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Microbial rRNA gene expression and co‐occurrence profiles associate with biokinetics and elemental composition in full‐scale anaerobic digesters 下载免费PDF全文
Ryan M. Ziels Bo H. Svensson Carina Sundberg Madeleine Larsson Anna Karlsson Sepehr Shakeri Yekta 《Microbial biotechnology》2018,11(4):694-709
This study examined whether the abundance and expression of microbial 16S rRNA genes were associated with elemental concentrations and substrate conversion biokinetics in 20 full‐scale anaerobic digesters, including seven municipal sewage sludge (SS) digesters and 13 industrial codigesters. SS digester contents had higher methane production rates from acetate, propionate and phenyl acetate compared to industrial codigesters. SS digesters and industrial codigesters were distinctly clustered based on their elemental concentrations, with higher concentrations of NH3‐N, Cl, K and Na observed in codigesters. Amplicon sequencing of 16S rRNA genes and reverse‐transcribed 16S rRNA revealed divergent grouping of microbial communities between mesophilic SS digesters, mesophilic codigesters and thermophilic digesters. Higher intradigester distances between Archaea 16S rRNA and rRNA gene profiles were observed in mesophilic codigesters, which also had the lowest acetate utilization biokinetics. Constrained ordination showed that microbial rRNA and rRNA gene profiles were significantly associated with maximum methane production rates from acetate, propionate, oleate and phenyl acetate, as well as concentrations of NH3‐N, Fe, S, Mo and Ni. A co‐occurrence network of rRNA gene expression confirmed the three main clusters of anaerobic digester communities based on active populations. Syntrophic and methanogenic taxa were highly represented within the subnetworks, indicating that obligate energy‐sharing partnerships play critical roles in stabilizing the digester microbiome. Overall, these results provide new evidence showing that different feed substrates associate with different micronutrient compositions in anaerobic digesters, which in turn may influence microbial abundance, activity and function. 相似文献
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Mirbolook Atena Rasouli-Sadaghiani MirHassan Sepehr Ebrahim Lakzian Amir Hakimi Mohammad 《Journal of Plant Growth Regulation》2021,40(2):831-847
Journal of Plant Growth Regulation - Plants require optimum amounts of nutrients for suitable growth and yield production. Accordingly, the most efficient methods of fertilization, including the... 相似文献
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Meghdad Abdollahpour-Alitappeh Majid Lotfinia Tohid Gharibi Jalal Mardaneh Behrouz Farhadihosseinabadi Pegah Larki Babak Faghfourian Koushan Sineh Sepehr Kazem Abbaszadeh-Goudarzi Ghasem Abbaszadeh-Goudarzi Behrooz Johari Mohammad Reza Zali Nader Bagheri 《Journal of cellular physiology》2019,234(5):5628-5642
Targeted delivery of therapeutic molecules into cancer cells is considered as a promising strategy to tackle cancer. Antibody–drug conjugates (ADCs), in which a monoclonal antibody (mAb) is conjugated to biologically active drugs through chemical linkers, have emerged as a promising class of anticancer treatment agents, being one of the fastest growing fields in cancer therapy. The failure of early ADCs led researchers to explore strategies to develop more effective and improved ADCs with lower levels of unconjugated mAbs and more-stable linkers between the drug and the antibody, which show improved pharmacokinetic properties, therapeutic indexes, and safety profiles. Such improvements resulted in the US Food and Drug Administration approvals of brentuximab vedotin, trastuzumab emtansine, and, more recently, inotuzumab ozogamicin. In addition, recent clinical outcomes have sparked additional interest, which leads to the dramatically increased number of ADCs in clinical development. The present review explores ADCs, their main characteristics, and new research developments, as well as discusses strategies for the selection of the most appropriate target antigens, mAbs, cytotoxic drugs, linkers, and conjugation chemistries. 相似文献
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In the present study, rat primary cultures were used to study the effect of lactate on the survival of hippocampal neurons in the presence or absence of glucose. Our results showed no extensive cell damage under glucose‐free conditions compared with glucose‐rich conditions. Addition of 10 and 50 mM lactate to glucose‐free and glucose‐rich media increased the cell damage significantly, as observed by morphology and lactate dehydrogenase activity. The results of the present study suggest that primary neurons in vitro are not sensitive to glucose deficiency and the presence of lactate damages the neurons in a concentration‐dependent manner. 相似文献
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Sepehr Bahadorani Jaehyoung Cho Thomas Lo Heidy Contreras Hakeem O. Lawal David E. Krantz Timothy J. Bradley David W. Walker 《Aging cell》2010,9(2):191-202
The ‘rate of living’ theory predicts that longevity should be inversely correlated with the rate of mitochondrial respiration. However, recent studies in a number of model organisms, including mice, have reported that interventions that retard the aging process are, in fact, associated with an increase in mitochondrial activity. To better understand the relationship between energy metabolism and longevity, we supplemented the endogenous respiratory chain machinery of the fruit fly Drosophila melanogaster with the alternative single‐subunit NADH–ubiquinone oxidoreductase (Ndi1) of the baker’s yeast Saccharomyces cerevisiae. Here, we report that expression of Ndi1 in fly mitochondria leads to an increase in NADH–ubiquinone oxidoreductase activity, oxygen consumption, and ATP levels. In addition, exogenous Ndi1 expression results in increased CO2 production in living flies. Using an inducible gene‐expression system, we expressed Ndi1 in different cells and tissues and examined the impact on longevity. In doing so, we discovered that targeted expression of Ndi1 in fly neurons significantly increases lifespan without compromising fertility or physical activity. These findings are consistent with the idea that enhanced respiratory chain activity in neuronal tissue can prolong fly lifespan. 相似文献
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