Analysis Of The Multiple Enzymes And Optimization Of Naringinase Production Of Solid Fermentation Of Pummelo Peel Using Aspergillus Aculeatus

Solid-state fermentation of agricultural byproducts is an important method to produce industrial enzymes,and also promotes the comprehensive utilization of agricultural and sideline products.Due to the complicated composition of agricultural and sideline products,a variety of enzymes can be produced in the microbial fermentation system.However,Only one or two enzymes have been studied by traditional fermentation methods,while others were neglected due to the vague cognition.In this paper,the solid-state fermentation of a by-product,pomelo peel,is studied under the action of Aspergillusaculeatus.Proteomics technology was used to analyze the extracellular enzymes;specific substrate was used to determine enzyme activity;and naringinase production is applied as the index to optimize the fermentation process.The main contributions of this paper are summarized as follows:?1?LTQ technology was used to examine the extracellular enzymes in fermentation system.A total of 134 groups of proteins were identified,most of which were acid proteins.The enzymes that relate to carbohydrate metabolism mainly included Pectin lyase,Pectin methylesterase,Alpha-mannosidase,Alpha-L-arabinofuranosidase,Bete-fructofuranosidase,glucanase,cellobiohydrolase,Beta-glucosidase,Alpha-L-rhamnosidase,etc.Enzymes that relate to protein metabolism mainly include Aminopeptidase,Serine carboxypeptidase,Aspartyl aminopeptidase,Lysine aminopeptidase,Aspartic protease,Carboxypeptidase and so on.?2?Activity analysis is conducted on Alpha-L-rhamnosidase,naringinase,acid phosphatase,Alpha-L-arabinofuranosidase and Bete-fructofuranosidase by specific substrate.Based on which we found that the highest enzymes activity of Alpha-L-rhamnosidase,naringinase,Alpha-L-arabinofuranosidase Bete-fructofuranosidase and acid phosphatase were 2.53,0.45,0.44,1459.54 and 31.54 IU/gds,respectively.?3?TheformationkineticsofAlpha-L-rhamnosidase,naringinase,Alpha-L-arabinofuranosidase,Bete-fructofuranosidase and acid phosphatase were examined.Results showed that the formation of Alpha-L-rhamnosidase and naringinase fitted the growth related style,the formation of Alpha-L-arabinofuranosidase fitted the growth uncorrelated style,and the formation of Bete-fructofuranosidase and acid phosphatase fitted the growthrelated style.?4?The fermentation process of naringinase was optimized,the optimized fermentation medium was derived by adding 10%?NH₄?₂HPO₃ and 2%soybean cake powder into pomelo peel powder?5 g?and then adding water to make the solid to liquid ratio?w/v?to be 1:1.5.The optimized medium is pretreated by crushing the pomelo peel to 60 mesh and setting the irradiation sterilization to be 9 KGy.Under this condition,After keeping this condition for eight days,the highest enzymes activity of Alpha-L-rhamnosidase and naringinase were 7.28 IU/gds and 4.72 IU/gds,respectively,which are 2.87 and 10.48 times higher than those in initial fermentation condition,respectively.This paper verified the existence of a variety of enzymes in the Aspergillus aculeatus fermented pomelo peel system by LTQ examination and specificity substrates analyse.The main enzyme activity components included pectin enzyme hydrolysis,cellulose hydrolysis enzyme and naringin hydrolytic enzyme.It is also observed that during fermentation process,different enzyme components showed different activity dynamic changes and kinetics synthesis.The production of enzymes could be affected by Nitrogen resource,moisture content,particle size of raw material and irradiation sterilization.These results provide reference for further research on enzyme production through agricultural and sideline products based solid-state fermentation.