南京林业大学学报（自然科学版）2024，Vol.48Issue(3)：71-80,10.DOI:10.12302/j.issn.1000-2006.202206022
岩土高效溶蚀菌株Bt NL-11发酵条件优化及应用效果分析
Optimization for fermentation conditions and analysis of application effect for high efficiency dissolution strain Bt NL-11 from Bacillus thuringiensis
摘要
Abstract
[Objective]This study aimed to scientifically manage abandoned mine slopes,explore the application and promotion of the soil bacteria permanent greening method in restoration,optimize the fermentation conditions,and analyze the application effect of the isolated and screened high-efficiency solubilizing bacteria.[Method]A variety of solubilizing microorganisms were isolated from the weathered rock wall soil in Nanjing Mufu Mountain,and a prominent solubilizing strain,NL-11,identified as Bacillus thuringiensis by 16S rRNA,was selected to optimize fermentation conditions,and its application effect was observed with the potting test.The three main factors affecting the growth of the strain(liquid volume,temperature,and time),were screened using the univariate and Plackett Burman tests;on this basis,the steepest climbing path was used to approximate the maximum response area;then,the Box-Behnken experimental design was used and the response surface analysis method was used for regression analysis.Finally,model reliability was verified by comparing the predicted values with the measured values.The optimized results were used to prepare the bacterial solution,and then adjusted to low(10 cfu/mL),medium(1 × 105 cfu/mL),and high(1 × 109 cfu/mL)concentrations and mixed into the substrate(T1,T2,and T3 treatments,respectively)for the pot experiments,and the treatment without the bacterial solution was set as a blank control(CK)to study the effects of the different bacterial solution concentrations on mineral weathering and plant and root growth.[Result]The model was accurate and reliable,and the optimal fermentation culture conditions for NL-11 were as follows:a liquid volume of 19.51 mL,an inoculum level of 2％,an initial pH of 7.0,a temperature of 30.30 ℃,and a time of 22.07 h.The number of viable bacteria in the fermentation broth under these optimized conditions reached 1.47 × 1010 cfu/mL,which was 2.03 times higher than that before optimization.The results of the pot tests showed that strain NL-11 could promote mineral weathering,and the effect of the high concentration of the bacterial solution was the most significant.Furthermore,strain NL-11 could promote the dissolution of mineral nutrients,and the effect of the high concentration of the bacterial solution was the most significant.Strain NL-11 could also promote plant and root growth,and the effect of the medium concentration was the most significant.[Conclusion]The optimization test significantly improved the production of fermentation of the live bacteria of strain NL-11 and provided technical support for the application of the strain in the management of slopes.The suitable concentration of the bacterial solution in spraying practice is 1 × 105 cfu/mL by the comprehensive evaluation of the application effect and consideration of the production cost and other factors.关键词
生态修复/苏云金芽孢杆菌/发酵条件优化/Box-Behnken设计Key words
ecological restoration/Bacillus thuringiensis/fermentation process optimization/Box-Behnken design分类
资源环境引用本文复制引用
王凌剑,贾赵辉,张金池,唐兴港,孙昕,孟苗婧,刘鑫..岩土高效溶蚀菌株Bt NL-11发酵条件优化及应用效果分析[J].南京林业大学学报（自然科学版）,2024,48(3):71-80,10.基金项目
江苏省林业科技创新与推广项目(LYKJ[2021]30) （LYKJ[2021]30）
江苏高校优势学科建设工程资助项目(PAPD). （PAPD）
