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https://www.readbyqxmd.com/read/28213032/applicability-of-a-colorimetric-method-for-evaluation-of-lactic-acid-bacteria-with-probiotic-properties
#1
Min Young Jung, Jina Lee, Boyeon Park, Hyelyeon Hwang, Sung-Oh Sohn, Se Hee Lee, Hyeong In Lim, Hae Woong Park, Jong-Hee Lee
Rapid colorimetric methods using various indicator reagents have been developed to monitor bacterial viability. Here, we examined the applicability of a method based on the reduction of resazurin or water-soluble tetrazolium salt-8 (WST-8) to screen lactic acid bacteria (LAB) for growth, tolerance against bile acid and low pH. The resazurin reduction test proved unsuitable for screening LAB such as Lactobacillus plantarum and Leuconostoc mesenteroides since it reacted with acid present in the cultures. LAB growth could be indirectly quantified by measuring WST-8 reduction...
June 2017: Food Microbiology
https://www.readbyqxmd.com/read/28204982/influence-of-carbon-sources-on-the-viability-and-resuscitation-of-acetobacter-senegalensis-during-high-temperature-gluconic-acid-fermentation
#2
Rasoul Shafiei, Raziyeh Zarmehrkhorshid, Majid Mounir, Philippe Thonart, Frank Delvigne
Much research has been conducted about different types of fermentation at high temperature, but only a few of them have studied cell viability changes during high-temperature fermentation. In this study, Acetobacter senegalensis, a thermo-tolerant strain, was used for gluconic acid production at 38 °C. The influences of different carbon sources and physicochemical conditions on cell viability and the resuscitation of viable but nonculturable (VBNC) cells formed during fermentation were studied. Based on the obtained results, A...
February 15, 2017: Bioprocess and Biosystems Engineering
https://www.readbyqxmd.com/read/28197768/expression-of-an-acid-urease-with-urethanase-activity-in-e-coli-and-analysis-of-urease-gene
#3
REVIEW
Xiaofeng Liu, Qian Zhang, Nandi Zhou, Yaping Tian
Urea in alcoholic beverage is a precursor of ethyl carbamate (EC), which is carcinogenic. Enzymatic elimination of urea has attracted much research interest. Acid urease with good tolerance toward ethanol and acid is ideal enzyme for such applications. In the present work, the structural genes of urease from Providencia rettgeri JN-B815, ureABC were efficiently expressed in E. coli BL21(DE3) in an active form (apourease) exhibiting both urease and urethanase (hydrolyze EC) activities. The specific activities of the purified apourease were comparatively low, which were 2...
February 14, 2017: Molecular Biotechnology
https://www.readbyqxmd.com/read/28187940/carbon-dioxide-consumption-of-the-microalga-scenedesmus-obtusiusculus-under-transient-inlet-co2-concentration-variations
#4
Juan Cabello, Marcia Morales, Sergio Revah
The extensive microalgae diversity offers considerable versatility for a wide range of biotechnological applications in environmental and production processes. Microalgal cultivation is based on CO2 fixation via photosynthesis and, consequently, it is necessary to evaluate, in a short time and reliable way, the effect of the CO2 gas concentration on the consumption rate and establish the tolerance range of different strains and the amount of inorganic carbon that can be incorporated into biomass in order to establish the potential for industrial scale application...
February 7, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28168102/endophytic-fungal-diversity-of-fragaria-vesca-a-crop-wild-relative-of-strawberry-along-environmental-gradients-within-a-small-geographical-area
#5
Kazutomo Yokoya, Sarah Postel, Rui Fang, Viswambharan Sarasan
BACKGROUND: Fungal endophytes are highly diverse ubiquitous asymptomatic microorganisms, some of which appear to be symbiotic. Depending on abiotic conditions and genotype of the plant, the diversity of endophytes may confer fitness benefits to plant communities. METHODS: We studied a crop wild relative (CWR) of strawberry, along environmental gradients with a view to understand the cultivable root-derived endophytic fungi that can be evaluated for promoting growth and tolerating stress in selected plant groups...
2017: PeerJ
https://www.readbyqxmd.com/read/28161849/survival-strategies-of-escherichia-coli-and-vibrio-spp-contribution-of-the-viable-but-nonculturable-phenotype-to-their-stress-resistance-and-persistence-in-adverse-environments
#6
REVIEW
M Orruño, V R Kaberdin, I Arana
In their natural ecosystems, bacteria are continuously exposed to changing environmental factors including physicochemical parameters (e.g. temperature, pH, etc.), availability of nutrients as well as interaction(s) with other organisms. To increase their tolerance and survival under adverse conditions, bacteria trigger a number of adaptation mechanisms. One of the well-known adaptation responses of the non-spore-forming bacteria is the acquisition of the viable but non-culturable (VBNC) state. This phenotype is induced by different stress factors (e...
