Properties of carbohydrate utilising variants of Chinese hamster cells

Variants of Chinese hamster ovary cells (CHO-K1) have been isolated which can grow on one of the following carbohydrates: lactose, sucrose, ribose or lactate. The ribose+ clones grow at the same rate on glucose as the parental cells whereas the others grow more slowly. With the exception of one ribose+ clone all excrete lactic acid while growing on glucose; none excrete significant amounts of lactic acid while growing on the alternative energy source. Wild-type cells and the variants accumulate radioactively labelled glucose and the corresponding radio-actively labelled alternative energy source to the same extent. The ribose+ variant that does not accumulate lactate while growing on glucose is also exceptional in its inability to utilise mannose.