Mitochondrial reduction of metmyoglobin: dependence on the electron transport chain     

Tang J  Faustman C  Mancini RA  Seyfert M  Hunt MC 《Journal of agricultural and food chemistry》2005,53(13):5449-5455

Reduction of ferric myoglobin (metmyoglobin, MetMb) to its ferrous form is important for maintaining fresh meat color because only reduced myoglobin can bind oxygen to form the consumer-preferred cherry red color in fresh meat. The objective of this study was to characterize an apparent mitochondria electron transport chain (ETC)-linked pathway for MetMb reduction in vitro. MetMb was reduced in the presence of mitochondria and succinate (p < 0.05); mitochondria or succinate alone did not facilitate MetMb reduction relative to controls (p > 0.05). Flushing samples with oxygen greatly decreased MetMb reduction, while flushing with argon increased MetMb reduction when compared with controls (p < 0.05). ETC inhibitors were used to localize the site where electrons became available for MetMb reduction. MetMb reduction was increased by rotenone addition and decreased by malonic acid (p < 0.05); the reduction was completely abolished by additions of antimycin A or myxothiazol when compared with controls (p < 0.05). These results suggest that electrons become available for MetMb reduction at a site(s) between complex III and IV. Mitochondrial ETC-linked MetMb reduction increased with increased mitochondrial density and succinate concentration (p < 0.05); the greatest MetMb reduction was observed at pH 7.2 and 37 degrees C, and ETC-linked MetMb reducing activity decreased with time postmortem (p < 0.05). These results indicate that ETC-linked MetMb reduction exists but would be minimally active in postmortem muscles.  相似文献   

Interactions between mitochondrial lipid oxidation and oxymyoglobin oxidation and the effects of vitamin E     

Tang J  Faustman C  Hoagland TA  Mancini RA  Seyfert M  Hunt MC 《Journal of agricultural and food chemistry》2005,53(15):6073-6079

Off-flavor and discoloration of meat products result from lipid oxidation and myoglobin (Mb) oxidation, respectively, and these two processes appear to be interrelated. The objective of this study was to investigate their potential interaction in mitochondria and the effects of mitochondrial alpha-tocopherol concentrations on lipid oxidation and metmyoglobin (MetMb) formation in vitro. The addition of ascorbic acid and ferric chloride (AA-Fe(3+)) increased ovine and bovine mitochondrial lipid oxidation when compared with their controls (p < 0.05); MetMb formation also increased with increased lipid oxidation relative to controls (p < 0.05). Reactions containing Mb and mitochondria with greater alpha-tocopherol concentrations demonstrated less lipid oxidation and MetMb formation than mitochondria with lower alpha-tocopherol concentrations. Greater mitochondrial alpha-tocopherol concentration was also correlated with increased mitochondrial oxygen consumption in vitro and with a more pronounced effect at pH 7.2 than at pH 5.6. Relative to controls, succinate addition to bovine mitochondria resulted in increased concentrations of ubiquinol 10 and alpha-tocopherol and decreased lipid and Mb oxidation (p < 0.05). Mitochondrial lipid oxidation was closely related to MetMb formation; both processes were inhibited by alpha-tocopherol in a concentration-dependent manner.  相似文献   

Color stability, reducing activity, and cytochrome c oxidase activity of five bovine muscles     

Seyfert M  Mancini RA  Hunt MC  Tang J  Faustman C  Garcia M 《Journal of agricultural and food chemistry》2006,54(23):8919-8925

The objective was to characterize the beef psoas major (PM), longissimus lumborum (LL), superficial semimembranosus (SSM), deep semimembranosus (DSM), and semitendinosus (ST) muscles for differences in instrumental and visual color, metmyoglobin-reducing activity (MRA), total reducing activity (TRA), and cytochrome c oxidase activity. The LL and ST had the most color stability and MRA (p < 0.05), the DSM and PM had the least (p < 0.05), and values for the SSM were intermediate. Visual color (r = -0.66) and a and chroma (r = 0.68) were more correlated with MRA than with TRA (r < 0.14 for all measures). This research supports previous reports that color stability among muscles is variable and that MRA is more useful than TRA for explaining the role of reducing activity in muscle-color stability.  相似文献   

Recombinant bovine S100A8 and A9 enhance IL-1β secretion of interferon-gamma primed monocytes     

Mirja Koy  Nina Hambruch  Jamal Hussen  Christiane Pfarrer  Hans-Martin Seyfert  Hans-Joachim Schuberth 《Veterinary immunology and immunopathology》2013

