Fig. 4

En masse selection strategy to obtain a pool of low-pH-tolerant segregants from the ACY503/CEN.PK113-1A cross. A Schematic view of an en masse collection of a pool of ACY503/CEN.PK113-1A acid-tolerant segregants. For the QTL mapping, initially a highly low-pH-resistant JAY270 segregant was selected (ACY503) and further crossed with a haploid of the opposite phenotype. The hybrid transformed with pMF_002 was sporulated and segregants were further collected using a cell sorter coupled with a flow cytometer in growing challenges of pH resistance. B Image of YPD plates with decreasing values of pH (4, 3, 2.5 and 2.1) where 500.000 ACY503/CEN.PK113-1A segregants were collected in flow cytometry. 79 segregants obtained at pH 2.1 were considered a “high resistance pool” and used for QTL mapping