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1.
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.2.
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.3.
Objectives
To improve the thermostability and catalytic property of a mesophilic 1,3-1,4-β-glucanase by combinational mutagenesis and to test its effect in congress mashing.Results
A mutant β-glucanase (rE-BglTO) constructed by combinational mutagenesis showed a 25 °C increase in optimal temperature (to 70 °C) a 19.5 °C rise in T 50 value and a 15.6 °C increase in melting temperature compared to wild-type enzyme. Its half-life values at 60 and 70 °C were 152 and 99 min, which were 370 and 800 % higher than those of wild-type enzyme. Besides, its specific activity and k cat value were 42,734 U mg?1 and 189 s?1 while its stability under acidic conditions was also improved. In flask fermentation, the catalytic activity of rE-BglTO reached 2381 U ml?1, which was 63 % higher than that of wild-type enzyme. The addition of rE-BglTO in congress mashing decreased the filtration time and viscosity by 21.3 and 9.6 %, respectively.Conclusions
The mutant β-glucanase showed high catalytic activity and thermostability which indicated that rE-BglTO is a good candidate for application in the brewing industry.4.
Objective
To produce tagatose from fructose with a high conversion rate and to establish a high-yield purification method of tagatose from the reaction mixture.Results
Fructose at 1 M (180 g l?1) was converted to 0.8 M (144 g l?1) tagatose by a three-step enzymatic cascade reaction, involving hexokinase, plus ATP, fructose-1,6-biphosphate aldolase, phytase, over 16 h with a productivity of 9 g l?1 h?1. No byproducts were detected. Tagatose was recrystallized from ethanol to a purity of 99.9% and a yield of 96.3%. Overall, tagatose at 99.9% purity was obtained from fructose with a yield of 77%.Conclusion
This is the first biotechnological production of tagatose from fructose and the first application of solvent recrystallization for the purification of rare sugars.5.
Juanita C. Lauer Suong Cu Rachel A. Burton Jason K. Eglinton 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2017,130(5):1053-1063
Key message
Novel barley (1 → 3, 1 → 4)-β-glucan endohydrolases with increased thermostability.Abstract
Rapid and reliable degradation of (1 → 3, 1 → 4)-β-glucan to produce low viscosity wort is an essential requirement for malting barley. The (1 → 3, 1 → 4)-β-glucan endohyrolases are responsible for the primary hydrolysis of cell wall β-glucan. The variation in β-glucanase genes HvGlb1 and HvGlb2 that encode EI and EII, respectively, were examined in elite and exotic germplasm. Six EI and 14 EII allozymes were identified, and significant variation was found in β-glucanase from Hordeum vulgare ssp. spontaneum (wild barley), the progenitor of modern cultivated barley. Allozymes were examined using prediction methods; the change in Gibbs free energy of the identified amino acid substitutions to predict changes in enzyme stability and homology modelling to examine the structure of the novel allozymes using the existing solved EII structure. Two EI and four EII allozymes in wild barley accessions were predicted to have improved barley β-glucanase thermostability. One novel EII candidate was identified in existing backcross lines with contrasting HvGlb2 alleles from wild barley and cv Flagship. The contrasting alleles in selected near isogenic lines were examined in β-glucanase thermostability analyses. The EII from wild barley exhibited a significant increase in β-glucanase thermostability conferred by the novel HvGlb2 allele. Increased β-glucanase thermostability is heritable and candidates identified in wild barley could improve malting and brewing quality in new varieties.6.
Mohsen?Mohammadi Thomas?K.?Blake Allen?D.?Budde Shiaoman?Chao Patrick?M.?Hayes Richard?D.?Horsley Donald?E.?Obert Steven?E.?Ullrich Kevin?P.?Smith
Key message
We report malt quality QTLs relevant to breeding with greater precision than previous mapping studies. The distribution of favorable alleles suggests strategies for marker-assisted breeding and germplasm exchange.Abstract
This study leverages the breeding data of 1,862 barley breeding lines evaluated in 97 field trials for genome-wide association study of malting quality traits in barley. The mapping panel consisted of six-row and two-row advanced breeding lines from eight breeding populations established at six public breeding programs across the United States. A total of 4,976 grain samples were subjected to micro-malting analysis and mapping of nine quality traits was conducted with 3,072 SNP markers distributed throughout the genome. Association mapping was performed for individual breeding populations and for combined six-row and two-row populations. Only 16 % of the QTL we report here had been detected in prior bi-parental mapping studies. Comparison of the analyses of the combined two-row and six-row panels identified only two QTL regions that were common to both. In total, 108 and 107 significant marker-trait associations were identified in all six-row and all two-row breeding programs, respectively. A total of 102 and 65 marker-trait associations were specific to individual six-row and two-row breeding programs, respectively indicating that most marker-trait associations were breeding population specific. Combining datasets from different breeding program resulted in both the loss of some QTL that were apparent in the analyses of individual programs and the discovery of new QTL not identified in individual programs. This suggests that simply increasing sample size by pooling samples with different breeding history does not necessarily increase the power to detect associations. The genetic architecture of malting quality and the distribution of favorable alleles suggest strategies for marker-assisted selection and germplasm exchange.7.
