370 UNITY AND DIVERSITY IN BIOCHEMISTRY 



The aldehyde may be dehydrogenated to an acid having one carbon 

 atom less than the starting amino acid, or the aldehyde may be reduced to 

 an alcohol 



R— CHO + 2H ^ R— CH2OH 



However most of the ketonic acids are oxidized by micro-organisms and 

 CO2 is formed. Soil consists of particles separated by water or a gaseous 

 atmosphere. This atmosphere contains more COg than the air. When the 

 soil is poorly aerated and there is much organic matter present, bacterial 

 action produces not only COg, but also some methane. The soil of rice- 

 fields contains practically no oxygen but there is much hydrogen and 

 methane present. 



REFERENCE 

 Thimann, K. V. (1955). The Life of Bacteria. Macmillan, New York. 



