Biological recovery of PHA from bacterial cells by using insects: A comparison between mealworms (Tenebrio molitor) and black soldier fly larvae (Hermetia illucens)

Résumé fourni par la source

Aims: The aim of this study was to explore the feasibility of using insects, specifically, black soldier fly (BSF) larvae and mealworms, for the direct recovery of polyhydroxyalkanoates (PHA) by feeding them with post-fermentation bacterial biomass, thereby eliminating the need for conventional cell-drying steps in downstream processing. Methodology and results:In this research, BSF larvae were fed on wet bacterial cells, while mealworms were fed on dried bacterial cells.Field emission scanning electron microscope (FESEM) micrographs revealed the presence of PHA granules in the faecal pellets of BSF larvae and mealworms.Gas chromatography (GC) analysis showed a 66 ± 2.6 wt% PHA content in the faecal pellets of BSF larvae, which increased to 90 ± 3.3 wt% post-purification.In comparison, faecal pellets of mealworms contained about 73 ± 1.5 wt% PHA, and up to 99 ± 1.1 wt%, after purification.Wide-angle X-ray diffraction (WAXD) analysis indicated that the recovered PHA granules from the BSF larvae were more amorphous than those from mealworms.The purified PHA from BSF larvae exhibited two melting points (Tm), when annealed, contrary to mealworms which had only one melting point.Additionally, the lipid content of BSF larvae increased up to 26.1 ± 0.0% from a baseline value of 21.9 ± 0.0% upon being fed with bacterial cells.In contrast, the lipid content of mealworms decreased from 17.8 ± 0.4% to 8.3 ± 0.2%.Conclusion, significance and impact of study: This study indicates that BSF larvae can be a suitable candidate for alleviating the costly downstream processes, through the recovery of PHA from post-fermentative bacterial cells without the need to dry the cells.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.