51-year-old man with diabetes and liver cirrhosis, on long-term corticosteroid therapy after skin-grafting surgery. The patient recovered soon after he was treated with vancomycin. This review focuses on the microbiological characteristics of this organism, and the diagnosis and treatment of this infection.
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