How Do Spores Select Where to Settle?: A Holographic Motility Analysis of Ulva Zoospores on Different Surfaces

1 INTRODUCTION

REFERENCES

2 THEORY OF HOLOGRAPHY

2.1 PROPERTIES OF LIGHT WAVES

2.1.1 Intensity

2.1.2 Interference

2.1.3 Coherence

2.1.4 Diffraction

2.2 HOLOGRAPHY

2.2.1 Principle

2.2.2 In-line holography

2.2.3 Numerical reconstruction

2.2.4 Resolution

REFERENCES

3 STATE OF THE ART

3.1 ALGA ULVA LINZA

3.2 INFLUENCE OF SURFACE PROPERTIES ON SETTLEMENT AND THE ADHESION STRENGTH OF ULVA SPORES

3.2.1 Wettability

3.2.2 Ethylene glycol containing surfaces coatings

3.2.3 Lubricity

3.2.4 Charge

3.2.5 Topography

3.3 MOTILITY OF MICROORGANISMS

3.3.1 Hydrodynamics basics: Life at low Reynolds number

3.3.2 Properties of swimming Microorganisms

3.3.3 Hydrodynamics interaction at solid boundaries

3.4 TRACKING IN 3D

REFERENCES

4 EXPERIMENTAL DETAILS

4.1 SETUP

4.1.1 Holographic Microscope

4.1.2 Wet cell

4.1.3 Subsonic noise isolation

4.1.4 Data acquisition program

4.1.5 Heat isolation

4.2 EXPERIMENTAL PROCEDURE

4.3 TRAJECTORY ANALYSIS

4.3.1 Reconstruction

4.3.2 Position determination

4.4 TRAJECTORY INTERPRETATION

4.5 SURFACE POSITION DETERMINATION

4.6 EXPERIMENTS WITH ULVA ZOOSPORES

4.7 INVESTIGATED SURFACES

REFERENCES

5 RESULTS: MOTILITY AND EXPLORATION BEHAVIOR OF ULVA ZOOSPORES

5.1 MOTILITY OF ULVA ZOOSPORES IN SOLUTION

5.1.1 Bulk motility: Global analysis of traces

5.1.2 Bulk motility: Detailed motion analysis for individual traces

5.1.2.1 Fast spore fraction

5.1.2.2 Slow spore fraction

5.1.3 Summary of the motility in solution

5.1.4 Discussion of the motility in solution

5.2 SURFACE EXPLORATION

5.2.1 Standard settlement study

5.2.2 Expected spore settlement during a holographic tracking experiment

5.2.3 Settlement analysis on the investigated surfaces

5.2.4 General exploration patterns

5.2.4.1 Swimming pattern: Orientation

5.2.4.2 Swimming pattern: Wobbling

5.2.4.3 Swimming pattern: Gyration

5.2.4.4 Swimming pattern: Hit and run

5.2.4.5 Swimming pattern: Spinning

5.2.4.6 Settlement

5.2.4.7 Swimming pattern: Hit and stick

5.3 SUMMARY OF THE RESULTS OF THE SURFACE EXPLORATION

5.3.1 General observations on motility for all investigated surfaces

5.3.2 Summary of results for the exploration behavior on AWG

5.3.3 Summary of results for the exploration behavior on PEG

5.3.4 Summary of results for the exploration behavior on FOTS

REFERENCES

6 DISCUSSION OF THE MOTILITY OF ULVA ZOOSPORES IN VICINITY TO SURFACES

6.1 OCCURRENCE AND TIME EVOLUTION OF THE EXPLORATION BEHAVIOR IN VICINITY TO DIFFERENT SURFACES

6.2 DETERRENT P