复合促生菌剂发酵条件优化及其对青稞促生效果评价

为研制复合植物根际促生菌(Plant growth promoting rhizobacteria,PGPR)菌剂,提升菌体生物量,提高菌剂促生能力,本研究以3株分离自高寒草地的优良PGPR菌株组成复合菌系,通过单因素试验及响应面法Box-Be-hnken试验设计,优化复合菌系发酵培养基成分及培养条件,并通过盆栽试验评...

Optimization of Fermentation Conditions of Three Growth Promoting Strains and Evaluation of Effects on Highland Barley

In order to develop a compound plant rhizosphere growth-promoting strains agent,increase the biomass of the strains and improve the growth-promoting ability of the strains.Here,three PGPR strains isolated from alpine grassland formed as a compound strain-agent.Through single factor test and Box-Behnken design,the composition of fermentation medium and cultural conditions of the compound strain-agent was optimized,and pot experiment was conducted to evaluate the growth promotion effects of microbial agents on highland barley before and after optimization.The results showed that the optimal fermentation medium for the compound growth-promoting strains agent was glycerol 13 mL·L^-1,peptone 9 g·L^-1,yeast powder 5 g·L^-1 and calcium carbonate 5 g·L^-1;the culture condition is pH=7.0,liquid volume 30 mL(per 150 mL erlenmeyer flask),inoculation volume 10%,and shaker rotation speed 220 r·min^-1.The number of viable strains in this formulation reached 4.6×10¹³ cfu·mL^-1,which was 148.39 times higher than that of the original formula.Compared with before optimization,the compound growth-promoting agent after optimization increased the plant height,fresh weight,chlorophyll content,total root length,root surface area and root volume of highland barley by 13.05%,22.83%,47.74%,73.21%,93.09%and 161.54%,the growth-promoting effect was significant.The results have laid the foundation for the development of the compound growth-promoting strains agent.