小叶榕抗菌活性内生菌发酵条件的优化

为了优化小叶榕抗菌活性内生菌的发酵条件，提高其发酵液生物量和抗菌物质的量。笔者采用单因子试验对小叶榕内生细菌QYPT-B01菌株发酵条件优化，确定了QYPT-B01菌株在本试验中的最优发酵条件为：玉米粉3%，豆饼粉4%，K2HPO4·3H2O 0.3%，初始pH 8.0，装液量30%，接种量1%，摇床转速160 r/min，培养温度34℃。在上述条件下培养48 h，发酵液中生物量达到峰值，测得OD值为7.95，与优化前相比较，OD值提高了52.0%（优化前OD值为5.23）。培养72 h，抗菌物质产量达到峰值，此时发酵滤液对铜绿假单胞菌的抑菌圈直径为26.42 mm，与优化前相比较，抑菌圈直径提高了13.5%（优化前抑菌圈直径为23.28 mm）。在优化的发酵条件下，QYPT-B01菌株发酵液的生物量和抗菌物质的量均有明显增多，为后续分离纯化、鉴定其发酵滤液中的抗菌物质，探究其抑菌机制，开发生防菌剂或新型抗生素奠定基础。

Endophytes with Antibacterial Activity Separated from Ficus microcarpa: Optimization of Fermentation Conditions

To optimize the fermentation conditions of endophytes with antibacterial activity separated from Ficus microphylla, and increase the biomass of fermentation broth and the amount of antibacterial substances, the optimal fermentation condition of the QYPT-B01 strain was optimized by single factor test. The results showed that: the optimum fermentation condition of the QYPT-B01 strain in this experiment was as follows: 3% corn flour, 4% bean cake powder, 0.3% K2HPO4 · 3H2O, initial pH value 8.0, loading amount 30% , fermentation inoculation amount 1%, shaking speed 160 r/min, culture temperature 34℃. Under the condition, the biomass reached the maximum value after culturing 48 h, the OD value of fermentation liquid was 7.95, which increased by 52.0% compared with 5.23 before optimization. The amount of antibacterial substances reached the maximum value after culturing 72 h, the bacteriostasis diameter of fermentation filtrate to Pseudomonas aeruginosa was 26.42 mm, which increased by 13.5% compared with 23.28 mm before optimization. Under the optimized fermentation condition, the biomass of the QYPT-B01 strain and the amount of antibacterial substances increase significantly, which lay a foundation for further separation and purification, identification of antibacterial substances in fermentation filtrate, exploration of the antibacterial mechanism, and the development of antimicrobial agents or new antibiotics.