March 2017: World Journal of Microbiology & Biotechnology
https://www.readbyqxmd.com/read/28159215/probiotic-and-antioxidant-properties-of-selenium-enriched-lactobacillus-brevis-lse-isolated-from-an-iranian-traditional-dairy-product
#7
Mojtaba Shakibaie, Tayebe Mohammadi-Khorsand, Mahboubeh Adeli-Sardou, Mandana Jafari, Sahar Amirpour-Rostami, Alieh Ameri, Hamid Forootanfar
The present study was designed to isolate a highly selenium-tolerant lactobacillus strain from an Iranian traditional dairy product named as Spar. Different criteria such as tolerance to the low pH, simulated gastric juice (SGJ), simulated intestinal juice (SIJ) and bile salts tolerance as well as Caco-2 cell adhesion assay were examined to evaluate the probiotic potentials of the selected isolate. Furthermore, the antioxidant properties of the isolate cultivated in medium containing and free of SeO3(2-) ions were evaluated using DPPH scavenging and reducing power assays...
March 2017: Journal of Trace Elements in Medicine and Biology
https://www.readbyqxmd.com/read/28148831/geographical-gradients-in-selection-can-reveal-genetic-constraints-for-evolutionary-responses-to-ocean-acidification
#8
REVIEW
Juan Diego Gaitán-Espitia, Dustin Marshall, Sam Dupont, Leonardo D Bacigalupe, Levente Bodrossy, Alistair J Hobday
Geographical gradients in selection can shape different genetic architectures in natural populations, reflecting potential genetic constraints for adaptive evolution under climate change. Investigation of natural pH/pCO2 variation in upwelling regions reveals different spatio-temporal patterns of natural selection, generating genetic and phenotypic clines in populations, and potentially leading to local adaptation, relevant to understanding effects of ocean acidification (OA). Strong directional selection, associated with intense and continuous upwellings, may have depleted genetic variation in populations within these upwelling regions, favouring increased tolerances to low pH but with an associated cost in other traits...
February 2017: Biology Letters
https://www.readbyqxmd.com/read/28148818/life-on-the-edge-o2-binding-in-atlantic-cod-red-blood-cells-near-their-southern-distribution-limit-is-not-sensitive-to-temperature-or-haemoglobin-genotype
#9
Samantha L Barlow, Julian Metcalfe, David A Righton, Michael Berenbrink
Atlantic cod are a commercially important species believed to be threatened by warming seas near their southern, equatorward upper thermal edge of distribution. Limitations to circulatory O2 transport, in particular cardiac output, and the geographic distribution of functionally different haemoglobin (Hb) genotypes have separately been suggested to play a role in setting thermal tolerance in this species. The present study assessed the thermal sensitivity of O2 binding in Atlantic cod red blood cells with different Hb genotypes near their upper thermal distribution limit and modelled its consequences for the arterio-venous O2 saturation difference, Sa-vO2 , another major determinant of circulatory O2 supply rate...
February 1, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28141889/transcriptomic-responses-to-seawater-acidification-among-sea-urchin-populations-inhabiting-a-natural-ph-mosaic
#10
Tyler G Evans, Melissa H Pespeni, Gretchen E Hofmann, Stephen R Palumbi, Eric Sanford
Increasing awareness of spatial and temporal variation in ocean pH suggests some marine populations may be adapted to local pH regimes and will therefore respond differently to present-day pH variation and to long-term ocean acidification. In the Northeast Pacific Ocean, differences in the strength of coastal upwelling cause latitudinal variation in prevailing pH regimes that are hypothesized to promote local adaptation and unequal pH tolerance among resident populations. In this study, responses to experimental seawater acidification were compared among six populations of purple sea urchins (Strongylocentrotus purpuratus) inhabiting areas that differ in their frequency of low pH exposure and that prior research suggests are locally adapted to seawater pH...
