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131.
Yuan Chun Wang Fang Wang Bao Chao Hou En Tao Wang Wen Feng Chen Xin Hua Sui Wen Xin Chen Yan Li Ya Bo Zhang 《Systematic and applied microbiology》2013
In a survey of rhizobia associated with the native legumes in Yunnan Province, China, seven and nine strains isolated from the root nodules of Psoralea corylifolia, Sesbania cannabina and Medicago lupulina were respectively classified into the novel genomic species groups I and II in the genus Ensifer (former Sinorhizobium) based on the sequence analyses of the 16S rRNA gene. Analyses of concatenated housekeeping genes (atpD, recA and glnII) further revealed that they were distinct lineages in the genus, and group I was most similar to Ensifer terangae and Ensifer garamanticus (both with 94.2% similarity), while group II was most similar to Ensifer adhaerens (94.0%). These groups could be distinguished from closely related species by DNA–DNA relatedness, MALID-TOF MS, cellular fatty acid profiles and a series of phenotypic characters. Therefore, two novel species were proposed: Ensifer psoraleae sp. nov. (seven strains, type strain CCBAU 65732T = LMG 26835T = HAMBI 3286T) and Ensifer sesbaniae sp. nov. (nine strains, type strain CCBAU 65729T = LMG 26833T = HAMBI 3287T). They had a DNA G + C mol% (Tm) of 58.9 and 60.4, respectively. Both of the type strains formed effective nodules on common bean (Phaseolus vulgaris) and their hosts of origin. In addition, the previously described species Sinorhizobium morelense and Sinorhizobium americanum were renamed as Ensifer morelense comb. nov. and Ensifer americanum comb. nov. according to the accumulated data from different studies. 相似文献
132.
Rong Hui Xinrong Li Cuiyun Chen Xin Zhao Rongliang Jia Lichao Liu Yongping Wei 《Physiologia plantarum》2013,147(4):489-501
Our understanding of plant responses to enhanced ultraviolet‐B (UV‐B) radiation has improved over recent decades. However, research on cryptogams is scarce and it remains controversial whether UV‐B radiation causes changes in physiology related to photosynthesis. To investigate the effects of supplementary UV‐B radiation on photosynthesis and chloroplast ultrastructure in Bryum argenteum Hedw., specimens were cultured for 10 days under four UV‐B treatments (2.75, 3.08, 3.25 and 3.41 W m–2), simulating depletion of 0% (control), 6%, 9% and 12% of stratospheric ozone at the latitude of Shapotou, a temperate desert area of northwest China. Analyses showed malondialdehyde content significantly increased, whereas chlorophyll (Chl) fluorescence parameters and Chl contents decreased with increased UV‐B intensity. These results corresponded with changes in thylakoid protein complexes and chloroplast ultrastructure. Overall, enhanced UV‐B radiation leads to significant decreases in photosynthetic function and serious destruction of the chloroplast ultrastructure of B. argenteum. The degree of negative influences increased with the intensity of UV‐B radiation. These results may not only provide a potential mechanism for supplemental UV‐B effects on photosynthesis of moss crust, but also establish a theoretical basis for further studies of adaptation and response mechanisms of desert ecosystems under future ozone depletion. 相似文献
133.
Metaeritrichium has been considered monotypic and endemic to China in traditional taxonomic treatments. However, our examinations of specimens and bibliography, combined with field observations, reveal that Metaeritrichium microuloides is conspecific with Actinocarya acaulis. Metaeritrichium is therefore treated as a synonym of Actinocarya. We also clarify the typification of Actinocarya acaulis. 相似文献
134.
Bao‐Kai Cui 《Nordic Journal of Botany》2013,31(3):326-330
Two new polypores (Ceriporiopsis lavendula B. K. Cui sp. nov. and Skeletocutis inflata B. K. Cui sp. nov.) are described from the Guangdong Province in southern China. Ceriporiopsis lavendula is characterized by having resupinate basidiocarps with lavender to grayish blue pore surface and very thin to almost absent subiculum, a monomitic hyphal system with clamped generative hyphae, and oblong‐ellipsoid to ellipsoid basidiospores. Moreover, it grows on wood of Castanopsis exclusively. Skeletocutis inflata is characterized by having pileate basidiocarps, smaller pores (8–10 per mm), inflated and partly dissolved skeletal hyphae in KOH. In addition, its tramal skeletal hyphae are parallel along the tubes. Identification keys to species of Ceriporiopsis and Skeletocutis occurring in China are provided. 相似文献
135.
136.
