The Cyanobacteria Anabaena
well as algae and green plants, use hydrogen atoms from water to reduce carbon
dioxide to form carbohydrates, and during this process oxygen gas is given
off (an oxygenic process). Cyanobacteria
were the first organisms on earth to carry out oxygenic photosynthesis.
cyanobacterium. Hans Paerl, author. Licensed for use, ASM