Immobilization of beneficial microbe Methylobacterium aminovorans in electrospun nanofibre as potential seed coatings for improving germination and growth of groundnut Arachis hypogaea

• Published in: Plant growth regulation Vol. 97; no. 2; pp. 419 - 427
• Main Authors: Mukiri, Chinna, Raja, K., Senthilkumar, M., Subramanian, K. S., Govindaraju, K., Pradeep, D., Ranjan, Syndhiya
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.06.2022; Springer Nature B.V
• Subjects: Agriculture; Bacteria; Biodegradability; Biodegradation; Biomedical and Life Sciences; Coatings; Drought; Electrospinning; Encapsulation; Entrapment; Enumeration; Germination; Groundnuts; Immobilization; Inoculation; Life Sciences; Methylobacterium; Microorganisms; Nanofibers; Nodules; Original Paper; Plant Anatomy/Development; Plant biomass; Plant growth; Plant Physiology; Plant roots; Plant Sciences; Polyvinyl alcohol; Seedlings; Seeds; Shelf life; Groundnut; Germination and growth; Nanofibre
• ISSN: 0167-6903; 1573-5087
• DOI: 10.1007/s10725-021-00737-1

Seed inoculation with microbial cells is one of the potential invigouration techniques for enhancing the emergence and growth of plants. Herein, we approached a new localized delivery of beneficial microbial cells ( Methylobacterium ) by invigorating seeds with electrospun Polyvinyl alcohol (PVA) nanofibre containing microbial cells. Methylobacterium is a growth promoting bacteria that has recently drawn attention in agriculture, particularly for drought management. PVA was used in this research because of its electrospinnability and biodegradability. Encapsulation study shows effective immobilization of bacteria cells ( Methylorubrum aminovorans ) in PVA nanofibre. SEM and TEM characterization further confirmed the entrapment of microbial cells. The microbial plating enumeration reveals 6.6 × 10 5  CFU g −1 of nanofibre to the initial loading population of 1 × 10 8  CFU. Viability of nanofibre encapsulated bacterial cells under ambient environment found 1.85 × 10 5  CFU g −1 , 2.2 × 10 4  CFU g −1 and 1.2 × 10 4  CFU g −1 on 10, 20 and 30 days after storage, respectively. In vitro bio-efficacy study exhibits that the seeds coated by PVA nanofibres containing M. aminovorans recorded higher germination, root & shoot length, seedling vigor, drymatter production, plant biomass, plant root volume, nodule numbers and fresh weight of nodules. The study concludes that microbial cells could be immobilized in electrospun nanofibre for extended shelf-life of microbial cells and as an effective seed coating for localized delivery.