Glutamine
In human blood, glutamine is the most abundant free amino acid.
Glutamic acid
Glutamic acid is produced on the largest scale of any amino acid, with an estimated annual production of about 1.5 million tons in 2006. Chemical synthesis was supplanted by the aerobic fermentation of sugars and ammonia in the 1950s, with the organism "Corynebacterium glutamicum" (also known as "Brevibacterium flavum") being the most widely used for production. Isolation and purification can be achieved by concentration and crystallization; it is also widely available as its hydrochloride salt.