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1.
Objective
To improve beer flavour stability by adding chitooligosaccharides that prevent formation of staling compounds and also scavenge radicals in stale beer.Results
Chitooligosaccharides, at 0.001–0.01%, inhibited the formation of staling compounds in forced aged beer. The formation of 5-hydroxymethylfurfural, trans-2-nonenal and phenylacetaldehyde were decreased by 105, 360 and 27%, respectively, when compared with those in stale beer without chitooligosaccharide addition. The capability of chitooligosaccharides to prevent staling compound formation depended on their molecular size (2 or 3 kDa). The DPPH/hydroxyl radical scavenging activity in fresh beer significantly lower than that in forced aged beer in the presence of chitooligosaccharides. When compared with stale beer without added chitooligosaccharides, the radical scavenging activity could be increased by adding chitooligosaccharides to forced aged beer.Conclusions
Chitooligosaccharides play an active part in the prevention of beer flavour deterioration by inhibiting the formation of staling compounds and increasing radical scavenging activity.2.
Objectives
To optimize the expression of type A ferulic acid esterase (FaeA) from Aspergillus niger in Pichia pastoris X-33 using codon optimization.Results
Recombinant FaeA was purified from the fermentation broth, with the maximum specific activity of 48.4 ± 0.1 U mg?1. Adding it during mashing process for beer brewing raised the filtration rate by 14.5% while the turbidity and viscosity declined by 22 and 6.9%, respectively. Addition of FaeA increased the concentrations of free ferulic acid (FA) and arabinoxylan (AX) in the wort, while the polymeric arabinoxylans content declined significantly.Conclusions
Recombinant FaeA was capable to prevent the oxidative gelation of PAX formation by breaking the cross-linking of FA among AX chains and improve the filtration performance of wort.3.
Rudolf Cejnar Kateřina Hložková Pavel Kotrba Pavel Dostálek 《Biotechnology letters》2016,38(12):2145-2151
Objectives
To convert α-acetolactate into acetoin by an α-acetolactate decarboxylase (ALDC) to prevent its conversion into diacetyl that gives beer an unfavourable buttery flavour.Results
We constructed a whole Saccharomyces cerevisiae cell catalyst with a truncated active ALDC from Acetobacter aceti ssp xylinum attached to the cell wall using the C-terminal anchoring domain of α-agglutinin. ALDC variants in which 43 and 69 N-terminal residues were absent performed equally well and had significantly decreased amounts of diacetyl during fermentation. With these cells, the highest concentrations of diacetyl observed during fermentation were 30 % less than those in wort fermented with control yeasts displaying only the anchoring domain and, unlike the control, virtually no diacetyl was present in wort after 7 days of fermentation.Conclusions
Since modification of yeasts with ALDC variants did not affect their fermentation performance, the display of α-acetolactate decarboxylase activity is an effective approach to decrease the formation of diacetyl during beer fermentation.4.
Weiqiu Lan Wei Wang Zhimin Yu Yanxia Qin Jing Luan Xianzhen Li 《Biotechnology letters》2016,38(11):1935-1940
Objectives
To study enhanced barley germination by chitooligosaccharide as an elicitor for improving the quality of malt.Results
Barley germination for both radical and leaf sprouts was enhanced when chitooligosaccharide was added to the steeping water in the first steeping cycle. The activities of hydrolases (α-/β-amylase, proteinase and β-glucanase) and antioxidases (superoxide dismutase and catalase) in the resultant malt were increased in a dose-dependent manner when chitooligosaccharide was supplemented in the steeping water. Maximal promotion was at 1 mg chitooligosaccharide/l for α-/β-amylase and proteinase, and at 10 mg/l for β-glucanase, superoxide dismutase and catalase. Malt quality, including free α-amino nitrogen content, Kolbach index, malt extract content, diastatic power, wort viscosity and the ratio of glucose, maltose and maltotriose, was significantly improved by chitooligosaccharide in seed priming at 1 mg/l.Conclusion
Application of chitooligosaccharide in the steeping water promotes barley germination and improves the quality of malt.5.