Elif Erdem Ibrahim Inan Harbiyeli Hazal Boral Macit Ilkit Meltem Yagmur Reha Ersoz 《Mycopathologia》2018,183(3):521-527
Purpose
To evaluate the efficiency of corneal collagen cross-linking (CXL) in addition to topical voriconazole in cases with mycotic keratitis.Design
Retrospective case series in a tertiary university hospital.Participants
CXL was performed on 13 patients with mycotic keratitis who presented poor or no response to topical voriconazole treatment.Methods
The clinical features, symptoms, treatment results and complications were recorded retrospectively. The corneal infection was graded according to the depth of infection into the stroma (from grade 1 to grade 3). The visual analogue scale was used to calculate the pain score before and 2 days after surgery.Main Outcome Measures
Grade of the corneal infection.Results
Mean age of 13 patients (6 female and 7 male) was 42.4 ± 17.7 years (20–74 years). Fungus was demonstrated in culture (eight patients) or cytological examination (five patients). Seven of the 13 patients (54%) were healed with topical voriconazole and CXL adjuvant treatment in 26 ± 10 days (15–40 days). The remaining six patients did not respond to CXL treatment; they initially presented with higher grade ulcers. Pre- and post-operative pain score values were 8 ± 0.8 and 3.5 ± 1, respectively (p < 0.05).Conclusions
The current study suggests that adjunctive CXL treatment is effective in patients with small and superficial mycotic ulcers. These observations require further research by large randomized clinical trials.8.
Transient expression of recombinant tissue plasminogen activator (rt-PA) gene in cucurbit plants using viral vector 总被引:1,自引:0,他引:1
Vahid Jalali Javaran Alireza Shafeinia Mokhtar Jalali Javaran Esmaeil Ghasemi Gojani Malihe Mirzaee 《Biotechnology letters》2017,39(4):607-612
Objective
To use a transient expression system to express a truncated human tissue plasminogen activator (K2S) gene in cucurbit plants.Results
The recombinant tissue plasminogen activator protein (K2S form) was expressed in active form in cucurbit plants. Its molecular weight was 43 kDa. The plant-derived rt-PA was determined using goat anti-rabbit antibody by western blotting. Among the infected lines, the highest expression of rt-PA was 62 ng/100 mg per leaf tissue as measured by ELISA. The enzymatic activity of the plant-derived rt-PA was 0.8 IU/ml.Conclusions
The K25 form of rt-PA was expressed for the first time using the viral expression system. Plant-derived rt-PA showed similar potency to commercially-available PA.9.
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.10.
Courtney D. Giles Timothy S. George Lawrie K. Brown Malika M. Mezeli Alan E. Richardson Charles A. Shand Renate Wendler Tegan Darch Daniel Menezes-Blackburn Patricia Cooper Marc I. Stutter David G. Lumsdon Martin S. A. Blackwell Catherine Wearing Hao Zhang Philip M. Haygarth 《Plant and Soil》2017,412(1-2):43-59
Background and Aims
Plant acquisition of endogenous forms of soil phosphorus (P) could reduce external P requirements in agricultural systems. This study investigated the interaction of citrate and phytase exudation in controlling the accumulation of P and depletion of soil organic P by transgenic Nicotiana tabacum plants.Methods
N. tabacum plant lines including wild-type, vector controls, transgenic plants with single-trait expression of a citrate transporter (A. thaliana frd3) or fungal phytases (phyA: A. niger, P. lycii) and crossed plant lines expressing both traits, were characterized for citrate efflux and phytase exudation. Monocultures and intercropped combinations of single-trait plants were grown in a low available P soil (12 weeks). Plant biomass, shoot P accumulation, rhizosphere soil pH and citrate-extractable-P fractions were determined. Land Equivalent Ratio and complementarity effect was determined in intercropped treatments and multiple-linear-regression was used to predict shoot P accumulation based on plant exudation and soil P depletion.Results
Crossed plant lines with co-expression of citrate and phytase accumulated more shoot P than single-trait and intercropped plant treatments. Shoot P accumulation was predicted based on phytase-labile soil P, citrate efflux, and phytase activity (Rsq=0.58, P < .0001). Positive complementarity occurred between intercropped citrate- and phytase-exuding plants, with the greatest gains in shoot P occurring in plant treatments with A. niger phyA expression.Conclusions
We show for the first time that trait synergism associated with the exudation of citrate and phytase by tobacco can be linked to the improved acquisition of P and the depletion of soil organic P.11.
