Betaine, also known as glycine trimethyl inner-salt, is a non-toxic, harmless natural compound quaternary amine alkaloid. Its molecular formula is C5H12NO2, its molecular weight is 118, and its melting point is 293℃. It tastes sweet and is a substance similar to vitamins.

Betaine widely exists in animals, plants and microorganisms in nature. Betaine is released into the natural environment during metabolism or after death and used as a substrate for microbial growth. Betaine degradation is common in both anaerobic and aerobic microorganisms. The content of betaine in beet is high. At present, there are mainly water extraction, alcohol extraction and chemical synthesis.

Laboratory results show that betaine can be completely degraded in sandy clay within 2 weeks under the action of soil microorganisms. The biological oxygen demand of industrial grade anhydrous betaine (content above 97%) is 1000mgO2/g betaine. The chemical oxygen demand (COD) was slightly higher, which was 1300mg O/g betaine. Using potassium dichromate (K2Cr2O7) as oxidant, the chemical oxygen consumption (CODCr) measured was 70-100mg O/g betaine.