A broad-host-range lytic phage vB_VhaS-R18L as a candidate against vibriosis

Vibriosis is one of the most common bacterial diseases that cause high rates of mortality and considerable economic losses in aquaculture. Phage therapy has been considered as a promising alternative method to antibiotics in the biocontrol of infectious diseases. Genome sequencing and characterization of the phage candidates are prerequisites before field applications to ensure environmental safety. In this study, a lytic phage, named vB_VhaS-R18L (R18L), was isolated from the coastal seawater of Dongshan Island, China. The phage was characterized in terms of morphology, genetic content, infection kinetics, lytic profile, and virion stability. Transmission electronic microscopy indicated that R18L is siphovirus-like, comprising an icosahedral head (diameter 88.6 ± 2.2 nm) and a long noncontractile tail (225 × 11 nm). Genome analysis indicated R18L to be a double-stranded DNA virus with a genome size of 80,965 bp and a G + C content of 44.96%. No genes that encode known toxins or genes implicated in lysogeny control were found in R18L. A one-step growth experiment showed that R18L had a latent period of approximately 40 min and a burst size of 54 phage particles per infected cell. R18L showed lytic activity against a wide range of at least five Vibrio species (V. alginolyticus, V. cholerae, V. harveyi, V. parahemolyticus, and V. proteolyticus). R18L was relatively stable at pH 6–11 and at temperatures ranging from 4°C to 50°C. The broad lytic activity across Vibrio species and the stability in the environment make R18L a potential candidate for phage therapy in controlling vibriosis in aquaculture systems

Nicotianamine, a Novel Enhancer of Rice Iron Bioavailability to Humans

Background: Polished rice is a staple food for over 50 % of the world’s population, but contains little bioavailable iron (Fe) to meet human needs. Thus, biofortifying the rice grain with novel promoters or enhancers of Fe utilization would be one of the most effective strategies to prevent the high prevalence of Fe deficiency and iron deficiency anemia in the developing world. Methodology/Principal Findings: We transformed an elite rice line cultivated in Southern China with the rice nicotianamine synthase gene (OsNAS1) fused to a rice glutelin promoter. Endosperm overexpression of OsNAS1 resulted in a significant increase in nicotianamine (NA) concentrations in both unpolished and polished grain. Bioavailability of Fe from the high NA grain, as measured by ferritin synthesis in an in vitro Caco-2 cell model that simulates the human digestive system, was twice as much as that of the control line. When added at 1:1 molar ratio to ferrous Fe in the cell system, NA was twice as effective when compared to ascorbic acid (one of the most potent known enhancers of Fe bioavailability) in promoting more ferritin synthesis. Conclusions: Our data demonstrated that NA is a novel and effective promoter of iron utilization. Biofortifying polished rice with this compound has great potential in combating global human iron deficiency in people dependent on rice for thei

Pleomorphobacterium xiamenense gen nov, sp nov, a moderate thermophile isolated from a terrestrial hot spring

Scientific Research Project of Marine Public Welfare Industry of China [201205020, 201005032, 200805032]An aerobic, motile, moderately thermophilic rod, designated strain CLWT, was isolated from a terrestrial hot spring in an exposition garden in Xiamen City, Fujian Province, the People's Republic of China. Strain CLWT formed beige, dry colonies on solid 2216E medium and flocks in liquid medium. Cells were Gram-stain-negative, short rods (1.0-3.0 mu m long and 0.4-0.6 mu m wide) with six or more polar flagella. The temperature and pH for growth of strain CLWT were 28-65 degrees C (optimum, 50-58 degrees C) and pH 5.5-9.5 (optimum, pH 6.0-8.0). Growth occurred in the presence of 0.3-6.0% NaCl (optimum 2.5-4.5 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that the closest relative of the isolate was Amaricoccus kaplicensis Ben 101(T) (94.3 % sequence similarity). The DNA G+C content of strain CLWT was 72.2 mol%. The respiratory quinone was ubiquinone 10. The predominant polar lipids consisted of phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids (>10%) were summed feature 8 (consisting of C-18:1 omega 7c and/or C-18.1 omega 6c), C-18:1 omega 7c 11-methyl and C-18:0. Based on phylogenetic, physiological and biochemical data and DNA G+C content, strain CLWT is considered to represent a novel species of a new genus in the family Rhodobacteraceae, for which the name Pleomorphobacterium xiamenense gen. nov., sp. nov. is proposed. The type strain of the type species is CLWT (=LMG 26245(T)=CGMCC 1.10808(T)=MCCC 1A06272(T))

