Poly(dl-lactide)-degrading enzyme production by immobilized Actinomadura keratinilytica strain T16-1 in a 5-L fermenter under various fermentation processes |
| |
| Institution: | 1. Department of Microbiology, Faculty of Science, Srinakharinwirot University, Watthana, Bangkok 10110, Thailand;2. Department of Microbiology, Faculty of Science, Kasetsart University, Jatujak, Bangkok 10900, Thailand;3. Department of Biological Chemistry, Faculty of Agriculture, Shizuoka University, Shizuoka, Japan;4. Department of Microbiology, Faculty of Science, Srinakharinwirot University, Watthana, Bangkok 10110, Thailand |
| |
| Abstract: | BackgroundPoly(dl-lactic acid), or PDLLA, is a biodegradable polymer that can be hydrolyzed by various types of enzymes. The protease produced by Actinomadura keratinilytica strain T16-1 was previously reported to have PDLLA depolymerase activity. However, few studies have reported on PDLLA-degrading enzyme production by bacteria. Therefore, the aims of this study were to determine a suitable immobilization material for PDLLA-degrading enzyme production and optimize PDLLA-degrading enzyme production by using immobilized A. keratinilytica strain T16-1 under various fermentation process conditions in a stirrer fermenter.ResultsAmong the tested immobilization materials, a scrub pad was the best immobilizer, giving an enzyme activity of 30.03 U/mL in a shake-flask scale. The maximum enzyme activity was obtained at aeration 0.25 vvm, agitation 170 rpm, 45°C, and 48 h of cultivation time. Under these conditions, a PDLLA-degrading enzyme production of 766.33 U/mL with 15.97 U/mL·h productivity was observed using batch fermentation in a 5-L stirrer fermenter. Increased enzyme activity and productivity were observed in repeated-batch (942.67 U/mL and 19.64 U/mL·h) and continuous fermentation (796.43 U/mL and 16.58 U/mL·h) at a dilution rate of 0.013/h. Scaled-up production of the enzyme in a 10-L stirrer bioreactor using the optimized conditions showed a maximum enzyme activity of 578.67 U/mL and a productivity of 12.06 U/mL·h.ConclusionsThis research successfully scaled-up the enzyme production to 5 and 10 L in a stirrer fermenter and is helpful for many applications of poly(lactic acid). |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
