Engineering Gut Symbionts: A Way to Promote Bee Growth?

Bees play a crucial role as pollinators, contributing significantly to ecosystems. However, the honeybee population faces challenges such as global warming, pesticide use, and pathogenic microorganisms. Promoting bee growth using several approaches is therefore crucial for maintaining their roles. To this end, the bacterial microbiota is well-known for its native role in supporting bee growth in several respects. Maximizing the capabilities of these microorganisms holds the theoretical potential to promote the growth of bees. Recent advancements have made it feasible to achieve this enhancement through the application of genetic engineering. In this review, we present the roles of gut symbionts in promoting bee growth and collectively summarize the engineering approaches that would be needed for future applications. Particularly, as the engineering of bee gut symbionts has not been advanced, the dominant gut symbiotic bacteria Snodgrassella alvi and Gilliamella apicola are the main focus of the paper, along with other dominant species. Moreover, we propose engineering strategies that will allow for the improvement in bee growth with listed gene targets for modification to further encourage the use of engineered gut symbionts to promote bee growth.

Distinct fungal microbiomes of two Thai commercial stingless bee species, Lepidotrigona terminata and Tetragonula pagdeni suggest a possible niche separation in a shared habitat.

Stingless bees, a social corbiculate bee member, play a crucial role in providing pollination services. Despite their importance, the structure of their microbiome, particularly the fungal communities, remains poorly understood. This study presents an initial characterization of the fungal community associated with two Thai commercial stingless bee species, Lepidotrigona terminata (Smith) and Tetragonula pagdeni (Schwarz) from Chiang Mai, Thailand. Utilizing ITS amplicon sequencing, we identified distinct fungal microbiomes in these two species. Notably, fungi from the phyla Ascomycota, Basidiomycota, Mucoromycota, Mortierellomycota, and Rozellomycota were present. The most dominant genera, which varied significantly between species, included Candida and Starmerella. Additionally, several key enzymes associated with energy metabolism, structural strength, and host defense reactions, such as adenosine triphosphatase, alcohol dehydrogenase, ß-glucosidase, chitinase, and peptidylprolyl isomerase, were predicted. Our findings not only augment the limited knowledge of the fungal microbiome in Thai commercial stingless bees but also provide insights for their sustainable management through understanding their microbiome.

Genome-scale metabolic modelling of extremophiles and its applications in astrobiological environments.

Metabolic modelling approaches have become the powerful tools in modern biology. These mathematical models are widely used to predict metabolic phenotypes of the organisms or communities of interest, and to identify metabolic targets in metabolic engineering. Apart from a broad range of industrial applications, the possibility of using metabolic modelling in the contexts of astrobiology are poorly explored. In this mini-review, we consolidated the concepts and related applications of applying metabolic modelling in studying organisms in space-related environments, specifically the extremophilic microbes. We recapitulated the current state of the art in metabolic modelling approaches and their advantages in the astrobiological context. Our review encompassed the applications of metabolic modelling in the theoretical investigation of the origin of life within prebiotic environments, as well as the compilation of existing uses of genome-scale metabolic models of extremophiles. Furthermore, we emphasize the current challenges associated with applying this technique in extreme environments, and conclude this review by discussing the potential implementation of metabolic models to explore theoretically optimal metabolic networks under various space conditions. Through this mini-review, our aim is to highlight the potential of metabolic modelling in advancing the study of astrobiology.

Seasonal Variations in Fungal Communities on the Surfaces of Lan Na Sandstone Sculptures and Their Biodeterioration Capacities.

Environmental factors and climate are the primary factors influencing the microbial colonization and deterioration of cultural heritage in outdoor environments. Hence, it is imperative to investigate seasonal variations in microbial communities and the biodeterioration they cause. This study investigated the surfaces of sandstone sculptures at Wat Umong Suan Phutthatham, Chiang Mai, Thailand, during wet and dry seasons using culture-dependent and culture-independent approaches. The fungi isolated from the sandstone sculptures were assessed for biodeterioration attributes including drought tolerance, acid production, calcium crystal formation, and calcium precipitation. The results show that most of the fungal isolates exhibited significant potential for biodeterioration activities. Furthermore, a culture-independent approach was employed to investigate the fungal communities and assess their diversity, interrelationship, and predicted function. The fungal diversity and the communities varied seasonally. The functional prediction indicated that pathotroph-saprotroph fungi comprised the main fungal guild in the dry season, and pathotroph-saprotroph-symbiotroph fungi comprised the dominant guild in the wet season. Remarkably, a network analysis revealed numerous positive correlations among fungal taxa within each season, suggesting a potential synergy that promotes the biodeterioration of sandstone. These findings offer valuable insights into seasonal variations in fungal communities and their impacts on the biodeterioration of sandstone sculptures. This information can be utilized for monitoring, management, and maintenance strategies aimed at preserving this valuable cultural heritage.

Microbial community profiling and culturing reveal functional groups of bacteria associated with Thai commercial stingless worker bees (Tetragonula pagdeni).

Stingless bees play a crucial role in the environment and agriculture as they are effective pollinators. Furthermore, they can produce various products that can be exploited economically, such as propolis and honey. Despite their economic value, the knowledge of microbial community of stingless bees, and their roles on the bees' health, especially in Thailand, are in its infancy. This study aimed to investigate the composition and the functions of bacterial community associated with Tetragonula pagdeni stingless bees using culture-independent and culture-dependent approaches with emphasis on lactic acid bacteria. The culture-independent results showed that the dominant bacterial phyla were Firmicutes, Proteobacteria and Actinobacteria. The most abundant families were Lactobacillaceae and Halomonadaceae. Functional prediction indicated that the prevalent functions of bacterial communities were chemoheterotrophy and fermentation. In addition, the bacterial community might be able to biosynthesize amino acid and antimicrobial compounds. Further isolation and characterization resulted in isolates that belonged to the dominant taxa of the community and possessed potentially beneficial metabolic activity. This suggested that they are parts of the nutrient acquisition and host defense bacterial functional groups in Thai commercial stingless bees.

