Study On The Technology Of Ion Beam Implanation And HVEF Compound Mutation Of Xylanase-Producing Strain Aspergillus Niger A3

With the development and broad application of microbiological technology,looking for new techniques and means in order to improve the progertitive velocity ofbacterium has become an important aim of the concerned researchers. Low-energyion implantation has been considered as a new kind of mutation breeding and foreigngene delivery technique. By means of implanting low-energy ions into organisms, thebiological effects and the function mechanisms of the technique are investigated, sowe can apply the technique to breeding and gene engineering. What's more, HVEFhas become more and more important due to its properties of economize energy,practicality and environmental conservation.In our experiments HVEF cooperate with N ions beam were employed. Wechose the Aspergillus niger A3 as the sample. Base on low-energy N ion implantationon microbe technique, we studied N ion beam implantation and HVEF compoundmutagenetic effectes. A series of experiments were done to improve metabolizeableyield and enzyme activity, finally we got high yield strain of ANE152823-3(358).Furthermore we revealed some basic mechanisms.First of all, by reviewing its character of endurance to N ions implantation, we studied the mutagenic effects on the Aspergillus niger A3 and its survival rate. Thenwe ascertained the best parameters: energy is 10keV, dose is 150×2.6×10¹³N⁺/cm². Onthis conditions, the positive mutational rate of Aspergillus niger A3 was 20%.Meanwhile AN153-5(277) was received and its enzymes activity increased 48.9%.Then we discussed the survival rate of Aspergillus niger A3 irradiated by HVEFwith different intensities and time. The results showed that under the dose of4.4kV/cm×2min and 3.6kV/cm×2min, high-voltage electrostatic field could give riseto an obvious activation on germination. Comparied with the control, the survival rateincreased 24%, while in other conditions, the survival rate decreased. Thecontemporary enzyme activities obviously increased. Meanwhile AE2825(248) wasreceived and its enzymes activity increased 33.3%.In this paper, we chiefly discussed the biological effects of HVEF on Aspergillusniger A3 Which was implanted by N ions beam. The electric field of 4.4 kV/cm×2minand 5.6 kV/cm×2min were applied to high yield strains which were treated by Nionsbeam. Effected by Nions and HVEF, the shapes and the growth ages of strains werechanged. In the shaking flask, we obtaind high yield strains. Compaired with controlthe enzymes activity of Aspergillus niger A3 was increased 92.5%. Meanwhile we gotANE152823-3(358). And the technology of fermentation was optimized. At the sametime we studied the basic mechanisms of the technique by mensurating SOD,POD,CAT of high yield strains. As a result three cell protective enzymes of high yieldstrains were increased compaired with control, meantime isozyme-spectra bands ofserum esteras is more and darker than control.The originalities of this paper as follows:Firstly, HVEF and ion beam implantation are applied to mutation breeding ofxylanase-produceing strain Aspergillus niger A3. And in order to increase its metabolizeable yield, the changes of the physiological and biochemical parameters ofAspergillus niger A3 were studed.Secondly, with industral castoff molasses instead of dextrose as additionalcarbon producer of ferment culture medium, high yield strain could produce xylanasewhich has properties of high efficiency, better stability and low cost. And thisaccelerates the application of xylanase and other feeding enzyme in commerce,facilitates enzyme preparation exerting their potential and function.