Calgranulin A (S100A8) and B (S100A9) are found at high levels in inflamed tissue and have been associated with acute and chronic inflammatory disorders. Calgranulins are discussed as damage-associated molecular patterns (DAMPs). To analyze the role of calgranulins for inflammatory responses, bovine S100A8 and S100A9 were cloned, successfully expressed and FPLC-purified. Both molecules did not induce NF-κB activation in boTLR4-transfected HEK293 cells and stimulation of bovine monocytes with both proteins did not result in interleukin 1β (IL-1β) secretion or an upregulated mRNA expression of selected genes (IL1B, TNF, CXCL8, IL10, IL12). However, Interferon γ (IFN-γ) primed bovine monocytes released significantly higher amounts of IL-1β after stimulation with S100A8, S100A9, and co-stimulation with adenosine triphosphate (ATP). In IL-4/IL-13-primed monocytes, the IL-1β release was completely abrogated. The results imply that TLR4/MyD88/NF-κB-independent S100A8/A9-mediated activation of the inflammasome in cattle is favored in a Th1 environment and that S100A8 and S100A9 act as a DAMP in cattle.  相似文献   

Tillage system affects fertilizer-induced nitrous oxide emissions     

Maike?Krauss  Hans-Martin?KrauseEmail author  Simone?Spangler  Ellen?Kandeler  Sebastian?Behrens  Andreas?Kappler  Paul?M?der  Andreas?Gattinger 《Biology and Fertility of Soils》2017,53(1):49-59

Since the development of effective N₂O mitigation options is a key challenge for future agricultural practice, we studied the interactive effect of tillage systems on fertilizer-derived N₂O emissions and the abundance of microbial communities involved in N₂O production and reduction. Soil samples from 0–10 cm and 10–20 cm depth of reduced tillage and ploughed plots were incubated with dairy slurry (SL) and manure compost (MC) in comparison with calcium ammonium nitrate (CAN) and an unfertilized control (ZERO) for 42 days. N₂O and CO₂ fluxes, ammonium, nitrate, dissolved organic C, and functional gene abundances (16S rRNA gene, nirK, nirS, nosZ, bacterial and archaeal amoA) were regularly monitored. Averaged across all soil samples, N₂O emissions decreased in the order CAN and SL (CAN?=?748.8?±?206.3, SL?=?489.4?±?107.2 μg kg^?1) followed by MC (284.2?±?67.3 μg kg^?1) and ZERO (29.1?±?5.9 μg kg^?1). Highest cumulative N₂O emissions were found in 10–20 cm of the reduced tilled soil in CAN and SL. N₂O fluxes were assigned to ammonium as source in CAN and SL and correlated positively to bacterial amoA abundances. Additionally, nosZ abundances correlated negatively to N₂O fluxes in the organic fertilizer treatments. Soils showed a gradient in soil organic C, 16S rRNA, nirK, and nosZ with greater amounts in the 0–10 than 10–20 cm layer. Abundances of bacterial and archaeal amoA were higher in reduced tilled soil compared to ploughed soils. The study highlights that tillage system induced biophysicochemical stratification impacts net N₂O emissions within the soil profile according to N and C species added during fertilization.  相似文献   

Characterization of two key molecules of teleost innate immunity from rainbow trout (Oncorhynchus mykiss): MyD88 and SAA     

Alexander Rebl  Tom Goldammer  Uwe Fischer  Bernd Kllner  Hans-Martin Seyfert 《Veterinary immunology and immunopathology》2009,131(1-2):122-126

Toll-like receptors (TLR) are relevant for piscine innate immunity. TLR activation recruits several downstream factors regulating the expression of immunorelevant genes. We have characterized two key factors of innate immunity from rainbow trout: MyD88 as an adaptor protein interacting directly with TLRs, and serum amyloid A as an effector molecule induced by the activated Toll-like receptor signaling cascade.Both factors share a remarkable high degree of structural conservation with their mammalian orthologs suggesting that innate immune defense mechanisms may also functionally be conserved between fish and mammals.  相似文献   

Bacterial pathogen associated molecular pattern and superantigens indirectly induce the accelerated death of bovine neutrophilic granulocytes     

Schuberth HJ  Dahnke J  Leibold W  Seyfert HM  Zerbe H 《Berliner und Münchener tier?rztliche Wochenschrift》2004,117(11-12):464-471