Albidovulum xiamenense sp nov., a moderately thermophilic bacterium from a terrestrial hot spring

An aerobic, motile, moderately thermophilic, rod-shaped bacterium, strain YBY-7(T), was isolated from a terrestrial hot spring of a garden exhibition located in Xiamen City, Fujian Province, People's Republic of China. Cells of strain Y8Y-7(T) were Gram-negative, irregular rods, 2-6 mu m long and 0.4-0.6 mu m wide, with polar flagella, and the organism formed beige colonies. The temperature and pH ranges for growth of strain YBY-7(T) were 28-65 degrees C (optimum 50-58 degrees C) and pH 6.5-9.5 (optimum pH 7.5-8.5). Growth occurred in the presence of 5.5% NaCl (optimum 3.0%). Phylogenetic analysis based on the 16S rRNA gene sequence revealed that Albidovulum inexpectatum FRR-10(T) was its closest neighbour (95.9% similarity). Ubiquinone (Q-10) was the sole respiratory quinone and the DNA G+C content of strain YBY-7(T) was 70.6 mol%. The predominant polar lipids were phosphatidylcholine, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were C-18:1 omega 7c (29.3%), C-19:0 cyclo omega 8c (25.6%), C-18:0 (23.6%) and C-16:0 (9.6%). Based on its physiological characteristics and our phylogenetic analysis, we propose that strain YBY-7(T) represents a novel species of the genus Albidovulum, for which the name Albidovulum xiamenense sp. nov. is proposed, with the type strain YBY-7(T) (=MCCC 1A06317(T) =CGMCC 1.10789(T) =LMG 26247(T)).Scientific Research Project of Marine Public Welfare Industry of China [200805032, 201205020

几种环境因子对虾蟹类非特异性免疫的影响(英文)

【中文摘要】 综述了近10a国内外有关重金属、氨态氮、亚硝酸盐、有机污染物等几种环境因子对虾蟹类非特异性免疫影响的研究成果,以期为通过改善养殖环境条件提高虾蟹类自身免疫抗病力提供理论依据。同时,为进一步深入开展该领域的研究工作积累资料。 【英文摘要】 This paper attempted to review and evaluate existing information about the effects of heavy metal,ammonia-N,nitrite and the organic pollutants on the non-special immune response of the shrimp and crab,which providing theory for improving the self-immunity of shrimp and crab by meliorating cultural environment. In addition,it could provide information for further study on this field

Characteristics of transgenic lines constitutively expressing NAS1 gene.

<p>(A) Thirty five day-old seedlings of UB1, UB2, and WT grown in nutrient solutions, bar = 2 cm. (B) NA concentration in leaves and unpolished grains of transgenic line EN1, EN2, UB1 and UB2. (C) and (D) Fe and Zn concentration in leaves of transgenic line EN1, EN2, UB1 and UB2, respectively. UB1 and UB2 are two transgenic lines overexpressing the <i>OsNAS1</i> gene in all tissues under the control of maize ubiquitin promoter.</p

Overexpression of the <i>OsNAS1</i> gene in rice endosperm.

<p>(A) Schematic representation of the T-DNA in rice transformation vector. GluB-1, 2.3 kilo-base-pair rice glutelin B1 promoter; <i>NAS1</i>, coding sequence of rice <i>OsNAS1</i> gene; Tnos, nopaline synthase terminator; 2×35S, double CaMV 35S promoter; TEV, tobacco etch virus 5′ untranslated region; <i>bar</i>: phosphinothricin acetyltransferase gene; Tvsp: soybean vegetative storage protein terminator; LB and RB, left and right T-DNA borders, respectively. (B) Reverse transcriptase PCR of <i>OsNAS1</i> in EN1-EN4 transgenic and WT immature grains. EN1-EN4 are four transgenic lines overexpressing <i>OsNAS1</i> in endosperm. <i>OsACTIN</i> was used as the internal standard. Total RNAs were extracted from the immature seeds 18 days after pollination. (C) Thirty five day-old seedlings of EN1, EN2, and WT grown in nutrient solutions, bar = 2 cm.</p

Nicotianamine (NA), Fe and Zn concentrations in the wild type (WT) and transgenic rice grain (EN1, EN2, EN3 and EN4).

<p>(A) NA concentration in unpolished grain (UPG) and polished grain (PG). (B) Fe and Zn concentrations in UPG and PG. EN1-EN4, four pGluB1-NAS1 independent transgenic lines. Asterisks indicate significant differences in NA, Fe or Zn concentrations between transgenic lines and WT (P≤0.05).</p