Honeybees are eusocial insects with close interaction with their surrounding environment. Gut microbiota in honeybees play a significant role in host health, biology, and interaction behavior with the surrounding environment. Apis florea, a wild bee, is the most primitive among all honeybees and is indigenous to the Indian subcontinent. Previous reports on reared honeybee species provide information on the gut microbiome. No such studies are reported on the gut microbiota of the wild honeybee species. This study aimed at studying the gut microbiome of the wild honeybee species, A. florea. The study reports the analysis and the identification of gut bacteria in the wild honeybee species, A. florea, employing culture-based and culture-independent methods. Cultured bacteria were identified and characterized by MALDI-TOF MS and 16S rRNA sequencing. A comprehensive analysis and identification of non-culturable bacteria were performed by 16S rRNA amplicon next-generation sequencing. This approach splits gut bacteria into four bacterial phyla, four families, and 10 genera in major. The dominant taxa identified in A. florea belonged to the family Enterobacteriaceae (79.47%), Lactobacillaceae (12.75%), Oxalobacteraceae (7.45%), and Nocardiaceae (0.13%). The prevailing bacteria belonged to Enterobacter, Lactobacillus, Escherichia-Shigella, Massilia, Klebsiella, Citrobacter, Pantoea, Serratia, Rhodococcus, and Morganella genera, belonging to phyla Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. This study observed the occurrence of a few bacteria that are not previously reported for their occurrence in other species of the Apis genus, making this investigation highly relevant with regard to the bee microbiome.

Curcumin is non-fluorescent in aqueous media; however, in the vicinity of hydrophobic surface it fluoresces. This property is used to assess the use of curcumin as a surface hydrophobic probe. The surface hydrophobicity of proteins was measured by calculating the binding affinity and surface hydrophobicity index value. Surface hydrophobicity of bovine serum albumin, β-lactoglobulin, soy lipoxygenase-1, ovalbumin, and lysozyme is in the following order: bovine serum albumin > β-lactoglobulin > soy lipoxygenase-1 > ovalbumin > lysozyme. The binding affinities of curcumin decreased with the decrease in surface hydrophobicity of proteins. The orders of surface hydrophobicity index value, determined using curcumin, show similar trend with the reported values of standard probes, viz. cis-parinaric acid and 1-anilinonaphthalene-8-sulfonate. The surface hydrophobicity index value of proteins determined using curcumin decreased in the presence of urea, suggesting the possible use of curcumin as a probe to determine the surface hydrophobicity of proteins.

Introduction: Honey bee gut microbiota have an important role in host health, nutrition, host-symbiont interaction, and interaction behavior with the surrounding environment. Recent discoveries of strain-level variation, characteristics of protective and nutritional capabilities, and reports of eco-physiological significance to the microbial community have emphasized the importance of honey bee gut microbiota. Many regions of Asia and Africa are inhabited by the dwarf honey bee, Apis florea. Studying its microflora and potential for pollination is therefore of foremost importance.Methods: In the present investigation, we aimed to explore the gut bacteriobiome composition of two distinct honey bee species, Apis florea and Apis cerana indica using high throughput sequencing. Functional predictions of bee gut bacterial communities using PICRUSt2 was carried out.Results and discussion: The phylum Proteobacteria dominated the bacterial community in both A. cerana indica (50.1%) and A. florea (86.7%), followed by Firmicutes (26.29 and 12.81%), Bacteroidetes (23.19 and 0.04%) and Actinobacteria (0.4 and 0.02%) respectively. The gut bacteria of A. cerana indica was more diverse than that of A. florea. The observed variations in bacterial genomic diversity among these critical pollinator species may have been influenced by the apiary management techniques, ecological adaptation factors or habitat size. These variations can have a significant effect in understanding host-symbiont interactions and functioning of gut microbiota highlighting the importance of metagenomic survey in understanding microbial community ecology and evolution. This is the first comparative study on variation in bacterial diversity between two Asian honey bees.

The facile biogenic synthesis of silver nanoparticles was done using avocado seed aqueous extract and silver salt. Avocado seed aqueous extract was used as an active biomolecule for in situ fabrication of self-assembled silver nanoparticles. This green approach to the mechanism for the formation of uniform sized silver nanoparticles was studied by ultraviolet-visible spectroscopy, field emission scanning electron microscopy and Fourier transform infrared spectroscopy. The effect of incubation time, concentration of silver nitrate, and avocado seed extract concentrations in the synthesis of silver nanoparticle was studied. Spectral splitting in the visible region with the generation of a new plasmon resonance band resulted with concurrent increase in the concentration of phytochemicals and reaction time during the synthesis of particles was observed. This was due to the chemisorption of phytochemicals accompanied by a charge-transfer transition, which may be responsible for the organization and self-assembly of nanoparticles. The phytochemicals present in the extract acted as a reducing agent and simultaneously fabricating the nanoparticles with the phenolics and sugar compounds. The antibrowning and antibacterial activity of silver nanoparticles were tested and could be exploited for their use in food packaging and preservation.