Hello smurf. I'm sorry you didn't get the results you were expecting, but by no means does that mean your experiment was a failure. If we knew the outcome before conducting the experiment, why do the experiment in the first place?
You ABSOLUTELY have data! Without data, you wouldn't be able to say that curry spices don't kill bacteria. For scientists looking for innovative ways to defeat bacteria, this can be a crucial piece of information so that they don't waste their time and money to determine what you already did. I'm sure those scientists would consider your experiment a huge success! In my experience, I typically learn more from tests where the conclusions didn't match the hypothesis.
I think your question is a great title: do curry spices kill bacteria? It is simple, to the point, and leaves no question as to what your experiment was about. A catchy title will not win you science fairs if you did not use sound scientific principles and present your conclusions in a manner understandable, useful, and interesting to others.
It will be critical for you to include on your board:
1. Discuss that conclusion contradicts your hypothesis...don't hide from it, and keep wording in a positive light!
2. Can you definitively say that your experimental procedures are not the cause of the contradictory results? In other words, is there something in your experimental procedures that you could change that could have changed the outcome of the test? How many samples did you do for each spice? The more samples the better to have greater confidence that your results are correct. If you didn't do at least 3 samples for each spice and if you have time, I suggest you collect more samples. Include sample size in your board.
3. How did you determine the spices didn't kill bacteria? Did you do some sort of a culture count? You can make graphs of before / after bacteria count for each spice (perhaps average culture count across all samples for each spice) to show there is no difference. Did you take pictures of the bacteria cultures? Pictures are great additions to presentation boards.
4. As I suggested above about scientists using this data to advance their own study of what is effective in killing bacteria, your results could be a stepping stone to further research. Include some ideas of how you think your results will be useful to others.
Be sure to read through the links under "Communicating Your Results" here. They offer great advice on what to include in your board, including when your results don't match your hypothesis.
https://www.sciencebuddies.org/science- ... ndex.shtml
If you provide more details of the data collected, we can talk more as to what data to present and how, if you like. In the meantime, I hope the information above helps. I want to emphasize this again...an experiment with results that does not support the hypothesis is not a failed experiment! Keep smiling and be proud of your test.
Good luck!