Lin Chen, Wei Zhou, Yi Zhou, Tingting Tan, Huamao Du, Lichun Feng
State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, College of Biotechnology, Southwest University, Chongqing400715, China.
Bull Entomol Res. 2020 Jun;110(3):309-320. doi: 10.1017/S0007485319000634. Epub 2019 Sep 27.
Nanosilver is an environment-friendly, harmless alternative of traditional disinfectants which can be potentially applied in the sericulture industry. However, the effects of nanosilver on the intestinal bacterial community of the silkworms (Bombyx mori L.) are unclear. In this study, Illumina MiSeq high-throughput sequencing technology was used to assess the intestinal bacterial community in both male and female silkworms while treated with different concentrations of nanosilver. We found that nanosilver significantly influenced the composition of silkworm intestinal bacterial community on the different taxonomic levels. Most conspicuously, the abundance of Firmicutes was increased by the treatment of 20 mg L-1 nanosilver but decreased by that of 100 mg L-1 nanosilver at the phylum level. The same trend was observed in Bacilli at the class level and in Enterococcus at the genus level. In some extreme cases, application of nanosilver eliminated the bacterium, e.g., Brevibacillus, but increased the population of several other bacteria in the host intestine, such as Blautia, Terrisporobacter, Faecalibacterium, and some bacteria could only be found in nanosilver treatment groups, e.g., Dialister. In addition, although nanosilver generally showed negative effects on the cocooning rate in a dose-dependent manner, we found that 20 mg L-1 nanosilver treatment significantly increased the body weight of silkworms and did not show negative effects on the survival rate. These results indicated that the intestinal bacteria community of silkworm larvae was significantly changed after nanosilver treatment which might consequently influence host growth and development.
纳米银是一种环境友好、无害的传统消毒剂替代品，具有在养蚕业中潜在应用的可能性。然而，纳米银对家蚕（Bombyx mori L.）肠道细菌群落的影响尚不清楚。在本研究中，利用Illumina MiSeq高通量测序技术评估了不同浓度纳米银处理下雄蚕和雌蚕的肠道细菌群落。我们发现，纳米银在不同分类水平上显著影响了家蚕肠道细菌群落的组成。最明显的是，在门水平上，20 mg L-1纳米银处理使厚壁菌门丰度增加，而100 mg L-1纳米银处理使其降低。在纲水平上的芽孢杆菌属和属水平上的肠球菌属也观察到相同趋势。在一些极端情况下，纳米银的应用消除了某些细菌，如短短芽孢杆菌，但增加了宿主肠道中其他几种细菌的数量，如布劳特氏菌属、地芽孢杆菌属、粪杆菌属，还有一些细菌仅在纳米银处理组中被发现，如戴阿利斯特菌属。此外，尽管纳米银通常以剂量依赖的方式对结茧率产生负面影响，但我们发现20 mg L-1纳米银处理显著增加了家蚕体重，且对存活率没有负面影响。这些结果表明，纳米银处理后家蚕幼虫的肠道细菌群落发生了显著变化，这可能会进而影响宿主的生长发育。
