Production, purification and characterization of novel beta glucosidase from newly isolated Penicillium simplicissimum H-11 in submerged fermentation

β-Glucosidase is an important component of the cellulase complex. It not only hydrolyzes cellobiose and short-chain cellooligos accharides to glucose, but also removes the inhibitory effect of cellobiose on the β-1, 4-endoglucanase and exoglucanase, thereby increasing the overall rate of cellulose biodegradation. β-glucosidasefrom culture supernatant of a fungus Penicillium simplicissimum was purified to homogeneity, by using ammonium sulfate fraction, Sephadex G-100 chromatography, and its properties were studied. The molecular mass of the enzyme was about 126.0 kDa, as identified by 12% SDS-PAGE. The optimum pH and temperature were 4.4 ~ 5.2 and 60°C, respectively. The enzyme was stable in pH 5.2 ~ 6.4 and under 40°C. Metal profile of the enzyme showed that Mn2+ enhances its activity, while Cu2+, Co2+ and Fe3+ cause obvious inhibition. The Km and Vmax was 14.881 mg/ml and 0.364 mg ml/min against salicin as a Substrate. This enzyme had secondary protein structure as evidenced by FTIR spectrum

Nitrate and Nitrite Promote Formation of Tobacco-Specific Nitrosamines via Nitrogen Oxides Intermediates during Postcured Storage under Warm Temperature

Tobacco-specific nitrosamines (TSNAs) are carcinogenic and are present in cured tobacco leaves. This study was designed to elucidate the mechanisms of TSNAs formation under warm temperature storage conditions. Results showed that nitrogen oxides (NOx) were produced from nitrate and nitrite in a short period of time under 45 ∘ C and then reacted with alkaloids to form TSNAs. Nitrite was more effective than nitrate in promoting TSNAs formation during 45 ∘ C storage which may be due to the fact that nitrite can produce a large amount of NOx in comparison with nitrate. Presence of activated carbon effectively inhibited the TSNAs formation because of the adsorption of NOx on the activated carbon. The results indicated that TSNAs are derived from a gas/solid phase nitrosation reaction between NOx and alkaloids. Nitrate and nitrite are major contributors to the formation of TSNAs during warm temperature storage of tobacco

Non-Sterilized Fermentative Production of Polymer-Grade L-Lactic Acid by a Newly Isolated Thermophilic Strain Bacillus sp. 2–6

-lactic acid is another limitation for PLA polymers to compete with conventional plastics.-lactic acid concentration of 182.0 g/liter was obtained from 30-liter fed-batch fermentation with an average productivity of 3.03 g/liter/h and product optical purity of 99.4%.-lactic acid production from renewable resources

The mitochondrial DNA 4,977-bp deletion and its implication in copy number alteration in colorectal cancer

<p>Abstract</p> <p>Background</p> <p>Qualitative and quantitative changes in human mitochondrial DNA (mtDNA) have been implicated in various cancer types. A 4,977 bp deletion in the major arch of the mitochondrial genome is one of the most common mutations associated with a variety of human diseases and aging.</p> <p>Methods</p> <p>We conducted a comprehensive study on clinical features and mtDNA of 104 colorectal cancer patients in the Wenzhou area of China. In particular, using a quantitative real time PCR method, we analyzed the 4,977 bp deletion and mtDNA content in tumor tissues and paired non-tumor areas from these patients.</p> <p>Results</p> <p>We found that the 4,977 bp deletion was more likely to be present in patients of younger age (≤65 years, p = 0.027). In patients with the 4,977 bp deletion, the deletion level decreased as the cancer stage advanced (p = 0.031). Moreover, mtDNA copy number in tumor tissues of patients with this deletion increased, both compared with that in adjacent non-tumor tissues and with in tumors of patients without the deletion. Such mtDNA content increase correlated with the levels of the 4,977 bp deletion and with cancer stage (p < 0.001).</p> <p>Conclusions</p> <p>Our study indicates that the mtDNA 4,977 bp deletion may play a role in the early stage of colorectal cancer, and it is also implicated in alteration of mtDNA content in cancer cells.</p

Potential of Workshop Measurement Positioning System to Measure Oscillation Frequencies of Rigid Structures

