Vermiculture-based molybdenum oxide nanoparticles synthesis, optimization, characterization and its impact on seed germination and seedling characteristics in green gram (Vigna radiata)

Here, we report the biosynthesis of molybdenum oxide (Mo5O14) nanoparticles (NPs) by co-precipitation methods using various vermiculture-based extracts and their impact on seed germination in Vigna radiata. The synthesis of Mo5O14 NPs was initially characterized by a color change from yellow to white and a surface plasmon resonance (SPR) peak at 360 nm in UV–visible spectroscopic analysis. In addition, X-ray diffraction (XRD) data revealed that the Mo5O14 NPs were crystalline with a tetragonal structure and a size of 35.32–41.86 nm. Furthermore, fourier transform infrared (FTIR) analysis of NPs absorption bands revealed the presence of unique functional groups, such as -OH stretching, CH2 stretching, and primary amide groups, providing strong evidence that the native protein served to a reduce, cap, and stabilize Mo5O14 NPs. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed that the ultrastructural profile of Mo5O14 NPs formed rod particles with an average particle length of 102 nm and width of 33 nm. The energy dispersive X-ray (EDX) pattern analysis confirmed the presence of Mo and O ions. Finally, the effects of Mo5O14 NPs on Vigna radiata seed fresh and dry biomass characteristics, root and shoot length, and seed germination were investigated, and it was found that a significant increase in the seed germination rate of all seven vermiculture-based Mo5O14 NPs was observed at 200 ppm. Consequently, our work provides a step forward in the development of vermiculture-based Mo5O14 NPs as a promising green agrochemical nano-fertilizer

Probiotic potential of exopolysaccharide producing lactic acid bacteria isolated from homemade fermented food products

In the current study, 41 bacterial isolates were obtained from homemade fermented food products (cheese, curd, fermented rice water, yogurt, and buttermilk). Among these bacterial isolates, 4 lactic acid bacteria (LAB) strains such as CH4, Sri3, Kri1, and R3 were screened based on their wide inhibitory potential against test indictors by the well diffusion method. Based on the morphological, biochemical and phylogenic characterization, the four selected probiotic LAB strains were identified viz., Lactococcus hircilactis strain CH4, Lactobacillus delbrueckii strain GRIPUMSK, Lactobacillus johnsonii strain PUMSKGRI, and Lactobacillus leichmannii strain SKGRIPUM. These 4 probiotic LAB strains exhibited 62.5–87.5% antibiotic sensitivity, non-haemolytic, thereby confirming their safe status. All of these strains were found to be extremely acid tolerant after 5 h at pH 2–3. These 4 strains were able to withstand 2% high bile salt concentrations for 5 h with a survival rate of 67.40–73.68%. After 5 h, all four isolates demonstrated good auto-aggregation capacity of greater than 40% and strong hydrophobicity towards xylene of greater than 40%. All the four selected isolates have produced antimicrobial metabolites of exopolysaccharides (196.4 U/mL- 217.9 U/mL), H2O2 (0.49–0.71 g L−1) and β-galactosidase (196.4–217.9 U/mL). These strains exhibited the ability to assimilate cholesterol ranged between 12.15 and 79.72%. Moreover, they were found to be highly potential, with a total score of 95.83%, and are now being used to make probiotic food products. Hence, this work affirms the use of selected four LAB strains as safe and highly effective probiotic candidates