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1.
Maja Nielsen Christian Holst-Fischer Bjørn Malmgren-Hansen Michael Bjerg-Nielsen Caroline Kragelund Henrik Bjarne Møller Lars Ditlev Mørck Ottosen 《Biotechnology letters》2017,39(11):1689-1698
Objective
To assess the effect of small temperature increases in mesophilic sludge-based digesters in order to develop and evaluate strategies for improving the biogas production in full-scale digesters.Results
Methane production was strongly affected by small temperature differences, and this result was consistent across samples from 15 full-scale digesters. The specific methane yield varied between 42 and 97.5 ml g VS?1 after 15 days of incubation at 35 °C, and improved when increasing the digester temperature to 39 °C. Only a limited quantity of additional gas was required to balance out the cost of heating and a positive energy balance was obtained. Further increases in temperature, in some cases, negatively affected the production when operated at 42 °C compared to 39 °C.Conclusions
Small temperature increases should be applied to mesophilic sludge-based digesters to optimize the biogas production and is applicable to digesters operated in the lower mesophilic temperature range.2.
3.
Fatiha Sounni Halah Aissam Oumaima Ghomari Mohammed Merzouki Mohammed Benlemlih 《Biotechnology letters》2018,40(2):297-301
Objectives
To assess the combination of electrocoagulation and anaerobic co-digestion of olive mill wastewaters (OMWW) with other substrates, such as chicken manure, in a continuous stirred tank reactor for biogas production.Results
Anaerobic digestion of OMWW treated by electrocoagulation allowed higher production of biogas, up to 0.74 l biogas g?1 COD introduced compared to untreated or diluted olive mill wastewaters (OMWW) (0.37 and 0.6 l biogas g?1 COD) respectively. Pretreated OMWW co-digested with chicken manure at different volumic ratios OMWW/manure in a continuous stirred tank reactor under mesophilic conditions revealed that OMWW/manure (7:3 v/v) was optimal for biogas production and process stability.Conclusion
Anaerobic digestion could achieve promising results in depollution and valorization of OMWW under a continuous stirred tank reactor.4.
Objectives
The effect of different formulations variables on protein integrity were investigated using lysozyme as a model protein for the development of biotherapeutic protein formulations for use in the clinic.Results
Buffer composition/concentration was the key variable of formulation reagents investigated in determining lysozyme stability and authenticity independent of protein concentration whilst the storage temperature and time, not surprisingly, were also key variables. Tryptic peptide mapping of the protein showed that the modifications occurred when formulated under specific conditions but not others. A model peptide system was developed that reflected the same behavior under formulation conditions as intact lysozyme.Conclusions
Peptide models may mirror the stability of proteins, or regions of proteins, in the same formulations and be used to help develop a rapid screen of formulations for stabilisation of biotherapeutic proteins.5.
Chao Zhao Yanan Chu Yanhong Li Chengfeng Yang Yuqing Chen Xumin Wang Bin Liu 《Biotechnology letters》2017,39(1):123-131
Objectives
To analyze the microbial diversity and gene content of a thermophilic cellulose-degrading consortium from hot springs in Xiamen, China using 454 pyrosequencing for discovering cellulolytic enzyme resources.Results
A thermophilic cellulose-degrading consortium, XM70 that was isolated from a hot spring, used sugarcane bagasse as sole carbon and energy source. DNA sequencing of the XM70 sample resulted in 349,978 reads with an average read length of 380 bases, accounting for 133,896,867 bases of sequence information. The characterization of sequencing reads and assembled contigs revealed that most microbes were derived from four phyla: Geobacillus (Firmicutes), Thermus, Bacillus, and Anoxybacillus. Twenty-eight homologous genes belonging to 15 glycoside hydrolase families were detected, including several cellulase genes. A novel hot spring metagenome-derived thermophilic cellulase was expressed and characterized.Conclusions
The application value of thermostable sugarcane bagasse-degrading enzymes is shown for production of cellulosic biofuel. The practical power of using a short-read-based metagenomic approach for harvesting novel microbial genes is also demonstrated.6.
