School of Resources and Environmental Engineering, Anhui University, Hefei 230601, Anhui Province, China; Anhui Province Engineering Laboratory for Mine Ecological Remediation, Hefei, China; Anhui Province Key Laboratory of Wetland Ecological Protection and Restoration, Hefei, China.
School of Resources and Environmental Engineering, Anhui University, Hefei 230601, Anhui Province, China; Anhui Province Engineering Laboratory for Mine Ecological Remediation, Hefei, China; Anhui Province Key Laboratory of Wetland Ecological Protection and Restoration, Hefei, China.
Ecotoxicol Environ Saf. 2023 May;256:114853. doi: 10.1016/j.ecoenv.2023.114853. Epub 2023 Apr 4.
Soil cadmium (Cd) pollution presents a severe pollution burden to flora and fauna due to its non-degradability and transferability. The Cd in the soil is stressing the silkworm (Bombyx mori) out through a soil-mulberry-silkworm system. The gut microbiota of B.mori are reported to shape host health. However, earlier research had not reported the effect of endogenous Cd-polluted mulberry leaves on the gut microbiota of B.mori. In the current research, we compared the phyllosphere bacteria of endogenous Cd-polluted mulberry leaves at different concentrations. The investigation of the gut bacteria of B.mori fed with the mulberry leaves was done to evaluate the impact of endogenous Cd- polluted mulberry leaves on the gut bacteria of the silkworm. The results revealed a dramatic change in the gut bacteria of B.mori whereas, the changes in the phyllosphere bacteria of mulberry leaves in response to an increased Cd concentration were insignificant. It also increased the α-diversity and altered the gut bacterial community structure of B. mori. A significant change in the abundance of dominant phyla of gut bacteria of B.mori was recorded. At the genus level, the abundance of Enterococcus, Brachybacterium and Brevibacterium group related to disease resistance, and the abundance of Sphingomonas, Glutamicibacter and Thermus related to metal detoxification was significantly increased after Cd exposure. Meanwhile, there was a significant decrease in the abundance of the pathogenic bacteria Serratia and Enterobacter. The results demonstrated that endogenous Cd-polluted mulberry leaves caused perturbations in the gut bacterial composition of B.mori, which may driven by Cd content rather than phyllosphere bacteria. A significant variation in the specific bacterial community indicated the adaptation of B. mori gut for its role in heavy metal detoxification and immune function regulation. The results of this study help to understand the bacterial community associated with endogenous Cd-polluted resistance in the gut of B.mori, which proves to be a novel addition in describing its response in activating the detoxification mechanism and promoting its growth and development. This research work will help to explore the other mechanisms and microbiota associated with the adaptations to mitigate the Cd pollution problems.
土壤镉（Cd）污染因其不可降解性和迁移性而对动植物造成严重的污染负担。土壤中的 Cd 通过土壤-桑树-蚕系统对蚕造成压力。据报道，家蚕的肠道微生物群会影响宿主的健康。然而，早期的研究尚未报道内源性 Cd 污染的桑叶对家蚕肠道微生物群的影响。在当前的研究中，我们比较了不同浓度内源性 Cd 污染桑叶的叶际细菌。通过评估内源性 Cd 污染桑叶对家蚕肠道细菌的影响，对家蚕肠道细菌进行了调查。结果表明，家蚕肠道细菌发生了剧烈变化，而随着 Cd 浓度的增加，桑树叶际细菌的变化则不明显。它还增加了家蚕的α多样性并改变了家蚕肠道细菌群落结构。家蚕肠道细菌主要菌群的丰度发生了显著变化。在属水平上，与疾病抵抗力相关的肠杆菌属、短杆菌属和短杆菌属以及与金属解毒相关的节杆菌属、谷氨酸杆菌属和嗜热菌属的丰度显著增加，而 Cd 暴露后与致病性相关的肠杆菌属和肠杆菌属的丰度显著降低。结果表明，内源性 Cd 污染的桑叶引起了家蚕肠道细菌组成的紊乱，这可能是由 Cd 含量而不是叶际细菌驱动的。特定细菌群落的显著变化表明家蚕肠道适应了重金属解毒和免疫功能调节的作用。本研究结果有助于了解与内源性 Cd 污染抗性相关的细菌群落在家蚕肠道中的作用，这为描述其激活解毒机制、促进生长发育的作用提供了新的补充。这项研究工作将有助于探索与适应减轻 Cd 污染问题相关的其他机制和微生物群。