Pathogen associated molecular patterns (PAMPs) and bacterial superantigens have many effects on mononuclear cells (MNC) and macrophages. Influences on neutrophilic granulocytes (PMN), especially by non methylated CpG motifs, gained less attention. Here we investigated whether PAMPs and the superantigen SEA have a direct or indirect influence on the survival rate of bovine PMN. Different CpG motifs, a reverse GpC motif, Lipopolysaccharide (LPS) and SEA did not result in a loss of viability of pure PMN. In the presence of MNC or in vitro generated macrophages (MdM), however, they induced an accelerated dying of PMN. The simultaneous stimulation of MNC/MdM with combinations of CpG motifs and LPS or SEA resulted in an additive or over additive effect: compared to control set ups, only 28-36% of the PMN remained viable in SEA/CpG stimulated MNC/PMN cocultures. Comparing autologous with allogeneic MNC/PMN or MdM/PMN cocultures, it showed up that not only the stimulated MNC or MdM population but also the individual reaction state of the PMN have an influence on the degree of PMN dying. Taken together, CpG motifs and other PAMPs as well as superantigens act in concert to reduce indirectly the viability of neutrophilic granulocytes and hence the functional capacity of an important effector cell population.  相似文献   

Pricing efficiency across destination markets for Norwegian salmon exports     

Atle Oglend  Hans-Martin Straume 《Aquaculture Economics & Management (Blackwell Science)》2019,23(2):188-203

This paper investigates how pricing efficiency of Norwegian salmon exports varies across destination market characteristics. Efficiency is defined as the rate at which individual transaction prices adjust to common market information, and is estimated by dynamic fixed effects panel models with parameters conditional on trade attributes using micro-level trade data. Our results show that contract type (Incoterms) used in transactions can be used to segment the Norwegian export markets into three types: (1) high-value trade to large distant markets, (2) medium-value trade to close high-income markets, and (3) lower-value large bulk trades to lower-income close markets. We find that pricing efficiency is lowest for committed trades over long distance using planes, and highest for less committed large bulk trades to close markets. Despite significant heterogeneity, the majority of salmon price variation (around ¾) is common, providing a clear justification for the representativeness of a salmon price index.  相似文献   

Surrogate taxa for biodiversity in agricultural landscapes of eastern Austria   总被引：2，自引：0，他引：2  

Norbert Sauberer  Klaus Peter Zulka  Hans-Martin Berg  Norbert Milasowszky  Christoph Plutzar  Christiane Storch  Harald Zechmeister 《Biological conservation》2004,117(2):181-190

In an agricultural landscape in eastern Austria eight terrestrial organism groups were investigated as potential biodiversity indicators. We present a cross-taxon congruence assessment obtained at the landscape scale using two groups of plants (bryophytes and vascular plants), five groups of invertebrates (gastropods, spiders, orthopterans, carabid beetles and ants) and one vertebrate taxon (birds). We tested four different approaches: correlated species counts, surrogate measures of the overall species richness that was assessed, a multi-taxa (or shopping basket) approach and a simple complementarity algorithm. With few exceptions, pairwise correlations between taxa, correlations between one taxon and the species richness of the remaining groups, and correlations between a combination of the richness of two taxa and the remaining species richness were highly positive. Complementarity-derived priority sets of sampling sites using one taxon as a surrogate for the pooled species richness of all other taxa captured significantly more species than selecting areas randomly. As an essential first step in selecting useful biodiversity indicators, we demonstrate that species richness of vascular plants and birds showed the highest correlations with the overall species richness. In a multi-taxa approach and in complementarity site selection, each of the eight investigated taxa had the capability to capture a high percentage of the overall species richness.  相似文献   

Host-response patterns of intramammary infections in dairy cows   总被引：2，自引：0，他引：2  

Schukken YH  Günther J  Fitzpatrick J  Fontaine MC  Goetze L  Holst O  Leigh J  Petzl W  Schuberth HJ  Sipka A  Smith DG  Quesnell R  Watts J  Yancey R  Zerbe H  Gurjar A  Zadoks RN  Seyfert HM;members of the Pfizer mastitis research consortium 《Veterinary immunology and immunopathology》2011,144(3-4):270-289

Many different bacterial species have the ability to cause an infection of the bovine mammary gland and the host response to these infections is what we recognize as mastitis. In this review we evaluate the pathogen specific response to the three main bacterial species causing bovine mastitis: Escherichia coli, Streptococcus uberis and Staphylococcus aureus. In this paper we will review the bacterial growth patterns, host immune response and clinical response that results from the intramammary infections. Clear differences in bacterial growth pattern are shown between bacterial species. The dominant pattern in E. coli infections is a short duration high bacteria count infection, in S. aureus this is more commonly a persistent infection with relative low bacteria counts and in S. uberis a long duration high bacteria count infection is often observed. The host immune response differs significantly depending on the invading bacterial species. The underlying reasons for the differences and the resulting host response are described. Finally we discuss the clinical response pattern for each of the three bacterial species. The largest contrast is between E. coli and S. aureus where a larger proportion of E. coli infections cause potentially severe clinical symptoms, whereas the majority of S. aureus infections go clinically unnoticed. The relevance of fully understanding the bovine host response to intramammary infection is discussed, some major gaps in our knowledge are highlighted and directions for future research are indicated.  相似文献