January 31, 2017: Molecular Ecology
https://www.readbyqxmd.com/read/28130767/production-and-characterization-of-organic-solvent-tolerant-cellulase-from-bacillus-amyloliquefaciens-ak9-isolated-from-hot-spring
#11
Muhammad Irfan, Ammara Tayyab, Fariha Hasan, Samiullah Khan, Malik Badshah, Aamer Ali Shah
A cellulase-producing bacterium, designated as strain AK9, was isolated from a hot spring of Tatta Pani, Azad Kashmir, Pakistan. The bacterium was identified as Bacillus amyloliquefaciens through 16S rRNA sequencing. Cellulase from strain AK9 was able to liberate glucose from soluble cellulose and carboxymethyl cellulose (CMC). Enzyme was purified through size exclusion chromatography and a single band of ∼47 kDa was observed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was purified with recovery of 35...
January 27, 2017: Applied Biochemistry and Biotechnology
https://www.readbyqxmd.com/read/28116241/genome-sequence-of-the-copper-resistant-and-acid-tolerant-desulfosporosinus-sp-bg-isolated-from-the-tailings-of-a-molybdenum-tungsten-mine-in-the-transbaikal-area
#12
Olga V Karnachuk, Vitalii V Kadnikov, Inna A Panova, Andrey V Mardanov, Alexey V Beletsky, Erzhena V Danilova, Marat R Avakyan, Nikolai V Ravin
Here, we report on the draft genome of a copper-resistant and acidophilic Desulfosporosinus sp. BG, isolated from the tailings of a molybdenum-tungsten mine in Transbaikal area. The draft genome has a size of 4.52 Mb and encodes transporters of heavy metals. The phylogenetic analysis based on concatenated ribosomal proteins revealed that strain BG clusters together with the other acidophilic copper-resistant strains Desulfosporosinus sp. OT and Desulfosporosinus sp. I2. The K(+)-ATPase, Na(+)/H(+) antiporter and amino acid decarboxylases may participate in enabling growth at low pH...
March 2017: Genomics Data
https://www.readbyqxmd.com/read/28110684/hydrothermal-synthesis-of-polyethylenimine-protected-high-luminescent-pt-nanoclusters-and-their-application-to-the-detection-of-nitroimidazoles
#13
Na Xu, Hong-Wei Li, Yuqing Wu
A novel one-step hydrothermal synthesis of highly fluorescent platinum nanoclusters protected by polyethylenimine (Pt-NCs@PEI) is described. The products are characterized well by UV-vis absorption, fluorescence spectra, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) imaging. The Pt-NCs@PEI possess high quantum yield at 28%, which is the relatively high one among the reported Pt-NCs; especially, the synthesis is in one-step and the reaction time is much shorter (<1 h) than the related methods...
March 15, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28107911/a-positively-charged-porous-graphitic-carbon-stationary-phase-for-hydrophilic-interaction-liquid-chromatography
#14
Yanjie Hou, Feifang Zhang, Xuefang Liu, Yanjun Ren, Bingcheng Yang
High chemical inertness of porous graphitic carbon particles (PGC) makes their surface modification rather difficult. Here a facile way is proposed to prepare a PGC stationary phase with quaternary ammonium-polyvinyl alcohol mixed functional groups for hydrophilic interaction liquid chromatography (HILIC) by generating a thin layer of polyvinyl alcohol (PVA) and poly(diallyldimethylammonium chloride) (DDAC) copolymer onto PGC particles. The phase shows obvious positively electrostatic character and typical HILIC character, exhibiting different selectivity relative to several HILIC phases and bare PGC...
March 1, 2017: Talanta
https://www.readbyqxmd.com/read/28089401/recycling-organic-wastes-to-agricultural-land-as-a-way-to-improve-its-quality-a-field-study-to-evaluate-benefits-and-risks
#15
P Alvarenga, P Palma, C Mourinha, M Farto, J Dôres, M Patanita, C Cunha-Queda, T Natal-da-Luz, M Renaud, J P Sousa
A field study was established to assess the effects of a sewage sludge (SS), a mixed municipal solid waste compost (MMSWC) and a compost produced from agricultural wastes (AWC), in a Vertisol, using Lolium multiflorum L. The amendments were applied for two consecutive years: 6, 12 and 24t dry matter ha(-1) for SS, and the amendment doses for MMSWC and AWC were calculated to deliver the same amount of organic matter (OM) per unit area. The amendments had significant beneficial effects on some soil properties (e...
