Effect of Different Lignocellulosic Diets on Bacterial Microbiota and Hydrolytic Enzyme Activities in the Gut of the Cotton Boll Weevil (Anthonomus grandis)

Abstract

Cotton boll weevils, Anthonomus grandis, are omnivorous coleopteran that can feed on diets with different compositions, including recalcitrant lignocellulosic materials. We characterized the changes in the prokaryotic community structure and the hydrolytic activities of A. grandis larvae fed on different lignocellulosic diets. A. grandis larvae were fed on three different artificial diets: cottonseed meal (CM), Napier grass (NG) and corn stover (CS). Total DNA was extracted from the gut samples for amplification and sequencing of the V3-V4 hypervariable region of the 16S rRNA gene. Proteobacteria and Firmicutes dominated the gut microbiota followed by Actinobacteria, Spirochaetes and a small number of unclassified phyla in CM and NG microbiomes. In the CS feeding group, members of Spirochaetes were the most prevalent, followed by Proteobacteria and Firmicutes. Bray–Curtis distances showed that the samples from the CS community were clearly separated from those samples of the CM and NG diets. Gut extracts from all three diets exhibited endoglucanase, xylanase, β-glucosidase and pectinase activities. These activities were significantly affected by pH and temperature across different diets. We observed that the larvae reared on a CM showed significantly higher activities than larvae reared on NG and CS. We demonstrated that the intestinal bacterial community structure varies depending on diet composition. Diets with more variable and complex compositions, such as CS, showed higher bacterial diversity and richness than the two other diets. In spite of the detected changes in composition and diversity, we identified a core microbiome shared between the three different lignocellulosic diets. These results suggest that feeding with diets of different lignocellulosic composition could be a viable strategy to discover variants of hemicellulose and cellulose breakdown systems.

High Diversity and Functional Complementation of Alimentary Canal Microbiota Ensure Small Brown Planthopper to Adapt Different Biogeographic Environments

“…Besides genetic structure, host diets, latitude and ecological environment are also quite different. The different food sources can lead to a change in diversity in the microbial community of alimentary canal, thus altering their function and metabolic pathways (Engel and Moran, 2013;Hansen and Moran, 2014; Ben Guerrero et al, 2016;Kelly et al, 2017). The annual diet of L. striatellus in Beijing and Baoding (temperate) consists of wheat and gramineous weeds (Bromus japonicus).…”

Evaluation of hydrolytic enzyme activities from digestive fluids of Anthonomus grandis (Coleoptera: Curculionidae)

“…Cotton boll weevil, as other insects, harbors digestive enzymes with capacity to deconstruct and hydrolyze the plant cell wall (Ben Guerrero et al, 2016). At present, the entire transcriptome of the A. grandis midgut has been sequenced and numerous glycosyl hydrolases enzymes have been identified (Firmino et al, 2013; Salvador et al, 2014).…”

“…One of them has been cloned and expressed and its β‐1,4‐endoglucanase activity has been characterized (Ibarra et al, 2019). In addition, the effect of different diets on bacterial gut microbiota and hydrolytic enzyme activities has been characterized in our previous work (Ben Guerrero et al, 2016).…”

The bacterial community associated with adult vine weevil (Otiorhynchus sulcatus) in UK populations growing on strawberry is dominated by Candidatus Nardonella

“…The influence of insect diet on shaping the bacterial microbiota composition was reported in the red palm weevil, Rhynchophorus ferrugineus Olivier, the cotton boll weevil. Anthonomus grandis Boheman, and the pine weevil, Hylobius abietis L. (Montagna et al., ; Ben Guerrero et al., ; Berasategui et al., ). Research by Berasategui et al.…”

“…The influence of insect diet on shaping the bacterial microbiota composition was reported in the red palm weevil, Rhynchophorus ferrugineus Olivier, the cotton boll weevil. Anthonomus grandis Boheman, and the pine weevil, Hylobius abietis L. (Montagna et al, 2015;Ben Guerrero et al, 2016;Berasategui et al, 2017). Research by Berasategui et al (2016) on the bacterial community composition in pine weevil populations across Europe revealed that despite significant variation in bacterial community composition, a core bacterial microbiota seemed to be shared by all pine weevil populations.…”