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71.
A bacterial strain capable of utilizing E-pyridine-3-aldoxime as a nitrogen source was isolated from soil after a 4-month acclimation period and was identified as
Rhodococcus sp. The strain contained a novel aldoxime dehydration activity that catalyzed a stoichiometric dehydration of E-pyridine-3-aldoxime to form 3-cyanopyridine. The enzyme activity was induced by various aldoximes and nitriles. The strain
metabolized the aldoxime as follows: E-pyridine-3-aldoxime was dehydrated to form 3-cyanopyridine, which was converted to nicotinamide by a nitrile hydratase,
and the nicotinamide was successively hydrolyzed to nicotinic acid by an amidase.
Received: 21 January 1998 / Accepted: 12 May 1998 相似文献
72.
Esther Shuyi Gan Wei Fun Cheong Kuan Rong Chan Eugenia Ziying Ong Xiaoran Chai Hwee Cheng Tan Sujoy Ghosh Markus R Wenk Eng Eong Ooi 《The EMBO journal》2017,36(10):1348-1363
Dengue virus (DENV) has been found to replicate in lymphoid organs such as the lymph nodes, spleen, and liver in post‐mortem analysis. These organs are known to have low oxygen levels (~0.5–4.5% O2) due to the vascular anatomy. However, how physiologically low levels of oxygen affect DENV infection via hypoxia‐induced changes in the immune response remains unknown. Here, we show that monocytes adapted to 3% O2 show greater susceptibility to antibody‐dependent enhancement of DENV infection. Low oxygen level induces HIF1α‐dependent upregulation of fragment crystallizable gamma receptor IIA (FcγRIIA) as well as HIF1α‐independent alterations in membrane ether lipid concentrations. The increased FcγRIIA expression operates synergistically with altered membrane composition, possibly through increase membrane fluidity, to increase uptake of DENV immune complexes for enhanced infection. Our findings thus indicate that the increased viral burden associated with secondary DENV infection is antibody‐dependent but hypoxia‐induced and suggest a role for targeting hypoxia‐induced factors for anti‐dengue therapy. 相似文献
73.
Maizura Ithnin Yang Xu Marhalil Marjuni Norhalida Mohamed Serdari Mohd Din Amiruddin Eng-Ti Leslie Low Yung-Chie Tan Soon-Joo Yap Leslie Cheng Li Ooi Rajanaidu Nookiah Rajinder Singh Shizhong Xu 《Tree Genetics & Genomes》2017,13(5):103
Palm oil has a balanced fatty acid composition and has no trans fat. As a result, its use in food has increased as food-labeling laws have changed to specify trans fat content. Increasing oil production is the main goal in oil palm breeding. Genetic mapping and genomic studies in palm trees are necessary to understand the genetic architecture of economic traits of importance for palm oil production. To help achieve this, we sampled 422 oil palms from MPOB (Malaysian Palm Oil Board)Angola germplasm collection and measured 13 economic traits from these palms. Multi-locus genome-wide association studies (GWAS) were conducted using least absolute shrinkage and selection operator (LASSO) and genome-wide efficient mixed model analysis. We identified 19 quantitative trait loci (QTLs) for 8 traits. Of these, four Angola-specific QTLs associated with bunch components were detected on chromosomes 4, 8, and 11. These QTLs are potentially useful for introgression of desirable genes from the Angola palms to advanced breeding populations for improvement of bunch and oil yield traits. The majority of the QTLs were detected by LASSO-A, in which the p values of individual markers were calculated based on bootstrapped standard errors. Many of the detected QTLs are nearby known QTLs detected from linkage studies reported by other research groups. We also conducted genomic selection (GS) for the 13 traits and concluded that GS can be an effective tool for oil palm breeding. This is the first GWAS and GS study conducted on oil palm germplasm from Angola, and the results can be very useful in oil palm genetic studies and breeding. 相似文献
74.
Caipang CM Verjan N Ooi EL Kondo H Hirono I Aoki T Kiyono H Yuki Y 《Fish & shellfish immunology》2008,25(3):315-320
White spot syndrome virus (WSSV) disease is a major threat to shrimp culture worldwide. Here, we assessed the efficacy of the oral administration of purified recombinant VP28, an envelope protein of WSSV, expressed in a Gram-positive bacterium, Brevibacillus brevis, in providing protection in shrimp, Penaeus japonicus, upon challenge with WSSV. Juvenile shrimp (2-3g in body weight) fed with pellets containing purified recombinant VP28 (50mug/shrimp) for 2weeks showed significantly higher survival rates than control groups when challenged with the virus at 3days after the last day of feeding. However, when shrimp were challenged 2weeks after the last day of feeding, survival rates decreased (33.4% and 24.93%, respectively). Survival rate was dose-dependent, increasing from 60.7 to 80.3% as the dose increased from 1 to 50mug/shrimp. At a dose of 50mug/shrimp, the recombinant protein provided protection as soon as 1day after feeding (72.5% survival). Similar results were obtained with larger-sized shrimp. These results show that recombinant VP28 expressed in a Gram-positive bacterium is a potential oral vaccine against WSSV. 相似文献
75.
