Optimization of the Antimicrobial Effects of Surfactin against Bacillus cereus Spores

2020 ◽  
Vol 83 (11) ◽  
pp. 1983-1988
Author(s):  
XIANQING HUANG ◽  
LIANJUN SONG ◽  
MINGWU QIAO ◽  
PINGAN ZHANG ◽  
QIUYAN ZHAO
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bacillus Cereus ◽  
Control Sample ◽  
Outer Wall ◽  
Experimental Results ◽  
Optimal Conditions ◽  
Design Expert ◽  
Temperature Time ◽  
Scanning Electron

ABSTRACT The purpose of this study was to establish a three-variable bactericidal model of temperature, time, and concentration to determine the optimal conditions for Bacillus cereus spore inactivation by surfactin. To obtain the binary regression equation of the inactivated spore model, a total of 17 simulations were performed using response surface methodology. The experimental results showed that the three factors each had a discernible but nonequal impact on the inactivation response value. Multiple regression analysis of experimental results using Design-Expert software yielded the following equation: Y = 1.47 + 0.39ξ1(temperature) + 0.38ξ2(time) + 0.39ξ3(concentration) − 0.20ξ1ξ2 + 0.22ξ1ξ2 − 0.12ξ2ξ3 − 0.23ξ12 − 0.11ξ22 − 0.40ξ32. Optimal inactivation of spores was achieved by treatment with surfactin at a concentration of 4 mg/mL for 40 h at 53°C, with the response value reaching 1.8. The spores were treated with surfactin under these conditions; the microstructural changes of spores were observed by use of scanning electron microscopy. We found that the structures of the outer wall of the spores were damaged, whereas the spores in the control sample showed no visible damage. HIGHLIGHTS

scholarly journals POTENSI KULTUR CAMPURAN BAKTERI ENDOFIT SEBAGAI PEMACU PERTUMBUHAN BIBIT TANAMAN KARET

2014 ◽  
Vol 32 (2) ◽  
pp. 129 ◽  
Author(s):  
Umi Hidayati ◽  
Iswandi Anas Chaniago ◽  
Abdul Munif ◽  
Siswanto Siswanto ◽  
Dwi Andreas Santosa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pseudomonas Aeruginosa ◽  
Bacillus Cereus ◽  
Scanning Electron

Bakteri endofit adalah bakteri yang hidup dalam jaringan tanaman, dapat diisolasi melalui sterilisasi permukaan jaringan tanaman. Isolasi bakteri endofit dari tanaman karet yang berpotensi sebagai pemacu pertumbuhan sangat penting dilakukan. Pembuatan kultur campuran dari bakteri endofit diharapkan meningkatkan potensi dalam memacu pertumbuhan yang dapat meningkatkan kualitas bibit batang bawah tanaman karet. Penelitian ini dilakukan dengan tujuan mendapatkan kultur campuran bakteri endofit sebagai pemacu pertumbuhan bibit tanaman karet. Lima bakteri endofit dari tanaman karet yang berpotensi sebagai pemacu pertumbuhan yaitu Bacillus cereus KPD6, Pseudomonas aeruginosa KPA32, Brachybacterium paraconglomeratum LPD74, bacterium (bakteri tidak dikenal) LPD76, dan Providencia vermicola KPA38, diuji kompatibilitas untuk mendapatkan kultur campuran yang dapat meningkatkan pertumbuhan bibit batang bawah PB 260. Semua bakteri endofit terpilih kompatibel satu dengan yang lain. Aplikasi kultur campuran untuk meningkatkan pertumbuhan bibit batang bawah PB 260 memberikan hasil 2 kultur campuran terbaik. Kultur campuran 1 terdiri 2 spesies bakteri yaitu Brachybacterium paraconglomeratum LPD74 dan Providencia vermicola KPA38.  Kultur campuran 2 terdiri 3 spesies bakteri yaitu  Bacillus cereus KPD6, Pseudomonas aeruginosa KPA32, dan Brachybacterium paraconglomeratum LPD74. Bakteri endofit mampu masuk ke planlet bibit karet microcutting yang dibuktikan dengan Scanning Electron Microscopy. Diterima : 19 Mei 2014; Direvisi : 30 Mei 2014; Disetujui : 21 Juni 2014  How to Cite : Hidayati, U., Chaniago, I. A., Munif, A., Siswanto., & Santosa, D. A. (2014). Potensi kultur campuran bakteri endofit sebagai pemacu pertumbuhan bibit tanaman karet. Jurnal Penelitian Karet, 32(2), 129-138. Retrieved from http://ejournal.puslitkaret.co.id/index.php/jpk/article/view/159

