کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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684637 | 889024 | 2009 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Isomaltulose production from sucrose by Protaminobacter rubrum immobilized in calcium alginate Isomaltulose production from sucrose by Protaminobacter rubrum immobilized in calcium alginate](/preview/png/684637.png)
Different culture conditions for Protaminobacter rubrum and enzymatic reaction parameters were evaluated with the goal of improving isomaltulose production. P. rubrum was grown in a medium with 1% (w/v) cane molasses and 0.5% yeast extract and achieved a maximum cell yield Yx/s of 0.295 g of cells/g sucrose and a specific growth rate (μ) of 0.192 h−1. The immobilization of P. rubrum cells was carried out with calcium alginate, glutaraldehyde and polyethyleneimine. Stabile immobilized cell pellets were obtained and used 24 times in batch processes. Enzymatic conversion was carried out at different sucrose concentrations and in pH 6 medium with 70% (w/v) sucrose at 30 °C an isomaltulose yield of 89–94% (w/v) was obtained. The specific activity of the P. rubrum immobilized pellets in calcium alginate at 30 °C ranged from 1.6 to 4.0 g isomaltulose g−1 pellet h−1, respectively with 70% and 65% sucrose solution, while in lower sucrose concentration had higher specific activities presumably due to substrate inhibition of the isomaltulose synthase in higher sucrose concentrations.
Journal: Bioresource Technology - Volume 100, Issue 18, September 2009, Pages 4252–4256