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171.
In this study, the effect of rhamnolipid biosurfactant produced by Pseudomonas fluorescens on bacterial strains, laboratory strains, and isolates from industrial wastewater was investigated. It was shown that biosurfactant,
depending on the concentration, has a neutral or detrimental effect on the growth and protein release of model Gram (+) strain
Bacillus subtilis 168. The growth and protein release of model Gram (−) strain Pseudomonas aeruginosa 1390 was not influenced by the presence of biosurfactant in the medium. Rhamnolipid biosurfactant at the used concentrations
supported the growth of some slow growing on hexadecane bacterial isolates, members of the microbial community. Changes in
cell surface hydrophobicity and permeability of some Gram (+) and Gram (−) isolates in the presence of rhamnolipid biosurfactant
were followed in experiments in vitro. It was found that bacterial cells treated with biosurfactant became more or less hydrophobic
than untreated cells depending on individual characteristics and abilities of the strains. For all treated strains, an increase
in the amount of released protein was observed with increasing the amount of biosurfactant, probably due to increased cell
permeability as a result of changes in the organization of cell surface structures. The results obtained could contribute
to clarify the relationships between members of the microbial community as well as suggest the efficiency of surface properties
of rhamnolipid biosurfactant from Pseudomonas fluorescens making it potentially applicable in bioremediation of hydrocarbon-polluted environments. 相似文献
172.
Mariño G Morselli E Bennetzen MV Eisenberg T Megalou E Schroeder S Cabrera S Bénit P Rustin P Criollo A Kepp O Galluzzi L Shen S Malik SA Maiuri MC Horio Y López-Otín C Andersen JS Tavernarakis N Madeo F Kroemer G 《Autophagy》2011,7(6):647-649
The acetylase inhibitor, spermidine and the deacetylase activator, resveratrol, both induce autophagy and prolong life span of the model organism Caenorhabditis elegans in an autophagydependent fashion. Based on these premises, we investigated the differences and similarities in spermidine and resveratrol-induced autophagy. The deacetylase sirtuin 1 (SIRT1) and its orthologs are required for the autophagy induction by resveratrol but dispensable for autophagy stimulation by spermidine in human cells, Saccharomyces cerevisiae and C. elegans. SIRT1 is also dispensable for life-span extension by spermidine. Mass spectrometry analysis of the human acetylproteome revealed that resveratrol and/or spermidine induce changes in the acetylation of 560 peptides corresponding to 375 different proteins. Among these, 170 proteins are part of the recently elucidated human autophagy protein network. Importantly, spermidine and resveratrol frequently affect the acetylation pattern in a similar fashion. In the cytoplasm, spermidine and resveratrol induce convergent protein de-acetylation more frequently than convergent acetylation, while in the nucleus, acetylation is dominantly triggered by both agents. We surmise that subtle and concerted alterations in the acetylproteome regulate autophagy at multiple levels. 相似文献
173.
Surviving in the High Arctic: dental variation in a casually introduced population of Microtus rossiaemeridionalis (Arvicolinae,Rodentia) on Svalbard
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A human‐mediated invasion of a temperate rodent Microtus rossiaemeridionalis on the High Arctic Archipelago of Svalbard in the first half of the 20th century provides an opportunity to explore extent and rate of morphological divergence over decades of isolation. We studied dental size and morphology in 124 voles captured on Svalbard (Spitsbergen) in 1997–2005 and compared the data to mainland conspecific populations across northern Eurasia. Both dental and cranial sizes in the Svalbard population fall within the limits of natural variation of the species. Dental morphology suggests that the population experiences strong effects of isolation as indicated by the significant increase in the frequency of rare dental morphs, possibly caused by inbreeding. No evidence for directional shift towards increased or decreased complexity of the morphotype dental patterns is revealed. Although the population on Svalbard is phenotypically different from the mainland populations (due to increased frequency of rare morphs), those differences are not enough to support the idea of initial rapid evolution related to colonization. The limited spatial extent and environmental homogeneity of suitable habitats on the island allowed the species to initially multiply but not to diversify so that the species exhibits phenotypic conservatism but suffers the consequences of small population size. 相似文献
174.
Jenni Inkinen Merja Ahonen Evgenia Iakovleva Pasi Karppinen Eelis Mielonen Riika Mkinen Katriina Mannonen Juha Koivisto 《Journal of biophotonics》2020,13(1)
Organic dirt on touch surfaces can be biological contaminants (microbes) or nutrients for those but is often invisible by the human eye causing challenges for evaluating the need for cleaning. Using hyperspectral scanning algorithm, touch surface cleanliness monitoring by optical imaging was studied in a real‐life hospital environment. As the highlight, a human eye invisible stain from a dirty chair armrest was revealed manually with algorithms including threshold levels for intensity and clustering analysis with two excitation lights (green and red) and one bandpass filter (wavelength λ = 500 nm). The same result was confirmed by automatic k‐means clustering analysis from the entire dirty data of visible light (red, green and blue) and filters 420 to 720 nm with 20 nm increments. Overall, the collected touch surface samples (N = 156) indicated the need for cleaning in some locations by the high culturable bacteria and adenosine triphosphate counts despite the lack of visible dirt. Examples of such locations were toilet door lock knobs and busy registration desk armchairs. Thus, the studied optical imaging system utilizing the safe visible light area shows a promising method for touch surface cleanliness evaluation in real‐life environments. 相似文献
175.
