Extraction of soil bacteria from a Ferralsol     

Knut Ehlers  Else K. Bünemann  Astrid Oberson  Emmanuel Frossard  Åsa Frostegård  Mao Yuejian  Lars R. Bakken 《Soil biology & biochemistry》2008,40(7):1940-1946

Extraction of intact bacteria from soil by dispersion and density gradient centrifugation may facilitate analyses of soil bacterial communities which are otherwise hampered by soil particles. Reasonable cell yield and representative fractions with sufficient purity can be extracted from most soils, but highly weathered, clayey and acidic tropical soils like Ferralsols represent a challenge to the method due to low cell yields. At an early stage of our studies with Ferralsols we also found substantial contamination of the extracted bacterial fractions by soil material, measured as total Al and Fe. We have adapted the method to a Ferralsol (pH 4.9, 64% clay, 21% silt, 15% sand) by factorial combinations of pH modification and salt (NaCl) concentration during soil dispersion, and evaluated the yield (microscopic cell counts), purity (optical density and Al + Fe content), and compared the composition of the extracted bacteria (phospholipid fatty acid analysis and 16S rDNA-denaturing gradient gel electrophoresis) versus that of the intact soil community. The cell yield was increased with a factor 2–3 by increasing the pH to 7.5, while it was decreased to a similar extent by adding NaCl (8 g l^?1). However, NaCl removed more than 99% of the Al + Fe contamination of the bacterial extracts, and the combination of modified pH and NaCl addition secured reasonable cell yield (4.6% of total number) and low contamination. The observed effects of pH and NaCl are probably due to changes in variable charge (by pH) and ion distribution (NaCl) around interacting particles (soil and bacteria), thus affecting their flocculation. Phospholipid fatty acid and denaturing gradient gel electrophoresis analysis indicate that the bias of the bacterial extracts compared to direct soil extracts increases with the addition of NaCl as well as by pH manipulation. Nevertheless, representativeness was acceptable as indicated by a Bray–Curtis similarity index (bacterial extracts versus soil) of 70% and 87% for phospholipid fatty acid profiles and denaturing gradient gel electrophoresis, respectively. Overall, the results reveal a trade-off among yield, purity and representativeness. Thus, depending on application and analyses, future users can choose the right treatment according to their specific purpose.  相似文献   

Determination of carotenoids, total phenolic content, and antioxidant activity of Arazá (Eugenia stipitata McVaugh), an Amazonian fruit     

Garzón GA  Narváez-Cuenca CE  Kopec RE  Barry AM  Riedl KM  Schwartz SJ 《Journal of agricultural and food chemistry》2012,60(18):4709-4717

The fruit of Arazá (Eugenia stipitata McVaugh) native to the Colombian Amazon is considered a potentially economically valuable fruit for the Andean economy due to its novel and unique taste. The fruit has an intense yellow color, but its chemical composition and properties have not been well studied. Here we report the identification and quantitation of carotenoids in the ripe fruit using high performance liquid chromatography (HPLC) with photodiode array detector (PDA) and atmospheric pressure chemical ionization (APcI) mass spectrometry (MS/MS). The qualitative carotenoid profile of the fruit according to maturity stage was also observed. Furthermore, antioxidant activity of the peel and pulp were assessed using the ferric reducing ability of plasma (FRAP), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods, in addition to chemical indexes and total phenolic content. Multiple carotenoids were identified in the peel and pulp including four xanthophylls (free and esterified as their mono and diesters) and two carotenes. One of the xanthophylls was tentatively identified as zeinoxanthin, while the others were identified as lutein, zeaxanthin, and β-cryptoxanthin. Carotenes included α-carotene and β-carotene. The total carotenoid content was significantly higher in the peel (2484 ± 421 μg/100 g FW) than in the pulp (806 ± 348 μg/100 g FW) with lutein, β-cryptoxanthin, and zeinoxanthin as the major carotenoid components. The unique carotenoid composition of this fruit can differentiate it from other carotenoid-rich fruits and perhaps be useful in authentication procedures. Overall, results from this study suggest that Colombian Arazá may be a good edible source of carotenoids important in retinal health as well as carotenoids with provitamin A activity. Therefore, Arazá fruit can be used as a nutraceutical ingredient and in production of functional foods in the Colombian diet.  相似文献   

Treatment of Young Spruce Shoots with SO2 and H2S: Effects on Fine Root Chromosomes in Relation to Changes in the Thiol Content and Redox State     

