Impact of heat treatment on microbiota of black soldier fly larvae reared on soybean curd residues

Abstract

Entomophagy has emerged as an alternative and viable source of high-quality animal-derived proteins and fats for livestock production or as a human food supplement. The use of black soldier fly larvae (BSFL) as a dietary protein source for animals needs to be hygienically safe. The authors analysed the microbial community structure of the BSFL raised on different diets and investigated the effect of various heat treatments on the bacterial composition through 16S rRNA gene amplicon pyrosequencing. The results revealed that the diet of BSFL could alter the bacterial community structure. However, there are substantial differences in the abundance or diversity of individual bacterial populations. The bacterial community was dominated by four common phyla, including Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria. Most of the samples show the presence of some potential foodborne pathogens such as Bacillus, Aeromonas, Campylobacter, Pseudomonas, Proteus, Klebsiella, Helicobacter, and Enterococcus. Furthermore, looking at the microbial community structure of BSFL, the post-harvest heat treatment showed a significant effect on human pathogens when compared to those in the control group without heat treatment. Enterococcus in BSFL raised on soybean curd residues (SCR) diet disappeared after heat treatments in all groups. Moreover, Staphylococcus in BSFL raised on artificial feed (AF) diet disappeared after heat treatment. The heat-treated samples of BSFL reared on SCR, and AF (Group OD22 samples dried in the oven for 22 minutes and at a temperature of 150 °C) had a better influence on the community structure as compared to all heat treatments. This study provides the baseline data on the microbial composition and potential pathogens of BSFL reared on different dietary sources and showed the effect of different heat treatments on the microbial community.

Larval biomass production from the co-digestion of mushroom root waste and soybean curd residues by black soldier fly larvae (Hermetia illucens L.)

“…A colony of black soldier ies known as Hermetia illucens, the Wuhan strain, has been cultivated for the last 14 years at the institution's State Key Laboratory of Agricultural Microbiology of HZAU, Wuhan (Soomro et al 2021;Zhou et al 2013). Before being utilized in the tests, BSFL were given MWR and SCR and y larva from a modi ed arti cial diet for a period of six days (the modi ed arti cial diet consisted of 75 g of bran, 75 g of maize our, and 350 g of water) (Ma et al 2018).…”

“…The capacity to effectively manage waste is essential to the long-term health of the ecosystem (Ji-bin et al 2020; Rehman et al 2022; Singh et al 2022). The conventional method of managing organic waste, which involves activities such as burning agro-industrial waste, may result in the emission of dangerous pollutants into the air (Rehman et al 2022; Saravanan et al 2022;Soomro et al 2021). On the other hand, disposing of it in land lls can be ine cient use of space and can pollute groundwater (Barati et al 2022).…”

Deciphering the functional diversity of the gut microbiota of the black soldier fly (Hermetia illucens): recent advances and future challenges

“…The composition of the microbiota associated with H. illucens residing in its gut has been addressed in numerous recent studies. From 2011 to early 2023, a total of 42 publications have documented the composition of the microbiota of this insect species using high throughput approaches (Tables 1, 2 and 3), with particular interest in the impact of food substrate on the diversity of bacterial communities present in the larval gut using the 16 S rRNA gene [30,[38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56]. Microbial communities associated with H. illucens were first examined by pyrosequencing technology [38,[57][58][59] and then mostly by Illumina sequencing [30, 39-44, 47, 48, 50, 52-56, 60-75].…”