WTS database

Title	Pub Year	Author Sort descending	SearchLink
Identification of lactic acid bacteria isolated from Tarhana, a traditional Turkish fermented food	2009	Department of Food Engineering, Food Microbiology Section, Faculty of Engineering, University of Ege, Turkey. ilkin.sengun@ege.edu.tr	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full International journal of food microbiology Periodical, Abbrev. Int.J.Food Microbiol. Pub Date Free Form 31-Oct Volume 135 Issue 2 Start Page 105 Other Pages 111 Notes JID: 8412849; 0 (Carbohydrates); 0 (DNA, Bacterial); 0 (DNA, Ribosomal); 0 (RNA, Ribosomal, 16S); 2008/11/04 [received]; 2009/07/22 [revised]; 2009/07/23 [accepted]; 2009/08/04 [aheadofprint]; ppublish Place of Publication Netherlands ISSN/ISBN 1879-3460; 0168-1605 Accession Number PMID: 19703719 Language eng SubFile Journal Article; Research Support, Non-U.S. Gov't; IM DOI 10.1016/j.ijfoodmicro.2009.07.033 [doi] Output Language Unknown(0) PMID 19703719 Abstract Tarhana is a traditional fermented product produced from a mixture of spontaneously fermented yogurt and wheat flour in Turkey. The aims of the present study were to enumerate and identify for the first time by molecular biology-based methods predominant lactic acid bacteria (LAB) isolated during processing of Tarhana. Samples were collected from eight different regions of Turkey. In order to explore the relationship between raw material and the microbiology of Tarhana, yogurt and wheat flour were also analyzed. A total of 226 Gram-positive and catalase-negative isolates were obtained from MRS, M17 and SBM (Slanetz and Bartley Medium). The isolates were grouped and identified using a combination of pheno- and genotypic methods including rep-PCR fingerprinting [(GTG)(5) primer], multiplex PCR, 16S rRNA gene sequencing and carbohydrate assimilation profiling. Pediococcus acidilactici were found to constitute 27% of the isolates, 19% were identified as Streptococcus thermophilus, 19% as Lactobacillus fermentum, 12% as Enterococcus faecium, 7% as Pediococcus pentosaceus, 5% as Leuconostoc pseudomesenteroides, 4% as Weissella cibaria, 2% as Lactobacillus plantarum, 2% as Lactobacillus delbrueckii spp. bulgaricus, 2% as Leuconostoc citreum, 1% as Lactobacillus paraplantarum and 0.5% as Lactobacillus casei. The different production sites investigated all had individual LAB profiles, but with P. acidilactici and S. thermophilus being isolated from the majority of samples. The main source of P. acidilactici and S. thermophilus was found to be the yogurt. Descriptors Bacterial Typing Techniques, Biodiversity, Carbohydrates, Colony Count, Microbial, DNA, Bacterial, DNA, Ribosomal, Fermentation, Flour/microbiology, Food Handling, Food Microbiology, Genotype, Humans, Lactobacillaceae/classification/genetics/isolation & purification, Phenotype, Polymerase Chain Reaction, RNA, Ribosomal, 16S, Sequence Analysis, RNA, Triticum/microbiology, Turkey, Yogurt/microbiology Links Book Title Database Publisher Data Source Authors Sengun,I. Y., Nielsen,D. S., Karapinar,M., Jakobsen,M. Original/Translated Title URL Date of Electronic 20090804 PMCID Editors
Presence of erythromycin and tetracycline resistance genes in lactic acid bacteria from fermented foods of Indian origin	2012	Department of Food Microbiology, CSIR-Central Food Technological Research Institute, Mysore, 570 020, India.	