Identification and Characterization of a New Alkaline SGNH Hydrolase from a Thermophilic Bacterium Bacillus sp. K91

( Tingting Yu ),( Junmei Ding ),( Qingxia Zheng ),( Nanyu Han ),( Jialin Yu ),( Yunjuan Yang ),( Junjun Li ),( Yuelin Mu ),( Qian Wu ),( Zunxi Huang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.4

est19 is a gene from Bacillus sp. K91 that encodes a new esterase. A comparison of the amino acid sequence showed that Est19 has typical Ser-Gly-Asn-His (SGNH) family motifs and could be grouped into the SGNH hydrolase family. The Est19 protein was functionally cloned, and expressed and purified from Escherichia coli BL21(DE3). The enzyme activity was optimal at 60°C and pH 9.0, and displayed esterase activity towards esters with short-chain acyl esters (C2-C6). A structural model of Est19 was constructed using phospholipase A1 from Streptomyces albidoflavus NA297 as a template. The structure showed an α/β-hydrolase fold and indicated the presence of the typical catalytic triad Ser49-Asp227-His230, which were further investigated by site-directed mutagenesis. To the best of our knowledge, Est19 is a new member of the SGNH hydrolase family identified from thermophiles, which may be applicable in the industrial production of semisynthetic β-lactam antibiotics after modification.

Effects of microbial enzymes on starch and hemicellulose degradation in total mixed ration silages

Ning, Tingting,Wang, Huili,Zheng, Mingli,Niu, Dongze,Zuo, Sasa,Xu, Chuncheng Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.2

Objective: This study investigated the association of enzyme-producing microbes and their enzymes with starch and hemicellulose degradation during fermentation of total mixed ration (TMR) silage. Methods: The TMRs were prepared with soybean curd residue, alfalfa hay (ATMR) or Leymus chinensis hay (LTMR), corn meal, soybean meal, vitamin-mineral supplements, and salt at a ratio of 25:40:30:4:0.5:0.5 on a dry matter basis. Laboratory-scale bag silos were randomly opened after 1, 3, 7, 14, 28, and 56 days of ensiling and subjected to analyses of fermentation quality, carbohydrates loss, microbial amylase and hemicellulase activities, succession of dominant amylolytic or hemicellulolytic microbes, and their microbial and enzymatic properties. Results: Both ATMR and LTMR silages were well preserved, with low pH and high lactic acid concentrations. In addition to the substantial loss of water soluble carbohydrates, loss of starch and hemicellulose was also observed in both TMR silages with prolonged ensiling. The microbial amylase activity remained detectable throughout the ensiling in both TMR silages, whereas the microbial hemicellulase activity progressively decreased until it was inactive at day 14 post-ensiling in both TMR silages. During the early stage of fermentation, the main amylase-producing microbes were Bacillus amyloliquefaciens (B. amyloliquefaciens), B. cereus, B. licheniformis, and B. subtilis in ATMR silage and B. flexus, B. licheniformis, and Paenibacillus xylanexedens (P. xylanexedens) in LTMR silage, whereas Enterococcus faecium was closely associated with starch hydrolysis at the later stage of fermentation in both TMR silages. B. amyloliquefaciens, B. licheniformis, and B. subtilis and B. licheniformis, B. pumilus, and P. xylanexedens were the main source of microbial hemicellulase during the early stage of fermentation in ATMR and LTMR silages, respectively. Conclusion: The microbial amylase contributes to starch hydrolysis during the ensiling process in both TMR silages, whereas the microbial hemicellulase participates in the hemicellulose degradation only at the early stage of ensiling.

