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- Title
破壁方法对红球菌11-3胞内几丁质脱乙酰酶释放的影响.
- Authors
肖 宇; 石文琪; 于宏伟; 马爱进; 桑亚新; 孙纪录
- Abstract
Rhodococcus sp. 11-3 is a high-yielding chitin deacetylase (CDA) strain. The enzyme catalyzes chitin to produce chitosan, which plays an important role in the green production of chitosan. However, the CDA produced by Rhodococcus sp. 11-3 is an intracellular enzyme, which has become a major obstacle to the catalytic reaction. In order to improve the release efficiency of CDA, different physical methods (repeated freezing and thawing, ultrasounding, ball milling, homogenization and liquid nitrogen grinding), chemical methods (surfactants treatment, chloroform treatment) and biological method (lysozyme treatment) were used to disrupt the cell wall of Rhodococcus sp. 11-3. The enzyme activity and release efficiency of CDA were determined, and the changes of cell morphology was observed by scanning electron microscope. The results showed that different methods had very different effects on the cell wall breaking. Among them} liquid nitrogen grinding was the best method. By using it, there were fine holes on the cell surface, the release efficiency of CDA was 45.13%, and the loss rate of total enzyme activity was 2.03%. Homogenization was next only to liquid nitrogen grinding, the release efficiency of CDA was 16.00%, and the loss rate of total enzyme activity was 9.18%. Then, Rhodococcus sp. 11-3 cell was treated with homogenization and liquid nitrogen grinding in succession. The results showed that more and larger pores were produced on the cell surface, the release efficiency of CDA was up to 86.17%, the loss rate of total enzyme activity was 9.11%, and the CDA activity in the supernatant was 480.2 U/mL, which was 1.48 times higher than that of liquid nitrogen grinding. Therefore, the combined treatment of homogenization and liquid nitrogen grinding could effectively disrupt the cell wall of Rhodococcus sp, 11-3 and improve the release efficiency of intracellular CDA. The results would promote the application of Rhodococcus sp. 11-3 CDA in the production of chitosan.
- Subjects
ENDOENZYMES; LIQUID nitrogen; SCANNING electron microscopes; RHODOCOCCUS; CHITIN; THAWING; MECHANICAL alloying
- Publication
Journal of Chinese Institute of Food Science & Technology, 2023, Vol 23, Issue 7, p68
- ISSN
1009-7848
- Publication type
Article
- DOI
10.16429/j.1009-7848.2023.07.008