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Antonie van Leeuwenhoek Periodical, Abbrev. Antonie Van Leeuwenhoek Pub Date Free Form Nov Volume 102 Issue 4 Start Page 541 Other Pages 551 Notes LR: 20131121; GENBANK/HQ615663; GENBANK/HQ615664; GENBANK/HQ615665; GENBANK/HQ615666; GENBANK/HQ615667; GENBANK/HQ615668; GENBANK/HQ615669; GENBANK/HQ615670; GENBANK/HQ615671; GENBANK/HQ615672; GENBANK/HQ615673; GENBANK/HQ615674; GENBANK/HQ615675; GENBANK Place of Publication Netherlands ISSN/ISBN 1572-9699; 0003-6072 Accession Number PMID: 22644346 Language eng SubFile Journal Article; Research Support, Non-U.S. Gov't; IM DOI 10.1007/s10482-012-9749-4 [doi] Output Language Unknown(0) PMID 22644346 Abstract Lactic acid bacteria (LAB) resistant to erythromycin were isolated from different food samples on selective media. The isolates were identified as Enterococcus durans, Enterococcus faecium, Enterococcus lactis, Enterococcus casseliflavus, Lactobacillus salivarius, Lactobacillus reuteri, Lactobacillus plantarum, Lactobacillus fermentum, Pediococcus pentosaceus and Leuconostoc mesenteroides. Of the total 60 isolates, 88 % harbored the ermB gene. The efflux gene msrA was identified in E. faecium, E. durans, E. lactis, E. casseliflavus, P. pentosaceus and L. fermentum. Further analysis of the msrA gene by sequencing suggested its homology to msrC. Resistance to tetracycline due to the genes tetM, tetW, tetO, tetK and tetL, alone or in combination, were identified in Lactobacillus species. The tetracycline efflux genes tetK and tetL occurred in P. pentosaceus and Enterococcus species. Since it appeared that LAB had acquired these genes, fermented foods may be a source of antibiotic resistance. Descriptors Links Book Title Database Publisher Data Source Authors Thumu,S.C., Halami,P.M. Original/Translated Title URL Date of Electronic 20120529 PMCID Editors
Identification of lactic acid bacteria in salted Chinese cabbage by SDS-PAGE and PCR-DGGE	2014	Department of Food Science and Biotechnology, and Institute of Life Sciences and Resources, Kyung Hee University, Yongin, 446-701, Korea.	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Journal of the science of food and agriculture Periodical, Abbrev. J.Sci.Food Agric. Pub Date Free Form 30-Jan Volume 94 Issue 2 Start Page 296 Other Pages 300 Notes CI: (c) 2013; JID: 0376334; 0 (DNA, Bacterial); 0 (RNA, Ribosomal, 16S); OTO: NOTNLM; 2013/04/01 [received]; 2013/05/20 [revised]; 2013/06/08 [accepted]; 2013/07/17 [aheadofprint]; ppublish Place of Publication England ISSN/ISBN 1097-0010; 0022-5142 Accession Number PMID: 23749756 Language eng SubFile Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't; IM DOI 10.1002/jsfa.6257 [doi] Output Language Unknown(0) PMID 23749756 Abstract BACKGROUND: Lactic acid bacteria (LAB) in salted Chinese cabbage, the main ingredient of kimchi, were analyzed by culture-dependent sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), followed by sequencing of the 16S rRNA gene and by culture-independent polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), followed by sequencing of the V3 region of the 16S rRNA gene. The results were compared to those of LAB that had previously been found in kimchi. RESULTS: The two identification methods produced distinct overall LAB profiles. The PCR-DGGE method detected a more diverse microflora, including non-LAB strains. The culture-dependent method uniquely detected Weissella sp. and was able to provide the quantitative distribution of LAB in samples. However, Leuconostoc mesenteroides, Lactobacillus curvatus and Leuconostoc carnosum, which had also been reported as the dominant LAB in kimchi in previous studies, were identified by both methods. CONCLUSION: The two identification methods gave different bacterial profiles, while both methods were sufficient to identify the most prevalent LAB in salted Chinese cabbage samples. The quantitative feature of the culture-dependent identification method would make it preferable for studying and monitoring LAB viability in kimchi at each fermentation stage. The availability of the culture-independent identification method to identify a broader bacterial profile, including non-LAB, would make it a more effective tool for controlling contamination of undesirable bacteria during kimchi fermentation. Descriptors Links Book Title Database Publisher Society of Chemical Industry Data Source Authors Hong,Y., Yang,H.S., Li,J., Han,S.K., Chang,H.C., Kim,H.Y. Original/Translated Title URL Date of Electronic 20130717 PMCID Editors
