Team:Newcastle/Results/Chemotaxis/Microscopy
Alternative Roots
Understanding Bacterial Behaviour Through Microscopy
Principle
The need for microscopy work was highlighted after we were unable to determine the relative chemotactic response of our bacteria towards naringenin. The use of brightfield microscopy allowed us to make observations of if our bacteria was still motile and compare their morphology to that of the literature used in the community model. Microscopy enabled the development of the cell density:optical density index, this index was also utilised in the community model to adapt the growth curve data collected during bacterial characterisation in standard laboratory conditions.
Optical Density to Cell Density Index
Through the use of a ha
Observing Bacterial Size
While producing the optical density:cell density index, it was also possible to use the haemocytometer to observe the phenotypic characteristics of our bacteria. This data would then be collated with the literature that was used to inform the Community Model about bacteria sizes. The use of microscopy also allowed us to assess the motility of our bacteria. By directly observing motility in liquid culture, the reasoning behind our results for quantitative capillary-based approach to characterising chemotaxis.
| Species (Strain) | Length in Literature (µm) | Average Length Under Microscope (µm) | Diameter in Literature (µm) | Average Diameter Under Microscope (µm) |
|---|---|---|---|---|
| Azorhizobium caulinodans (ORS571) | 1.5-2.5 [1] | 1.9 | 0.5-0.6 [1] | 0.5 |
| Azospirillum brasilense (SP245) | 2.1-3.8[2] | 2.0 | 1.0 [2] | 0.7 |
| Herbaspirillum seropedicae (Z67) | 1.5-5 [3] | 2.4 | 0.7 [3] | 0.65 |
Table 1: Qualitative analysis of Azorhizobium caulinodans, Azospirillum brasilense, Herbaspirillum seropedicae colonies grown on solid media.
ibidi, Cells in Focus
INSERT MIC GRAPH HERE
REFERENCES & Attributions
1. Yang X-e, Wu X, Hao H-l, & He Z-l (2008) Mechanisms and Assessment of Water Eutrophication. Journal of Zhejiang University. Science. B 9(3):197-209.
2. Usman MN, MG; Musa, I (2015) Effect of Three Levels of NPK Fertilizer on Growth Parameters and Yield of Maize-Soybean Intercrop. International Journal of Scientific and Research Publications 5(9).
3. Liu W, et al. (2017) Azorhizobium caulinodans Transmembrane Chemoreceptor TlpA1 Involved in Host Colonization and Nodulation on Roots and Stems. Frontiers in Microbiology 8:1327..
4. Pedrosa FO, et al. (2011) Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses. PLoS Genetics 7(5):e1002064.
Attributions:
Primary Author: Connor Trotter
Stylisation: Connor Trotter, Umar Farooq
Troubleshooting: Umar Farooq