Journal
JOURNAL OF APPLIED MICROBIOLOGY
Volume 127, Issue 3, Pages 713-723Publisher
OXFORD UNIV PRESS
DOI: 10.1111/jam.14354
Keywords
biopolymers; bioremediation; exopolysaccharide; rhizosphere; stress response
Categories
Funding
- [NCN OPUS7 2014/13/B/ST4/04998]
Ask authors/readers for more resources
Aim Study is focused on the influence of cadmium addition to growth media on production yield, their size and molecular mass of exopolysaccharides (EPS) synthesized by three rhizosphere bacteria strains. Inhibition of bacterial growth by increasing concentrations of Cd2+ was also analysed. Methods and Results The highest impact of Cd2+ was noticed on the growth of Arthrobacter sp. and Rhizobium metallidurans. Chryseobacterium sp. and Arthrobacter sp. produced significantly lower when compared to R. metallidurans amounts of EPS under the influence of Cd2+. In all bacterial strains both size and molecular mass decreased after addition of Cd2+ to growth media. It causes a change in EPS conformation to more planar, which minimizes the volume of liquid in the interglobular space next to the bacterial wall. Results confirmed strong effect of Cd2+ on the structure and synthesis of bacterial EPS what can be a key factor in the interactions between rhizosphere bacteria and host plants in heavy metal polluted soils. Conclusion This work proves that due to the presence of cadmium ions, the size and conformation of EPS produced by selected bacterial strains is changed to minimize their impact on cell. We suggest that shifting in EPS conformation from bigger globular particles to the smaller planar ones could be one of the probable mechanisms of Cd resistance in metallotolerant bacteria, and finally explain increased efficiency of heavy metal phytoextraction by EPS-producing plant growth-promoting micro-organisms. Significance and Impact of the Study One of the most promising remediation technique for Cd-contaminated areas is the phytoremediation in which rhizosphere bacteria play an important role by protecting plants' roots from toxic condition thus enhancing efficiency of intake. EPS secretion by bacteria is one of the most common mechanisms to protect the cell from impact of unpleasant environmental conditions, for example, toxicity of heavy metals like Cd.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available