Rapid determination of polycyclic aromatic hydrocarbons in grilled meat using microwave-assisted extraction and dispersive liquid-liquid microextraction coupled to gas chromatography-mass spectrometry	2015	Department of Food Science and Technology, Faculty of Nutrition Science, Food Science and Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Chemistry, Faculty	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Meat Science Periodical, Abbrev. Meat Sci. Pub Date Free Form May Volume 103 Issue Start Page 61 Other Pages 67 Notes CI: Copyright (c) 2015; JID: 101160862; 0 (Polycyclic Hydrocarbons, Aromatic); 0 (Water Pollutants, Chemical); OTO: NOTNLM; 2014/06/18 [received]; 2014/12/09 [revised]; 2015/01/05 [accepted]; 2015/01/08 [aheadofprint]; ppublish Place of Publication England ISSN/ISBN 1873-4138; 0309-1740 Accession Number PMID: 25618021 Language eng SubFile Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't; IM DOI 10.1016/j.meatsci.2015.01.001 [doi] Output Language Unknown(0) PMID 25618021 Abstract A simple and rapid analytical tech nique for the simultaneous determination of 16 polycyclic aromatic hydrocarbons (PAHs) in grilled meat was developed using microwave-assisted extraction and dispersive liquid-liquid microextraction (MAE-DLLME) followed by gas chromatography-mass spectrometry (GC-MS). The effective parameters in DLLME process were optimized. Good linear relationships were obtained for 16 PAHs in a range of 1-200 ng g(-1), with a correlation coefficient (R(2)) higher than 0.98. Limits of detection and limits of quantification were 0.15-0.3 ng g(-1) and 0.47-1 ng g(-1), respectively. The relative standard deviations (RSD%) for seven analyses were less than 9%. The recoveries of those compounds in grilled meat were obtained from 85% to 104%. Low consumption of the solvent, high recovery, short extraction time, no matrix interference and good merit figures compared to other methods are advantages of the proposed method. The performance of the present method was evaluated for the determination of PAHs in various types of real grilled meat samples, and satisfactory results were obtained. Descriptors Links Book Title Database Publisher Elsevier Ltd Data Source Authors Kamankesh,M., Mohammadi,A., Hosseini,H., Modarres Tehrani,Z. Original/Translated Title URL Date of Electronic 20150108 PMCID Editors
Study of Lactic Acid Bacteria Community From Raw Milk of Iranian One Humped Camel and Evaluation of Their Probiotic Properties	2015	Department of Food Science and Technology, Ferdowsi University of Mashhad, Mashhad, IR Iran.; Department of Food Science and Technology, Ferdowsi University of Mashhad, Mashhad, IR Iran.; Department of Veterinary Research and Biotechnology, Razi Vaccine a	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Jundishapur journal of microbiology Periodical, Abbrev. Jundishapur J.Microbiol. Pub Date Free Form 31-May Volume 8 Issue 5 Start Page e16750 Other Pages Notes LR: 20150613; JID: 101515122; OID: NLM: PMC4458354; OTO: NOTNLM; 2015/05 [ecollection]; 2013/12/09 [received]; 2014/04/13 [revised]; 2014/04/22 [accepted]; 2015/05/31 [epublish]; epublish Place of Publication Iran ISSN/ISBN 2008-3645; 2008-3645 Accession Number PMID: 26060561 Language eng SubFile Journal Article DOI 10.5812/jjm.8(5)2015.16750 [doi] Output Language Unknown(0) PMID 26060561 Abstract BACKGROUND: Camel milk is amongst valuable food sources in Iran. On the other hand, due to the presence of probiotic bacteria and bacteriocin producers in camel milk, probiotic bacteria can be isolated and identified from this food product. OBJECTIVES: The objectives of the present research were the isolation and molecular identification of lactic acid bacteria from camel milk and evaluation of their probiotic