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101.
A putative 2-methyl-6-phytylbenzoquinone (MPBQ) methyltransferase gene, SLL0418, was identified from the Synechocystis PCC6803 genome based on its homology to previously characterized gamma-tocopherol methyltransferases. Genetic and biochemical evidence confirmed open reading frame (ORF) SLL0418 encodes a MPBQ methyltransferase. An SLL0418 partial knockout mutant accumulated beta-tocopherol with no effect in the overall tocopherol content of the cell. In vitro assays of the SLL0418 gene expressed in Escherichia coli showed the enzyme efficiently catalyzes methylation of ring carbon 3 of MPBQ. In addition, the enzyme also catalyzes the methylation of ring carbon 3 of 2-methyl-6-solanylbenzoquinol in the terminal step of plastoquinone biosynthesis. 相似文献
102.
Bacillus spp. and related genera native to soils of the pristine sacred groves from Meghalaya, India were characterized using biochemical and 16S rRNA gene analysis which revealed dominance of Bacillus, Paenibacillus, Lysinibacillus and Viridibacillus in the groves. Biochemical estimation was carried out for in vitro testing of plant growth promoting traits present in these isolates. PCR screening were performed for plant growth-promoting related genes involved in the biosynthesis of acid phosphatase (AcPho), indolepyruvate decarboxylase (ipdC), 1-aminocyclopropane-1-carboxylate deaminase (accd) and siderophore biosynthesis protein (asbA). 76% of the sacred grove isolates gave an amplified fragment for AcPho. Three of the isolates gave an amplified fragment for IpdC gene. Apart from 2 isolates, all the other isolates including the reference strains were positive for the amplification of the accd gene indicating their potential to produce ACC deaminase enzyme. 42% of the isolates gave an amplified fragment for asbA gene indicating the potential ability of these isolates to produce the catechol type siderophore, petrobactin. Overall findings indicated multiple PGP genetic traits present in these isolates which suggested that these isolates are capable of expressing multiple PGP traits. Phylogenetic and sequence analysis of accd and asbA genes from the isolates revealed that asbA genes from Paenibacillus taichungiensis SG3 and Paenibacillus tylopili SG24 indicated the occurrence of intergeneric horizontal transfer between Paenibacillus and Bacillus. 相似文献
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M. C. Kalita T. Mohapatra A. Dhandapani D. K. Yadava K. Srinivasan A. K. Mukherjee R. P. Sharma 《Journal of plant biochemistry and biotechnology.》2007,16(1):41-48
Forty-two genotypes representing oilseed Brassica species were analyzed for the level of genetic diversity and molecular identity using Random Amplified Polymorphic DNA (RAPD), Inter-Simple Sequence Repeat (ISSR) and 5'-Anchored Simple Sequence Repeat (ASSR) markers. DNA profiles revealed high degree of interspecific polymorphism, while the level was considerably low within a species, particularly in B. juncea. The UPGMA clusters clearly delineated genotypes of the respective Brassica species. Comparison of cophenetic matrices indicated a high degree of correspondence between dendrograms generated by different marker systems. A minimum of 10 random primers (approximately 105 bands) were required for the RAPD profiles to generate the expected cluster. Comparatively less number of primers was required to do the same in case of ISSR (4 primers) and ASSR (3 primers). The principal component analysis revealed similar genetic relationship among the genotypes as in cluster analysis. Although none of the DNA profiles could individually identify all the B. juncea genotypes, a combined DNA profile consisting 125 markers from the informative primers of all the three DNA marker systems could do the same. A positive correlation was found among the marker utility parameters (calculated for individual primers of different marker systems) such as marker index (MI), resolving power (Rp) and discrimination coefficient (D) with the number of genotypes identified by each primer with a few exceptions. Single plant analysis for a set of five B. juncea varieties revealed absence of intra-varietal heterogeneity in case of ASSR profiles, thereby suggesting its utility in varietal identification and differentiation. 相似文献
105.
Rocktotpal Konwarh Dipankar Kalita Charulata Mahanta Manabendra Mandal Niranjan Karak 《Applied microbiology and biotechnology》2010,87(6):1983-1992
The present work reports the integration of polymer matrix-supported nanomaterial and enzyme biotechnology for development
of industrially feasible biocatalysts. Aqueous leaf extract of Mesua ferrea L. was used to prepare silver nanoparticles distributed within a narrow size range (1–12 nm). In situ oxidative technique
was used to obtain poly(ethylene glycol)-supported iron oxide nanoparticles (3–5 nm). Sonication-mediated mixing of above
nanoparticles generated the immobilization system comprising of polymer-supported silver–iron oxide nanoparticles (20–30 nm).
