Development of two culture media for mass cultivation of <Emphasis Type="Italic">Azospirillum</Emphasis> spp. and for production of inoculants to enhance plant growth

High yield culture medium is fundamental for production of inoculants for plant growth-promoting bacteria. Based on substitution of glucose in tryptone–yeast extract–glucose medium by Na-gluconate or glycerol, two new culture media were developed for mass cultivation of the commonly used plant growth-promoting bacterium Azospirillum sp. After 18 h of incubation, these modifications increased populations of different strains of Azospirillum (to ∼10¹¹ cells ml⁻¹ single cell count] and ∼5 × 10⁹ CFU ml⁻¹ plate count method]), significantly reduced generation time, and were also suitable for production of common synthetic inoculants.