Microencapsulation of Bacillus megaterium NCT-2 and its effect on remediation of secondary salinization soil

Abstract

Aim: To prolong the shelf life of Bacillus megaterium NCT-2 by preparing microcapsules through spray drying, and evaluate their efficiency in secondary salinisation soil remediation.

Methods: The wall material and spray drying conditions were optimised. Morphological characteristics of microcapsule were measured, and soil remediation effects were tested under field conditions.

Results: A relatively higher survival rate of B. megaterium microcapsule was obtained with 1:1 of chitosan/maltodextrin (w/w) when spray drying was performed at 150.0 °C, with the feed flow rates of 800 mL h⁻¹ and 1000 mL h⁻¹, respectively. The span value of 0.93 ± 0.01 was obtained under above conditions. Microcapsule survival rate was 64.09 ± 0.12% after 6 months of storage. Moreover, microcapsule successfully decreased NO₃⁻ and EC value in strongly saline soil by 46.5 ± 1.48% and 45.2 ± 1.51%, respectively.

Conclusion: Bacillus megaterium NCT-2 microcapsules have application potential in the remediation of secondary salinisation soil.

Keywords:

• Bacillus megaterium
• microcapsules
• secondary salinisation
• spray drying
• biological agent

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported by the National Key Research and Development Programme [2016YFD0800803], the National Nature Science Foundations of China [31702003], Young Elite Scientists Sponsorship Programme by CAST [2017QNRC001], Sponsored by “Chenguang Program” supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission [17CG07], Project funded by China Postdoctoral Science Foundation [2019M651505] and Yunnan expert workstation [2017IC071].