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Chen J.,Municipal Key Laboratory of Microorganism and Environmental Engineering | Chen J.,Zhejiang Wanli University | Li W.,Zhejiang Wanli University | Luo N.,Zhejiang Wanli University | And 4 more authors.
Chinese Journal of Applied and Environmental Biology | Year: 2010

An extracellular protease producing strain ArcB82306 was isolated from Canada Basin seawater in the Arctic. 16S rDNA gene sequencing analysis indicated that strain ArcB82306 was a member of Pseudoalteromonas. Zymogram analyses revealed four or more proteolytic active bands in the culture supernatant. The optimum temperature and pH for the proteolytic activity were 45 °C. and 9, respectively. The enzyme activities were inhibited by PMSF but not by EDTA and E-64, indicating that the protease was serine protease. The activity of protease was not substantially inhibited by the heavy metals Ni2+, Zn 2+, Hg2+, Cu2+, Fe3+, Ca 2+ and Mg2+. Reducing agents as DTT and mercaptoehanol and surfactants like Triton X-100 and Tween-80 did not reduce the protease activity. Fig 6, Tab 1, Ref 16. Source


Yang J.-F.,Municipal Key Laboratory of Microorganism and Environmental Engineering | Yang J.-F.,Zhejiang Wanli University | Yang J.-F.,Huazhong Agricultural University | Chen J.-G.,Municipal Key Laboratory of Microorganism and Environmental Engineering | And 2 more authors.
Evidence-based Complementary and Alternative Medicine | Year: 2011

For the first time, a mollicute-like organism (MLO) was cultured from moribund mud crabs (Scylla serrata) during an outbreak of clearwater disease in Zhejiang Province, China. The MLO displayed a fried-egg colony morphology in culture, did not possess a cell wall, and was not retained by 0.45 μm and 0.2 μm filters. It was able to ferment glucose, sucrose, lactose, and maltose, but it did not utilize arginine and urea. The MLO grew in the absence of bovine serum and was not susceptible to digitonin. Sequence analysis of the 16SrRNA gene revealed that this MLO had 99 identity with Acholeplasma laidlawii PG-8A, which indicates that the organism isolated from mud crabs is a member of the genus Acholeplasma. © 2011 Ji-Gang Chen et al. Source


Chen J.-G.,Zhejiang Wanli University | Chen J.-G.,Municipal Key Laboratory of Microorganism and Environmental Engineering | Yang J.-F.,Zhejiang Wanli University | Yang J.-F.,Municipal Key Laboratory of Microorganism and Environmental Engineering | And 7 more authors.
Agricultural Sciences in China | Year: 2010

Glaciecola polaris strain ARK149, a Gram-negative bacterium from Arctic seas, was used to derive lipopolysaccharide (LPS), and the effect of the LPS inducing some innate immunity parameters was investigated in Japanese sea bass, Lateolabrax japonicus. The results showed that the LPS could enhance the phagocytosis activity, lysozyme activity, and bacteriolytic activity in L. japonicus, significantly (P < 0.05) at 1, 7, 14, 21, 28, and 35 d after LPS-injection. The indexes of three parameters increased to the peak of value at 28th d post LPS-injection. Moreover, RT-PCR analysis suggested that LPS significantly up-regulated the expression of both IL-8 and hepcidin in several tissues. These data suggest that the LPS extracted from Glaciecola polaris strain ARK149 can induce innate immunity in L. japonicus. © 2010 Chinese Academy of Agricultural Sciences. Source


Wang H.-L.,Municipal Key Laboratory of Microorganism and Environmental Engineering | Wang H.-L.,Zhejiang Wanli University | Yang J.-F.,Municipal Key Laboratory of Microorganism and Environmental Engineering | Yang J.-F.,Zhejiang Wanli University | And 4 more authors.
Chinese Journal of Ecology | Year: 2011