Astrid Wonisch  Michael Tausz  Maria Müller  Wilfried Weidner  Luit J. De Kok  Dieter Grill 《Water, air, and soil pollution》1999,116(1-2):423-428

Three year old spruce trees (Picea omorika) were exposed to 100 and 225 nl l^-1 SO₂ and H₂S for three weeks. The number of chromosomal aberrations and the mitotic index in the root tip meristems, and glutathione and cysteine contents in fine roots were determined twice weekly. An increase in glutathione content in fine roots of H₂S exposed plants was only detectable after 13 days of fumigation. The number of chromosomal aberrations increased significantly after 9 days of exposure to 225 nl l^-1 H₂S and after 13 days of exposure to 225 nl l^-1 SO₂ or 100 nl l^-1 H₂S. This increase in chromosomal damage persisted up to the end of the 3 week treatment. Neither SO₂ nor H₂S exposure affected the cysteine content or the redox state of glutathione in fine roots. These results suggest that the development of chromosomal aberrations during SO₂ and H₂S exposures does not directly reflect changes in thiol/glutathione content or redox state in the fine roots.  相似文献   

Bonding,bridging and linking social networks: A qualitative study of the emergency management of Cyclone Pam,Vanuatu          下载免费PDF全文

Astrid Vachette  David King  Alison Cottrell 《Asia Pacific viewpoint》2017,58(3):315-330

Cyclone Pam (March 2015) was an unprecedented event in Vanuatu forcing the simultaneous involvement of national and long‐term international actors, well integrated into the national disaster governance system, as well as numerous short‐term international actors, unfamiliar with the geopolitical and cultural disaster context of the country. Cooperation between these three groups of actors evolved through the three scales of bonding, bridging and linking social networking. This paper questions the different drivers and challenges within and across these scales of social networks affecting cooperation among the three different groups of actors during an emergency. Using a mixed methodology based on social network analysis, this paper utilises the case study of Cyclone Pam in Vanuatu to study the strengths and weaknesses of the disaster governance system in place based on bonding and bridging social capital to conduct disaster risk management and to prepare the integration of linking social capital when external support is needed. This paper contributes to the identification of key considerations in the development of resilience‐building strategies: the interactions of diverse actors to address disaster management needs and the reciprocal impacts of these interactions within and across the three different scales of social networks.  相似文献   

Selection of bacteria and fungi for control of soilborne seedling diseases of maize     

Pfeiffer  Tobias  von Galen  Astrid  Zink  Petra  Hübner  Sebastian  Linkies  Ada  Felgentreu  Dieter  Drechsel  Jannika  Birr  Tim  Röder  Olaf  Kotte  Mathias  Dietel  Kristin  Junge  Helmut  Schwarz  Elisa  Koch  Eckhard 《植物病害和植物保护杂志》2021,128(5):1227-1241

Journal of Plant Diseases and Protection - Plant-based screening experiments were conducted with the aim of identifying biocontrol bacteria and fungi for seed treatment of maize. Candidate...  相似文献   

USING SEMI‐AUTOMATED SEGMENTATION OF COMPUTED TOMOGRAPHY DATASETS FOR THREE‐DIMENSIONAL VISUALIZATION AND VOLUME MEASUREMENTS OF EQUINE PARANASAL SINUSES     

Markus Brinkschulte  Astrid Bienert‐Zeit  Matthias Lüpke  Maren Hellige  Carsten Staszyk  Bernhard Ohnesorge 《Veterinary radiology & ultrasound》2013,54(6):582-590

The system of the paranasal sinuses morphologically represents one of the most complex parts of the equine body. A clear understanding of spatial relationships is needed for correct diagnosis and treatment. The purpose of this study was to describe the anatomy and volume of equine paranasal sinuses using three‐dimensional (3D) reformatted renderings of computed tomography (CT) slices. Heads of 18 cadaver horses, aged 2–25 years, were analyzed by the use of separate semi‐automated segmentation of the following bilateral paranasal sinus compartments: rostral maxillary sinus (Sinus maxillaris rostralis), ventral conchal sinus (Sinus conchae ventralis), caudal maxillary sinus (Sinus maxillaris caudalis), dorsal conchal sinus (Sinus conchae dorsalis), frontal sinus (Sinus frontalis), sphenopalatine sinus (Sinus sphenopalatinus), and middle conchal sinus (Sinus conchae mediae). Reconstructed structures were displayed separately, grouped, or altogether as transparent or solid elements to visualize individual paranasal sinus morphology. The paranasal sinuses appeared to be divided into two systems by the maxillary septum (Septum sinuum maxillarium). The first or rostral system included the rostral maxillary and ventral conchal sinus. The second or caudal system included the caudal maxillary, dorsal conchal, frontal, sphenopalatine, and middle conchal sinuses. These two systems overlapped and were interlocked due to the oblique orientation of the maxillary septum. Total volumes of the paranasal sinuses ranged from 911.50 to 1502.00 ml (mean ± SD, 1151.00 ± 186.30 ml). 3D renderings of equine paranasal sinuses by use of semi‐automated segmentation of CT‐datasets improved understanding of this anatomically challenging region.  相似文献   