January 12, 2017: Waste Management
https://www.readbyqxmd.com/read/28088165/genomic-characterization-of-ensifer-aridi-a-proposed-new-species-of-nitrogen-fixing-rhizobium-recovered-from-asian-african-and-american-deserts
#16
Antoine Le Quéré, Nisha Tak, Hukam Singh Gehlot, Celine Lavire, Thibault Meyer, David Chapulliot, Sonam Rathi, Ilham Sakrouhi, Guadalupe Rocha, Marine Rohmer, Dany Severac, Abdelkarim Filali-Maltouf, Jose-Antonio Munive
BACKGROUND: Nitrogen fixing bacteria isolated from hot arid areas in Asia, Africa and America but from diverse leguminous plants have been recently identified as belonging to a possible new species of Ensifer (Sinorhizobium). In this study, 6 strains belonging to this new clade were compared with Ensifer species at the genome-wide level. Their capacities to utilize various carbon sources and to establish a symbiotic interaction with several leguminous plants were examined. RESULTS: Draft genomes of selected strains isolated from Morocco (Merzouga desert), Mexico (Baja California) as well as from India (Thar desert) were produced...
January 14, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28073063/self-assembled-micelles-based-on-chondroitin-sulfate-poly-d-l-lactideco-glycolide-block-copolymers-for-doxorubicin-delivery
#17
Hui Zhang, Jiangkang Xu, Liang Xing, Jianbo Ji, Aihua Yu, Guangxi Zhai
Doxorubicin (DOX) is one of the most common chemotherapeutic agents for the treatment of various cancers, but its clinical usage is limited by dose-dependent cardiotoxicity. We have recently synthesized a series of Chondroitin sulfate/poly (d,l-lactideco-glycolide) block copolymers (Chs-b-PLGA) with different length of hydrophobic block by an end-to-end coupling strategy. The structure of the amphiphilic block copolymers with low critical micelle concentration (∼28mg/L) were confirmed by (1)H NMR. The copolymers could self-assemble into stable micelles in aqueous environment with homogeneous size distribution and negative zeta potential...
April 15, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28056071/species-specific-responses-of-juvenile-rockfish-to-elevated-pco2-from-behavior-to-genomics
#18
Scott L Hamilton, Cheryl A Logan, Hamilton W Fennie, Susan M Sogard, James P Barry, April D Makukhov, Lauren R Tobosa, Kirsten Boyer, Christopher F Lovera, Giacomo Bernardi
In the California Current ecosystem, global climate change is predicted to trigger large-scale changes in ocean chemistry within this century. Ocean acidification-which occurs when increased levels of atmospheric CO2 dissolve into the ocean-is one of the biggest potential threats to marine life. In a coastal upwelling system, we compared the effects of chronic exposure to low pH (elevated pCO2) at four treatment levels (i.e., pCO2 = ambient [500], moderate [750], high [1900], and extreme [2800 μatm]) on behavior, physiology, and patterns of gene expression in white muscle tissue of juvenile rockfish (genus Sebastes), integrating responses from the transcriptome to the whole organism level...
2017: PloS One
https://www.readbyqxmd.com/read/28034294/probiotic-properties-of-lactobacillus-fermentum-strains-isolated-from-human-oral-samples-and-description-of-their-antibacterial-activity
#19
Virginia Fuochi, Giovanni Li Volti, Pio Maria Furneri
BACKGROUND: Gram positive bacteria produce peptides, defined bacteriocins which exhibit good antibacterial activity. OBJECTIVE: We evaluated the ability of L. fermentum to produce bacteriocins having therefore, good probiotic features and finally, be safe towards microglial cells. METHOD: Eight wild strains, identified using molecular techniques, were investigated for the evaluation of resistance to bile salts, low pH, H2O2 production, biofilm formation, antibacterial activity and safety on microglia cells (BV2)...
29, 2016: Current Pharmaceutical Biotechnology
https://www.readbyqxmd.com/read/28008101/muscle-metabolic-and-neuromuscular-determinants-of-fatigue-during-cycling-in-different-exercise-intensity-domains
#20
Matthew I Black, Andrew M Jones, Jamie R Blackwell, Stephen J Bailey, Lee J Wylie, Sinead T J McDonagh, Christopher Thompson, James Kelly, Paul Sumners, Katya J Mileva, Joanna L Bowtell, Anni Vanhatalo
The lactate or gas exchange threshold (GET) and the critical power (CP) are closely associated with human exercise performance. We tested the hypothesis that the limit of tolerance (Tlim) during cycle exercise performed within the exercise intensity domains demarcated by GET and CP is linked to discrete muscle metabolic and neuromuscular responses. Eleven males performed a ramp incremental exercise test, 4-5 severe-intensity (SEV; >CP) constant-work-rate (CWR) tests until Tlim, a heavy-intensity (HVY; <CP but >GET) CWR test until Tlim, and a moderate-intensity (MOD; <GET) CWR test until Tlim Muscle biopsies revealed that a similar (P>0...
December 22, 2016: Journal of Applied Physiology
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