AUTHOR=Li Xiayu , Zhang Yong , Zhou Linlin , Gao Tian , Zhao Yu , Liu Song , Su Qingqing , Wei Chaoling , Yang Yunqiu , Long Yanhua 

TITLE=Bacillus cereus (EG-Q3) in the Gut of Ectropis grisescens Contributes to Host Response to Starvation Conditions

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.785415

DOI=10.3389/fmicb.2022.785415

ISSN=1664-302X

ABSTRACT=<p>The gut bacteria of insects play an important role in their nutrition, maintenance, and ecological adaption. <italic>Ectropis grisescens</italic> is the most important leaf-feeding pest in tea gardens in China. In order to explore whether <italic>E. grisescens</italic> adaptation under starvation stress is related to its gut bacteria, we used a culture-independent method to compare the composition and diversity of their gut bacteria under starvation treatment. The results revealed no significant changes in core gut bacteria composition and diversity within 24 h of starvation. However, non-core gut bacterial <italic>Bacillus</italic> increased significantly under starvation conditions. <italic>B. cereus</italic> strain EG-Q3 isolated from the gut of <italic>E. grisescens</italic> in carbon source-selected medium showed the ability to degrade fat bodies from <italic>E. grisescens in vitro</italic> and <italic>in vivo</italic>. Moreover, the fat-lowering ratio of <italic>E. grisescens</italic> fed with <italic>B. cereus</italic> strain EG-Q3 (6.76 ± 1.281%) was significantly higher than that of the control group (3.96 ± 0.801%, <italic>t</italic> = 4.15, df = 8, <italic>p</italic> &lt; 0.01) after starvation for 4 h. These findings suggest that non-core gut bacterial <italic>B. cereus</italic> strain EG-Q3 contributes to host adaptation to starvation. Together, this research provides evidence that <italic>E. grisescens</italic> may benefit from non-core gut bacteria under starvation conditions.</p>