Gut microbiota associated with two species of domesticated honey bees from Thailand

Bee-Associated Beneficial Microbes-Importance for Bees and for Humans

Bees are one of the best-known and, at the same time, perhaps the most enigmatic insects on our planet, known for their organization and social structure, being essential for the pollination of agricultural crops and several other plants, playing an essential role in food production and the balance of ecosystems, being associated with the production of high-value-added inputs, and a unique universe in relation to bees' microbiota. In this review, we summarize information regarding on different varieties of bees, with emphasis on their specificity related to microbial variations. Noteworthy are fructophilic bacteria, a lesser-known bacterial group, which use fructose fermentation as their main source of energy, with some strains being closely related to bees' health status. The beneficial properties of fructophilic bacteria may be extendable to humans and other animals as probiotics. In addition, their biotechnological potential may ease the development of new-generation antimicrobials with applications in biopreservation. The concept of "One Health" brings together fundamental and applied research with the aim of clarifying that the connections between the different components of ecosystems must be considered part of a mega-structure, with bees being an iconic example in that the healthy functionality of their microbiota is directly and indirectly related to agricultural production, bee health, quality of bee products, and the functional prosperity for humans and other animals. In fact, good health of bees is clearly related to the stable functionality of ecosystems and indirectly relates to humans' wellbeing, a concept of the "One Health".

A phylogenomic and comparative genomic analysis of Commensalibacter, a versatile insect symbiont

BACKGROUND

To understand mechanisms of adaptation and plasticity of pollinators and other insects a better understanding of diversity and function of their key symbionts is required. Commensalibacter is a genus of acetic acid bacterial symbionts in the gut of honey bees and other insect species, yet little information is available on the diversity and function of Commensalibacter bacteria. In the present study, whole-genome sequences of 12 Commensalibacter isolates from bumble bees, butterflies, Asian hornets and rowan berries were determined, and publicly available genome assemblies of 14 Commensalibacter strains were used in a phylogenomic and comparative genomic analysis.

RESULTS

The phylogenomic analysis revealed that the 26 Commensalibacter isolates represented four species, i.e. Commensalibacter intestini and three novel species for which we propose the names Commensalibacter melissae sp. nov., Commensalibacter communis sp. nov. and Commensalibacter papalotli sp. nov. Comparative genomic analysis revealed that the four Commensalibacter species had similar genetic pathways for central metabolism characterized by a complete tricarboxylic acid cycle and pentose phosphate pathway, but their genomes differed in size, G + C content, amino acid metabolism and carbohydrate-utilizing enzymes. The reduced genome size, the large number of species-specific gene clusters, and the small number of gene clusters shared between C. melissae and other Commensalibacter species suggested a unique evolutionary process in C. melissae, the Western honey bee symbiont.

CONCLUSION

The genus Commensalibacter is a widely distributed insect symbiont that consists of multiple species, each contributing in a species specific manner to the physiology of the holobiont host.

Whole Genome Sequence Analysis of a Novel Apilactobacillus Species from Giant Honeybee (Apis dorsata) Gut Reveals Occurrence of Genetic Elements Coding Prebiotic and Probiotic Traits

Apilactobacillus spp. are classified as obligate fructophilic lactic acid bacteria (FLAB) that inhabit fructose-rich niches such as honeybee gut. Lactic acid bacteria are an important component of the gut microbiome and play a crucial role in maintaining gut health. In this study, a new FLAB strain HBW1, capable of producing glucan-type exopolysaccharide, was isolated from giant honeybee (Apis dorsata) gut and subjected to whole genome sequencing (WHS) to determine its health-beneficial traits. The genome size of the isolate was 1.49 Mb with a GC content of 37.2%. For species level identity, 16S rDNA sequence similarity, genome to genome distance calculator (dDDH), and average nucleotide identity (ANI) values were calculated. Phylogenetic analysis showed that the isolate HBW1 belongs to the Apilactobacillus genus. The dDDH and ANI values in comparison with closely clustered Apilactobacillus kunkeei species were 52% and 93.10%, respectively. Based on these values, we concluded that HBW1 is a novel species of Apilactobacillus, and we propose the name Apilactobacillus waqarii HBW1 for it. Further, WHS data mining of HBW1 revealed that it harbors two glucosyltransferase genes for prebiotic glucan-type exopolysaccharide synthesis. Moreover, chaperon (clp) and methionine sulfoxide reductase (msrA, msrB, and msrC) genes as well as nutritional marker genes for folic acid (folD) and riboflavin biosynthesis (rib operon), important for conferring probiotic properties, were also detected. Occurrence of these genetic traits make HBW1 an excellent candidate for application to improve gut function.

Whole Genome Sequence Analysis of a Novel Apilactobacillus Species from Giant Honeybee (Apis dorsata) Gut Reveals Occurrence of Genetic Elements Coding Prebiotic and Probiotic Traits

Apilactobacillus spp. are classified as obligate fructophilic lactic acid bacteria (FLAB) that inhabit fructose-rich niches such as honeybee gut. Lactic acid bacteria are an important component of the gut microbiome and play a crucial role in maintaining gut health. In this study, a new FLAB strain HBW1, capable of producing glucan-type exopolysaccharide, was isolated from giant honeybee (Apis dorsata) gut and subjected to whole genome sequencing (WHS) to determine its health-beneficial traits. The genome size of the isolate was 1.49 Mb with a GC content of 37.2%. For species level identity, 16S rDNA sequence similarity, genome to genome distance calculator (dDDH), and average nucleotide identity (ANI) values were calculated. Phylogenetic analysis showed that the isolate HBW1 belongs to the Apilactobacillus genus. The dDDH and ANI values in comparison with closely clustered Apilactobacillus kunkeei species were 52% and 93.10%, respectively. Based on these values, we concluded that HBW1 is a novel species of Apilactobacillus, and we propose the name Apilactobacillus waqarii HBW1 for it. Further, WHS data mining of HBW1 revealed that it harbors two glucosyltransferase genes for prebiotic glucan-type exopolysaccharide synthesis. Moreover, chaperon (clp) and methionine sulfoxide reductase (msrA, msrB, and msrC) genes as well as nutritional marker genes for folic acid (folD) and riboflavin biosynthesis (rib operon), important for conferring probiotic properties, were also detected. Occurrence of these genetic traits make HBW1 an excellent candidate for application to improve gut function.