“…Estimation and measurement of hydrogen production were reported in previous papers. 2 • 7 ) For hydrogen production, cells were suspended in the reaction medium, which was Pringsheim and Wiessner's medium (pH 6.8)8) modified by the omission of NaCI, KN0 3 , and yeast extract. In this paper, this medium was called the reaction mixture, and used as the cell suspension buffer.…”