For atmospheric pressure plasma jets(APPJ),the gas temperature is essential for their applications.A spectral diagnosis of APPJ’s gas temperature is conducted in this work.The optical emission spectra of helium APPJ ...For atmospheric pressure plasma jets(APPJ),the gas temperature is essential for their applications.A spectral diagnosis of APPJ’s gas temperature is conducted in this work.The optical emission spectra of helium APPJ are captured by using an optical spectrometer system.Then,the grating secondary spectrum of OH(A2∑+(ν=0)→X2П(ν=0))are used to diagnose the gas temperature of plasmas because the spectrum has excellent resolution.Meanwhile,the vibrational temperatures are estimated by using the vibration sequence of N2band(SPS,the second positive system).On the basis of the method,some important conclusions were obtained.First,the spectral identifying indicates that the grating primary spectrum covers a whole wavelength range from 200 nm to 900 nm,and that the grating secondary spectrum overlaps with the primary spectrum from 400 nm to 900 nm.Second,the gas temperature(about 320 K)is close to the room temperature,while the vibrational temperature of the N2(SPS)is about 5 000 K.The trend of the two temperatures changing with the applied voltage is discussed in the end.展开更多
对从高盐稀态酱醪中筛选得到的米曲霉(Aspergillus oryzae)K9进行常压室温等离子体(atmospheric and room temperature plasma,ARTP)复合紫外诱变,并利用高盐含量平板进行驯化培养和筛选,旨在得到产耐盐高活性蛋白酶的菌株。首先对K9进...对从高盐稀态酱醪中筛选得到的米曲霉(Aspergillus oryzae)K9进行常压室温等离子体(atmospheric and room temperature plasma,ARTP)复合紫外诱变,并利用高盐含量平板进行驯化培养和筛选,旨在得到产耐盐高活性蛋白酶的菌株。首先对K9进行ARTP诱变,筛选得到优势菌株S-G27,其中性蛋白酶活性较K9提高35.82%;接着以S-G27为出发菌株进行紫外诱变,筛选得到优势菌株G-U2,其中性蛋白酶活性较K9提高56.81%;G-U2所产蛋白酶的耐盐性进一步提高,在15%NaCl溶液中,G-U2中性蛋白酶活性残留率为K9的1.94倍;G-U2稳定性良好,第7代时菌株的中性蛋白酶活性残留率为92%;和出发菌株K9相比,G-U2的菌丝更短、孢子更多、孢子体积更大且表面纹饰更多;诱变未引起黄曲霉毒素相关基因的表达,符合生产安全要求。在模拟发酵酱油实验中,发酵终点G-U2中性蛋白酶活性、酸性蛋白酶活性、氨基酸态氮质量浓度分别较K9高出120.19%、52.29%、18.37%。展开更多
利用常温常压等离子体诱变(Atmospheric and Room Temperature Plasma, ARTP)蜡状芽孢杆菌,筛选获得酶活提升的菌株。结果表明,蜡状芽孢杆菌在种子液中培养6 h可达到对数期中后期,常温常压等离子体诱变时间为60 s时,蜡状芽孢杆菌的致死...利用常温常压等离子体诱变(Atmospheric and Room Temperature Plasma, ARTP)蜡状芽孢杆菌,筛选获得酶活提升的菌株。结果表明,蜡状芽孢杆菌在种子液中培养6 h可达到对数期中后期,常温常压等离子体诱变时间为60 s时,蜡状芽孢杆菌的致死率达到85%,筛选得到一株壳聚糖酶活性提高13.19%的突变株,然后进行酶活稳定性验证,经六代培养的平均酶活为9.643367 U/mL,波动在5%之内,表明其产酶量高,稳定性强,可用于后续出发菌株。诱变后菌株经电镜观察,发现菌落形态无明显变化,但是菌株的个体形态发生了变化,比原始菌株细长,证明酶活提高是ARTP诱变起到的作用。展开更多
基金Project supported by China National Fund for Distinguished Young Scientists （51125029）, China Foundation for the Author of National Excellent Doctoral Dissertation （200338）, Intersection Subject Program of Xi＇an Jiaotong University （xjj2012132）, Fundamental Research Fund for the Central Universities （xjj2010160）, China National Science Foundation for Young Scientists （51307133）.
文摘For atmospheric pressure plasma jets(APPJ),the gas temperature is essential for their applications.A spectral diagnosis of APPJ’s gas temperature is conducted in this work.The optical emission spectra of helium APPJ are captured by using an optical spectrometer system.Then,the grating secondary spectrum of OH(A2∑+(ν=0)→X2П(ν=0))are used to diagnose the gas temperature of plasmas because the spectrum has excellent resolution.Meanwhile,the vibrational temperatures are estimated by using the vibration sequence of N2band(SPS,the second positive system).On the basis of the method,some important conclusions were obtained.First,the spectral identifying indicates that the grating primary spectrum covers a whole wavelength range from 200 nm to 900 nm,and that the grating secondary spectrum overlaps with the primary spectrum from 400 nm to 900 nm.Second,the gas temperature(about 320 K)is close to the room temperature,while the vibrational temperature of the N2(SPS)is about 5 000 K.The trend of the two temperatures changing with the applied voltage is discussed in the end.
文摘对从高盐稀态酱醪中筛选得到的米曲霉(Aspergillus oryzae)K9进行常压室温等离子体(atmospheric and room temperature plasma,ARTP)复合紫外诱变,并利用高盐含量平板进行驯化培养和筛选,旨在得到产耐盐高活性蛋白酶的菌株。首先对K9进行ARTP诱变,筛选得到优势菌株S-G27,其中性蛋白酶活性较K9提高35.82%;接着以S-G27为出发菌株进行紫外诱变,筛选得到优势菌株G-U2,其中性蛋白酶活性较K9提高56.81%;G-U2所产蛋白酶的耐盐性进一步提高,在15%NaCl溶液中,G-U2中性蛋白酶活性残留率为K9的1.94倍;G-U2稳定性良好,第7代时菌株的中性蛋白酶活性残留率为92%;和出发菌株K9相比,G-U2的菌丝更短、孢子更多、孢子体积更大且表面纹饰更多;诱变未引起黄曲霉毒素相关基因的表达,符合生产安全要求。在模拟发酵酱油实验中,发酵终点G-U2中性蛋白酶活性、酸性蛋白酶活性、氨基酸态氮质量浓度分别较K9高出120.19%、52.29%、18.37%。
文摘利用常温常压等离子体诱变(Atmospheric and Room Temperature Plasma, ARTP)蜡状芽孢杆菌,筛选获得酶活提升的菌株。结果表明,蜡状芽孢杆菌在种子液中培养6 h可达到对数期中后期,常温常压等离子体诱变时间为60 s时,蜡状芽孢杆菌的致死率达到85%,筛选得到一株壳聚糖酶活性提高13.19%的突变株,然后进行酶活稳定性验证,经六代培养的平均酶活为9.643367 U/mL,波动在5%之内,表明其产酶量高,稳定性强,可用于后续出发菌株。诱变后菌株经电镜观察,发现菌落形态无明显变化,但是菌株的个体形态发生了变化,比原始菌株细长,证明酶活提高是ARTP诱变起到的作用。
