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1.
Maranda Esterhuizen-Londt Stefanie Hertel Stephan Pflugmacher 《Biotechnology letters》2017,39(10):1537-1545
Objectives
To evaluate the remediation efficiency of Mucor hiemalis by comparing media elimination, uptake, and biotransformation of microcystin-LR with exposure to pure toxin versus a crude bloom extract.Results
With exposure to the extract, the elimination rate of microcystin-LR from the media, which was 0.28 ng MC-LR l?1 h?1, was significantly higher compared to that achieved with exposure to the pure toxin (0.16 ng MC-LR l?1 h?1) after 24 h. However, intracellular breakdown of microcystin-LR was significantly lower in the extract exposed pellets compared to the pure toxin treated fungal pellets over time. This coincided with reduced intracellular glutathione S-transferase activity with crude extract exposure which could be responsible for the detection of only the glutathione conjugate of microcystin-LR.Conclusion
This paper signifies the importance of using laboratory exposure scenarios which resemble conditions in nature to fully understand and evaluate remediation efficiency. There is merit in using M. hiemalis for mycoremediation of cyanotoxins in surface waters.2.
Improving N management through intercropping alleviates the inhibitory effect of mineral N on nodulation in pea 总被引:7,自引:0,他引:7
Background and aims
Symbiotic N2 fixation is essential in the development of sustainable agriculture, but the nodulation of legumes is usually inhibited by N fertilization. Here, the intercropping of maize and pea in strips under various N managements was used as a means to alleviate the inhibitory effect of mineral N on pea nodulation and N2 fixation and to improve system performance.Methods
N natural abundance (δ 15N) analysis was employed to quantify N2 fixation in the 3 years (2012 to 2014) of field experiment in Hexi Corridor of Northwestern China. Four N management systems with N rate of 0 kg N ha?1 (the control), 90?+?45 kg N ha?1 (base N plus topdressing N), 90?+?90 kg N ha?1, and 90?+?135 kg N ha?1 were implemented in the maize/pea strip intercropping to form different ratios of base N to topdressing N.Results
Intercropped pea improved nodule biomass per plant by 99 %, increased nitrogen derived from the atmosphere (Ndfa) by 35 %, and promoted aboveground plant tissue N accumulation by 35 % as compared with sole pea, averaged across the four N treatments. Compared to the highest N fertilizer treatment, a reduction of topdressing to 45 kg N ha?1 increased the nodule biomass of intercropped pea by 116 %, Ndfa by 35 %, and grain yield by 6 %.Conclusions
Adaptation of suitable N management in cereal/legume intercropping systems will allow an effective conversion of atmospheric N2 into crop available N and thus maximizing the system productivity.3.
Anna Antecka Michał Blatkiewicz Marcin Bizukojć Stanisław Ledakowicz 《Biotechnology letters》2016,38(4):667-672
Objective
This work is the first application of a morphological engineering technique called microparticle-enhanced cultivation (MPEC) aimed at the facilitation of laccase production in the submerged cultures by two basidiomycetes species Cerrena unicolor and Pleurotus sapidus.Results
The positive effect of the applied 10 μm Al2O3 microparticles at concentrations from 5 to 30 g Al2O3 l?1 was shown. Laccase activity increased 3.5-fold for C. unicolor and 2-fold for P. sapidus at 15 g Al2O3 l?1 on 9 and 14 day of the cultivation, respectively, compared to the control culture without microparticles. The increase of laccase activity in the cultivation broths was caused by the action of Al2O3 microparticles on the agglomeration of hyphae. It led to the decrease of the size of the pellets, (on average by 2 mm for C. unicolor), the change of their shape (star-shaped pellets for C. unicolor) and the change of their structure (more compact pellets for P. sapidus).Conclusions
Application of MPEC for the submerged cultures of two laccase-producing basidiomycetes proved successful in increasing of enzyme production.4.