properties. MATERIALS AND METHODS: A total of ten samples of camel milk were collected from the Golestan province of Iran under aseptic conditions. Bacteria were isolated by culturing the samples on selective medium. Isolates were identified by amplification of the 16S rDNA and Internal Transcribed Spacer (ITS) region between the 16S and 23S rRNA genes by Polymerase Chain Reaction (PCR) and were then screened and grouped by the Amplified Ribosomal DNA Restriction Analysis (ARDRA) method. To evaluate probiotic properties, representative isolates of different ARDRA profiles were analyzed. The antimicrobial activity of Lactic Acid Bacteria (LAB) against Pediococcus pentosaceus, Escherichia coli and Bacillus cereus was examined by the agar diffusion assay. Acid and bile tolerance of isolates were evaluated. RESULTS: A total of 64 isolates were analyzed based on biochemical tests and morphological characteristics. The most frequently isolated LAB was Enterococci. Weissella, Leuconostoc, Lactobacilli and Pediococci were less frequently found. Based on restriction analysis of the ITS, the isolates were grouped into nine different ARDRA patterns that were identified by ribosomal DNA sequencing as P. pentosaceus, Enterococcus faecium strain Y-2, E. faecium strain JZ1-1, E. faecium strain E6, E. durans, E. lactis, Leuconostoc mesenteroides, Lactobacillus casei and Weissella cibaria. The results showed that antimicrobial activity of the tested isolates was remarkable and P. pentosaceus showed the most antibacterial activity. In addition, E. durans, E. lactis, L. casei and P. pentosaceus were selected as probiotic bacteria. CONCLUSIONS: This study revealed the presence of bacteriocin-producing bacteria and probiotic bacteria in camel milk from the Golestan province of Iran. Descriptors Links Book Title Database Publisher Data Source Authors Davati,N., Tabatabaee Yazdi,F., Zibaee,S., Shahidi,F., Edalatian,M.R. Original/Translated Title URL Date of Electronic 20150531 PMCID PMC4458354 Editors
Microwave-assisted extraction and dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry for isolation and determination of polycyclic aromatic hydrocarbons in smoked fish	2012	Department of Food Science and Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Journal of chromatography.A Periodical, Abbrev. J.Chromatogr.A Pub Date Free Form 11-May Volume 1237 Issue Start Page 30 Other Pages 36 Notes CI: Copyright (c) 2012; JID: 9318488; 0 (Polycyclic Compounds); 2012/01/10 [received]; 2012/02/28 [revised]; 2012/02/29 [accepted]; 2012/03/10 [aheadofprint]; ppublish Place of Publication Netherlands ISSN/ISBN 1873-3778; 0021-9673 Accession Number PMID: 22483095 Language eng SubFile Journal Article; IM DOI 10.1016/j.chroma.2012.02.078 [doi] Output Language Unknown(0) PMID 22483095 Abstract A simple and efficient method was developed using microwave-assisted extraction (MAE) and dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry (GC-MS) for the extraction and quantification of 16 polycyclic aromatic hydrocarbons (PAHs) in smoked fish. Benzo[a]pyrene, chrysene and pyrene were employed as model compounds and spiked to smoked fish to assess the extraction procedure. Several parameters, including the nature and volume of hydrolysis, extracting and disperser solvents, microwave time and pH, were optimized. In the optimum condition for MAE, 1g of fish sample was extracted in 12 mL KOH (2M) and ethanol with a 50:50 ratio in a closed-vessel system. For DLLME, 500 muL of acetone (disperser solvent) containing 100 muL of ethylene tetrachloride (extraction solvent) was rapidly injected by syringe into 12 mL of the sample extract solution (previously adjusted to pH 6.5), thereby forming a cloudy solution. Phase separation was performed by centrifugation and a volume of 1.5 muL of the sedimented phase was analyzed by GC-MS in select ion monitoring (SIM) mode. Satisfactory results were