A commercially important enzyme, Aspergillus niger amyloglucosidase was coupled onto the immobilization system through sonication. The immobilization enzyme registered a multi-fold
increment in the specific activity (807 U/mg) over the free counterpart (69 U/mg). Considerable initial activity of the immobilized
enzyme was retained even after storing the system at room temperature as well as post-repeated magnetic recycling. Evaluation
of the commendable starch saccharification rate, washing performance synergy with a panel of commercial detergents, and antibacterial
potency strongly forwards the immobilized enzyme as a multi-functional industrially feasible system. 相似文献
106.
The structural, surface morphological, optical absorption and emission features of Y2O3:Ce (0%–5%) were studied. The samples had a body-centred cubic crystal structure. The undoped sample had a crystallite size of 29.03 nm, and it varied after doping with Ce. The grain size of the samples varied from 23.00 to 50.78 nm. All the samples exhibited a strong absorption band at 206 nm due to F-centre absorption and absorption involving the delocalised bands. In addition, the doped samples exhibited a secondary band at ~250 nm due to 4f → 5d transitions of Ce3+ ions. The optical bandgap of the undoped sample was found to be ~5.37 eV, and it decreased to 5.20 eV with an increase in Ce concentration to 5%. The undoped sample under 350-nm excitation exhibited a broad photoluminescence (PL) emission band with the maxima at 406 nm and a secondary band at 463 nm. In contrast, multiple PL peaks were centred at ~397, 436, 466, 488 and 563 nm in all the doped samples. The average lifetime of the emission band at 406 nm was 1.05 ns and that of the emission band at ~466 nm was 1.63 ns. The material has potential for solid-state lighting applications. 相似文献
107.
Stéphane Raeppel Nancy Zhou Frédéric Gaudette Silvana Leit Isabelle Paquin Guillaume Larouche Oscar Moradei Sylvie Fréchette Ljubomir Isakovic Daniel Delorme Marielle Fournel Ann Kalita Aihua Lu Marie-Claude Trachy-Bourget Pu Theresa Yan Jianhong Liu Jubrail Rahil James Wang Jeffrey M. Besterman Koji Murakami Arkadii Vaisburg 《Bioorganic & medicinal chemistry letters》2009,19(3):644-649
Analogues of the clinical compound MGCD0103 (A) were designed and synthesized. These compounds inhibit recombinant human HDAC1 with IC50 values in the sub-micromolar range. In human cancer cells growing in culture these compounds induce hyperacetylation of histones, cause expression of the tumor suppressor protein p21WAF1/CIP1, and inhibit cellular proliferation. Lead molecule of the series, compound 25 is metabolically stable, possesses favorable pharmacokinetic characteristics and is orally active in vivo in different mouse tumor xenograft models. 相似文献
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Sebastian Gnat Wanda Ma?ek Ewa Oleńska Sylwia Wdowiak-Wróbel Micha? Kalita Barbara ?otocka Magdalena Wójcik 《PloS one》2015,10(10)
The phylogeny of symbiotic genes of Astragalus glycyphyllos L. (liquorice milkvetch) nodule isolates was studied by comparative sequence analysis of nodA, nodC, nodH and nifH loci. In all these genes phylograms, liquorice milkvetch rhizobia (closely related to bacteria of three species, i.e. Mesorhizobium amorphae, Mesorhizobium septentrionale and Mesorhizobium ciceri) formed one clearly separate cluster suggesting the horizontal transfer of symbiotic genes from a single ancestor to the bacteria being studied. The high sequence similarity of the symbiotic genes of A. glycyphyllos rhizobia (99–100% in the case of nodAC and nifH genes, and 98–99% in the case of nodH one) points to the relatively recent (in evolutionary scale) lateral transfer of these genes. In the nodACH and nifH phylograms, A. glycyphyllos nodule isolates were grouped together with the genus Mesorhizobium species in one monophyletic clade, close to M. ciceri, Mesorhizobium opportunistum and Mesorhizobium australicum symbiovar biserrulae bacteria, which correlates with the close relationship of these rhizobia host plants. Plant tests revealed the narrow host range of A. glycyphyllos rhizobia. They formed effective symbiotic interactions with their native host (A. glycyphyllos) and Amorpha fruticosa but not with 11 other fabacean species. The nodules induced on A. glycyphyllos roots were indeterminate with apical, persistent meristem, an age gradient of nodule tissues and cortical vascular bundles. To reflect the symbiosis-adaptive phenotype of rhizobia, specific for A. glycyphyllos, we propose for these bacteria the new symbiovar “glycyphyllae”, based on nodA and nodC genes sequences. 相似文献