Wenwen Zhang Zhaohui Chen Mengmeng Wu Zhong Shi Feng Zhu Guoqiang li Ting Ma 《Biotechnology letters》2016,38(6):991-997
Objective
To improve the production of welan gum and obtain a carotenoid-free strain while reducing the fermentation and post-treatment costs.Results
The vitreoscilla globin (vgb) gene combined with the β-galactosidase (lacZ) promoter was inserted into the phytoene synthase (crtB) gene region of the chromosome in Alcaligenes sp. ATCC31555. When the recombinant strain was grown in a 5 l fermentor, welan gum was produced at 24 ± 0.4 g l?1 compared to 21 g ± 0.4 g l?1 in the wild type. Furthermore, the carotenoid-free welan gum produced using Alcaligenes sp. ATCC31555 VHb strain was less expensive with improved properties.Conclusions
Alcaligenes sp. ATCC31555 VHb strain was a better neutral welan-producing strain with a higher production than the wild-type strain.5.
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.6.
Background and Aims
Rock fragments within topsoil have important effects on soil properties and plant growth. This study mainly aimed to investigate the relationships between rock fragments, soil carbon (C) and nitrogen (N) densities and vegetation biomass in an alpine steppe.Methods
Rock fragments, plant and soil samples were collected from four topographic positions (top, upper, lower, and bottom) on a hillslope.Results
Volumetric rock fragment content within the 0–30 cm soil profile varied from 17.8 to 30.5%, the upper position value was significantly greater (P < 0.05) than those at other positions. The highest aboveground biomass was observed at the lower position (921 kg ha?1), while the highest belowground biomass within the 0–30 cm profile was found at the upper position (4460 kg ha?1). More fine earth and plant litter input accompanied by lower C and N losses induced by rainfall erosion resulted in higher soil organic C and total N densities (28.6 Mg C ha?1 and 2.87 Mg N ha?1) at the lower position.Conclusions
Rock fragments may promote root growth but limit aboveground biomass production, and can therefore change the biomass distribution pattern. Our findings provide more evidence for scientifically assessing alpine steppe productivity.7.
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.8.
Baolong Wang Xin Wang Chris Wayne Xiangxiang Wang Lei Han Li Ye Qun Zhao Guixiang Jiang Meiqing Feng 《Biotechnology letters》2016,38(5):801-807
Objective
To produce a therapeutic protein (endostatin) by fusion with two fragments of the carboxyl-terminal peptide (CTP) of the human chorionic gonadotropin β-subunit in Pichia pastoris.Results
Two CTP sequences were fused to the C-terminal of human endostatin, and the fusion protein (endo-CTP) was expressed by P. pastoris. Endo-CTP inhibited proliferation of endothelial cells with an IC50 of 7 μg ml?1, and 30 % of cells were annexin V-positive after treatment with 20 μg endo-CTP ml?1 for 48 h. Migration of endothelial cells was inhibited by endo-CTP in a concentration-dependent manner. The half-life of endo-CTP in Sprague–Dawley rats was much longer than that of its commercial counterpart (Endostar).Conclusion
A long-acting endostatin can be produced using CTP technology.9.
Yan Ru Wu Yun Gyeong Kang Ji Won Shin Mi Jin Kim Jung-Woog Shin 《Biotechnology letters》2017,39(8):1121-1127
Objective
To control the oscillatory behavior of the intracellular calcium ([Ca2+]i) concentration in endothelial cells via mechanical factors (i.e., various hydrostatic pressures) because [Ca2+]i in these cells is affected by blood pressure.Results
Quantitative analyses based on real-time imaging showed that [Ca2+]i oscillation frequency and relative concentration increased significantly when 200 mm Hg pressure, mimicking hypertension, was applied for >10 min. Peak height and peak width decreased significantly at 200 mm Hg. These trends were more marked as the duration of the 200 mm Hg pressure was increased. However, no change was observed under normal blood pressure conditions 100 mm Hg.Conclusion
We generated a simple in vitro model to study [Ca2+]i behavior in relation to various pathologies and diseases by eliminating possible complicating effects induced by chemical cues.10.
