Facing increasing human population, expansion of large cities and a rising throw-away-society economy, effective waste management has become a major challenge. The recycling and processing of biodegradable material, be it organic waste, wastewater or a renewable resource, is an excellent option for avoiding negative impacts on the environment and climate. Currently, biodegradable wastes can be incinerated in disposed on landfills, anaerobically digested or directly treated at composting plants. However, from a thermodynamic point of view, organic wastes which contain valuable bio-molecules should be used at an energetically higher level: Suppose we were asked to imagine the best possible way to use these sludges. The process should require no energy, no chemicals, not even water. It should be self-contained and not emit a drop of effluent, and aside from some CO2 it should not produce greenhouse gases or offensive odours. The process should operate with the simplicity of a garbage bin, have no moving parts, and require little maintenance. This bioconversion process should be powered by a well established creature. It must have the ability to thrive in the presence of salts, alcohols, ammonia and a variety of food toxins. Upon reaching maturity, this creature should be rigidly regimented by evolution to migrate into a collection vessel for self- harvesting, and the bundle of nutrients it contains should rival the finest fish meal. Is the bioconversion process nothing but a fanciful leap of imagination? Surprisingly the process does, indeed, exist, and it may once become the fastest, cleanest, most efficient, and most economical way to recycle many types of organic agricultural waste. This process is driven by the larvae of the black soldier fly (BSF), Hermetia illucens.
The aims of this project are:
Characterisation and comparison of different organic waste resources
Adaptation of process conditions to BSF life-history
Qualitative and quantitative chemical-physical analysis of the gained larvae and their suitability to serve as animal feed
Identification of the larval digestive tract microbiota
Hygiene screening and monitoring of pathogens.
Involved students
Simon Oberegger (bachelor thesis)
Katharina Stonig (bachelor thesis)
Anna Serra (bachelor thesis)
References
2021
Impact of processed food (canteen and oil wastes) on the development of black soldier fly (Hermetia illucens) larvae and their gut microbiome functions
Thomas Klammsteiner, Andreas Walter, Tajda Bogataj, Carina D. Heussler, Blaž Stres, Florian M. Steiner, Birgit C. Schlick-Steiner, and Heribert Insam
Canteens represent an essential food supply hub for educational institutions, companies, and business parks. Many people in these locations rely on a guaranteed service with consistent quality. It is an ongoing challenge to satisfy the demand for sufficient serving numbers, portion sizes, and menu variations to cover food intolerances and different palates of customers. However, overestimating this demand or fluctuating quality of dishes leads to an inevitable loss of unconsumed food due to leftovers. In this study, the food waste fraction of canteen leftovers was identified as an optimal diet for black soldier fly (Hermetia illucens) larvae based on 50% higher consumption and 15% higher waste reduction indices compared with control chicken feed diet. Although the digestibility of food waste was nearly twice as high, the conversion efficiency of ingested and digested chicken feed remains unparalleled (17.9 ± 0.6 and 37.5 ± 0.9 in CFD and 7.9 ± 0.9 and 9.6 ± 1.0 in FWD, respectively). The oil separator waste fraction, however, inhibited biomass gain by at least 85% and ultimately led to a larval mortality of up to 96%. In addition to monitoring larval development, we characterized physicochemical properties of pre- and post-process food waste substrates. High-throughput amplicon sequencing identified Firmicutes, Proteobacteria, and Bacteroidota as the most abundant phyla, and Morganella sp., Acinetobacter sp., and certain Lactobacillales species were identified as indicator species. By using metagenome imputation, we additionally gained insights into the functional spectrum of gut microbial communities. We anticipate that the results will contribute to the development of decentralized waste-management sites that make use of larvae to process food waste as it has become common practice for biogas plants.
@article{klammsteiner_impact_2021,title={Impact of processed food (canteen and oil wastes) on the development of black soldier fly (<i>Hermetia illucens</i>) larvae and their gut microbiome functions},volume={12},copyright={All rights reserved},issn={1664-302X},url={https://www.frontiersin.org/articles/10.3389/fmicb.2021.619112/full},doi={10.3389/fmicb.2021.619112},language={English},urldate={2021-02-04},journal={Frontiers in Microbiology},author={Klammsteiner, Thomas and Walter, Andreas and Bogataj, Tajda and Heussler, Carina D. and Stres, Blaž and Steiner, Florian M. and Schlick-Steiner, Birgit C. and Insam, Heribert},month=jan,year={2021},publisher={Frontiers},keywords={16S amplicon sequencing, Animal feedstuff, Circular economy, Growth parameters, Metabolism, microbial communities, Oil waste, Waste valorization},pages={619112},dimensions=true,}
2020
The core gut microbiome of black soldier fly (Hermetia illucens) larvae raised on low-bioburden diets
Thomas Klammsteiner, Andreas Walter, Tajda Bogataj, Carina D. Heussler, Blaž Stres, Florian M. Steiner, Birgit C. Schlick-Steiner, Wolfgang Arthofer, and Heribert Insam
An organism’s gut microbiome handles most of the metabolic processes associated with food intake and digestion but can also strongly affect health and behavior. A stable microbial core community in the gut provides general metabolic competences for substrate degradation and is robust against extrinsic disturbances like changing diets or pathogens. Black Soldier Fly larvae (BSFL; Hermetia illucens) are well known for their ability to efficiently degrade a wide spectrum of organic materials. The ingested substrates build up the high fat and protein content in their bodies that make the larvae interesting for the animal feedstuff industry. In this study, we subjected BSFL to three distinct types of diets carrying a low bioburden and assessed the diets’ impact on larval development and on the composition of the bacterial and archaeal gut community. No significant impact on the gut microbiome across treatments pointed us to the presence of a predominant core community backed by a diverse spectrum of low-abundance taxa. Actinomyces spp., Dysgonomonas spp., and Enterococcus spp. as main members of this community provide various functional and metabolic skills that could be crucial for the thriving of BSFL in various environments. This indicates that the type of diet could play a lesser role in guts of BSFL than previously assumed and that instead a stable autochthonous collection of bacteria provides the tools for degrading of a broad range of substrates. Characterizing the interplay between the core gut microbiome and BSFL helps to understand the involved degradation processes and could contribute to further improving large-scale BSFL rearing.
