Natural & Medical Sciences Research Center, University of Nizwa, 616, Oman; Department of Engineering Technology, College of Technology, University of Houston, Sugar Land, 77479 TX, USA.
Department of Biology, University of North Carolina at Greensboro, NC 27412, USA.
J Hazard Mater. 2022 Feb 5;423(Pt A):127046. doi: 10.1016/j.jhazmat.2021.127046. Epub 2021 Aug 28.
Mangroves (Avicennia marina) growing in intertidal areas are often exposed to diesel spills, adversely damaging the ecosystem. Herein, we showed for the first time that mangrove seedlings' associations with bacteria could reprogram host-growth, physiology, and ability to degrade diesel. We found four bacterial strains [Sphingomonas sp.-LK11, Rhodococcus corynebacterioides-NZ1, Bacillus subtilis-EP1 Bacillus safensis-SH10] exhibiting significant growth during diesel degradation (2% and 5%, v/v) and higher expression of alkane monooxygenase compared to control. This is in synergy with reduced long-chain n-alkanes (C24-C30) during microbe-diesel interactions in the bioreactor. Among individual strains, SH10 exhibited significantly higher potential to improve mangrove seedling's morphology, anatomy and growth during diesel treatment in rhizosphere compared to control. This was also evidenced by reduced activities and gene expression of antioxidant enzymes (catalases, peroxidases, ascorbic peroxidases, superoxide dismutases and polyphenol peroxidases) and lipid peroxidation during microbe-diesel interactions. Interestingly, we noticed significantly higher soil-enzyme activities (phosphatases and glucosidases) and essential metabolites in seedling's rhizosphere after bacteria and diesel treatments. Degradation of longer n-alkane chains in the rhizosphere also revealed a potential pathway that benefits mangroves by bacterial strains during diesel contaminations. Current results support microbes' application to rhizoengineer plant growth, responses, and phytoextraction abilities in environments contaminated with diesel spills. AVAILABILITY OF DATA AND MATERIALS: The datasets generated during the current study are available in the NCBI GenBank ((https://www.ncbi.nlm.nih.gov).
红树林（红树属）生长在潮间带，经常暴露于柴油溢油中，对生态系统造成不利影响。在此，我们首次表明，红树林幼苗与细菌的共生关系可以重新编程宿主的生长、生理和降解柴油的能力。我们发现了 4 种细菌菌株[鞘氨醇单胞菌-LK11、棒状杆菌-Rhodococcus corynebacterioides-NZ1、枯草芽孢杆菌-Bacillus subtilis-EP1 和 Safensis 芽孢杆菌-Bacillus safensis-SH10]，它们在柴油降解（2%和 5%，v/v）过程中表现出显著的生长，并表现出较高的烷烃单加氧酶表达，与对照相比。这与在生物反应器中微生物-柴油相互作用过程中长链正构烷烃（C24-C30）的减少是协同的。在个体菌株中，与对照相比，SH10 显著提高了在柴油处理过程中红树林幼苗根系形态、解剖结构和生长的潜力。这也可以从抗氧化酶（过氧化氢酶、过氧化物酶、抗坏血酸过氧化物酶、超氧化物歧化酶和多酚过氧化物酶）和微生物-柴油相互作用过程中的脂质过氧化作用的活性和基因表达的降低得到证明。有趣的是，我们注意到在细菌和柴油处理后，幼苗根系的土壤酶活性（磷酸酶和葡萄糖苷酶）和必需代谢物显著增加。在根际中较长的正构烷烃链的降解也揭示了一种潜在的途径，即在柴油污染期间，细菌菌株可以使红树林受益。目前的结果支持微生物在受柴油污染的环境中应用于植物生长、响应和植物提取能力的根际工程。数据和材料的可利用性：本研究生成的数据集可在 NCBI GenBank 中获得((https://www.ncbi.nlm.nih.gov)。