Renato de Souza Pinto Lemgruber Kaspar Valgepea Mark P. Hodson Ryan Tappel Sean D. Simpson Michael Köpke Lars K. Nielsen Esteban Marcellin 《Metabolomics : Official journal of the Metabolomic Society》2018,14(3):35
Introduction
Quantification of tetrahydrofolates (THFs), important metabolites in the Wood–Ljungdahl pathway (WLP) of acetogens, is challenging given their sensitivity to oxygen.Objective
To develop a simple anaerobic protocol to enable reliable THFs quantification from bioreactors.Methods
Anaerobic cultures were mixed with anaerobic acetonitrile for extraction. Targeted LC–MS/MS was used for quantification.Results
Tetrahydrofolates can only be quantified if sampled anaerobically. THF levels showed a strong correlation to acetyl-CoA, the end product of the WLP.Conclusion
Our method is useful for relative quantification of THFs across different growth conditions. Absolute quantification of THFs requires the use of labelled standards.7.
Yuan Zhong Zhiguo Liu Christine Isaguirre Yan Liu Wei Liao 《Biotechnology for biofuels》2016,9(1):253
Background
Anaerobic digestate is the effluent from anaerobic digestion of organic wastes. It contains a significant amount of nutrients and lignocellulosic materials, even though anaerobic digestion consumed a large portion of organic matters in the wastes. Utilizing the nutrients and lignocellulosic materials in the digestate is critical to significantly improve efficiency of anaerobic digestion technology and generate value-added chemical and fuel products from the organic wastes. Therefore, this study focused on developing an integrated process that uses biogas energy to power fungal fermentation and converts remaining carbon sources, nutrients, and water in the digestate into biofuel precursor-lipid.Results
The process contains two unit operations of anaerobic digestion and digestate utilization. The digestate utilization includes alkali treatment of the mixture feed of solid and liquid digestates, enzymatic hydrolysis for mono-sugar release, overliming detoxification, and fungal fermentation for lipid accumulation. The experimental results conclude that 5 h and 30 °C were the preferred conditions for the overliming detoxification regarding lipid accumulation of the following fungal cultivation. The repeated-batch fungal fermentation enhanced lipid accumulation, which led to a final lipid concentration of 3.16 g/L on the digestate with 10% dry matter. The mass and energy balance analysis further indicates that the digestate had enough water for the process uses and the biogas energy was able to balance the needs of individual unit operations.Conclusions
A fresh-water-free and energy-positive process of lipid production from anaerobic digestate was achieved by integrating anaerobic digestion and fungal fermentation. The integration addresses the issues that both biofuel industry and waste management encounter—high water and energy demand of biofuel precursor production and few digestate utilization approaches of organic waste treatment.8.
Ke Liu Youzhi Zhou Jinsong Zhang Jianlin Chu Yewei Zhang Bingfang He 《Biotechnology letters》2017,39(12):1903-1910
Objective
To isolate a thermostable pyrimidine nucleoside phosphorylase (PyNP) from mesophilic bacteria by gene mining.Results
BbPyNP from Brevibacillus borstelensis LK01 was isolated by gene mining. BbPyNP had a highest 60% identity with that of reported PyNPs. BbPyNP could catalyze the phosphorolysis of thymidine, 2′-deoxyuridine, uridine and 5-methyuridine. BbPyNP had good thermostability and retained 73% of its original activity after 2 h incubation at 50 °C. BbPyNP had the highest activity at an optimum alkaline pH of 8.5. BbPyNP was stable from pH 7 to 9.8. Under preliminary optimized conditions, the biosynthesis of various 5-halogenated pyrimidine nucleosides by BbPyNP reached the yield of 61–84%.Conclusion
An efficient approach was estimated in isolating thermostable PyNP from mesophilic bacteria.9.
