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PRINT ISSN : 2319-7692
Online ISSN : 2319-7706 Issues : 12 per year Publisher : Excellent Publishers Email : editorijcmas@gmail.com / submit@ijcmas.com Editor-in-chief: Dr.M.Prakash Index Copernicus ICV 2018: 95.39 NAAS RATING 2020: 5.38 |
Immobilization is a wide spread technique in the last three decades. It is a powerful method which can improve properties of enzymes like stability, activity, resistance to inhibition due to the by-products in fermentation and its quick recovery. In the present investigation a halophilic organism Bacillus mycoides producing α-amylase was isolated from saline water. A mixed fermenter system was made for citric acid production using starch. α-amylase of Bacillus mycoides was used for conversion of starch into glucose and further Aspergillus niger was used for conversion of glucose into citric acid. The enzyme activity of free enzyme and free cells was assayed by DNSA method. Effect of gel concentration, cell concentration and enzyme concentration was studied for both immobilized cells and enzyme. The activity of immobilized enzyme was high by 78% as compared to that of immobilized cells at 1.5% of gel concentration. Activity of enzyme and cell was high at 1.5ml of its concentration. The activity of enzyme was high as compared to cell by 75.5%. It was found that the enzyme and cells were stable and gave high activity at 6.0pH and 60oC after immobilization. Then under all optimum conditions immobilized beads of Bacillus mycoides cells and α-amylase beads were paced in 20% starch solution and beads of Aspergillus niger were added into it for citric acid production. The productivity for starch hydrolysis and citric acid was then checked in different bioreactors and was found maximum in Air lift- fermenter which was 73% and 80% high as compared with shake flask and column reactor.