Dry-Season Soil and Co-Cultivated Host Plants Enhanced Propagation of Arbuscular Mycorrhizal Fungal Spores from Sand Dune Vegetation in Trap Culture.

The use of arbuscular mycorrhizal fungi (AMF) as biofertilizer in agriculture is a sustainable approach to fertilization. The first step in the production of AMF biofertilizer is inoculation of mycotrophic plants with a composite of soil and native plant roots, containing potentially viable AMF spores from natural habitats, to a trap culture. A single host plant or a consortium of host plants can be used to propagate AMF spores. However, the difference in the comparative efficiency of mono- and co-cultivated host plants used for the production of AMF spores and the maintenance of original AMF community composition has not been well elucidated. Here, we prepared trap culture with nutrient-poor soil from coastal sand dune vegetation collected during the dry season when the AMF spore density and relative abundance of Glomeromycota ITS2 sequences were significantly higher (p = <0.05) than in the wet season. The AMF communities in the soil were mainly composed of Glomus spp. Maize (Zea mays L.) and/or Sorghum (Sorghum bicolor (L.). Moench) were grown in trap cultures in the greenhouse. Our results demonstrated that co-cultivation of the host plants increased the production of AMF spores but, compared to mono-cultivation of host plants, did not better sustain the native AMF community compositions in the coastal sand dune soil. We propose that the co-cultivation of host plants in a trap culture broadens AMF-host plant compatibilities and thus sustains the symbiotic association of the natively diverse AMF. Therefore, the results of this study suggest that further research is needed to confirm whether the co-culturing of more than one host plant is as efficient a strategy as using a monoculture of a single host plant.

Genome Characterisation of an Isoprene-Degrading Alcaligenes sp. Isolated from a Tropical Restored Forest.

Isoprene is a climate-active biogenic volatile organic compound (BVOC), emitted into the atmosphere in abundance, mainly from terrestrial plants. Soil is an important sink for isoprene due to its consumption by microbes. In this study, we report the ability of a soil bacterium to degrade isoprene. Strain 13f was isolated from soil beneath wild Himalayan cherry trees in a tropical restored forest. Based on phylogenomic analysis and an Average Nucleotide Identity score of >95%, it most probably belongs to the species Alcaligenes faecalis. Isoprene degradation by Alcaligenes sp. strain 13f was measured by using gas chromatography. When isoprene was supplied as the sole carbon and energy source at the concentration of 7.2 × 105 ppbv and 7.2 × 106 ppbv, 32.6% and 19.6% of isoprene was consumed after 18 days, respectively. Genome analysis of Alcaligenes sp. strain 13f revealed that the genes that are typically found as part of the isoprene monooxygenase gene cluster in other isoprene-degrading bacteria were absent. This discovery suggests that there may be alternative pathways for isoprene metabolism.

Influence of oil, dispersant, and pressure on microbial communities from the Gulf of Mexico.

The Deepwater Horizon incident in the Gulf of Mexico in 2010 released an unprecedented amount of petroleum hydrocarbons 1500 meters below the sea surface. Few studies have considered the influence of hydrostatic pressure on bacterial community development and activity during such spills. The goal of this study was to investigate the response of indigenous sediment microbial communities to the combination of increased pressure, hydrocarbons and dispersant. Deep-sea sediment samples collected from the northern Gulf of Mexico were incubated at atmospheric pressure (0.1 MPa) and at elevated pressure (10 MPa), with and without the addition of crude oil and dispersant. After incubations at 4 °C for 7 days, Colwellia and Psychrobium were highly abundant in all samples. Pressure differentially impacted members of the Alteromonadales. The influences of pressure on the composition of bacterial communities were most pronounced when dispersant was added to the incubations. Moritella and Thalassotalea were greatly stimulated by the addition of dispersant, suggesting their roles in dispersant biodegradation. However, Moritella was negatively impacted by increasing pressure. The presence of dispersant was shown to decrease the relative abundance of a known hydrocarbon degrader, Cycloclasticus, while increasing pressure increased its relative abundance. This study highlights the significant influence of pressure on the development of microbial communities in the presence of oil and dispersant during oil spills and related response strategies in the deep sea.

Influence of pressure and dispersant on oil biodegradation by a newly isolated Rhodococcus strain from deep-sea sediments of the gulf of Mexico.

A new Rhodococcus strain, capable of degrading crude oil, was isolated from the Gulf of Mexico deep-sea sediment and was investigated for its biodegradation characteristics under atmospheric as well as under deep-sea pressure (1500 m = 15 MPa). Additionally, the effect of dispersant (Corexit EC9500A) addition was studied. Rhodococcus sp. PC20 was shown to degrade 60.5 ±â€¯10.7% of the saturated and aromatic fraction of crude oil at atmospheric pressure and 74.2 ±â€¯9.1% at deep-sea level pressure within 96 h. Degradation rates, especially for monoaromatic hydrocarbons, were significantly higher at elevated pressure compared to atmospheric pressure. This study found a growth inhibiting effect at a dispersant to oil ratio of 1:100 and higher. This effect of the dispersant was enhanced when elevated pressure was applied.