@article{klammsteiner_core_2020,title={The core gut microbiome of black soldier fly (<i>Hermetia illucens</i>) larvae raised on low-bioburden diets},volume={11},copyright={Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC-BY-NC-ND)},issn={1664-302X},url={https://www.frontiersin.org/articles/10.3389/fmicb.2020.00993/full?&utm_source=Email_to_authors_&utm_medium=Email&utm_content=T1_11.5e1_author&utm_campaign=Email_publication&field=&journalName=Frontiers_in_Microbiology&id=499002},doi={10.3389/fmicb.2020.00993},language={English},urldate={2020-05-21},journal={Frontiers in Microbiology},author={Klammsteiner, Thomas and Walter, Andreas and Bogataj, Tajda and Heussler, Carina D. and Stres, Blaž and Steiner, Florian M. and Schlick-Steiner, Birgit C. and Arthofer, Wolfgang and Insam, Heribert},month=may,year={2020},publisher={Frontiers},keywords={16S amplicon sequencing, Animal feedstuff, Circular economy, microbial communities, Waste valorization, AGIV, Actinomyces, Larval metabolism},pages={993},dimensions=true,}
Suitability of black soldier fly frass as soil amendment and implication for organic waste hygienization
Thomas Klammsteiner, Veysel Turan, Marina Fernández-Delgado Juárez, Simon Oberegger, and Heribert Insam
Because of its nutritious properties, the black soldier fly has emerged as one of the most popular species in advancing circular economy through the re-valorization of anthropogenic organic wastes to insect biomass. Black soldier fly frass accumulates as a major by-product in artificial rearing set-ups and harbors great potential to complement or replace commercial fertilizers. We applied frass from larvae raised on different diets in nitrogen-equivalent amounts as soil amendment, comparing it to NH4NO3 fertilizer as a control. While the soil properties did not reveal any difference between mineral fertilizer and frass, principal component analysis showed significant differences that are mainly attributed to nitrate and dissolved nitrogen contents. We did not find significant differences in the growth of perennial ryegrass between the treatments, indicating that frass serves as a rapidly acting fertilizer comparable to NH4NO3. While the abundance of coliform bacteria increased during frass maturation, after application to the soil, they were outcompeted by gram-negatives. We thus conclude that frass may serve as a valuable fertilizer and does not impair the hygienic properties of soils.
@article{klammsteiner_suitability_2020,title={Suitability of black soldier fly frass as soil amendment and implication for organic waste hygienization},volume={10},copyright={http://creativecommons.org/licenses/by/3.0/},url={https://www.mdpi.com/2073-4395/10/10/1578},doi={10.3390/agronomy10101578},language={en},number={10},urldate={2020-10-16},journal={Agronomy},author={Klammsteiner, Thomas and Turan, Veysel and Juárez, Marina Fernández-Delgado and Oberegger, Simon and Insam, Heribert},month=oct,year={2020},publisher={MDPI},keywords={circular economy, organic waste, animal feedstuff, fertilizer, greenhouse, insect larva},pages={1578},dimensions=true,}
2018
Vom Abfall zum Futtermittel: Maden als Proteinquelle
Thomas Klammsteiner, Carina D. Heussler, Andreas Walter, and Heribert Insam
Biobased Future - Mitteilungsblatt über Biomasse für Energie und Industrie in einer nachhaltigen Wirtschaft, Apr 2018
@article{klammsteiner_proteinquelle_2018,title={Vom Abfall zum Futtermittel: Maden als Proteinquelle},volume={9},copyright={All rights reserved},shorttitle={Biobased {Future}},url={https://nachhaltigwirtschaften.at/resources/iea_pdf/reports/biobased-future-april-2018.pdf},language={German},journal={Biobased Future - Mitteilungsblatt über Biomasse für Energie und Industrie in einer nachhaltigen Wirtschaft},author={Klammsteiner, Thomas and Heussler, Carina D. and Walter, Andreas and Insam, Heribert},month=apr,year={2018},publisher={Bundesministerium für Verkehr, Innovation und Technologie},keywords={AGIV},pages={11},dimensions=true}
Vom Abfall zum Futtermittel: Maden als ProteinquelleBiobased Future - Mitteilungsblatt über Biomasse für Energie und Industrie in einer nachhaltigen Wirtschaft, Apr 2018