Victoria E. Cotero Simon Y. Kimm Tiberiu M. Siclovan Rong Zhang Evgenia M. Kim Kazuhiro Matsumoto Tatsuo Gondo Peter T. Scardino Siavash Yazdanfar Vincent P. Laudone Cristina A. Tan Hehir 《PloS one》2015,10(6)
The ability to visualize and spare nerves during surgery is critical for avoiding chronic morbidity, pain, and loss of function. Visualization of such critical anatomic structures is even more challenging during minimal access procedures because the small incisions limit visibility. In this study, we focus on improving imaging of nerves through the use of a new small molecule fluorophore, GE3126, used in conjunction with our dual-mode (color and fluorescence) laparoscopic imaging instrument. GE3126 has higher aqueous solubility, improved pharmacokinetics, and reduced non-specific adipose tissue fluorescence compared to previous myelin-binding fluorophores. Dosing and kinetics were initially optimized in mice. A non-clinical modified Irwin study in rats, performed to assess the potential of GE3126 to induce nervous system injuries, showed the absence of major adverse reactions. Real-time intraoperative imaging was performed in a porcine model. Compared to white light imaging, nerve visibility was enhanced under fluorescence guidance, especially for small diameter nerves obscured by fascia, blood vessels, or adipose tissue. In the porcine model, nerve visualization was observed rapidly, within 5 to 10 minutes post-intravenous injection and the nerve fluorescence signal was maintained for up to 80 minutes. The use of GE3126, coupled with practical implementation of an imaging instrument may be an important step forward in preventing nerve damage in the operating room. 相似文献
176.
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178.
Ovchinnikova E Journet EP Chabaud M Cosson V Ratet P Duc G Fedorova E Liu W den Camp RO Zhukov V Tikhonovich I Borisov A Bisseling T Limpens E 《Molecular plant-microbe interactions : MPMI》2011,24(11):1333-1344
A successful nitrogen-fixing symbiosis requires the accommodation of rhizobial bacteria as new organelle-like structures, called symbiosomes, inside the cells of their legume hosts. Two legume mutants that are most strongly impaired in their ability to form symbiosomes are sym1/TE7 in Medicago truncatula and sym33 in Pisum sativum. We have cloned both MtSYM1 and PsSYM33 and show that both encode the recently identified interacting protein of DMI3 (IPD3), an ortholog of Lotus japonicus (Lotus) CYCLOPS. IPD3 and CYCLOPS were shown to interact with DMI3/CCaMK, which encodes a calcium- and calmodulin-dependent kinase that is an essential component of the common symbiotic signaling pathway for both rhizobial and mycorrhizal symbioses. Our data reveal a novel, key role for IPD3 in symbiosome formation and development. We show that MtIPD3 participates in but is not essential for infection thread formation and that MtIPD3 also affects DMI3-induced spontaneous nodule formation upstream of cytokinin signaling. Further, MtIPD3 appears to be required for the expression of a nodule-specific remorin, which controls proper infection thread growth and is essential for symbiosome formation. 相似文献
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180.
Bulge loops are common features of RNA structures that are involved in the formation of RNA tertiary structures and are often sites for interactions with proteins and ions. Minimal thermodynamic data currently exist on the bulge size and sequence effects. Using thermal denaturation methods, thermodynamic properties of 1- to 5-nt adenine and guanine bulge loop constructs were examined in 10 mM MgCl2 or 1 M KCl. The loop parameters for 1- to 5-nt purine bulge loops in RNA constructs were between 3.07 and 5.31 kcal/mol in 1 M KCl buffer. In 10 mM magnesium ions, the ΔΔG° values relative to 1 M KCl were 0.47–2.06 kcal/mol more favorable for the RNA bulge loops. The loop parameters for 1- to 5-nt purine bulge loops in DNA constructs were between 4.54 and 5.89 kcal/mol. Only 4- and 5-nt guanine constructs showed significant change in stability for the DNA constructs in magnesium ions. A linear correlation is seen between the size of the bulge loop and its stability. New prediction models are proposed for 1- to 5-nt purine bulge loops in RNA and DNA in 1 M KCl. We show that a significant stabilization is seen for small bulge loops in RNA in the presence of magnesium ions. A prediction model is also proposed for 1- to 5-nt purine bulge loop RNA constructs in 10 mM magnesium chloride. 相似文献