Shuhao Huo Feifei Zhu Bin Zou Ling Xu Fengjie Cui Wenhua You 《Biotechnology letters》2018,40(4):689-696
Objectives
To demonstrate the effectiveness of a novel two-stage system coupling hydrolytic acidification with algal microcosms for the treatment of acrylonitrile butadiene styrene (ABS) resin-manufacturing wastewater.Results
After hydrolytic acidification, the BOD5/COD ratio increased from 0.22 to 0.56, showing improved biodegradability of the wastewater. Coupled with hydrolytic acidification, the algal microcosms showed excellent capability of in-depth removal of COD, NH3–N and phosphorus with removal rates 83, 100, and 89%, respectively, and aromatic pollutants, including benzene, were almost completely removed. The biomass concentration of Chlorella sp. increased from 5 × 106 to 2.1 × 107 cells/ml after wastewater treatment.Conclusions
This two-stage coupling system achieved deep cleaning of the benzene-containing petrochemical wastewater while producing greater algae biomass resources at low cost.11.
Qingdai Liu Xiaoqian Ma Haijiao Cheng Ning Xu Jun Liu Yanhe Ma 《Biotechnology letters》2017,39(6):913-919
Objectives
To improve the production of α-ketoglutaric acid (α-KG) from l-glutamate by whole-cell biocatalysis.Results
A novel and highly active l-glutamate oxidase, SmlGOX, from Streptomyces mobaraensis was overexpressed and purified. The recombinant SmlGOX was approx. 64 kDa by SDS-PAGE. SmlGOX had a maximal activity of 125 ± 2.7 U mg?1 at pH 6.0, 35 oC. The apparent Km and Vmax values of SmlGOX were 9.3 ± 0.5 mM and 159 ± 3 U mg?1, respectively. Subsequently, a co-expression plasmid containing the SmlGOX and KatE genes was constructed to remove H2O2, and the protein levels of SmlGOX were improved by codon optimization. Finally, by optimizing the whole-cell transformation conditions, the production of α-KG reached 77.4 g l?1 with a conversion rate from l-glutamate of 98.5% after 12 h.Conclusions
An efficient method for the production of α-KG was established in the recombinant Escherichia coli, and it has a potential prospect in industrial application.12.
Objectives
To improve the production and activity of an alkaline zinc metalloprotease from Salinivibrio proteolyticus in response to ZnSO4 (ionic and nanoparticle forms) and low intensity direct electric current (LIDC).Results
A DC of 50 µA for 10 min increased enzyme production from 35 to 53 U ml?1 when applied to the stationary phase bacterial cells. Zn2+ improved enzyme production better than zinc nanoparticles (52 vs. 43.5 U ml?1). Zinc nanoparticles (0.5 mM) added to an enzyme reaction mixture containing casein (0.65 %) and 20 mM Tris/HCl buffer (pH 8) improved enzyme activity more than Zn2+ (42 vs. 36 U ml?1).Conclusion
LIDC exposure (50 µA, 10 min) to the stationary phase bacterial cells increases metalloprotease production in Salinivibrio. A low concentration of zinc nanoparticles (0.5 mM) increases maximum enzyme activity.13.