Estrogen promotes the onset and development of idiopathic scoliosis via disproportionate endochondral ossification of the anterior and posterior column in a bipedal rat model

Shuhui Zheng,Hang Zhou,Bo Gao,Yongyong Li,Zhiheng Liao,Taifeng Zhou,Chengjie Lian,Zizhao Wu,Deying Su,Tingting Wang,Peiqiang Su,Caixia Xu 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

This study aimed to verify the effects of estrogen on the onset and development of adolescent idiopathic scoliosis and the mechanisms associated with these effects by constructing a pubescent bipedal rat model. Experiments were conducted to investigate whether scoliosis progression was prevented by a Triptorelin treatment. One hundred twenty bipedal rats were divided into female, OVX (ovariectomy), OVX + E2, Triptorelin, sham, and male groups. According to a spinal radiographic analysis, the scoliosis rates and curve severity of the female and OVX + E2 groups were higher than those in the OVX, Triptorelin, and male groups. The measurements obtained from the sagittal plane of thoracic vertebrae CT confirmed a relatively slower growth of the anterior elements and a faster growth of the posterior elements between T11 and T13 in the female and OVX + E2 groups than in the OVX and Triptorelin groups. Histomorphometry and immunohistochemistry revealed a significantly longer hypertrophic zone of the vertebral cartilage growth plates that expressed more type X collagen and less type II collagen in the OVX and Triptorelin groups than in the female and OVX + E2 groups. Ki67 immunostaining confirmed an increase in the proliferation of vertebral growth plate chondrocytes in the OVX group compared with the female and OVX + E2 groups. In conclusion, estrogen obviously increased the incidence of scoliosis and curve severity in pubescent bipedal rats. The underlying mechanism may be a loss of coupling of the endochondral ossification between the anterior and posterior columns. Triptorelin decreased the incidence of scoliosis and curve magnitudes in bipedal female rats. Introduction Adolescent

The effect of crash pulse on occupant injury in frontal coach collisions

Sun Tingting,Xiong Xin,Zheng Zhuan,Shi Xiaolong,Fan Jianwei 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

The purpose of this study is to reveal the effect of different acceleration curves on occupant injury risk in the frontal collision of coaches. Based on characteristics of frontal crash acceleration curves, the influence of characteristic parameters on occupant injury was studied using a two-factor variance analysis method. The finite element-rigid body coupling method was used to establish a coupled simulation for the dummy and the sled and evaluate differences in the effects on occupant injury between the acceleration curves of four different coaches and the acceleration envelope of the ECE R80 standard. Results indicate that the upper limit of the simplified curve has the greatest influence on occupant injury and it displays a positive correlation. The acceleration curve stipulated by ECE R80 is too idealized, which may lead to inadequacies in safety protection capability in vehicle and seat design.

Autophagy inhibition contributes to epigallocatechin-3-gallate-mediated apoptosis in papillary thyroid cancer cells

Bu Ling,Zheng Tingting,Mao Chaoming,Fei Wu,Mou Xiao,Xu Chengcheng,Luo Xuan,Lu Qingyan,Dong Liyang,Wang Xuefeng 대한독성 유전단백체 학회 2021 Molecular & cellular toxicology Vol.17 No.4

