Biotechnology Bulletin ›› 2023, Vol. 39 ›› Issue (11): 217-225.doi: 10.13560/j.cnki.biotech.bull.1985.2023-0123

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Preparation of Compound Halotolerant Bioinoculant and Study on Its Growth-promoting Effect

CHE Yong-mei(), LIU Guang-chao, GUO Yan-ping, YE Qing, ZHAO Fang-gui, LIU Xin()   

  1. Key Lab of Plant Biotechnology in Universities of Shandong Province, Life Science College, Qingdao Agricultural University, Qingdao 266109
  • Received:2023-02-15 Online:2023-11-26 Published:2023-12-20
  • Contact: LIU Xin E-mail:yongmeiche@163.com;liuxin6080@126.com

Abstract:

Soil salinization is a major factor seriously limiting crop growth and yield. Using soil beneficial microorganisms for saline field amendment is the reliable and sustainable approach. Two halotolerant bacteria strains, Microbacterium oxydans C8 and Stenotrophomonas maltophilia B4, were isolated from saline field in our previous study. Strain C8 has the ability to dissolve potassium, organic and inorganic phosphorus as well as produce auxin. Strain B4 is capable of solubilizing organic phosphorus and producing auxin. In this paper, the effect of mixed culture of C8 and B4 on their functions was studied. The results showed that the mixed culture of C8 and B4 demonstrated significantly stronger ability of dissolving potassium, phosphorus and produce auxin than a single strain. Orthogonal experiments and response surface test were used to optimize the fermentation medium and condition of C8 and B4 mixture, the results showed that the optimized fermentation medium was as follows: glucose 10 g/L, yeast extract 10 g/L, sodium chloride 4.5 g/L. The optimized fermentation conditions were: pH 7.4, temperature 28.8℃, rotating speed 129 r/min, inoculation amount 2%, the liquid content 20% and culture time 23 h. Using tobacco as material, the growth-promoting effects of compound bioinoculant of C8 and B4 were studied. The results showed that, the compound bioinoculant significantly prompted plant growth under salt stress.

Key words: salt-tolerant and growth-promoting bacteria inoculant, optimization of fermentation, tobacco, growth-promoting effect