Electrochemical surface modification of carbon mesh anode to improve the performance of air-cathode microbial fuel cells

A convenient and promising alternative to surface modification of carbon mesh anode was fulfilled by electrochemical oxidation in the electrolyte of nitric acid or ammonium nitrate at ambient temperature. It was confirmed that such an anode modification method was low cost and effective not only in improving the efficiency of power generation in microbial fuel cells (MFCs) for synthetic wastewater treatment, but also helping to reduce the period for MFCs start-up. The MFCs with anode modification in electrolyte of nitric acid performed the best, achieving a Coulombic efficiency enhancement of 71 %. As characterized, the electrochemical modification resulted in the decrease of the anode potential and internal resistance but the increase of current response and nitrogen-containing and oxygen-containing functional groups on the carbon surface, which might contribute to the enhancement on the performances of MFCs.     

Pilot-scale production of fuel ethanol from concentrated food waste hydrolysates using Saccharomyces cerevisiae H058

The aim of this study was to develop a bioprocess to produce ethanol from food waste at laboratory, semipilot and pilot scales. Laboratory tests demonstrated that ethanol fermentation with reducing sugar concentration of 200 g/L, inoculum size of 2 % (Initial cell number was 2 × 10⁶ CFU/mL) and addition of YEP (3 g/L of yeast extract and 5 g/L of peptone) was the best choice. The maximum ethanol concentration in laboratory scale (93.86 ± 1.15 g/L) was in satisfactory with semipilot scale (93.79 ± 1.11 g/L), but lower than that (96.46 ± 1.12 g/L) of pilot-scale. Similar ethanol yield and volumetric ethanol productivity of 0.47 ± 0.02 g/g, 1.56 ± 0.03 g/L/h and 0.47 ± 0.03 g/g, 1.56 ± 0.03 g/L/h after 60 h of fermentation in laboratory and semipilot fermentors, respectively, however, both were lower than that (0.48 ± 0.02 g/g, 1.79 ± 0.03 g/L/h) of pilot reactor. In addition, simple models were developed to predict the fermentation kinetics during the scale-up process and they were successfully applied to simulate experimental results.     

Proteomic methods reveal cyclophilin a function as a host restriction factor against rotavirus infection

Rotavirus (RV) infection is the main cause of acute dehydrating diarrhea in infants and young children below 5 years old worldwide. RV infection causes a global shutoff of host proteins as many other viruses do. However, previous studies revealed that RV could selectively upregulated the expression of some host proteins that then played important roles in RV infection. To globally explor such host proteins that were upregulated in early human rotavirus (HRV) infection, proteomic methods were used and a total of ten upregulated host proteins were unambiguously identified. Cyclophilin A (CYPA), a peptidyl‐prolyl cis‐trans isomerase, was among these upregulated host proteins. Following infection, CYPA was recruited to the viroplasm and interacted with HRV structural protein VP2; CYPA reduced host susceptibility to HRV infection and inhibited replication of HRV by repressing the expression of viral proteins. Furthermore, we found that the increased expression of CYPA in enterocytes of small intestine correlated to the period when BALB/c mice became resistant to RV diarrhea. Together, we identified CYPA as a novel host restriction factor that confered protection against RV infection and might contribute to host susceptibility to RV diarrhea.     

Bottom‐up proteome analysis of E. coli using capillary zone electrophoresis‐tandem mass spectrometry with an electrokinetic sheath‐flow electrospray interface

The Escherichia coli proteome was digested with trypsin and fractionated using SPE on a C18 SPE column. Seven fractions were collected and analyzed by CZE‐ESI‐MS/MS. The separation was performed in a 60‐cm‐long linear polyacrylamide‐coated capillary with a 0.1% v/v formic acid separation buffer. An electrokinetic sheath‐flow electrospray interface was used to couple the separation capillary with an Orbitrap‐Velos operating in higher‐energy collisional dissociation mode. Each CZE‐ESI‐MS/MS run lasted 50 min and total MS time was 350 min. A total of 23 706 peptide spectra matches, 4902 peptide IDs, and 871 protein group IDs were generated using MASCOT with false discovery rate less than 1% on the peptide level. The total mass spectrometer analysis time was less than 6 h, the sample identification rate (145 proteins/h) was more than two times higher than previous studies of the E. coli proteome, and the amount of sample consumed (<1 μg) was roughly fourfold less than previous studies. These results demonstrate that CZE is a useful tool for the bottom‐up analysis of prokaryote proteomes.     