achieved when this method was applied to analyze the PAHs in smoked fish samples. The MAE-DLLME method coupled with GC-MS provided excellent enrichment factors (in the range of 244-373 for 16 PAHs) and good repeatability (with a relative standard deviation between 2.8 and 9%) for spiked smoked fish. The calibration graphs were linear in the range of 1-200 ng g(-1), with the square of the correlation coefficient (R(2))>0.981 and detection limits between 0.11 and 0.43 ng g(-1). The recoveries of those compounds in smoked fish were from 82.1% to 105.5%. A comparison of this method with previous methods demonstrated that the proposed method is an accurate, rapid and reliable sample-pretreatment method that gives very good enrichment factors and detection limits for extracting and determining PAHs from smoked fish. Descriptors Links Book Title Database Publisher Elsevier B.V Data Source Authors Ghasemzadeh-Mohammadi,V., Mohammadi,A., Hashemi,M., Khaksar,R., Haratian,P. Original/Translated Title URL Date of Electronic 20120310 PMCID Editors
Identification and antimicrobial susceptibility of lactic acid bacteria from retail fermented foods	2007	Department of Food Science, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803, USA. bge@lsu.edu	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Journal of food protection Periodical, Abbrev. J.Food Prot. Pub Date Free Form Nov Volume 70 Issue 11 Start Page 2606 Other Pages 2612 Notes JID: 7703944; 0 (Anti-Bacterial Agents); 0 (DNA, Bacterial); 0 (DNA, Ribosomal Spacer); 0 (RNA, Ribosomal, 16S); 0 (RNA, Ribosomal, 23S); ppublish Place of Publication United States ISSN/ISBN 0362-028X; 0362-028X Accession Number PMID: 18044442 Language eng SubFile Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.; IM DOI Output Language Unknown(0) PMID 18044442 Abstract One important safety criterion of using lactic acid bacteria (LAB) in food applications is to ensure that they do not carry transferable antimicrobial resistance (AR) determinants. In this study, 63 LAB belonging to six genera, Streptococcus, Lactobacillus, Lactococcus, Enterococcus, Leuconostoc, and Pediococcus, were recovered from 28 retail fermented food products in Maryland, identified to species with 16S-23S rRNA spacer PCRs, and characterized for antimicrobial susceptibility against eight antimicrobials. Besides intrinsic resistance to ciprofloxacin or vancomycin in some lactobacilli, tetracycline resistance was observed in two Streptococcus thermophilus isolates from one cheese and one sour cream sample and was associated with the presence of a nonconjugative tet(S) gene. The results indicated a low level of AR among naturally occurring and starter LAB cultures in fermented dairy and meat products in the United States; therefore, the probability for foodborne LAB to serve as reservoirs of AR is low. Further studies involving a larger sample size are needed to assess the potential risk of AR gene transfer from LAB in fermented food products. Descriptors Anti-Bacterial Agents/pharmacology, Base Sequence, Colony Count, Microbial, Conjugation, Genetic, Consumer Product Safety, DNA, Bacterial/analysis, DNA, Ribosomal Spacer, Dairy Products/microbiology, Dose-Response Relationship, Drug, Drug Resistance, Bacterial, Drug Resistance, Multiple, Bacterial, Fermentation, Food Microbiology, Humans, Lactobacillus/drug effects/isolation & purification, Lactococcus/drug effects/isolation & purification, Leuconostoc/drug effects/isolation & purification, Meat Products/microbiology, Microbial Sensitivity Tests, Pediococcus/drug effects/isolation & purification, Polymerase Chain Reaction/methods, RNA, Ribosomal, 16S/chemistry, RNA, Ribosomal, 23S/chemistry, Species Specificity, Streptococcus/drug effects/isolation & purification Links Book Title Database Publisher Data Source Authors Ge,B., Jiang,P., Han,F., Saleh,N. K., Dhiman,N., Fedorko,D. P., Nelson,N. A., Meng,J. Original/Translated Title URL Date of Electronic PMCID Editors
