A new basal medium to test carbon utilization for plant pathogenic bacteria

Abstract

Glucose, , sucrose, sodium tartrate, or L-arginine were tested as a carbon source in eight basal media using 99 bacterial strains belonging to 63 species in 14 genera, including some strains of non-plant pathogens. From these results and those from additional tests using nine carbon sources, Dye's medium OY was useful for testing carbohydrates and sugar alcohols, and BMC developed in this study as a basal medium was useful for testing various carbon sources such as carbohydrates, sugar alcohols, organic acids and amino acids. BMC medium contains 0.4g NH₄H₂PO₄, 0.6g (NH₄)₂HPO₄, 0.2g KCl, 0.2g MgSO₄⋅7H₂O, 5g NaCl, 0.2g yeast extract, 10ml 0.5% bromthymol blue (BTB) solution, and 16g agar in 990ml of distilled water with pH 6.8. This medium can be used only for bacteria giving a positive reaction within 1 week on BMC supplemented with 0.5% glucose. Further study is needed to develop a medium for bacteria that require nutritionally rich media, such as the genus Clavibacter. When the results obtained by different basal media are examined, attention must be paid to the nutrient levels in the media and to the culture durations. It is especially important to note that negative results may be questionable because of an absence or excess of certain nutrients.