National Forage Breeding Innovation Base (JAAS), Nanjing, 210014, PR China; Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, PR China; Botany and Microbiology Department, Faculty of Science, Suez University, Suez, Egypt.
National Forage Breeding Innovation Base (JAAS), Nanjing, 210014, PR China; Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, PR China; Key Laboratory for Crop and Animal Integrated Farming of Ministry of Agriculture and Rural Affairs, Nanjing, 210014, PR China.
Microbiol Res. 2021 Jan;242:126594. doi: 10.1016/j.micres.2020.126594. Epub 2020 Sep 18.
Environmental pollution with heavy metals becomes an issue of serious concern worldwide. Cadmium is considered one which adversely affects living organisms. Recently, the usage of endophytic bacteria to enhance the plant growth and phytoremediation of heavy metals contaminated sites is gaining great attention. The current study focused on utilizing the spores of Bacillus megaterium BM18-2 as biofertilizer for enhancing the growth of Cd hyperaccumulator Hybrid Pennisetum and Cd tolerance of the plant. Therefore, the production of the highest proportion of BM18-2 spores in short incubation time was investigated using different culture media. The results revealed that the maximum proportion of BM18-2 spores (90%) was obtained following incubation for 48 h in Tryptone- yeast extract media (TY). Furthermore, several growth parameters of H. Pennisetum were shown to be significantly improved by inclusion of BM18-2 spores into Cd contaminated soil in contrast to non- inoculated plant. The chlorophyll concentration of the leaves rose by 5%, 13%, and 22.89% with increasing Cd concentration of soil (20, 40 and 60 mg/Kg, respectively). The percentage of total nitrogen content of the root, stem and leaf was increased due to the bacterial spores inoculation and the highest percentage was recorded in the leaf in all treatments. Moreover, Cd phytoremediation capacity of H. Pennisetum greatly enhanced with the application of BM18-2 spores into the soil. An obvious correlation was also observed between Cd accumulation and bacterial colonization where the Cd accumulation enhanced by 21.9%, 16.5%, and 94.6% and the maximum count of BM18-2 (27 × 10, 194 × 10,and 145 × 10 CFU/g) were recorded in the root system in 20, 40, and 60 mg/Kg Cd spiked soil, respectively. Consequently, the spores of BM18-2 was proven to succeed as biofertilizer to improve growth of H. pennisetum during Cd stress which subsequently improved the phytoremediation of Cd contaminated soil.
重金属环境污染成为全球关注的严重问题。镉被认为是一种对生物有不利影响的物质。最近，利用内生细菌来增强植物生长和修复重金属污染场地的植物修复技术受到了广泛关注。本研究主要利用巨大芽孢杆菌 BM18-2 的孢子作为生物肥料，以提高 Cd 超积累植物杂交狼尾草的生长和植物对 Cd 的耐受性。因此，研究了不同培养基中短时间孵育时 BM18-2 孢子产量的最高比例。结果表明，在 Tryptone-酵母提取物培养基（TY）中孵育 48 小时，BM18-2 孢子的比例最高（90%）。此外，与未接种植物相比，将 BM18-2 孢子添加到 Cd 污染土壤中，显著改善了 H. Pennisetum 的多个生长参数。随着土壤中 Cd 浓度（分别为 20、40 和 60 mg/Kg）的增加，叶片中的叶绿素浓度分别提高了 5%、13%和 22.89%。根、茎和叶的总氮含量百分比由于细菌孢子的接种而增加，并且在所有处理中，叶片中的最高百分比。此外，H. Pennisetum 的 Cd 植物修复能力随着 BM18-2 孢子在土壤中的应用而大大增强。在 Cd 积累与细菌定殖之间也观察到了明显的相关性，其中 Cd 积累量增加了 21.9%、16.5%和 94.6%，在 20、40 和 60 mg/Kg Cd 污染土壤中，BM18-2 的最大计数（27×10、194×10 和 145×10 CFU/g）记录在根系中。因此，BM18-2 的孢子被证明是成功的生物肥料，可以在 Cd 胁迫下提高杂交狼尾草的生长，从而提高 Cd 污染土壤的植物修复能力。
