γ-聚谷氨酸高产菌株的筛选及改良酸化植烟土壤效果研究

为挖掘具有缓解植烟土壤酸化能力的微生物菌株，采用盆栽试验和大田试验相结合的方法，应用生物形态学和分子生物学筛选鉴定了γ-聚谷氨酸（γ-PGA）高产菌株并研究其对酸化植烟土壤的改良效果。结果表明：（1）从黄土高原干旱土壤中筛选得到一株谷氨酸非依赖型γ-PGA高产菌株副地衣芽孢杆菌285-3（Bacillus paralicheniformis）；（2）菌株285-3可有效缓解根系分泌物和复合肥料导致的土壤酸化，土壤pH平均提高0.3个单位以上；（3）菌株285-3配施有机肥，可显著降低酸化植烟土壤可交换酸度，对烟草青枯病的防效达到47.05%，同时提高烟叶产质量。综上所述，副地衣芽孢杆菌285-3对酸化植烟土壤有较好的改良效果，与有机肥合用具有控病和提高烟叶产质量的作用。

Screening of Poly-γ-glutamic Acid Producer and its Effect on Improving Acidified Tobacco Planting Soil

In order to explore the microbial strains with the ability to alleviate the acidification of tobacco planting soil, a combination of biomorphology and molecular biology, pot experiment and field experiment were used to screen and identify high-yielding γ-PGA strains and study their improvement effects on acidified tobacco planting soil. The results showed that:(1) Aglutamate-independent γ-PGA producing strain Bacillus paralicheniformis 285-3 was screened from the arid soil of the Loess Plateau. (2) Strain 285-3 effectively alleviated soil acidification caused by root exudates and compound fertilizers, and increased soil pH by more than 0.3 units on average. (3) The combination of strain 285-3 and organic fertilizer significantly reduced the exchangeable acidity of acidified tobacco planting soil, and the control effect of tobacco bacterial wilt reached 47.05%, while improved the yield and quality of tobacco. In conclusion, Bacillus paralicheniformis 285-3 has a good improvement effect on acidified tobacco plating soil, and can control disease and improve yield and quality of tobacco when combined with organic fertilizer.