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

Abstract

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 bene cial microbial cells (Methylobacterium) by invigorating seeds with electrospun Polyvinyl alcohol (PVA) nano bre contains microbial cells. Methylobacterium is a growth promoting bacteria recently draws 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 nano bre, and SEM and TEM characterization further con rmed the entrapment of microbial cells. The microbial plating enumeration reveals 6.6 x 10 5 CFU g − 1 of nano bre to the initial loading population of 1 × 10 8 CFU. Viability of nano bre 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. In vitro bio-e cacy study exhibits that the seeds coated by PVA nano bres containing M. aminovorans recorded higher germination, root & shoot length, seedling vigour, drymatter production, plant biomass, plant root volume, nodule numbers and fresh weight of nodules. The data of this study concludes that microbial cells could be immobilized in electrospun nano bre for extended shelf-life of microbial cells and as effective seed coating for localized delivery.

Microbial seed coating: An attractive tool for sustainable agriculture

“…saccharata, T. aestivum , and Beta vulgaris ) [ 195 ]. In addition, it has been reported that the use of Methylorubrum aminovorans in the coating process of Arachis hypogaea's seeds caused an increase in germination and growth [ 196 ].…”

Engineered Living Materials For Sustainability

“…320 For example, Mukiri et al encapsulated the beneficial bacteria Methylobacterium aminovorans in electrospun PVA nanofibers for seed coating and demonstrated their efficiency in improving plant germination and growth. 321 The microorganisms inside the fibers remained viable even after 30 days under ambient conditions, indicating their long-lasting usefulness in improving seed quality.…”

“…Moreover, the polymer matrix in the electrospun fibers can act as a protective shell that assists the living systems in resisting environmental stress and cell dehydration, thus enabling the long-term storage of living organisms . For example, Mukiri et al encapsulated the beneficial bacteria Methylobacterium aminovorans in electrospun PVA nanofibers for seed coating and demonstrated their efficiency in improving plant germination and growth . The microorganisms inside the fibers remained viable even after 30 days under ambient conditions, indicating their long-lasting usefulness in improving seed quality.…”

Electrospinning Living Bacteria: A Review of Applications from Agriculture to Health Care

“…Methylorubrum aminovorans was electrospun into poly(vinyl alcohol) nanofibers and onto groundnut (Arachis hypogaea) seeds, as seen in Figure 6. 94 The biocompatibility of poly(vinyl alcohol) is especially important for Arachis hypogaea, commonly known as peanuts, as the fruit is grown under the soil. As a hydrophilic polymer, poly(vinyl alcohol) aids in germination and plant growth by uptaking water and retaining high moisture levels.…”