We introduce a simple model of yeast-like growth of fungi colonies, which
exhibits a continuous roughening transition far from equilibrium from a smooth
(α=0) to rough phase (α=1/2) in 1+1 dimensions. At the
transition some scaling exponents are calculated by mapping the problem onto a
directed percolation process. The model reproduces the roughening transition
observed in some experiments of fungal growthComment: Minor changes, accepted for publication in PRL, LaTeX, 4 pages with 4
figures, uses eps