Can you kindly suggest the best statistical test to compare the yield of a protein from a bacterial culture carried out in different pH? Is one-way ANOVA a suitable method?
No. ph is a factor in your experiment and so must be included. Look at Montgomery Design and Analysis of Experiments to see what design to choose. It's better to do this prior to collecting data. Best wishes, David Booth
A one-way anova _may_ be appropriate. It depends on the nature and properties of the measured variable. You may want to look in to the assumptions and appropriate uses of a one-way anova for more information.
Also, pH is a continuous measurement. In your case, a one-way anova would be treating it as a categorical (nominal, factor) variable. It may be advantageous for you to treat pH as a continuous variable , and use, for example, linear, polynomial, or nonlinear regression.