This paper was completed under the careful guidance and strong support of teacher XX. Teacher X's rigorous and realistic learning attitude, high professionalism, serious and diligent work style and bold and innovative enterprising spirit have had an important impact on me. Her profound knowledge, broad vision and keen thinking deeply inspired me. At the same time, I also learned a lot about microbial fermentation in my graduation project, and my experimental skills have been greatly improved.
In addition, I would like to thank my senior sister for her guidance in my experiment and thesis writing. She helped me a lot to finish this paper. I would also like to thank XX and XX for their selfless help, which enabled me to finish my thesis smoothly. At the same time, teacher XX in the lab often helps me, and I thank him from the bottom of my heart.
Finally, once again, I would like to express my heartfelt thanks to the teachers and classmates who care about and help me.