Haplotype C of growth hormone (GH) gene in Japanese Black cattle: Structure of GH protein and a novel method for detection of the gene     

Abolfazl Bahrami  Astrid Ardiyanti  Kaoru Tonosaki  Keiichi Suzuki  Nanako Tanida  Takuji Hirayama  Sang‐Gun Roh  Takeshi Nishio  Kazuo Katoh 《Animal Science Journal》2013,84(12):802-804

From a series of studies on single nucleotide polymorphisms (SNPs) in the bovine growth hormone (GH) gene of Japanese Black cattle, the type‐C (127^Val and 172^Met) that is specific for this breed has been intensively focused upon because of the economic importance for carcass traits, such as intramuscular oleic acid contents. In the present study, we intended to analyze the 3‐D structure of GH of haplotype C, and developed a novel method to detect the type C gene. Three‐D analysis of the type C protein showed that the amino acid residues (127^Val and 172^Met), which are present in the third and fourth helixes, respectively, and are important for binding with GH receptors, are shifted to deeper positions in the molecule compared with that for type A (127^Leu and 172^Thr), implying the alteration of binding interaction with receptors. A novel, efficient and cost‐effective method (Dot‐blot‐SNP technique) for type C genotyping was successfully established, of which the basal method was a reported genotyping of SNPs for a large number of plants, reducing the cost to 10% or less of direct sequencing.  相似文献   

Regulatory puzzle of xyn1 gene (xylanase1) expression in Trichoderma reesei          下载免费PDF全文

Robert L Mach　 Elisabeth Würleitner　 Astrid R Stricker　 Roman Rauscher　 Christian Wacenovsky 《浙江大学学报(农业与生命科学版)》2004,30(4):431-431

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Presumed cholesterinic granulomas detected on CT in horses are associated with increased lateral ventricle height and age     

Ralph A Lloyd‐Edwards  Dorien S Willems  Martijn Beukers  Astrid van den Brom‐Spierenburg  Johannes C M Vernooij  Stefanie Veraa 《Veterinary radiology & ultrasound》2020,61(3):269-278

Cholesterinic granulomas are mass‐like lesions that form at the choroid plexus of the ventricular system. Large cholesterinic granulomas within the lateral ventricles have been reported to cause severe neurological signs. However, little data are available about their prevalence or appearance in the overall population. The objective was to report the prevalence of presumed cholesterinic granulomas on CT in a population of horses, and investigate associations between presumed cholesterinic granuloma presence, lateral ventricle size, age, and neurological signs. The study was cross sectional, CT scans of the head were assessed for presumed cholesterinic granuloma presence and size, and lateral ventricle height. Computed tomography findings and clinical information were compared using nonparametric testing. Computed tomography scans of 139 horses were included. Presumed cholesterinic granulomas were found in 22 horses (15.8%), nine were unilateral and 13 bilateral. A significant increase in prevalence was observed with age (P < .0001), with 38% of horses over 15 years old affected. The median volume of presumed cholesterinic granulomas was 242 mm³ with a range from 51 to 2420 mm³. The mean lateral ventricle height was significantly increased in horses with presumed cholesterinic granulomas present (P = .004), with a median of 7.3 mm compared to 4.9 mm without. Neurological signs were not associated with presumed cholesterinic granuloma presence or lateral ventricle height. Fourth ventricle mineralizations were found in seven horses, which may represent cholesterinic granulomas. In conclusion, presumed cholesterinic granulomas occurred in a large proportion of the examined population and are associated with increased lateral ventricle dilation and advanced age.  相似文献   

In vitro and in vivo responses of mucosa from the large colon of horses to ischemia and reperfusion     

Graham AS  Grosche A  Morton AJ  Polyak MM  Freeman DE 《American journal of veterinary research》2011,72(7):982-989

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