Dorothea Lesche Roland Geyer Daniel Lienhard Christos T. Nakas Gaëlle Diserens Peter Vermathen Alexander B. Leichtle 《Metabolomics : Official journal of the Metabolomic Society》2016,12(10):159
Background
Centrifugation is an indispensable procedure for plasma sample preparation, but applied conditions can vary between labs.Aim
Determine whether routinely used plasma centrifugation protocols (1500×g 10 min; 3000×g 5 min) influence non-targeted metabolomic analyses.Methods
Nuclear magnetic resonance spectroscopy (NMR) and High Resolution Mass Spectrometry (HRMS) data were evaluated with sparse partial least squares discriminant analyses and compared with cell count measurements.Results
Besides significant differences in platelet count, we identified substantial alterations in NMR and HRMS data related to the different centrifugation protocols.Conclusion
Already minor differences in plasma centrifugation can significantly influence metabolomic patterns and potentially bias metabolomics studies.10.
N. Cesbron A.-L. Royer Y. Guitton A. Sydor B. Le Bizec G. Dervilly-Pinel 《Metabolomics : Official journal of the Metabolomic Society》2017,13(8):99
Introduction
Collecting feces is easy. It offers direct outcome to endogenous and microbial metabolites.Objectives
In a context of lack of consensus about fecal sample preparation, especially in animal species, we developed a robust protocol allowing untargeted LC-HRMS fingerprinting.Methods
The conditions of extraction (quantity, preparation, solvents, dilutions) were investigated in bovine feces.Results
A rapid and simple protocol involving feces extraction with methanol (1/3, M/V) followed by centrifugation and a step filtration (10 kDa) was developed.Conclusion
The workflow generated repeatable and informative fingerprints for robust metabolome characterization.11.
Objectives
To compare the degradation performance and biodiversity of a polyvinyl alcohol-degrading microbial community under aerobic and anaerobic conditions.Results
An anaerobic–aerobic bioreactor was operated to degrade polyvinyl alcohol (PVA) in simulated wastewater. The degradation performance of the bioreactor during sludge cultivation and the microbial communities in each reactor were compared. Both anaerobic and aerobic bioreactors demonstrated high chemical oxygen demand removal efficiencies of 87.5 and 83.6 %, respectively. Results of 16S rDNA sequencing indicated that Proteobacteria dominated in both reactors and that the microbial community structures varied significantly under different operating conditions. Both reactors obviously differed in bacterial diversity from the phyla Planctomycetes, Chlamydiae, Bacteroidetes, and Chloroflexi. Betaproteobacteria and Alphaproteobacteria dominated, respectively, in the anaerobic and aerobic reactors.Conclusions
The anaerobic–aerobic system is suitable for PVA wastewater treatment, and the microbial genetic analysis may serve as a reference for PVA biodegradation.12.
Background
In recent years the visualization of biomagnetic measurement data by so-called pseudo current density maps or Hosaka-Cohen (HC) transformations became popular.Methods
The physical basis of these intuitive maps is clarified by means of analytically solvable problems.Results
Examples in magnetocardiography, magnetoencephalography and magnetoneurography demonstrate the usefulness of this method.Conclusion
Hardware realizations of the HC-transformation and some similar transformations are discussed which could advantageously support cross-platform comparability of biomagnetic measurements.13.
Takeo Moriya Yoshinori Satomi Hiroyuki Kobayashi 《Metabolomics : Official journal of the Metabolomic Society》2016,12(12):179
Introduction
Human plasma metabolomics offer powerful tools for understanding disease mechanisms and identifying clinical biomarkers for diagnosis, efficacy prediction and patient stratification. Although storage conditions can affect the reliability of data from metabolites, strict control of these conditions remains challenging, particularly when clinical samples are included from multiple centers. Therefore, it is necessary to consider stability profiles of each analyte.Objectives
The purpose of this study was to extract unstable metabolites from vast metabolome data and identify factors that cause instability.Method
Plasma samples were obtained from five healthy volunteers, were stored under ten different conditions of time and temperature and were quantified using leading-edge metabolomics. Instability was evaluated by comparing quantitation values under each storage condition with those obtained after ?80 °C storage.Result
Stability profiling of the 992 metabolites showed time- and temperature-dependent increases in numbers of significantly changed metabolites. This large volume of data enabled comparisons of unstable metabolites with their related molecules and allowed identification of causative factors, including compound-specific enzymatic activity in plasma and chemical reactivity. Furthermore, these analyses indicated extreme instability of 1-docosahexaenoylglycerol, 1-arachidonoylglycerophosphate, cystine, cysteine and N6-methyladenosine.Conclusion
A large volume of data regarding storage stability was obtained. These data are a contribution to the discovery of biomarker candidates without misselection based on unreliable values and to the establishment of suitable handling procedures for targeted biomarker quantification.14.
