The Gut Bacteria of Gampsocleis gratiosa (Orthoptera: Tettigoniidae) by Culturomics

Abstract

Gampsocleis gratiosa Brunner von Wattenwyl, 1862, is a type of omnivorous chirping insect with a long history of artificial breeding. It has high economic value and is also an excellent orthopteran model organism. In this study, 12 types of culture media combined with 16S rRNA sequencing were employed to isolate 838 bacterial strains from the gut of G. gratiosa. After sequence comparison, a total of 98 species of bacteria were identified, belonging to 3 phyla, 5 classes, 11 orders, 20 families, and 45 genera. Firmicutes and Proteobacteria accounted for the majority (92.86%). At the order level, Enterobacteriaceae, Bacillales, and Lactobacillales predominated (79.59%). At the genus level, Klebsiella (11.22%) and Enterococcus (7.14%) predominated. This study also enumerated the strain morphological, physiological and biochemical properties of 98 species of bacteria, including colony morphology, Gram staining, bacterial motility test, temperature gradient growth, pH gradient growth, citrate utilization test, temperature oxidase test, contact enzyme test, methyl red test, V-P test, indole test, gelatin liquefaction test, nitrate reduction test, hydrogen sulfide test, starch hydrolysis test, cellulose decomposition test, esterase (corn oil) test and antibiotic susceptibility testing. Additionally, 16 antibiotics were utilized to test the bacterial susceptibility of the strains. This study explored the types and community structure of some culturable microorganisms in the intestinal tract of G. gratiosa and recorded their physiological characteristics. These data reflect the physiological functions of the intestinal microorganisms of G. gratiosa and provide support for subsequent research on the interaction mechanism between microorganisms and their hosts.

Keywords: Gampsocleis gratiosa; culturomics; gut bacteria.

Figure 1

Culture results of gradient bacteria suspension in each culture medium. Different groups represent different concentrations of bacterial suspension. (a) 10⁻²; (b) 10⁻⁴; (c) 10⁻⁶; (d) 10⁻⁸. Different letters on the figure indicate different media. L: LB; T: TSA; C: BLA; G: GAO; N: NAM; M: MRS; A: AER; E:EE; H: CAR; Y: YCFA; O: ENT; S: SS.

Figure 2

The classification results of 98 bacterial species. (a) Phylum level; (b) Order level; (c) Genus level.

Figure 3

The distribution of genus-level bacteria in different media. The genus of which abundance is less than 1% in all samples were classified into “Other”.

Figure 4

The number of strain types obtained from each culture medium. The y-axis represents the number of strain types, and the different colors indicate the extent of the distribution of strain in twelve media. (a) Genus level; (b) Species level.

Figure 5

The morphological and physiological and biochemical characteristics of the identified bacteria. The x-axis represents the name of test, whereas the y-axis represents the proportion of all strains.

Figure 6

The specific results of drug susceptibility testing of 98 species of bacteria.