Diversity of the gut microbiome in three grasshopper species using 16S rRNA and determination of cellulose digestibility

Abstract

Background Grasshoppers are typical phytophagous pests, and they have large appetites with high utilization of plants fibers, the digestion of which may depend on the microorganisms in their intestines. Grasshoppers have the potential to be utilized in bioreactors, which could improve straw utilization efficiency in the future. In this study, we describe the gut microbiome in three species of grasshoppers, Oedaleus decorus asiaticus, Aiolopus tamulus and Shirakiacris shirakii, by constructing a 16S rDNA gene library and analyzed the digestibility of cellulose and hemicellulose in the grasshoppers by using moss black phenol colorimetry and anthrone colorimetry. Results There were 509,436 bacterial OTUs (Operational Taxonomic Units) detected in the guts of all the grasshoppers sampled. Among them, Proteobacteria and Firmicutes were the most common, Aiolopus tamulus had the highest bacterial diversity, and Shirakiacris shirakii had the highest bacterial species richness. The intestinal microflora structure varied between the different species of grasshopper, with Aiolopus tamulus and Shirakiacris shirakii being the most similar. Meanwhile, the time at which grasshopper specimens were collected also led to changes in the intestinal microflora structure in the same species of grasshoppers. Klebsiella may form the core elements of the microflora in the grasshopper intestinal tract. The digestibility of cellulose/hemicellulose among the three species grasshoppers varied (38.01/24.99%, 43.95/17.21% and 44.12/47.62%). LEfSe analysis and Spearman correlation coefficients showed that the hemicellulosic digestibility of Shirakiacris shirakii was significantly higher than that of the other two species of grasshopper, which may be related to the presence of Pseudomonas, Stenotrophomonas, Glutamicibacter, Corynebacterium, and Brachybacterium in Shirakiacris shirakii intestinal tract. Conclusion The intestinal microbial communities of the three grasshoppers species are similar on phylum level, but the dominant genera of different species grasshoppers are different. The cellulose digestibility of the three species of grasshoppers is relatively high, which may be correlated with the presence of some gut microbiome. Increasing the understanding of the structure and function of the grasshopper intestinal microflora will facilitate further research and the utilization of intestinal microorganisms in the future.

Dietary differences between grasshoppers are associated with life history tradeoffs in an alpine meadow

“…These results also resonate with the life history tradeoff between fecundity and dispersal. Plants with high C/N (mostly monocots) are posited to provide sufficient energy for flight (Bernays & Chapman, 1994; Wang et al, 2020), which facilitates searching and colonizing distant habitats, and the ability to find mates and food.…”

“…For example, laboratory studies of a cricket species (Gryllus firmus) have shown that nutritional requirements and fecundity are related to their flight capability (Clark et al, 2013(Clark et al, , 2015. Specifically, individuals of Gryllus firmus with flight capability prefer a diet with higher C/N, presumably because both structural and nonstructural carbohydrates can be assimilated and hence become an energy source (Beever et al, 1985;Bernays & Chapman, 1994;Wang et al, 2020), and because the consumption of excess N-rich diet relative to physiological demands may impede intake and assimilation of adequate amounts of carbohydrate (Clissold et al, 2006) and hence can be harmful especially for them (Elsayed et al, 2017; K. P. Lee et al, 2008;Milbrath et al, 1998). Nevertheless, the relationship between flight capability and dietary preferences have not been examined in field studies addressing multiple generalist herbivorous insect species.…”

Analysis of Intestinal Microbial Diversity of Four Species of Grasshoppers and Determination of Cellulose Digestibility

“…The following formulas were used to calculate the cellulose digestibility and hemicellulose digestibility of grasshoppers. Refer to Wang for specific methods [ 22 ]. …”

Assessing the pathogenicity of gut bacteria associated with tobacco caterpillar Spodoptera litura (Fab.)

“…These gut microbes serve an immense range of functions including provision of nutrients, digestion, protection from pathogens, detoxification of secondary plant metabolites, communication and reproduction 1 . Contribution of symbiotic microorganisms in decomposition of cellulose components of plant material has been well documented in termites and grasshoppers 2 , 3 . Buchnera aphidicola associated with aphids is known to fulfil the requirement of essential amino acids that are lacking in plant sap 4 , 5 .…”