  Pattern formation in microbial colonies of competing strains under purely
space-limited population growth has recently attracted considerable research
interest. We show that the reproduction time statistics of individuals has a
significant impact on the sectoring patterns. Generalizing the standard Eden
growth model, we introduce a simple one-parameter family of reproduction time
distributions indexed by the variation coefficient {\delta} \in [0, 1], which
includes deterministic ({\delta} = 0) and memoryless exponential distribution
({\delta} = 1) as extreme cases. We present convincing numerical evidence and
heuristic arguments that the generalized model is still in the KPZ universality
class, and the changes in patterns are due to changing prefactors in the
scaling relations, which we are able to predict quantitatively. At the example
of Saccharomyces cerevisiae, we show that our approach using the variation
coefficient also works for more realistic reproduction time distributions.