Natasha Järviö Patrik J. G. Henriksson Jeroen B. Guinée 《The International Journal of Life Cycle Assessment》2018,23(5):1078-1090
Purpose
Mangrove forests have been recognized as important regulators of greenhouse gases (GHGs), yet the resulting land use and land-use change (LULUC) emissions have rarely been accounted for in life cycle assessment (LCA) studies. The present study therefore presents up-to-date estimates for GHG emissions from mangrove LULUC and applies them to a case study of shrimp farming in Vietnam.Methods
To estimate the global warming impacts of mangrove LULUC, a combination of the International Panel for Climate Change (IPCC) guidelines, the Net Committed Emissions, and the Missed Potential Carbon Sink method were used. A literature review was then conducted to characterize the most critical parameters for calculating carbon losses, missed sequestration, methane fluxes, and dinitrogen monoxide emissions.Results and discussion
Our estimated LUC emissions from mangrove deforestation resulted in 124 t CO2 ha?1 year?1, assuming IPCC’s recommendations of 1 m of soil loss, and 96% carbon oxidation. In addition to this, 1.25 t of carbon would no longer be sequestered annually. Discounted over 20 years, this resulted in total LULUC emissions of 129 t CO2 ha?1 year?1 (CV = 0.441, lognormal distribution (ln)). Shrimp farms in the Mekong Delta, however, can today operate for 50 years or more, but are 1.5 m deep (50% oxidation). In addition to this, Asian tiger shrimp farming in mixed mangrove concurrent farms (the only type of shrimp farm that resulted in mangrove deforestation since 2000 in our case study) resulted in 533 kg methane and 1.67 kg dinitrogen monoxide per hectare annually. Consequently, the LULUC GHG emissions resulted in 184 and 282 t CO2-eq t?1 live shrimp at farm gate, using mass and economic allocation, respectively. These GHG emissions are about an order of magnitude higher than from semi-intensive or intensive shrimp farming systems. Limitations in data quality and quantity also led us to quantify the uncertainties around our emission estimates, resulting in a CV of between 0.4 and 0.5.Conclusions
Our results reinforce the urgency of conserving mangrove forests and the need to quantify uncertainties around LULUC emissions. It also questions mixed mangrove concurrent shrimp farming, where partial removal of mangrove forests is endorsed based upon the benefits of partial mangrove conservation and maintenance of certain ecosystem services. While we recognize that these activities limit the chances of complete removal, our estimates show that large GHG emissions from mangrove LULUC question the sustainability of this type of shrimp farming, especially since mixed mangrove farming only provide 5% of all farmed shrimp produced in Vietnam.14.
Henri de Parseval Sébastien Barot Jacques Gignoux Jean-Christophe Lata Xavier Raynaud 《Plant and Soil》2017,412(1-2):97-114
Background and aims
Relevant soil properties and nutrient distributions influencing crop root growth might be different under no-till (NT) and mouldboard plough (MP) management. The possible different root systems within different managements might have key impact on crop nutrient uptake and consequently crop production. Our objective was to assess the long-term combined effects of tillage and phosphorus (P) fertilization on corn (Zea mays L.) root distribution and morphology.Methods
Corn root and soil samples were collected during the silking stage at five depths (0–5, 5–10, 10–20, 20–30 and 30–40 cm) and three horizontal distances perpendicular to the corn row (5, 15 and 25 cm) under MP and NT with three P fertilizations (0, 17.5, and 35 kg P ha?1) for a long-term (22 years) experiment in eastern Canada. Root morphology and soil properties were determined.Results
NT practice decreased corn root biomass by ?26 % compared to MP, mainly by decreasing the primary and secondary roots. Additionally, corn roots in NT tend to be more expansive on the surface layer with higher root length and surface densities for the depth of 0–5 cm at two sampling distances of 15 and 25 cm. The 35 kg P ha?1 rate increased the root biomass by 26 and 41 % compared to the 0 and 17.5 kg P ha?1 rates.Conclusions
No-tillage practice and low rates of P fertilization reduce corn roots. This is probably caused by the weed competition in NT and the continued downward P status with low P rates over 22 years.15.
Background and aims
Studies have found significant differences in methane (CH4) emissions among rice cultivars; however, it is unclear whether this difference is related to radial oxygen loss (ROL) from the roots.Methods
Based on a 2-year in situ field study and solution culture experiments on 16 rice cultivars, we investigated CH4 emission levels and their dependence on ROL.Results
We detected significant differences in CH4 emission and ROL among rice cultivars. The lowest and highest CH4 emission levels were 4.10 and 7.35 g m?2 for early rice, and 14.36 and 23.33 g m?2 for late rice, respectively. The maximum and minimum ROL values were 3.77 and 1.73 mmol plant?1 h?1 for early rice, and 4.18 and 2.08 mmol plant?1 h?1 for late rice, respectively. Seasonal total CH4 emission was negatively correlated with ROL in the early rice season (p?<?0.01), and (p?<?0.01) in the late rice season. ROL was positively correlated with the number of roots per plant (RN), root tips per plant (RT), and root volume per plant (RV).Conclusions
We suggest that ROL can be used as a predictive index for CH4 emissions. RN, RT, and RV were the most important factors influencing ROL in rice cultivars.16.