Olivier Lefebvre Wai K. Ooi Zhe Tang Md. Abdullah-Al-Mamun Daniel H.C. Chua How Y. Ng 《Bioresource technology》2009,100(20):4907-4910
Microbial fuel cells (MFCs) are considered as a promising way for the direct extraction of biochemical energy from biomass into electricity. However, scaling up the process for practical applications and mainly for wastewater treatment is an issue because there is a necessity to get rid of unsustainable platinum (Pt) catalyst. In this study, we developed a low-cost cathode for a MFC making use of sputter-deposited cobalt (Co) as the catalyst and different types of cathode architecture were tested in a single-chambered air-cathode MFC. By sputtering the catalyst on the air-side of the cathode, increased contact with ambient oxygen significantly resulted in higher electricity generation. This outcome was different from previous studies using conventionally-coated Pt cathodes, which was due to the different technology used. 相似文献
76.
Lisa F. P. Ng Angela Chow Yong-Jiang Sun Dyan J. C. Kwek Poh-Lian Lim Frederico Dimatatac Lee-Ching Ng Eng-Eong Ooi Khar-Heng Choo Zhisheng Her Philippe Kourilsky Yee-Sin Leo 《PloS one》2009,4(1)
Background
Little is known about the immunopathogenesis of Chikungunya virus. Circulating levels of immune mediators and growth factors were analyzed from patients infected during the first Singaporean Chikungunya fever outbreak in early 2008 to establish biomarkers associated with infection and/or disease severity.Methods and Findings
Adult patients with laboratory-confirmed Chikungunya fever infection, who were referred to the Communicable Disease Centre/Tan Tock Seng Hospital during the period from January to February 2008, were included in this retrospective study. Plasma fractions were analyzed using a multiplex-microbead immunoassay. Among the patients, the most common clinical features were fever (100%), arthralgia (90%), rash (50%) and conjunctivitis (40%). Profiles of 30 cytokines, chemokines, and growth factors were able to discriminate the clinical forms of Chikungunya from healthy controls, with patients classified as non-severe and severe disease. Levels of 8 plasma cytokines and 4 growth factors were significantly elevated. Statistical analysis showed that an increase in IL-1β, IL-6 and a decrease in RANTES were associated with disease severity.Conclusions
This is the first comprehensive report on the production of cytokines, chemokines, and growth factors during acute Chikungunya virus infection. Using these biomarkers, we were able to distinguish between mild disease and more severe forms of Chikungunya fever, thus enabling the identification of patients with poor prognosis and monitoring of the disease. 相似文献77.
Invasive species may have negative impacts on many narrow range endemics and species restricted to oceanic islands. Predicting
recent impacts of invasive species on long-lived trees is difficult because the presence of adult plants may mask population
changes. We examined the impact of introduced black rats (Rattus rattus) on two palm species restricted to cloud forests and endemic to Lord Howe Island, a small oceanic island in the southern
Pacific. We combined estimates of the standing size distribution of these palms with the proximal impacts of rats on fruit
survival in areas baited to control rats and in unbaited areas. The size distribution of palms with trunks was comparable
across baited and unbaited sites. Small juvenile palms lacking a trunk (<50 cm tall) were abundant in baited areas, but rare
in unbaited sites for Lepidorrhachis mooreana, and rare or absent in 3 out of 4 unbaited Hedyscepe
canterburyana sites. All ripe fruits were lost to rats in the small fruited L. mooreana. Fruit removal was widespread but less (20–54%) in H. canterburyana. Both palms showed evidence of a reduced capacity to maintain a juvenile bank of palms through regular recruitment as a consequence
of over 90 years of rat impact. This will limit the ability of these species to take advantage of episodic canopy gaps. Baiting
for rat control reduced fruit losses and resulted in the re-establishment of a juvenile palm bank. Conservation of both endemic
palms necessitates control (or eradication) of rat populations on the unique cloud forest summits of the island. 相似文献
78.
79.
John Masani Nduko Ken’ichiro Matsumoto Toshihiko Ooi Seiichi Taguchi 《Applied microbiology and biotechnology》2014,98(6):2453-2460
Poly(lactate-co-3-hydroxybutyrate) (P(LA-co-3HB)) was previously produced from xylose in engineered Escherichia coli. The aim of this study was to increase the polymer productivity and LA fraction in P(LA-co-3HB) using two metabolic engineering approaches: (1) deletions of competing pathways to lactate production and (2) overexpression of a galactitol transporter (GatC), which contributes to the ATP-independent xylose uptake. Engineered E. coli mutants (ΔpflA, Δpta, ΔackA, ΔpoxB, Δdld, and a dual mutant; ΔpflA?+?Δdld) and their parent strain, BW25113, were grown on 20 g l?1 xylose for P(LA-co-3HB) production. The single deletions of ΔpflA, Δpta, and Δdld increased the LA fraction (58–66 mol%) compared to BW25113 (56 mol%). In particular, the ΔpflA?+?Δdld strain produced P(LA-co-3HB) containing 73 mol% LA. Furthermore, GatC overexpression increased both polymer yields and LA fractions in ΔpflA, Δpta, and Δdld mutants, and BW25113. The ΔpflA?+?gatC strain achieved a productivity of 8.3 g l?1, which was 72 % of the theoretical maximum yield. Thus, to eliminate limitation of the carbon source, higher concentration of xylose was fed. As a result, BW25113 harboring gatC grown on 40 g l?1 xylose reached the highest P(LA-co-3HB) productivity of 14.4 g l?1. On the other hand, the ΔpflA?+?Δdld strain grown on 30 g l?1 xylose synthesized 6.4 g l?1 P(LA-co-3HB) while maintaining the highest LA fraction (73 mol%). The results indicated the usefulness of GatC for enhanced production of P(LA-co-3HB) from xylose, and the gene deletions to upregulate the LA fraction in P(LA-co-3HB). The polymers obtained had weight-averaged molecular weights in the range of 34,000–114,000. 相似文献
80.