All living organisms retain the enzymatic machinery to partially oxidize glucose without the help of oxygen...What do you mean by this line???
The given line refers to the process of glycolysis.
It tells us how all living organisms use the certain enzymes to oxidise glucose without oxygen.
Glycolysis is the process which occurs in cytoplasm of all living organisms. In glycolysis one molecule of sugar is broken down into two molecule of pyruvate producing net two molecules of ATP, two molecules of NADPH and two molecules of water. In anaerobic organisms glycolysis is known as fermentation.