Background Epigallocatechin-3-gallate is a natural polyphenolic compound that induces apoptosis in papillary thyroid cancer cells. However, its underlying molecular mechanism was not completely clarified. Objectives The present study demonstrated the role of apoptosis and autophagy in EGCG-treated papillary thyroid cancer cells and the relationship between these processes. Results EGCG significantly suppressed the viability of TPC-1 papillary thyroid cancer cells at an IC50 of 17.2 μM. EGCG induced TPC-1 cell apoptosis and cell cycle arrest at S phase and downregulated the protein expression of cyclin A and cyclin-dependent kinase-2. EGCG decreased reactive oxygen species levels, upregulated Bax expression, downregulated Bcl-2 expression and increased cytochrome C levels in the cytosol. Treatment with EGCG also increased the levels of cleaved caspase 3, cleaved caspase 9 and cleaved poly(ADP-ribose) polymerase. EGCG induced an autophagic response via the upregulation of the autophagy-related protein LC3-II and suppression of the AKT/mTOR signalling pathway. Autophagy inhibition further enhanced EGCG-induced cell apoptosis and ROS suppression, which indicated that autophagy played a cytoprotective role in EGCG-treated TPC-1 cells. Conclusion Taken together, these results demonstrated that autophagy inhibition was beneficial to EGCG–mediated apoptosis in papillary thyroid cancer cells. Background Epigallocatechin-3-gallate is a natural polyphenolic compound that induces apoptosis in papillary thyroid cancer cells. However, its underlying molecular mechanism was not completely clarified. Objectives The present study demonstrated the role of apoptosis and autophagy in EGCG-treated papillary thyroid cancer cells and the relationship between these processes. Results EGCG significantly suppressed the viability of TPC-1 papillary thyroid cancer cells at an IC50 of 17.2 μM. EGCG induced TPC-1 cell apoptosis and cell cycle arrest at S phase and downregulated the protein expression of cyclin A and cyclin-dependent kinase-2. EGCG decreased reactive oxygen species levels, upregulated Bax expression, downregulated Bcl-2 expression and increased cytochrome C levels in the cytosol. Treatment with EGCG also increased the levels of cleaved caspase 3, cleaved caspase 9 and cleaved poly(ADP-ribose) polymerase. EGCG induced an autophagic response via the upregulation of the autophagy-related protein LC3-II and suppression of the AKT/mTOR signalling pathway. Autophagy inhibition further enhanced EGCG-induced cell apoptosis and ROS suppression, which indicated that autophagy played a cytoprotective role in EGCG-treated TPC-1 cells. Conclusion Taken together, these results demonstrated that autophagy inhibition was beneficial to EGCG–mediated apoptosis in papillary thyroid cancer cells.

Dynamics Associated with Prolonged Ensiling and Aerobic Deterioration of Total Mixed Ration Silage Containing Whole Crop Corn

Wang, Huili,Ning, Tingting,Hao, Wei,Zheng, Mingli,Xu, Chuncheng Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.1

This study investigated the dynamics associated with prolonged ensiling and aerobic deterioration of whole crop corn (WCC) silages and total mixed ration (TMR) silages containing WCC (C-TMR silages) to clarify the differences that account for the enhanced aerobic stability of TMR silages. Laboratory-scale barrel silos were randomly opened after 7, 14, 28, and 56 d of ensiling and were subjected to analyses of fermentation quality, microbial and temperature dynamics during aerobic exposure. WCC and C-TMR silages were both well preserved and microorganisms were inhibited with prolonged ensiling, including lactic acid bacteria. Yeast were inhibited to below the detection limit of 500 cfu/g fresh matter within 28 d of ensiling. Aerobic stability of both silages was enhanced with prolonged ensiling, whereas C-TMR silages were more aerobically stable than WCC silages for the same ensiling period. Besides the high moisture content, the weak aerobic stability of WCC silage is likely attributable to the higher lactic acid content and yeast count, which result from the high water-soluble carbohydrates content in WCC. After silo opening, yeast were the first to propagate and the increase in yeast levels is greater than that of other microorganisms in silages before deterioration. Besides, increased levels of aerobic bacteria were also detected before heating of WCC silages. The temperature dynamics also indicated that yeast are closely associated with the onset of the aerobic deterioration of C-TMR silage, whereas for WCC silages, besides yeast, aerobic bacteria also function in the aerobic deterioration. Therefore, the inclusion of WCC might contribute to the survival of yeast during ensiling but not influence the role of yeast in deterioration of C-TMR silages.

Characterization of culturable yeast species associating with whole crop corn and total mixed ration silage

Huili Wang,Wei Hao,Tingting Ning,Mingli Zheng,C.C. Xu 아세아·태평양축산학회 2018 Animal Bioscience Vol.31 No.2

