Objective To explore the effects of glnA gene on the production of curdlan by Agrobacterium. Methods A glnA gene knockout strain ΔglnA was constructed in this paper. The growth and metabolism of ΔglnA strain and the changes in yield, gel properties and infrared structure of the obtained gum were analyzed, and the expression of genes related to the synthesis of curdlan was explored by quantitative real-time polymerase chain reaction. Results The amino nitrogen consumption of the ΔglnA strain during fermentation was consistent with that of CGMCC11546. In terms of sucrose consumption, there was no significant difference before 12 h, but there was a significant difference between the ΔglnA strain and CGMCC11546 after 15 h, and sucrose consumption was significantly reduced compared to CGMCC11546. The ΔglnA strain could produce approximately 4 g/L of natural gum, which was 60% lower than CGMCC11546. Conclusion The glnA gene does not affect bacterial growth or the structure of collagen, but it can reduce the synthesis of collagen. This study provides insights into the role of glnA in curdlan production and lays a molecular biological foundation for further efforts to enhance curdlan yield.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |