Gut Microbiota of Tenebrio molitor and Their Response to Environmental Change

Abstract

A bacterial community analysis of the gut of Tenebrio molitor larvae was performed using pyrosequencing of the 16S rRNA gene. A predominance of genus Spiroplasma species in phylum Tenericutes was observed in the gut samples, but there was variation found in the community composition between T. molitor individuals. The gut bacteria community structure was not significantly affected by the presence of antibiotics or by the exposure of T. molitor larvae to a highly diverse soil bacteria community. A negative relationship was identified between bacterial diversity and ampicillin concentration; however, no negative relationship was identified with the addition of kanamycin. Ampicillin treatment resulted in a reduction in the bacterial community size, estimated using the 16S rRNA gene copy number. A detailed phylogenetic analysis indicated that the Spiroplasma-associated sequences originating from the T. molitor larvae were distinct from previously identified Spiroplasma type species, implying the presence of novel Spiroplasma species. Some Spiroplasma species are known to be insect pathogens; however, the T. molitor larvae did not experience any harmful effects arising from the presence of Spiroplasma species, indicating that Spiroplasma in the gut of T. molitor larvae do not act as a pathogen to the host. A comparison with the bacterial communities found in other insects (Apis and Solenopsis) showed that the Spiroplasma species found in this study were specific to T. molitor.

Sustainable farming of the mealworm Tenebrio molitor for the production of food and feed

“…Another study found that the three dominant bacterial phyla were Tenericutes (44.2%), Proteobacteria (39.22%) and Firmicutes (13.09%), and the genus Spiroplasma was the most abundant OTU (44.1%) [48]. A third study confirmed the dominance of Tenericutes (36.6%), Proteobacteria (34.1%), and Firmicutes (26.2%), and at the genus level also Spiroplasma (38.7%) [53]. Members of the genus Spiroplasma are small, helical, motile and wall-less bacteria [54].…”

“…The microbiota of the mealworm beetle is vulnerable to antibiotics, which reduce the bacterial diversity as well as the bacterial load, but it is stable against environmental factors [53]. Furthermore, sterile mealworms perform poorly, suggesting that the microbiota is required for the efficient digestion and detoxification of plant secondary products [76].…”

Biodegradation of plastic wastes by confused flour beetle Tribolium confusum Jacquelin du Val larvae

“…Also, some Spiroplasma spp. known as insect pathogen effects on the larvae of T. confusum without causing any harm (Jung et al, 2014). Although it is difficult to know which microbial genera or families are responsible for the degradation of polystyrene because only a few degrading bacteria have been isolated.…”

Production and recovery of poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) from biodiesel liquid waste (BLW)

“…The remarkable findings of of the ability of mealworm in extracting PHAs granules has led to this study. Mealworms are omnivorous insects that can grow on low‐quality feeds such as organic wastes . They can survive on P. mendocina PSU cells that were cultivated in MSM medium containing BLW.…”