Xiaoyu Guo Zhimin Yu Meihui Zhang Wenzhu Tang Yumei Sun Xianzhen Li 《Biotechnology letters》2018,40(9-10):1335-1341
Objective
To enhance the production of phenolic compounds during barley germination using chitooligosaccharide as an elicitor to improve the antioxidant capacity of malt.Results
When used as an elicitor for barley germination, chitooligosaccharide with a molecular weight of 3 kDa, added at 10 mg/kg barley kernels during the first steeping cycle, led to the maximum production of phenolic compounds. Compared with the control with no chitooligosaccharide added to the steeping water, the total phenolic content was increased by 54.8%. Increases in the total phenolic content of the barley malt occurred when chitooligosaccharide was applied during the first or both the first and the second steeping cycles. Thus the antioxidant capacity of barley malt was increased significantly by adding chitooligosaccharide during the steeping process.Conclusion
Applying chitooligosaccharides during the steeping process increased the content of phenolic compounds thus improving the antioxidant capacity of the barley malt.6.
Background
Some studies indicate that the commonly recommended 30 s application time for the post contamination treatment of hands may not be necessary as the same effect may be achieved with some formulations in a shorter application time such as 15 s.Method
We evaluated the bactericidal activity of an ethanol-based hand gel (Sterillium® Comfort Gel) within 15 s in a time-kill-test against 11 Gram-positive, 16 Gram-negative bacteria and 11 emerging bacterial pathogens. Each strain was evaluated in quadruplicate.Results
The hand gel (85% ethanol, w/w) was found to reduce all 11 Gram-positive and all 16 Gram-negative bacteria by more than 5 log10 steps within 15 s, not only against the ATCC test strains but also against corresponding clinical isolates. In addition, a log10 reduction > 5 was observed against all tested emerging bacterial pathogens.Conclusion
The ethanol-based hand gel was found to have a broad spectrum of bactericidal activity in only 15 s which includes the most common species causing nosocomial infections and the relevant emerging pathogens. Future research will hopefully help to find out if a shorter application time for the post contamination treatment of hands provides more benefits or more risks.7.
Purpose
Global beer consumption is growing steadily and has recently reached 187.37 billion litres per year. The UK ranked 8th in the world, with 4.5 billion litres of beer produced annually. This paper considers life cycle environmental impacts and costs of beer production and consumption in the UK which are currently unknown. The analysis is carried out for two functional units: (i) production and consumption of 1 l of beer at home and (ii) annual production and consumption of beer in the UK. The system boundary is from cradle to grave.Methods
Life cycle impacts have been estimated following the guidelines in ISO 14040/44; the methodology for life cycle costing is congruent with the LCA approach. Primary data have been obtained from a beer manufacturer; secondary data are sourced from the CCaLC, Ecoinvent and GaBi databases. GaBi 4.3 has been used for LCA modelling and the environmental impacts have been estimated according to the CML 2001 method.Results and discussion
Depending on the type of packaging (glass bottles, aluminium and steel cans), 1 l of beer requires for example 10.3–17.5 MJ of primary energy and 41.2–41.8 l of water, emits 510–842 g of CO2 eq. and has the life cycle costs of 12.72–14.37 pence. Extrapolating the results to the annual consumption of beer in the UK translates to a primary energy demand of over 49,600 TJ (0.56 % of UK primary energy consumption), water consumption of 1.85 bn hl (5.3 % of UK demand), emissions of 2.16 mt CO2 eq. (0.85 % of UK emissions) and the life cycle costs of £553 million (3.2 % of UK beer market value). Production of raw materials is the main hotspot, contributing from 47 to 63 % to the impacts and 67 % to the life cycle costs. The packaging adds 19 to 46 % to the impacts and 13 % to the costs.Conclusions
Beer in steel cans has the lowest impacts for five out of 12 impact categories considered: primary energy demand, depletion of abiotic resources, acidification, marine and freshwater toxicity. Bottled beer is the worst option for nine impact categories, including global warming and primary energy demand, but it has the lowest human toxicity potential. Beer in aluminium cans is the best option for ozone layer depletion and photochemical smog but has the highest human and marine toxicity potentials.8.
