bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2022.12.22.520758

Decrypting the microbiota on the black soldier fly's (Hermetia illucens L., Diptera: Stratiomyidae) egg surface and their origin during development

Heussler, C. D.·Klammsteiner, T.·Stonig, K. T.·Insam, H.·Schlick-Steiner, B. C.·Steiner, F. M.
View original source ↗Export metadata ↓

Abstract

The increasing global population leads to a soaring demand for protein for food and feed, and also challenges in organic waste management are growing. All this leads to environmental stress, causing biodiversity loss and an increase in greenhouse gas emissions. Alternative and sustainable animal protein sources are needed to reduce the negative environmental impact of food production. In the last years, the black soldier fly (BSF) has been proposed to substitute animal protein, since BSF may consume and reduce a variety of waste organic matter. Successful industrial rearing of BSF depends on a flourishing reproduction of adults, which is influenced not only by environmental but also by physiological factors. The BSF female oviposits single eggs into clutches close to decomposing organic matter and conspecific eggs. Studies have shown that microbes play a significant role in the oviposition of BSF eggs. In this study, we focus on the surface microbiota of the egg and its origin. We investigated if the microbiota is inoculated before, during, or actively after oviposition. For this purpose, we analysed the microbiota in the larval haemolymph and the gut of larvae raised on sterilized and non-sterilized feed, the pupal cell pulp, the wash of the egg-laying apparatus and the eggs directly collected after oviposition, the ovarian eggs and the empty female abdomen, the eggs with contact to adult BSF, and sterilized eggs. The bacterial communities were identified through 16S rRNA gene sequencing to assess the stage in BSF development during which the microbial colonization of the egg surface occurs. We demonstrated that bacteria differ among life stages resulting in a shift during BSF development from dominance of Enterobacteriaceae during the larval stage to dominance of Burkholderiaceae spp. in all analysed eggs. A predominant microbiota is present before oviposition and persists through all life stages, however, the overall populations structure successively shifts during development. A better understanding of egg surface microbiota and oviposition attractants could significantly increase egg production and facilitate the mass harvesting of BSF larvae. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=125 SRC="FIGDIR/small/520758v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@1faf08borg.highwire.dtl.DTLVardef@1c66b02org.highwire.dtl.DTLVardef@19b5658org.highwire.dtl.DTLVardef@141b369_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical abstract.C_FLOATNO Illustration of the sampling procedure to assess egg surface microbiome of black soldier fly and its origin: Larval fed with unsterile (GU) and sterile (GS) feed and the larval haemolymph of GS (LH), the pupal cell pulp (CP), and from the female adults after mating, a wash of the egg-laying apparatus (WS) and the afterwards placed eggs of the egg-laying apparatus (EA), eggs collected from the ovary (EO) and the empty female abdomen (FA), eggs collected from a fly cage after forced exposure to adults (EC) and sterilized (ES). C_FIG

Source connections

Explore related subjects

microbiologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Heussler, C. D., Klammsteiner, T., Stonig, K. T., Insam, H., Schlick-Steiner, B. C., Steiner, F. M.. 2022-12-23. Decrypting the microbiota on the black soldier fly's (Hermetia illucens L., Diptera: Stratiomyidae) egg surface and their origin during development. https://doi.org/10.1101/2022.12.22.520758

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

A population-scale landscape of the subgingival microbiome reveals divergent routes to periodontal dysbiosis

Periodontitis is an archetypical mucosal inflammatory disease in which microbiome dysbiosis at the tooth-epithelial interface interacts with host genetic and behavioral risk factors to drive immune-mediated tissue destruction. Although subgingival microbiome compositional shifts are thought to parallel disease severity, microbiome variation at the population-level and its relationship to periodontal clinical phenotypes and disease-modifying factors remain poorly defined. Here, we use unsupervised manifold learning to map the compositional landscape of the subgingival microbiome in 1,355 adults spanning periodontal health to severe periodontitis. We identified eight latent microbiome states organized along a branching continuum from eubiosis to dysbiosis. An intermediate microbial configuration marked ecological destabilization and bifurcation into two distinct periodontitis-associated dysbiotic trajectories, distinguished by links to gingival inflammation and smoking. Although the microbiome trajectories broadly tracked periodontal destruction, a minority of individuals showed discordant microbiome-clinical phenotypes, with some individuals with periodontitis retaining otherwise eubiotic microbiomes enriched for low-abundance pathobionts, while some cases of health or mild disease had highly dysbiotic communities, suggesting distinct host susceptibility. Together, these findings define a population-scale ecological landscape of the subgingival microbiome, reveal divergent trajectories to periodontal dysbiosis, and highlight heterogeneity in the relationship between microbial community structure and clinical disease expression.

microbiology↗
bioRxiv2026

The iron-binding siderophore enterobactin is required for the response of multi-drug resistant Klebsiella pneumoniae to zinc limitation

To persist during infection Klebsiella pneumoniae must overcome nutrient iron and zinc limitation imposed by the host immune system through a process called nutritional immunity. Secreted small molecule siderophores are a major virulence determinant of Klebsiella pneumoniae pathogenesis and are presumed to overcome nutritional immunity by binding iron for bacterial acquisition. In this work, we set out to identify how a multi-drug resistant K. pneumoniae grows in zinc limited environments. Using unbiased transcriptomics, proteomics, and an arrayed transposon screen, we identified that synthesis and uptake of the siderophore enterobactin is required to allow for growth in low zinc conditions. Iron-specific chelators did not replicate this phenotype and addition of supplemental iron through heme in growth media could not complement severe growth defects of enterobactin mutant K. pneumoniae experiencing zinc limitation. Finally, zinc starvation induced enterobactin production independent of the canonical zinc uptake regulator (Zur) transcription factor suggesting an unidentified regulatory mechanism by which Gram-negative pathogens may respond to zinc stress. Together, these studies expand the role of enterobactin beyond iron regulation and highlight a previously unreported link between iron and zinc homeostasis in Klebsiella pneumoniae.

microbiology↗
bioRxiv2026

A microbiota-derived protease links phage susceptibility to host epithelial responses

Bacteriophages are major ecological drivers of gut microbial ecology, yet whether bacterial mechanisms that determine phage susceptibility have consequences for the mammalian host remains poorly understood. Here, we identify dipeptidyl peptidase 11 (Dpp11a), the predominant active serine protease of the prevalent gut commensal Phocaeicola vulgatus, as an unexpected bacterial defence factor. Dpp11a protects against environmental proteases and confers resistance to bacteriophage infection. Metatranscriptomic analyses further reveal increased expression of both dpp11a and P. vulgatus-associated phage transcripts in ulcerative colitis stool samples, indicating that both components of this interaction are transcriptionally active in disease-associated human microbiomes. Using the microfluidic gut-on-a-chip co-culture model HuMiX, we show that the absence of Dpp11 is accompanied by altered epithelial tight-junction remodelling during phage-bacterial infection. Together, our findings reveal that the consequences of bacterial phage defence can extend beyond phage-bacterium interactions to the mammalian epithelium.

microbiology↗