In July (summer) and October (autumn) 2007 and in January (winter) and April (spring) 2008, an investigation was made on the spatiotemporal distribution of nitrifying and denitrifying bacteria in the surface seawater, overlying water, and sediment in Xiangshan Bay. A cylindrical high-fidelity gravity sampler instead of conventional grab sampler was used for collecting samples, and principal component analysis and multivariate linear stepwise regression analysis were adopted to analyze the relationships between bacterial abundance and environmental parameters. The abundance of nitrifying and denitrifying bacteria in the water and sediment in July and October 2007 and in January and April 2008 ranged from 30×104 -2.4×104 cells·ml-1 and 30×104 -2.4×104 cells·g-1, with the mean values in surface water, overlying water, and sedi-ment being 2.24×104 cells·ml-1, 3.61×104 cells·ml-1, and 6.45×104 cells·g-1, respectively for nitrifying bacteria, and 4.84×104 cells·ml-1, 5.31×104 cells·ml-1, and 3.12×104 cells ·g-1, respectively for denitrifying bacteria. The abundance of nitrifying bacteria in surface seawater and overlying water was significantly higher in winter, compared to other three seasons, and that in sediment was higher in autumn and winter, compared to the other two seasons. For denitrifying bacteria, its abundance was higher in autumn and summer than in spring and winter. In investigation period, there was an apparent spatial distribution of nitrifying and denitrifying bacterial abundance in the Bay. Vertically, the abundance of denitrifying bacteria was higher in surface water than in overlying water and sediment, but that of nitrifying bacteria was in adverse; horizontally, the abundance of both nitrifying and denitrifying bacteria was significantly higher in the middle part of the Bay and in the junction of branch and main ports. Such a spatial distribution pattern of nitrifying and denitrifying bacteria in the Bay demonstrated that the coastal land pollution from human industrial and agricultural activities and mariculture played key roles. Multivariate statistical analysis demonstrated that nutrients N and P, dissolved oxygen, water temperature, salinity, organic pollution, and primary productivity were the main factors affecting the spatiotemporal distribution of nitrifying and denitrifying bacteria in Xiangshan Bay. Source


Yang J.,Huazhong Agricultural University | Yang J.,Municipal Key Laboratory of Microorganism and Environmental Engineering | Yang J.,Zhejiang Wanli University | Wang H.,Municipal Key Laboratory of Microorganism and Environmental Engineering | And 7 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2011

Marine bacteria in water or sediment are often closely linked to environmental conditions in their surrounding, thus influencing their distribution and abundance. In order to estimate the distribution of marine bacteria in Xiangshan Bay, undisturbed overlying seawater, sediment and surface seawater bacteria were analysed by staining with 4, 6-Diamidino-2- Phenylindole and observed with Epifluorescence Microscope (EFM). Environmental parameters such as seawater temperature (ST), salinity (SS), pH, dissolved oxygen (DO), chemical oxygen demand (COD) as well as NO - 3-N, NO - 2-N, DIN, NH + 4-N, DIP, TN, PO 3- 4-P and chlorophyll a (Chla) values were measured at the same time. Samples were collected with a cylindrical high fidelity gravity sampler instead of the conventional grab sampler. Bacteria abundance in July 2007, October 2007, January 2008 and April 2008, representing the situation for summer, autumn, winter and spring, ranged from 1.50×10 5 to 9.78×10 10 cells/mL (cells/g), with a mean of 2.76×10 9 cells/mL (cells/g). Significantly high values could be observed for bacteria abundance in July (summer) compared to other sampling time. A red tide outbreak during the sampling event in April 2008 could have contributed to the lowest bacteria abundance value observed for the whole study period. In vertical direction, the number of bacteria in the overlying water or in the sediment was higher than that in the surface seawater. The mean number of bacteria abundance in overlying water, in the sediment and in surface seawater was 9.70× 10 7 cells/mL, 7.40×10 9cells/mL and 4.61 ×10 9 cells/mL respectively. In horizontal direction, we draw the contour maps of the number of bacteria with the software 'surfer 8.0'. According to the contour map we found that the number of bacteria decreased from the top to the mouth of the bay with higher abundance near the breeding areas. Very high values of bacteria abundance was also observed near power plant: sample from station S25 showed higher bacteria abundance than other stations during all the cruises. Seawater temperature, the nutrients (NO - 3-N, DIN), pH, Chla and COD of the surface seawater were significantly positive (P < 0.01) correlated with the bacteria abundance of the surface seawater while DO and the nutrients (NH + 4-N) of the surface seawater were significant negative correlated (P < 0.01) with the bacteria abundance of the surface seawater. Bacteria abundance of overlying seawater were significant positive correlated (P <0.01) to seawater temperature, the nutrients (NO - 2-N, DIP) and the pH of bottom seawater whereas DO was significant negative correlated (P < 0.01). The results of multivariate statistical analysis showed that dissolved oxygen, seawater temperature, the nutrients (N, P), pH and organic pollution were the main factors influencing the abundance and distribution of marine bacteria in Xiangshan Bay. Such spatial distribution of bacteria demonstrated that anthropogenic coastal land pollution from industrial and agricultural activities and from maricultures played the key roles in the occurrence of marine benthic bacteria. Source

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