Objective: This study investigated the association of yeast species with improved aerobic stability of total mixed ration (TMR) silages with prolonged ensiling, and clarified the characteristics of yeast species and their role during aerobic deterioration. Methods: Whole crop corn (WCC) silages and TMR silages formulated with WCC were ensiled for 7, 14, 28, and 56 d and used for an aerobic stability test. Predominant yeast species were isolated from different periods and identified by sequencing analyses of the 26S rRNA gene D1/D2 domain. Characteristics (assimilation and tolerance) of the yeast species and their role during aerobic deterioration were investigated. Results: In addition to species of Candida glabrata and Pichia kudriavzevii (P. kudriavzevii) previously isolated in WCC and TMR, Pichia manshurica (P. manshurica), Candida ethanolica (C. ethanolica), and Zygosaccharomyces bailii (Z. bailii) isolated at great frequency during deterioration, were capable of assimilating lactic or acetic acid and tolerant to acetic acid and might function more in deteriorating TMR silages at early fermentation (7 d and 14 d). With ensiling prolonged to 28 d, silages became more (p<0.01) stable when exposed to air, coinciding with the inhibition of yeast to below the detection limit. Species of P. manshurica that were predominant in deteriorating WCC silages were not detectable in TMR silages. In addition, the predominant yeast species of Z. bailii in deteriorating TMR silages at later fermentation (28 d and 56 d) were not observed in both WCC and WCC silages. Conclusion: The inhibition of yeasts, particularly P. kudriavzevii, probably account for the improved aerobic stability of TMR silages at later fermentation. Fewer species seemed to be involved in aerobic deterioration of silages at later fermentation and Z. bailii was most likely to initiate the aerobic deterioration of TMR silages at later fermentation. The use of WCC in TMR might not influence the predominant yeast species during aerobic deterioration of TMR silages.

Research on B-C E-commerce Website Information Architecture Level

Kan Liu,Xiaokai Chen,Tingting Zheng,Zhihua Liu 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.4

Detection of reactive oxygen species generated by microwave electrodeless discharge lamp and application in photodegradation of H2S

Jiang Yu,Yang Yu,Tingting Zhang,Liqiong Zheng 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.7

The photodegradation of hydrogen sulfide (H2S) was examined using a self-made microwave electrodeless discharge lamp (MEDL). The features of the MEDL had been tested. The results showed that the MEDL absorbed 18.3, 32.7 and 41.8W power at the microwave (MW) output power of 165, 330 and 660W, respectively. The intensity of the emitted light increased with increasing MW output power. The reactive oxygen species (ROS) generated by irradiated air and nitrogen were detected, respectively. It was illustrated that the irradiated air could generate a number of ROS, at least including 1O2 and •OH. And the amount of ROS increased with increasing MW output power. In photodegradation of H2S process, the effects of MW output power and gas composition were investigated. The removal efficiency of H2S under nitrogen was obviously lower compared with that under air. The removal efficiency of H2S increased with increasing MW output power.

Fermentation Characteristics and Lactic Acid Bacteria Succession of Total Mixed Ration Silages Formulated with Peach Pomace

Xiaodong Hu,Wei Hao,Huili Wang,Tingting Ning,Mingli Zheng,C.C. Xu 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.4

The objective of this study was to assess the use of peach pomace in total mixed ration (TMR) silages and clarify the differences in aerobic stability between TMR and TMR silages caused by lactic acid bacteria (LAB). The TMR were prepared using peach pomace, alfalfa hay or Leymus chinensis hay, maize meal, soybean meal, cotton meal, limestone, a vitamin-mineral supplement, and salt in a ratio of 6.0:34.0:44.4:7.0:5.0:2.5:1.0:0.1 on a dry matter (DM) basis. Fermentation quality, microbial composition, and the predominant LAB were examined during ensiling and aerobic deterioration. The results indicated that the TMR silages with peach pomace were well fermented, with low pH and high lactic acid concentrations. The aerobic stability of TMR silages were significantly higher than that of TMR. Compared with TMR silages with alfalfa hay, TMR silage with Leymus chinensis hay was much more prone to deterioration. Although the dominant LAB were not identical in TMR, the same dominant species, Lactobacillus buchneri and Pediococcus acidilactici, were found in both types of TMR silages after 56 d of ensiling, and they may play an important role in the aerobic stability of TMR silages.