Organic nitrogen uptake of Scots pine seedlings is independent of current carbohydrate supply	2013	Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umea, Sweden.	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Tree physiology Periodical, Abbrev. Tree Physiol. Pub Date Free Form Jun Volume 33 Issue 6 Start Page 590 Other Pages 600 Notes LR: 20151119; JID: 100955338; 0 (Ammonium Compounds); 0 (Nitrates); 0 (Nitrogen Isotopes); 7440-44-0 (Carbon); 9005-25-8 (Starch); 94ZLA3W45F (Arginine); N762921K75 (Nitrogen); OTO: NOTNLM; ppublish Place of Publication Canada ISSN/ISBN 1758-4469; 0829-318X Accession Number PMID: 23824240 Language eng SubFile Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.; IM DOI 10.1093/treephys/tpt041 [doi] Output Language Unknown(0) PMID 23824240 Abstract In boreal forests, seedling establishment is limited by various factors including soil nitrogen (N) availability. Seedlings may absorb N from soil in a variety of inorganic and organic forms; however, the energy and thus carbohydrate requirements for uptake and assimilation of N vary with N source. We studied the importance of current photoassimilates for the acquisition and allocation of different N sources by Scots pine (Pinus sylvestris (L.)) seedlings. Girdling was used as a tool to impair phloem transport of photoassimilates, and hence gradually deprive roots of carbohydrates. Seedlings were cultivated in a greenhouse on equimolar N concentrations of one of the N sources-arginine, ammonium or nitrate-and then girdled prior to a pulse-chase uptake experiment with isotopically labeled N sources. Girdling proved to be efficient in decreasing levels of soluble sugars and starch in the roots. Uptake rate of arginine N was highest, intermediate for ammonium N and lowest for nitrate N. Moreover, the uptake of arginine N was unaffected by girdling, while the uptake of the two inorganic N sources decreased to 45-56% of the ungirdled controls. In arginine-treated seedlings, 95-96% of the acquired arginine N resided in the roots, whereas a significant shift in the N distribution toward the shoot was evident in girdled seedlings treated with inorganic N. This spatial shift was especially pronounced in nitrate-treated seedlings suggesting that the reduction and following incorporation into roots was limited by the availability of current photoassimilates. These results suggest that there are energetic benefits for seedlings to utilize organic N sources, particularly under circumstances where carbohydrate supply is limited. Hence, these putative benefits might be of importance for the survival and growth of seedlings when carbohydrate reserves are depleted in early growing season, or in light-limited environments, such as those sustained by continuous cover forestry systems. Descriptors Links Book Title Database Publisher Data Source Authors Gruffman,L., Palmroth,S., Nasholm,T. Original/Translated Title URL Date of Electronic PMCID Editors
Plant nitrogen status and co-occurrence of organic and inorganic nitrogen sources influence root uptake by Scots pine seedlings	2014	Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umea, Sweden.	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Tree physiology Periodical, Abbrev. Tree Physiol. Pub Date Free Form Feb Volume 34 Issue 2 Start Page 205 Other Pages 213 Notes LR: 20151119; JID: 100955338; 0 (Ammonium Compounds); 0 (Inorganic Chemicals); 0 (Nitrates); 0 (Organic Chemicals); 94ZLA3W45F (Arginine); N762921K75 (Nitrogen); OTO: NOTNLM; 2014/01/30 [aheadofprint]; ppublish Place of Publication Canada ISSN/ISBN 1758-4469; 0829-318X Accession Number PMID: 24488801 Language eng SubFile Journal Article; Research Support, Non-U.S. Gov't; IM DOI 10.1093/treephys/tpt121 [doi] Output Language Unknown(0) PMID 24488801 Abstract Insights into how the simultaneous