The Fracture Failure Analysis of Precision Centrifuge Spindle

2014 ◽  
Vol 971-973 ◽  
pp. 802-805
Author(s):  
Wei Feng Zhang ◽  
Li Yan ◽  
Fu Xia Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Fracture Mechanics ◽  
Failure Analysis ◽  
Fatigue Failure ◽  
High Speed ◽  
Experimental Results ◽  
Fracture Failure ◽  
Scanning Electron

For the problem of high-speed rotating centrifuge spindle fracture failures, relevant analyses are conducted from the perspective of microstructure, chemical composition and fracture mechanics by using scanning electron microscopy and related instruments. Experimental results and analyses indicate that the spindle fracture is fatigue failure, mainly caused by cold cracks generated on the journal surfacing. Based on the analysis results, improvements and measures are suggested to better solve the spindle weld fracture failure problems.

IDENTIFY OF THE MICRO-DEFECTS IN SEMI-INSULATING GaAs

2002 ◽  
Vol 16 (28n29) ◽  
pp. 4484-4486
Author(s):  
YUESHENG XU ◽  
CHUNLING ZHANG ◽  
LEI TANG ◽  
CAICHI LIU ◽  
JINGCHEN HAO
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gallium Arsenide ◽  
Strong Interaction ◽  
Chemical Etching ◽  
Experimental Results ◽  
Transmission Electron ◽  
Koh Etching ◽  
Scanning Electron

The micro-defects in semi-insulating gallium arsenide (SI-GaAs) were investigated by means of chemical etching (ultrasonic aided Abtahams-Buiocchi etching, melting KOH etching), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The experimental results showed that the micro-defects in SI-GaAs are micro-precipitates of As with the size of microns. Micro-defects and dislocations have strong interaction, dislocations absorb the micro-defects and micro-defects decorate on the dislocations.

Research Based on Scanning Electron Microscopy to Determine Original Water-Cement Ratio of Hardened Concrete

2014 ◽  
Vol 936 ◽  
pp. 1485-1489 ◽  
Author(s):  
Yue Li ◽  
Huan Tong ◽  
Jin Bo Yang ◽  
Wan Guo Dong
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Results ◽  
Hardened Concrete ◽  
Capillary Porosity ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
The Relationship ◽  
Original Water ◽  
Scanning Electron

In order to detect the influence of age on the experiment that use scanning electron microscopy (SEM) to determinate the original water-cement ratio (w/c) of hardened concrete, a series of concrete mixes are tested. Experimental results show that early ages do have an effect on the water-cement ratio of hardened concrete that determined from scanning electron microscopy, this effect will decrease while age increases. The relationship between capillary porosity, w/c and age is analyzed and a calculation equation is given.

The Study of Electroless Ni-B Coating on 45 Steel

2012 ◽  
Vol 501 ◽  
pp. 185-189
Author(s):  
Jian Zhang Guo ◽  
Qian Liu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Energy Dispersive Spectrometer ◽  
Salt Spray ◽  
High Hardness ◽  
Experimental Results ◽  
Electroless Ni ◽  
Scanning Electron ◽  
Optimal Formula

In order to improve the corrosion resistance and the hardness of the 45 steel, under comparison tests, the electroless Ni-B was prepared on the 45 steel. We made a contrast test to get the optimal formula. The coating under the optimal formula was characterized by Scanning Electron Microscopy(SEM), Energy Dispersive Spectrometer(EDS), metallurgical microscope and salt spray cabinet. The experimental results showed that the electroless Ni-B coating on 45 steel was low boron coating, with high hardness, and the hardness of the coating could catch HV524; the thickness of the coating was 16μm.