A workshop measuring and positioning system (wMPS) is a large three-dimensional (3D) coordinate-measurement system based on optoelectronic scanning. It is capable of large-range coverage, high measurement accuracy and frequency, and multi-task synchronous measurement. Existing geodetic instruments cannot measure the intrinsic parameters of strong rigid structures. Thus, this study conducted experiments to explore the feasibility of the wMPS to measure the intrinsic parameters of rigid structures. A test bed was established using a reverse-engineering method to simulate the oscillation frequency of the structure. Displacement data, which changed with the time series through the fast Fourier transformation method, were analyzed to determine the feasibility and range of the wMPS in measuring intrinsic parameters of the structure. The experimental results demonstrated that the wMPS can measure the vibrational frequency up to 9 Hz with a 3-mm amplitude and up to 4 Hz with a 30-mm amplitude

Design and Implementation of A Circuit Board Calibration System

With the development of science and technology, the traditional artificial detection methods cannot meet the requirements of modern equipment testing and calibration. Combined with the actual demand, a kind of circuit boards calibration system are put forward. It can to realize automatic testing and calibration of the circuit boards. Many functions of the calibration system such as automatic testing, self-test and monitoring are summarized. The hardware is introduced which including the industrial computer system, calibration adapter and so on. Then, development platform, the thought of program design and the structure of the software are introduced in detail. The function of automatic calibration to specific circuit boards are realized. Because the system has good commonality and easy to extend to upgrade, the development ideas and experiences can be applied to similar circuit boards automatic testing system

The complete chloroplast genome of Lilium nepalense (Liliaceae)

Lilium nepalense is a useful plant species not only for its showy flowers but also has high medicinal value. In this study, the whole chloroplast genome of L. nepalense was sequenced for the first time. The genome size of L. nepalense, was 152,956bp, with typical tetragonal structure: one large single copy (82,573 bp), one small single copy (17,527 bp), and a pair of inverted repeat regions (IRs, 26,428 bp). The overall GC content was 37.0%. The complete genome contained 131 genes, including 85 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Phylogenetic analysis showed that L. nepalense was a close relationship between L. leucanthum and L. henryi. Phylogenetic analysis placed L. nepalense under the family Liliaceae

The complete chloroplast genome and phylogenetic analysis of Gentiana arethusae Burkill (Gentianaceae) from China

Gentiana arethusae Burkill is a perennial herb classified in the Gentianaceae. In this study, the complete chloroplast genome of G. arethusae was sequenced and analyzed. The chloroplast genome is 137,458 bp in length and encodes a total of 116 genes, including 71 protein-coding, 37 tRNA, and eight rRNA genes. The genome has a low GC content of 38.0%. Phylogenetic analysis of the genome of G. arethusae resolved it in a clade with Gentiana obconica and Gentiana veitchiorum. The complete chloroplast genome of G. arethusae will be helpful to study the genetic diversity and phylogenetics of the Gentianaceae

Design and Implementation of A Circuit Board Calibration System

With the development of science and technology, the traditional artificial detection methods cannot meet the requirements of modern equipment testing and calibration. Combined with the actual demand, a kind of circuit boards calibration system are put forward. It can to realize automatic testing and calibration of the circuit boards. Many functions of the calibration system such as automatic testing, self-test and monitoring are summarized. The hardware is introduced which including the industrial computer system, calibration adapter and so on. Then, development platform, the thought of program design and the structure of the software are introduced in detail. The function of automatic calibration to specific circuit boards are realized. Because the system has good commonality and easy to extend to upgrade, the development ideas and experiences can be applied to similar circuit boards automatic testing system

The complete chloroplast genome of Lilium rosthornii Diels (Liliopsida: Liliaceae) from Hunan, China

Lilium rosthornii is the perennial herbaceous bulbous plant belonging to the Lily of the Liliaceae, with high ornamental value and medicinal values. In this present study, we sequenced the complete chloroplast genome of Lilium rosthornii by Illumina Hiseq X Ten and PacBio RS technologies firstly. The genome size of L. rosthornii, was 152,242bp, with typical tetragonal structure: one large single-copy (LSC, 81,875 bp), one small single-copy (SSC, 17,553 bp), and a pair of inverted repeat regions (IRs, 26,407 bp). The overall GC content was 37.02%. The complete genome contained 131 genes, including 85 protein-coding genes, 38 tRNA genes, and eight rRNA genes. Phylogenetic analysis placed L. rosthornii under the family Liliaceae