Jian-Rong Guo Lei Yin Yong-Quan Chen Xiao-Ju Jin Xun Zhou Na-Na Zhu Xiao-Qian Liu Han-Wei Wei Li-Shuang Duan 《Cell communication and signaling : CCS》2018,16(1):84
Background
Impaired wound healing frequently occurs in diabetes mellitus (DM) and is implicated in impaired angiogenesis. Long non-coding RNA (lncRNA) H19 has been reported as being reduced in DM and played a critical role in inducing angiogenesis. Thus, we hypothesized that H19 may affect impaired wound healing in streptozotocin (STZ)-induced diabetic mice transfused with autologous blood preserved in standard preservative fluid or modified preservative fluid.Methods
Fibroblasts in injured skin were isolated and cultured in vitro. After location of H19 in fibroblasts using fluorescence in situ hybridization (FISH), RNA-pull down, RNA immunoprecipitation (RIP), chromatin immunoprecipitation (ChIP), Co immunoprecipitation (COIP) and dual luciferase reporter gene assay were used to verify the binding of H19 to HIF-1α.Results
The modified preservative fluid preserved autologous blood increased the H19 expression in fibroblasts, and maintained better oxygen-carrying and oxygen release capacities as well as coagulation function. Furthermore, H19 promoted HIF-1α histone H3K4me3 methylation and increased HIF-1α expression by recruiting EZH2. H19 promoted fibroblast activation by activating HIF-1α signaling pathway in fibroblasts and enhanced wound healing in diabetic mice.Conclusions
Taken together, H19 accelerated fibroblast activation by recruiting EZH2-mediated histone methylation and modulating the HIF-1α signaling pathway, whereby augmenting the process of modified preservative fluid preserved autologous blood enhancing the postoperative wound healing in diabetic mice.9.
Background
Cell surface hydrophobicity (CSH) is one of the key physicochemical features of biodemulsifier-producing bacteria that influence their demulsification capability maintenance in petroleum contaminated environments.Methods
In present study, biodemulsifier-producing bacteria were isolated from petroleum contaminated environments using different isolation media and the correlation between their CSH and demulsifying ability was investigated. The demulsifying ability of isolates was measured through demulsification tests on water in kerosene emulsions. The microbial adhesion to the hydrocarbon (MATH) assay was used to denote their CSH.Results
The evaluation of CSH showed that majority of biodemulsifier producing bacteria have high CSH which indicating a positive correlation between CSH and demulsifying capability.Conclusions
According to these results it can be concluded that CSH can be used as an indicator for assessment of biodemulsifier-producing bacteria and screening of new isolates for their biodemulsifier production.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 reduce the amount of citrulline produced by arginine-consuming bacteria in the moromi mash during soy sauce production.Results
Bacillus amyloliquefaciens JY06, a salt-tolerant strain with high arginine consumption ability and low citrulline accumulation capacity, was isolated from moromi mash. The concentration of citrulline was decreased from 26.8 to 5.1 mM and ethyl carbamate in soy sauce, after sterilization, decreased from 97 to 17 μg kg?1 when B. amyloliquefaciens JY06 was added during fermentation. The aroma of the sauce was improved by increasing the ester content.Conclusions
B. amyloliquefaciens JY06 is a beneficial bacterium that can be used in soy sauce fermentation to eliminate ethyl carbonate and enhance the flavor of the sauce.12.
Cong-Hui Yao Gao-Yuan Liu Kui Yang Richard W. Gross Gary J. Patti 《Metabolomics : Official journal of the Metabolomic Society》2016,12(9):143
Introduction
Palmitate, the typical end product released from fatty acid synthase, is of interest to many researchers performing metabolomics. Although palmitate can be readily detected by using mass spectrometry, many metabolomic platforms involve the use of plastic consumables that introduce a competing background signal of palmitate.Objectives
The goal of this study was to quantify palmitate contamination in metabolomics and isotope tracer studies and to examine the reliability of approaches for reducing error.Methods
We measured the quantitative error introduced by palmitate contamination from 4 vendors of plastic consumables used in combination with several different extraction solvents.Results
The background palmitate signal was as much as sixfold higher than the biological palmitate signal from 4 million 3T3-L1 cells. Importantly, the palmitate contamination signal was highly variable between plastic consumables (even within the same lot) and therefore could not be accurately removed by subtracting the background as measured from a blank. In addition to affecting relative and absolute quantitation, the palmitate background signal from disposable plastics also led to the underestimation of labeled palmitate in isotope tracer experiments.Conclusion
When measuring palmitate standard solutions, the best results were obtained when glass vials and glass pipettes were used. However, much of the palmitate background signal could be eliminated by pre-rinsing plastic vials and plastic pipette tips with methanol prior to sample introduction. For isotope tracer studies, error could also be minimized by estimating palmitate enrichment from palmitoylcarnitine, which does not have a competing contamination signal from plastic consumables.13.