Jamie V. de Seymour Stephanie Tu Xiaoling He Hua Zhang Ting-Li Han Philip N. Baker Karolina Sulek 《Metabolomics : Official journal of the Metabolomic Society》2018,14(6):79
Introduction
Intrahepatic cholestasis of pregnancy (ICP) is a common maternal liver disease; development can result in devastating consequences, including sudden fetal death and stillbirth. Currently, recognition of ICP only occurs following onset of clinical symptoms.Objective
Investigate the maternal hair metabolome for predictive biomarkers of ICP.Methods
The maternal hair metabolome (gestational age of sampling between 17 and 41 weeks) of 38 Chinese women with ICP and 46 pregnant controls was analysed using gas chromatography–mass spectrometry.Results
Of 105 metabolites detected in hair, none were significantly associated with ICP.Conclusion
Hair samples represent accumulative environmental exposure over time. Samples collected at the onset of ICP did not reveal any metabolic shifts, suggesting rapid development of the disease.15.
Elba Garreta-Lara Bruno Campos Carlos Barata Silvia Lacorte Romà Tauler 《Metabolomics : Official journal of the Metabolomic Society》2016,12(5):86
Introduction
Climate change is a major concern for the scientific community, demanding novel information about the effects of environmental stressors on living organisms. Metabolic profiling is required for achieving the most extensive possible range of compounds and their concentration changes on stressed conditions.Objectives
Individuals of the crustacean species Daphnia magna were exposed to three different abiotic factors linked to global climate change: high salinity, high temperature levels and hypoxia. Advanced chemometric tools were used to characterize the metabolites affected by the exposure.Method
An exploratory analysis of gas chromatography-mass spectrometry (GC–MS) data was performed to discriminate between control and exposed daphnid samples. Due to the complexity of these GC–MS data sets, a comprehensive untargeted analysis of the full scan data was performed using multivariate curve resolution-alternating least squares (MCR-ALS) method. This approach enabled to resolve most of the metabolite signals from interference peaks caused by derivatization reactions. Metabolites with significant changes in their peak areas were tentatively identified and the involved metabolic pathways explored.Results
D. magna metabolic biomarkers are proposed for the considered physical factors. Metabolites related with energy metabolic pathways including some amino acids, carbohydrates, organic acids and nucleosides were identified as potential biomarkers of the investigated treatments.Conclusions
The proposed untargeted GC–MS metabolomics strategy and multivariate data analysis tools were useful to investigate D. magna metabolome under environmental stressed conditions.16.
Ivan Muñoz Jannick H. Schmidt 《The International Journal of Life Cycle Assessment》2016,21(8):1069-1075
Purpose
The fifth assessment report by the IPCC includes methane oxidation as an additional indirect effect in the global warming potential (GWP) and global temperature potential (GTP) values for methane. An analysis of the figures provided by the IPCC reveals they lead to different outcomes measured in CO2-eq., depending on whether or not biogenic CO2 emissions are considered neutral. In this article, we discuss this inconsistency and propose a correction.Methods
We propose a simple framework to account for methane oxidation in GWP and GTP in a way that is independent on the accounting rules for biogenic carbon. An equation with three components is provided to calculate metric values, and its application is tested, together with the original IPCC figures, in a hypothetical example focusing on GWP100.Results and discussion
The hypothetical example shows that the only set of GWP100 values consistently leading to the same outcome, regardless of how we account for biogenic carbon, is the one proposed in this article. Using the methane GWP100 values from the IPCC report results in conflicting net GHG emissions, thus pointing to an inconsistency.Conclusions
In order to consistently discriminate between biogenic and fossil methane sources, a difference of 2.75 kg CO2-eq. is needed, which corresponds to the ratio of the molecular weights of CO2 and methane (44/16). We propose to correct the GWP and GTP values for methane accordingly.17.
