The determination and synthesis of riboflavin in cultures of microorganisms.

Research on growth factors essential to the metabolism of microorganisms and higher animals has proceeded with ever increasing strides in the past fifty years. The correlation of microbial growth factors with animal vitamins was a recent development. Indeed, as recently as 1936, B.C.J.G. Knight (15) stated, “It is not unlikely that some of the animal vitamins may be required by bacteria, but at present it has not been shown that any pure animal vitamin is required as an essential nutrient by any”. The work covered in this thesis concerns itself with one vitamin, namely, riboflavin. At first it was proposed to investigate the use of waste materials as substrates for the bacterial synthesis of riboflavin. However, four years elapsed before the work was completed and chemically synthesized riboflavin had become very cheap. The commercial production of riboflavin from waste materials was, therefore, considered unfeasible. Nevertheless, the investigation was continued and many strains of riboflavin synthesizing bacteria were isolated. Methods for the fluorometric and microbiological assay of riboflavin were applied to bacterial cultures. Riboflavin concentrates have been prepared from some of these cultures. At the same time species of bacteria which required riboflavin for growth and some of the conditions for the synthesis of riboflavin by Vibrio perimastix were investigated. [...