Xinchang Kou Tongqing Su Ningning Ma Qi Li Peng Wang Zhengfang Wu Wenju Liang Weixin Cheng 《Plant and Soil》2018,422(1-2):129-134
Background
Seeds host bacterial inhabitants but only a limited knowledge is available on which taxa inhabit seed, which niches could be colonized, and what the routes of colonization are.Scope
Within this commentary, a discussion is provided on seed bacterial inhabitants, their taxa, and from where derive the seed colonizers.Conclusions
Seeds/and grains host specific bacteria deriving from the anthosphere, carposphere, or from cones of gymnosperms and inner tissues of plants after a long colonization from the soil to reproductive organs.14.
Rachel A. Spicer Christoph Steinbeck 《Metabolomics : Official journal of the Metabolomic Society》2018,14(1):16
Introduction
Data sharing is being increasingly required by journals and has been heralded as a solution to the ‘replication crisis’.Objectives
(i) Review data sharing policies of journals publishing the most metabolomics papers associated with open data and (ii) compare these journals’ policies to those that publish the most metabolomics papers.Methods
A PubMed search was used to identify metabolomics papers. Metabolomics data repositories were manually searched for linked publications.Results
Journals that support data sharing are not necessarily those with the most papers associated to open metabolomics data.Conclusion
Further efforts are required to improve data sharing in metabolomics.15.
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.16.
Introduction
Untargeted metabolomics is a powerful tool for biological discoveries. To analyze the complex raw data, significant advances in computational approaches have been made, yet it is not clear how exhaustive and reliable the data analysis results are.Objectives
Assessment of the quality of raw data processing in untargeted metabolomics.Methods
Five published untargeted metabolomics studies, were reanalyzed.Results
Omissions of at least 50 relevant compounds from the original results as well as examples of representative mistakes were reported for each study.Conclusion
Incomplete raw data processing shows unexplored potential of current and legacy data.17.
Youzhong Liu Sara Forcisi Mourad Harir Magali Deleris-Bou Sibylle Krieger-Weber Marianna Lucio Cédric Longin Claudine Degueurce Régis D. Gougeon Philippe Schmitt-Kopplin Hervé Alexandre 《Metabolomics : Official journal of the Metabolomic Society》2016,12(4):69
Introduction
Bacterial malolactic fermentation (MLF) has a considerable impact on wine quality. The yeast strain used for primary fermentation can systematically stimulate (MLF+ phenotype) or inhibit (MLF?) bacteria and the MLF process as a function of numerous winemaking practices, but the underlying molecular evidence still remains a mystery.Objectives
The goal of the study was to elucidate such evidence by the direct comparison of extracellular metabolic profiles of MLF+ and MLF? phenotypes.Methods
We have applied a non-targeted metabolomic approach combining ultrahigh-resolution FT-ICR-MS analysis, powerful statistical tools and a comprehensive wine metabolite database.Results
We discovered around 2500 unknown masses and 800 putative biomarkers involved in phenotypic distinction. For the putative biomarkers, we also developed a biomarker identification workflow and elucidated the exact structure (by UPLC-Q-ToF–MS2) and/or exact physiological impact (by in vitro tests) of several novel biomarkers, such as D-gluconic acid, citric acid, trehalose and tripeptide Pro-Phe-Val. In addition to valid biomarkers, molecular evidence was reflected by unprecedented chemical diversity (around 3000 discriminant masses) that characterized both the yeast phenotypes. While distinct chemical families such as phenolic compounds, carbohydrates, amino acids and peptides characterize the extracellular metabolic profiles of the MLF+ phenotype, the MLF? phenotype is associated with sulphur-containing peptides.Conclusion
The non-targeted approach used in this study played an important role in finding new and unexpected molecular evidence.18.
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.19.
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.20.