The ability of PSII to extract electrons from water, with molecular oxygen as a by-product, is a remarkable biochemical and evolutionary innovation. From an evolutionary perspective, the invention of PSII approximately 2.7 Ga led to the accelerated accumulation of biomass in the biosphere and the accumulation of oxygen in the atmosphere, a combination that allowed for the evolution of a much more complex and extensive biosphere than would otherwise have been possible. From the biochemical and enzymatic perspective, PSII is remarkable because of the thermodynamic and kinetic obstacles that needed to have been overcome to oxidize water as the ultimate photosynthetic electron donor. This article focuses on how proton release is an integral part of how these kinetic and thermodynamic obstacles have been overcome: the sequential removal of protons from the active site of H2O-oxidation facilitates the multistep oxidation of the substrate water at the Mn4CaO x , the catalytic heart of the H2O-oxidation reaction. As noted previously, the facilitated deprotonation of the Mn4CaO x cluster exerts a redox-leveling function preventing the accumulation of excess positive charge on the cluster, which might otherwise hinder the already energetically difficult oxidation of water. Using recent results, including the characteristics of site-directed mutants, the role of the second sphere of amino acid ligands and the associated network of water molecules surrounding the Mn4CaO x is discussed in relation to proton transport in other systems. In addition to the redox-leveling function, a trapping function is assigned to the proton release step occurring immediately prior to the dioxygen chemistry. This trapping appears to involve a yet-to-be clarified gating mechanism that facilitates to coordinated release of a proton from the neighborhood of the active site thereby insuring that the backward charge-recombination reaction does not out-compete the forward reaction of dioxygen chemistry during this final step of H2O-oxidation. 相似文献
137.
Xiao-Yong Zhang Jie Bao Juan Zhong Xin-Ya Xu Xu-Hua Nong Shu-Hua Qi 《Applied microbiology and biotechnology》2013,97(22):9657-9663
Many marine natural products hold great potential for the development of new and much needed drugs. However, the production of active metabolites by marine-derived microorganisms is usually very low, and large-scale culture has to be involved to meet the need of chemical structural modification and deep pharmacy study. In order to enhance the production of a novel cytotoxic sulfur-containing chromone oxalicumone A (OA), germinating spores of a marine-derived wild strain Penicillium oxalicum SCSGAF 0023 were mutated by microwave and ultraviolet light irradiation, which led to the obtainment of a mutant P. oxalicum SCSIO 24–2 that could produce fivefold increase in OA production (3.42?±?0.21 mg/l) as compared to the wild strain. This is the first report that germinating spores are applied in marine-derived Penicillium sp. mutating to enhance the production of OA. Further, Plackett–Burman design and central composite design were adopted to optimize the basic medium components for increasing OA production by the mutant SCSIO 24–2 in shake flasks. The results indicated that three medium components including mannitol, maltose, and l-cysteine had significant effects on OA production, and their concentrations were optimized as 36, 27.9, and 0.99 g/l, respectively. In the optimized medium, the OA production (18.31?±?0.27 mg/l) by mutant SCSIO 24–2 was 4.4-fold higher than that in the basic medium. These results of this work promise to improve the present production of OA and may be adopted to enhance other objective products' production by marine-derived fungi. 相似文献
138.
In vitro rapid evolution of fungal immunomodulatory proteins by DNA family shuffling 总被引:1,自引:0,他引:1
Xue-Fei Wang Qi-Zhang Li Ting-Wen Bao Wei-Ran Cong Wen-Xia Song Xuan-Wei Zhou 《Applied microbiology and biotechnology》2013,97(6):2455-2465
Fungal immunomodulatory proteins (FIPs) found in a wide variety of mushrooms hold significant therapeutic potential. Despite much research, the structural determinants for their immunomodulatory functions remain unknown. In this study, a DNA shuffling technique was used to create two shuffled FIP protein libraries: an intrageneric group containing products of shuffling between FIP-glu (FIP gene isolated from Ganoderma lucidum) and FIP-gsi (FIP gene isolated from Ganoderma sinense) genes and an intergeneric group containing the products of shuffling between FIP-glu, FIP-fve (FIP gene isolated from Flammulina velutipes), and FIP-vvo (FIP gene isolated from Volvariella volvacea) genes. The gene shuffling generated 426 and 412 recombinant clones, respectively. Using colony blot analysis, we selected clones that expressed relatively high levels of shuffled gene products recognized by specific polyclonal antibodies. We analyzed the DNA sequences of the selected shuffled genes, and testing of their protein products revealed that they maintained functional abilities to agglutinate blood cells and induce cytokine production by splenocytes from Kunming mice in vitro. Meanwhile, the relationships between protein structure and the hemagglutination activity and between the changed nucleotide sites and expression levels were explored by bioinformatic analysis. These combined analyses identified the nucleotide changes involved in regulating the expression levels and hemagglutination activities of the FIPs. Therefore, we were able to generate recombinant FIPs with improved biological activities and expression levels by using DNA shuffling, a powerful tool for the generation of novel therapeutic proteins and for their structural and functional studies. 相似文献
139.
140.
L.‐L. Fu Y. Yang H.‐L. Xu Y. Cheng X. Wen L. Ouyang J.‐K. Bao Y.‐Q. Wei B. Liu 《Cell proliferation》2013,46(1):67-75