scholarly journals Influence of Non-Thermal Atmospheric Pressure Plasma Jet on Extracellular Activity of α-Amylase in Aspergillus oryzae

2021 ◽  
Vol 11 (2) ◽  
pp. 691
Author(s):  
Mayura Veerana ◽  
Eun Ha Choi ◽  
Gyungsoon Park

In a previous study, we found that plasma can enhance spore germination and α-amylase secretion in A. oryzae, a beneficial fungus used in fermentation. To confirm this, in the current study, we investigated the effects of plasma on development and α-amylase secretion using an enlarged sample size and a different plasma source: a plasma jet. There was a ~10% (p < 0.01) increase in spore germination upon non-thermal atmospheric pressure plasma jet (NTAPPJ) treatment for 5 min and 10 min, as compared with the control (no plasma treatment). The activity of α-amylase detected in potato dextrose broth (PDB) media during incubation was significantly elevated in plasma-treated samples, with a more obvious increase upon 10 min and 15 min treatments and 24–96 h incubation periods. The levels of the oxidation reduction potential (ORP) and NOX (nitrogen oxide species) were higher in the plasma-treated samples than in the control samples, suggesting that these two variables could serve as standard indicators for enhancing α-amylase activity after plasma treatment. Genome sequencing analysis showed approximately 0.0016–0.0017% variations (changes in 596–655 base pairs out of a total of 37,912,014 base pairs) in the genomic DNA sequence of A. oryzae after plasma treatment. Our results suggest that NATPPJ can enhance the spore germination and extracellular activity of α-amylase, probably by increasing the levels of ORP and NOX to an optimum level.

2011 ◽  
Vol 688 ◽  
pp. 186-190 ◽  
Author(s):  
Hao Long Chen ◽  
Zin Ching Liou ◽  
Shian Jang Lin

A convenient method for direct and large-area growth of one-dimensional (1-D) CuO and ZnO nanostructures on a conductive brass substrate has been developed. The ZnO and CuO nanostructures have been simultaneously induced and growth on a brass (70Cu-30Zn alloy) substrate by using an atmospheric-pressure plasma jet (APPJ) with pure oxygen as the reaction gas in an ambient environment. Various one-dimensional (1-D) nanostructures such as nano-particles, nanowires, nanobelts, nanocombs, and nanosheets have been in situ grown on the brass substrates under different plasma treatment times. The plasma power of 150W and scanning speed of sample stage 1 mm/sec with different treating times were used in plasma surface treatment processing. The nano-scaled ZnO and CuO formation and its structure were characterized by means of grazing-incidence X-ray diffraction, Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The results showed that the nano-scaled CuO and ZnO growth process was as follows: nano-particles, nano-crystal clusters then nano-crystal columns with increasing plasma treatment times. The growth of nano-scaled oxide formed in sequence that CuO was first grew on the brass substrate then ZnO. The morphologies of nano-scaled ZnO resembled bulbs and long-legged tetrapods. However, the morphologies of nano-scaled CuO were likely bulbs and flake nanostructures. This approach could prepare CuO and ZnO nanostructures on a brass substrate without size limitations. The possible growth mechanisms and structure of nano-scaled CuO and ZnO are discussed in this paper. The simplicity of the preparation procedure and the potential technological of the product were be interested in this study.


Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 683
Author(s):  
Huiliang Jin ◽  
Caixue Tang ◽  
Haibo Li ◽  
Yuanhang Zhang ◽  
Yaguo Li

The continuous phase plate (CPP) is the vital diffractive optical element involved in laser beam shaping and smoothing in high-power laser systems. The high gradients, small spatial periods, and complex features make it difficult to achieve high accuracy when manufacturing such systems. A high-accuracy and high-efficiency surface topography manufacturing method for CPP is presented in this paper. The atmospheric pressure plasma jet (APPJ) system is presented and the removal characteristics are studied to obtain the optimal processing parameters. An optimized iterative algorithm based on the dwell point matrix and a fast Fourier transform (FFT) is proposed to improve the accuracy and efficiency in the dwell time calculation process. A 120 mm × 120 mm CPP surface topography with a 1326.2 nm peak-to-valley (PV) value is fabricated with four iteration steps after approximately 1.6 h of plasma processing. The residual figure error between the prescribed surface topography and plasma-processed surface topography is 28.08 nm root mean square (RMS). The far-field distribution characteristic of the plasma-fabricated surface is analyzed, for which the energy radius deviation is 11 μm at 90% encircled energy. The experimental results demonstrates the potential of the APPJ approach for the manufacturing of complex surface topographies.


2019 ◽  
Vol 675 ◽  
pp. 34-42 ◽  
Author(s):  
Md. Mokter Hossain ◽  
Quang Hung Trinh ◽  
Duc Ba Nguyen ◽  
M.S.P. Sudhakaran ◽  
Young Sun Mok

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