Novel POMGnT1 mutations cause muscle-eye-brain disease in Chinese patients

Muscle-eye-brain (MEB) disease is a congenital muscular dystrophy (CMD) phenotype characterized by hypotonia at birth, brain structural abnormalities and ocular malformations. To date, few MEB cases have been reported in China where clinical recognition and genetic confirmatory testing on a research basis are recent developments. Here, we report the clinical and molecular genetics of three MEB disease patients. The patients had different degrees of muscle, eye and brain symptoms, ranging from congenital hypotonia, early-onset severe myopia and mental retardation to mild weakness, independent walking and language problems. This confirmed the expanding phenotypic spectrum of MEB disease with varying degrees of hypotonia, myopia and cognitive impairment. Brain magnetic resonance imaging showed cerebellar cysts, hypoplasia and characteristic brainstem flattening and kinking. Four candidate genes (POMGnT1, FKRP, FKTN and POMT2) were screened, and six POMGnT1 mutations (four novel) were identified, including five missense and one splice site mutation. Pathogenicity of the two novel variants in one patient was confirmed by POMGnT1 enzyme activity assay, protein expression and subcellular localization of mutant POMGnT1 in HeLa cells. Transfected cells harboring this patient’s L440R mutant POMGnT1 showed POMGnT1 mislocalization to both the Golgi apparatus and endoplasmic reticulum. We have provided clinical, histological, enzymatic and genetic evidence of POMGnT1 involvement in three unrelated MEB disease patients in China. The identification of novel POMGnT1 mutations and an expanded phenotypic spectrum contributes to an improved understanding of POMGnT1 structure–function relationships, CMD pathophysiology and genotype–phenotype correlations, while underscoring the need to consider POMGnT1 in Chinese MEB disease patients.     

不同微生物来源的加氧酶及其催化反应特征的研究进展

加氧酶作为一种氧化还原酶,可催化分子氧的氧原子与一大类有机化合物反应,被广泛应用于环保行业、美容保健行业、移植免疫过程、医药中间体的生产、资源开发利用、生态环境的生物修复、病虫害的防治等。本文综述了来源于真菌、细菌以及放线菌的加氧酶的研究进展,包括酶的性质、结构特点、催化机理及催化反应途径、应用等,并对微生物中加氧酶的研究前景进行了展望。     

菌糠二次利用栽培黑木耳试验研究

为充分利用营养没有得到充分吸收的栽培过食用菌的废弃菌糠、明确在牡丹江地区再利用食用菌菌糠生产黑木耳的适宜比例,以灵芝和鲍鱼菇的废弃菌糠为试验材料,进行不同配方的对比试验。试验结果表明：黑木耳培养料中灵芝菌糠体积分数为30%时栽培效果最佳,显著优于参入鲍鱼菇菌糠的各种培养料配方（P〈0.01）。因此,可以利用灵芝菌糠废料作为替代料栽培黑木耳使用。     

Optical Magnetic Resonances in Subwavelength Ag–MgF2–Ag Grating Structures

Optical magnetic responses were demonstrated in subwavelength Ag–MgF₂–Ag grating structures for transverse magnetic-polarized light. The subwavelength Ag–MgF₂–Ag grating structures were fabricated using e-beam lithography followed by a lift-off process. By fixing the Ag–MgF₂–Ag strip dimension, the effect of the stripe width on the magnetic resonances was compared for two different grating pitches. With further reduced grating pitch, we pushed the optical magnetic resonances to near UV (deep blue). Numerical simulations confirmed our experimental observations and were in good agreement with the experimental results.