Crystal Structure of BiFeO3 Synthesized Using the Hydrothermal Processing

2014 ◽  
Vol 602-603 ◽  
pp. 947-950
Author(s):  
Zhen Wang ◽  
Hai Yan Chen ◽  
Lin Qiang Gao ◽  
Xin Zou
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Single Phase ◽  
Hydrothermal Processing ◽  
Optimal Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

BiFeO3 nanoparticles were successfully synthesized by a hydrothermal method by a mineralizer (KNO3). Structural characterization was performed by thermal analysis, powder X-ray diffraction (XRD) and scanning electron microscopy (TEM).The results showed that the products were perovskite structure BiFeO3 powders. Optimal conditions for the synthesis of single-phase BiFeO3 ceramics were obtained.

Effect of Ti Content on Microstructure and Hardness of A356 Alloy

2012 ◽  
Vol 535-537 ◽  
pp. 932-935
Author(s):  
Min Qu ◽  
Liu Bin Zheng ◽  
Ming Zhao ◽  
Ting Ting Li ◽  
Feng Bin Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
A356 Alloy ◽  
Experimental Results ◽  
Grain Refiner ◽  
The Law ◽  
Ti Content ◽  
Scanning Electron

In order to refine the microstructure of A356 alloy, the effect of different contents of Ti on A356 alloy was analyzed with scanning electron microscopy (SEM). Experimental results show that it is not following the law of the more the content of Ti is, the finer the microstructure in the range of 0% to 7.5% Ti. However, the microstructure undergoes a first refining as the content of Ti is less than 0.3% and then coarsening with the increasing of Ti. Further, the mechanism of grain refiner is explained from three aspects. Finally, the hardness of A356 alloy is studied to verify the effect of different contents of Ti. The results confirm that the variety of hardness is in accordance with that of microstructure.

scholarly journals Effect of the molecular weight of polyvinylpyrrolidone on the structure and morphology of materials based on substituted hydroxyapatite for bone implants

2018 ◽  
Vol 226 ◽  
pp. 03012
Author(s):  
Elizaveta A. Mukhanova ◽  
Inna A. Suprunova ◽  
Yana A. Suprunova ◽  
Igor Yu. Zabiyaka
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Scanning Electron Microscopy ◽  
Thermodynamic Stability ◽  
Structural Transformations ◽  
Experimental Results ◽  
Molecular Weights ◽  
Structure And Morphology ◽  
Size And Morphology ◽  
Scanning Electron

In this work, we study the influence of various molecular weights of polyvinylpyrrolidone (PVP) on synthesis substituted hydroxyapatite. Using the scanning electron microscopy we estimated the size and morphology of the particle. We studied the structural transformations of phosphates and the effect of polymer sizes on the structure and morphology. We revealed the thermodynamic stability of the structure of hydroxyapatite due to experimental results.

Influence of Silica Fume/Nanosilica on the Strength and Microstructure of Phosphoaluminate Cement

2011 ◽  
Vol 291-294 ◽  
pp. 1447-1449
Author(s):  
Chen Jing Lv ◽  
Shu Xia Ren ◽  
Xiu Shu Tian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silica Fume ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
Hydration Time ◽  
X Ray ◽  
Hydration Rate ◽  
Splitting Strength ◽  
Scanning Electron

The influence of Silica fume/Nanosilica on the Performance of phosphoaluminate cement was studied in the paper. The microstructure and morphology was determined by X-ray diffraction and scanning electron microscopy. The experimental results show that the phosphoaluminate cement with 4% of added Silica fume/Nanosilica(1:1) by weight of cement has an optimum splitting strength, in which the increase of splitting strength are about 15.1%,11.8% and 24.6% at 3days,7days and 28 days. The reason for causing the above results are the hydration rate and the amount of the hydrates of PALC with 4% Silica fume/Nanosilica have been increased significantly at different hydration time because of the role played by Silica fume and Nanosilica together.

Growth Mechanism and Characterization of Porous CuS Microspheres

2012 ◽  
Vol 568 ◽  
pp. 348-351
Author(s):  
Shuang Xu ◽  
Nuan Song ◽  
Chang Li Qiu ◽  
Yao Ping Zhang ◽  
Jian Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Mechanism ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

In this paper, a facile method was presented to fabricate CuS porous microspheres, which were formed by the intergrowth of CuS polycrystalline nanoslices. The obtained sample has been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electronic diffraction (SAED), and scanning electron microscopy (SEM). On the basis of the experimental results, we proposed a self-assemble mechanism to elucidate the formation of CuS nanoslice structure.

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