Department of Biotechnology, Himachal Pradesh University, Summer Hill, Shimla 171005, India.
Bioresour Technol. 2011 Jan;102(2):2083-5. doi: 10.1016/j.biortech.2010.07.118. Epub 2010 Aug 4.
The efficiency of three oxygen-vectors liquid paraffin, silicone oil and n-dodecane in the production of L-asparaginase by Bacillus brevis was evaluated at 4% (v/v) concentration. All of the three oxygen-vectors were found to exhibit a stimulatory effect on L-asparaginase activity. Liquid paraffin at 6% (v/v) resulted in 34% increase in the L-asparaginase activity accompanied by a 48% increase in the production of cell mass at a 10 L scale. This improvement in L-asparaginase activity and cell mass production in the presence of liquid paraffin can be related to the fact that liquid paraffin was capable of maintaining dissolved O2 concentration above 28% through out the course of the fermentation. Maintenance of the dissolved O2 concentration above 28% could be viewed in terms of an adequate oxygen supply to the rapidly dividing cells of the bacterium, which in turn resulted in enhancement in cell mass production and l-asparaginase activity.
在 4%（v/v）浓度下，评估了三种氧载体液体石蜡、硅油和正十二烷在短芽孢杆菌生产 L-天冬酰胺酶中的效率。发现这三种氧载体都对 L-天冬酰胺酶活性表现出刺激作用。液体石蜡在 6%（v/v）时，使 L-天冬酰胺酶活性增加 34%，同时在 10 L 规模下细胞质量增加 48%。在液体石蜡存在下，L-天冬酰胺酶活性和细胞质量生产的这种提高可以归因于液体石蜡能够在发酵过程中使溶解氧浓度保持在 28%以上。可以认为溶解氧浓度保持在 28%以上是为细菌的快速分裂细胞提供了足够的氧气供应，这反过来又导致细胞质量生产和 L-天冬酰胺酶活性的增强。