Friedrich Laidig Hans-Peter Piepho Dirk Rentel Thomas Drobek Uwe Meyer 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2017,130(11):2411-2429
Key message
Evaluation of breeding progress for spring barley varieties in Germany showed that both grain yield and malting quality were considerably improved during the last 33 years, and that genetic effects of protein concentration and malting traits were not associated.Abstract
Based on historical data, this study aimed to investigate yield potential and malting quality of 187 varieties tested and released in German registration trials to evaluate the value for cultivation and use (VCU) during 1983–2015, and to quantify the environmental variability and the association among traits. We used mixed linear models with multiple linear regression terms to dissect genetic and non-genetic trend components. Grain yield increased by 43% (23.4 dt ha?1) in VCU trials and 35% (14.0 dt ha?1) on-farm relative to 1983. All yield components contributed significantly. Malting quality was also considerably improved by 2.3% for extract content up to 25.1% for friability, relative to 1983, nearly completely due to new varieties. Total variability of individual traits was very different between traits (2.4–24.4% relative to 1983). The relative influence of genotypes on total variation was low for grain yield and its components, whereas it was considerably larger for other traits. We found remarkable differences between phenotypic and genetic correlation coefficients for grain yield and protein concentration with malting traits. The observed positive phenotypic relation between grain yield and malting quality can be attributed to a shift of selection and environmental effects, but genetic correlations showed a negative association. Genetic effects of protein concentration and malting quality were not correlated indicating that both were not genetically linked. Considerable yield progress and improvement of malting quality were achieved despite of their weak to moderate negative genetic dependence.12.
13.
Jungoh Ahn Min-Jung Jang Kok Siong Ang Hongweon Lee Eui-Sung Choi Dong-Yup Lee 《Biotechnology letters》2016,38(12):2137-2143
Objectives
To evaluate different codon optimization parameters on the Saccharomyces cerevisiae-derived mating factor α prepro-leader sequence (MFLS) to improve Candida antarctica lipase B (CAL-B) secretory production in Pichia pastoris.Results
Codon optimization based on the individual codon usage (ICU) and codon context (CC) design parameters enhanced secretory production of CAL-B to 7 U/ml and 12 U/ml, respectively. Only 3 U/ml was obtained with the wild type sequence while the sequence optimized using both ICU and CC objectives showed intermediate performance of 10 U/ml. These results clearly show that CC is the most relevant parameter for the codon optimization of MFLS in P. pastoris, and there is no synergistic effect achieved by considering both ICU and CC together.Conclusion
The CC optimized MFLS increased secretory protein production of CAL-B in P. pastoris by fourfold.14.
John M. Wentworth Naiara G. Bediaga Megan A. S. Penno Esther Bandala-Sanchez Komal N. Kanojia Konstantinos A. Kouremenos Jennifer J. Couper Leonard C. Harrison ENDIA Study Group 《Metabolomics : Official journal of the Metabolomic Society》2018,14(10):130
Background
Cord blood lipids are potential disease biomarkers. We aimed to determine if their concentrations were affected by delayed blood processing.Method
Refrigerated cord blood from six healthy newborns was centrifuged every 12 h for 4 days. Plasma lipids were analysed by liquid chromatography/mass spectroscopy.Results
Of 262 lipids identified, only eight varied significantly over time. These comprised three dihexosylceramides, two phosphatidylserines and two phosphatidylethanolamines whose relative concentrations increased and one sphingomyelin that decreased.Conclusion
Delay in separation of plasma from refrigerated cord blood has minimal effect overall on the plasma lipidome.15.