presence of organic and inorganic nitrogen (N) forms influences root absorption will help elucidate the relative importance of these N forms for plant nutrition in the field as well as for nursery cultivation of seedlings. Uptake of the individual N forms arginine, ammonium (NH4(+)) and nitrate (NO3(-)) was studied in Scots pine (Pinus sylvestris (L.)) seedlings supplied as single N sources and additionally in mixtures of NO3(-) and NH4(+) or NO3(-) and arginine. Scots pine seedlings displayed a strong preference for NH4(+)-N and arginine-N as compared with NO3(-)-N. Thus, NO3(-) uptake was generally low and decreased in the presence of NH4(+) in the high-concentration range (500 microM N), but not in the presence of arginine. Moreover, uptake of NO3(-) and NH4(+) was lower in seedlings displaying a high internal N status as a result of high N pre-treatment, while arginine uptake was high in seedlings with a high internal N status when previously exposed to organic N. These findings may have practical implications for commercial cultivation of conifers. Descriptors Links Book Title Database Publisher Data Source Authors Gruffman,L., Jamtgard,S., Nasholm,T. Original/Translated Title URL Date of Electronic 20140130 PMCID Editors
Decomposition and nitrogen dynamics of (15)N-labeled leaf, root, and twig litter in temperate coniferous forests	2013	Department of Forest Ecosystems and Society, Oregon State University, 321 Richardson Hall, Corvallis, OR, 97331, USA, tiff.vanhuysen@gmail.com.	Read more...
Source Type Print(0) Ref Type Journal Article Periodical, Full Oecologia Periodical, Abbrev. Oecologia Pub Date Free Form Dec Volume 173 Issue 4 Start Page 1563 Other Pages 1573 Notes JID: 0150372; 0 (Nitrogen Isotopes); 0 (Soil); N762921K75 (Nitrogen); 2012/07/02 [received]; 2013/06/06 [accepted]; 2013/07/25 [aheadofprint]; ppublish Place of Publication Germany ISSN/ISBN 1432-1939; 0029-8549 Accession Number PMID: 23884664 Language eng SubFile Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; IM DOI 10.1007/s00442-013-2706-8 [doi] Output Language Unknown(0) PMID 23884664 Abstract Litter nutrient dynamics contribute significantly to biogeochemical cycling in forest ecosystems. We examined how site environment and initial substrate quality influence decomposition and nitrogen (N) dynamics of multiple litter types. A 2.5-year decomposition study was installed in the Oregon Coast Range and West Cascades using (15)N-labeled litter from Acer macrophyllum, Picea sitchensis, and Pseudotsuga menziesii. Mass loss for leaf litter was similar between the two sites, while root and twig litter exhibited greater mass loss in the Coast Range. Mass loss was greatest from leaves and roots, and species differences in mass loss were more prominent in the Coast Range. All litter types and species mineralized N early in the decomposition process; only A. macrophyllum leaves exhibited a net N immobilization phase. There were no site differences with respect to litter N dynamics despite differences in site N availability, and litter N mineralization patterns were species-specific. For multiple litter x species combinations, the difference between gross and net N mineralization was significant, and gross mineralization was 7-20 % greater than net mineralization. The mineralization results suggest that initial litter chemistry may be an important driver of litter N dynamics. Our study demonstrates that greater amounts of N are cycling through these systems than may be quantified by only measuring net mineralization and challenges current leaf-based biogeochemical theory regarding patterns of N immobilization and mineralization. Descriptors Links Book Title Database Publisher Data Source Authors van Huysen,T.L., Harmon,M.E., Perakis,S.S., Chen,H. Original/Translated Title URL Date of Electronic 20130725 PMCID Editors

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