纳米硒合成细菌Lxz-41的鉴定、培养条件优化及其在富硒猕猴桃栽培中的应用

本实验利用16S rDNA测序分析和Biolog GenⅢ细菌鉴定板对一株具有纳米硒合成功能的细菌lxz-41进行鉴定,通过单因素和响应面试验优化了该菌株以亚硒酸钠为原料合成纳米硒的培养基组分和培养条件,并将合成的纳米硒在猕猴桃栽培中进行初步应用实验。结果表明:lxz-41菌株被鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens),且对亚硒酸钠具有较高的耐受性。该菌株合成纳米硒的最佳条件为蔗糖4.5%,尿素0.1%,酵母粉1%,磷酸氢二钾0.3%,磷酸二氢钾0.1%,氯化钠0.5%,亚硒酸钠0.15%,初始pH为7.0,培养温度40.5 ℃,转速160 r/min,在此条件下培养18 h,纳米硒的最高转化率为86.8%±4.7%。将该纳米硒应用在猕猴桃栽培中确实增加了果肉中硒的含量,翠香品种果肉中硒含量达到0.050 mg/kg,华优品种果肉中硒含量达到0.035 mg/kg,且富硒效果要好于亚硒酸钠。本实验为微生物源纳米硒的制备及富硒作物的栽培提供了新的途径和技术依据。

Identification,Culture Conditions Optimization of Nano-selenium Synthetic Bacteria lxz-41 and Its Application in Se-enriched Kiwifruit Cultivation

In this experiment,16S rDNA sequencing analysis and Biolog GenⅢ plate were used to identify a strain of lxz-41 with nano-selenium synthesis function. The medium composition and culture conditions of the synthesis of nanoselenium were optimized by the single factor and Box-Benhnken experiment with the sodium selenite as material,and the nano-selenium was applied in Kiwifruit cultivation. The results showed that the lxz-41 strain was identified as Bacillus amyloliquefaciens and was highly tolerant to sodium selenite. The optimal conditions for the synthesis of nano-selenium by lxz-41were as follows:4.5% sucrose,0.1% urea,1% yeast powder,0.3% dipotassium hydrogen phosphate,0.1% potassium dihydrogen phosphate,0.5% sodium chloride,0.15% sodium selenite,the initial pH was 7.0,the culture temperature was 40.5 ℃ and the rotation speed was 160 r/min.After culturing for 18 h at the condition,the highest conversion rate of nano-selenium was 86.8%±4.7%. The results of application in Kiwifruit showed that the nano-selenium indeed increased the content of selenium in flesh. The selenium content in flesh of Cui-Xiang was 0.050 mg/kg,and Hua-You was 0.035 mg/kg,and the rich selenium effect was better than inorganic selenium. This experiment provided a new way and technical basis for the preparation of nanoselenium from microbial and the cultivation of selenium-enriched crops.