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.17.
Bernhard Zehetgruber Johannes Kobler Thomas Dirnböck Robert Jandl Rupert Seidl Andreas Schindlbacher 《Plant and Soil》2017,420(1-2):239-252
Aims
Slow or failed tree regeneration after forest disturbance is increasingly observed in the central European Alps, potentially amplifying the carbon (C) loss from disturbance. We aimed at quantifying C dynamics of a poorly regenerating disturbance site with a special focus on the role of non-woody ground vegetation.Methods
Soil CO2 efflux, fine root biomass, ground vegetation biomass, tree increment and litter input were assessed in (i) an undisturbed section of a ~ 110 years old Norway spruce stand, (ii) in a disturbed section which was clear-cut six years ago (no tree regeneration), and (iii) in a disturbed section which was clear-cut three years ago (no tree regeneration).Results
Total soil CO2 efflux was similar across all stand sections (8.5 ± 0.2 to 8.9 ± 0.3 t C ha?1 yr.?1). The undisturbed forest served as atmospheric C sink (2.1 t C ha?1 yr.?1), whereas both clearings were C sources to the atmosphere. The source strength three years after disturbance (?5.5 t C ha?1 yr.?1) was almost twice as high as six years after disturbance (?2.9 t C ha?1 yr.?1), with declining heterotrophic soil respiration and the high productivity of dense graminoid ground vegetation mitigating C loss.Conclusions
C loss after disturbance decreases with time and ground vegetation growth. Dense non-woody ground vegetation cover can hamper tree regeneration but simultaneously decrease the ecosystem C loss. The role of ground vegetation should be more explicitly taken into account in forest C budgets assessing disturbance effects.18.
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.19.
M. Abawi R. Rozemeijer P. Agostoni R. C. van Jaarsveld C. S. van Dongen M. Voskuil A. O. Kraaijeveld P. A. F. M. Doevendans P. R. Stella 《Netherlands heart journal》2017,25(9):498-509
Objectives
To assess the effect of body mass index (BMI) on outcome among patients with severe aortic stenosis (AS) admitted for transcatheter aortic valve implantation (TAVI).Background
Being overweight or obese is associated with improved outcome following certain medical treatments, suggesting the existence of a BMI paradox. However, the relationship between BMI and mortality after TAVI remains controversial.Methods
Patients were classified according to World Health Organisation criteria such as normal weight, overweight, or obesity according to their BMI (18.5 to 24.9?kg/m2, 25.0 to 29.9?kg/m2, and ≥30.0?kg/m2, respectively).Results
A total of 549 consecutive patients (age: 80.2 ± 7.5 years; logistic European system for cardiac operative risk evaluation [EuroSCORE]: 17.3 ± 9.9%) who underwent TAVI for AS were included. Of these patients, 43% (n = 237) had normal weight, 36% (n = 200) were overweight, and 20% (n = 112) were obese. There were no differences in peri-operative bleeding or vascular complication rates between the groups. All-cause mortality after 30 days, and 1 year, were higher in normal weight patients compared with overweight and obese patients (7% vs. 5 and 4%, p = 0.383, and 19% vs. 9 and 10%, p = 0.006, respectively). After adjustment for several confounding factors, overweight was associated with a decreased 30-day and 1?year all-cause mortality outcome (hazard ratio [HR] 0.69; 95% confidence interval [CI] 0.47–0.99, and HR 0.65; 95% CI 0.45–0.94, respectively).Conclusions
Despite the well-documented adverse effects of increased body weight on health, being overweight is associated with improved survival following TAVI when compared with normal weight.20.
Chunqiu He Wen Dong Jing Li Yanpeng Li Chao Huang Yanling Ma 《Biotechnology letters》2017,39(9):1381-1388