Huihui Xu Yang Zhang Xin Feng Kunyuan Tie Yuan Cao Wenyu Han 《Biotechnology letters》2017,39(6):897-903
Objectives
To identify and characterize a novel antimicrobial peptide, catesbeianin-1.Results
Catesbeianin-1 is 25 amino acids long and is α-helical, cationic and amphipathic. It had antimicrobial activity against Gram-positive and Gram-negative bacteria. It was resistant against trypsin and pepsin. Catesbeianin-1 exhibited moderate hemolytic activity (approx 8%) at 100 μg/ml, and its HC50 (50% hemolytic concentration) was 300 μg/ml. Its cytotoxicity was approx 10–20% at 100 μg/ml, and its CC50 (50% cytotoxic concentration) was >100 μg/ml. The LD50 of catesbeianin-1 in mice was 80 mg/kg. At 3.1 µg/ml, catesbeianin-1 significantly inhibited the growth of methicillin-resistant Staphylococcus aureus.Conclusions
A new antimicrobial peptide from the skin of Lithobates catesbeianus (American bullfrog) may represent a template for the development of novel antimicrobial agents.16.
Laleh Shariati Mehran Modaress Hossein Khanahmad Zahra Hejazi Mohammad Amin Tabatabaiefar Mansoor Salehi Mohammad Hossein Modarressi 《Biotechnology letters》2016,38(8):1243-1250
Objective
To compare methods for erythroid differentiation of K562 cells that will be promising in the treatment of beta-thalassemia by inducing γ-globin synthesis.Results
Cells were treated separately with: RPMI 1640 medium without glutamine, RPMI 1640 medium without glutamine supplemented with 1 mM sodium butyrate, RPMI 1640 medium supplemented with 1 mM sodium butyrate, 25 µg cisplatin/ml, 0.1 µg cytosine arabinoside/ml. The highest differentiation (84 %) with minimum toxicity was obtained with cisplatin at 15 µg /ml. Real-time RT-PCR showed that expression of the γ-globin gene was significantly higher in the cells differentiated with cisplatin compared to undifferentiated cells (P < 0.001).Conclusions
Cisplatin is useful in the experimental therapy of ß-globin gene defects and can be considered for examining the basic mechanism of γ-reactivation.17.
Wei Li Yi Xue Jingjing Li Jing Yuan Xiaotang Wang Wei Fang Zemin Fang Yazhong Xiao 《Biotechnology letters》2016,38(2):345-349
Objectives
To express and characterize a putative α-glucosidase, Pagl, from Pseudoalteromonas sp. K8 obtained via genome mining approach.Results
Pagl was expressed and purified to homogeneity, with a molecular mass of 60 kDa. It was optimally active at pH 8.5 and 30 °C, and showed cold-adapted activity. Pagl exhibited specific activity towards substrates with α-1,4-linkage, with the highest specific activity of 19.4 U/mg for maltose, followed by pNPαG and maltodextrins, suggesting that Pagl belongs to the type II α-glucosidase. Interestingly, the activity of Pagl is significantly enhanced (2.7 times) in the presence of 200 mM glucose.Conclusion
The unique catalytic properties of Pagl make it an attractive candidate for several industrial applications.18.
Objectives
To establish an efficient expression system for a fusion protein of glutathione S-transferase and cecropin B (GST-CB) and to clarify the antibacterial mechanism of CB.Results
The optimal incubation time and methanol concentration for induced expression of CB were 36 h and 1 % w/v, respectively. The yield of GST-CB was 2.2 g/l. The minimum inhibitory concentrations of GST-CB towards Staphylococcus aureus subsp. saprophyticus (ATCC 15305) and Escherichia coli strain CFT073 were 250 and 125 μg/ml, respectively. Notably, mutations of proline 24 (P24) in CB produced a polypeptide without antimicrobial activity.Conclusion
The fusion protein GST-CB, which has a broad spectrum antimicrobial activity, can be abundantly expressed in Pichia pastoris GS115, and P24 may be an important amino acid for the antimicrobial activity of GST-CB.19.
Songwen Tan Xuncai Chen Chunzhi Cui Yang Hou Weiguo Li Hong You 《Biotechnology letters》2017,39(1):91-96
Objective
To develop a method to treat saline phenolic wastewater in a biological contact oxidation reactor (BCOR) with immobilized cells of a marine microorganism, Oceanimonas sp., isolated from seawater.Results
Cells were immobilized on fibre carriers in the BCOR. Saline wastewater with phenol at 1.5 g/l and NaCl at 6 % (w/v) was treated. In continuous assays, 99 % removal of phenol was achieved and a kinetic model for the phenol degradation is presented based on Monod’s equation.Conclusion
The BOCR system using immobilized cells of Oceanimonas efficiently treats saline phenolic wastewaters without having decrease the salinity of the wastewater.20.