Thijs Welle Anna T. Hoekstra Ineke A. J. J. M. Daemen Celia R. Berkers Matheus O. Costa 《Metabolomics : Official journal of the Metabolomic Society》2017,13(7):83
Introduction
Swine dysentery caused by Brachyspira hyodysenteriae is a production limiting disease in pig farming. Currently antimicrobial therapy is the only treatment and control method available.Objective
The aim of this study was to characterize the metabolic response of porcine colon explants to infection by B. hyodysenteriae.Methods
Porcine colon explants exposed to B. hyodysenteriae were analyzed for histopathological, metabolic and pro-inflammatory gene expression changes.Results
Significant epithelial necrosis, increased levels of l-citrulline and IL-1α were observed on explants infected with B. hyodysenteriae.Conclusions
The spirochete induces necrosis in vitro likely through an inflammatory process mediated by IL-1α and NO.18.
Background
Acetoin and 2,3-butanediol are two important biorefinery platform chemicals. They are currently fermented below 40°C using mesophilic strains, but the processes often suffer from bacterial contamination.Results
This work reports the isolation and identification of a novel aerobic Geobacillus strain XT15 capable of producing both of these chemicals under elevated temperatures, thus reducing the risk of bacterial contamination. The optimum growth temperature was found to be between 45 and 55°C and the medium initial pH to be 8.0. In addition to glucose, galactose, mannitol, arabionose, and xylose were all acceptable substrates, enabling the potential use of cellulosic biomass as the feedstock. XT15 preferred organic nitrogen sources including corn steep liquor powder, a cheap by-product from corn wet-milling. At 55°C, 7.7?g/L of acetoin and 14.5?g/L of 2,3-butanediol could be obtained using corn steep liquor powder as a nitrogen source. Thirteen volatile products from the cultivation broth of XT15 were identified by gas chromatography–mass spectrometry. Acetoin, 2,3-butanediol, and their derivatives including a novel metabolite 2,3-dihydroxy-3-methylheptan-4-one, accounted for a total of about 96% of all the volatile products. In contrast, organic acids and other products were minor by-products. α-Acetolactate decarboxylase and acetoin:2,6-dichlorophenolindophenol oxidoreductase in XT15, the two key enzymes in acetoin metabolic pathway, were found to be both moderately thermophilic with the identical optimum temperature of 45°C.Conclusions
Geobacillus sp. XT15 is the first naturally occurring thermophile excreting acetoin and/or 2,3-butanediol. This work has demonstrated the attractive prospect of developing it as an industrial strain in the thermophilic fermentation of acetoin and 2,3-butanediol with improved anti-contamination performance. The novel metabolites and enzymes identified in XT15 also indicated its strong promise as a precious biological resource. Thermophilic fermentation also offers great prospect for improving its yields and efficiencies. This remains a core aim for future work.19.
Xiaobo Dong Haiyun Li Yucheng Jiang Mancheng Hu Shuni Li Quanguo Zhai 《Biotechnology letters》2016,38(9):1483-1491
Objectives
To degrade enzymatically bisphenol A (BPA) that causes serious environmental concerns and is difficult to be degraded by chemical or physical methods.Results
BPA (150 mg l?1) was completely degraded by chloroperoxidase (CPO)/H2O2 within 7 min at room temperature, atmospheric pressure with the enzyme at 6 μg CPO ml?1. The degradation products were identified by HPLC–MS, which suggested involvement of multiple steps. Enzymatic treatment followed by existing bioremediation technologies (activated sludge) enhanced removal of COD from 9 to 54 %. Using an ecotoxicity evaluation with Chlorella pyrenoidosa, the degradation products had a lower toxicity than BPA.Conclusion
BPA can be degraded rapidly and efficiently under mild conditions with chloroperoxidase at 6 μg ml?1. The degradation products had a lower toxicity than BPA.20.
Ningning Sun Yuanchao Qian Weiwei Wang Yaohua Zhong Meixue Dai 《Biotechnology letters》2018,40(7):1119-1126