Glutamate wastewater as a culture medium for <Emphasis Type="Italic">Azospirillum rugosum</Emphasis> production and its impact on plant growth

Monosodium glutamate wastewater (MSGW) was used as a culture medium for Azospirillum rugosum strain IMMIB AFH-6 inoculant (In) by optimizing the dilution at 2.5% and pH 7.0 ± 0.1. A. rugosum growth studies were carried out in shake flasks and subsequently tested for plant growth promotion by seed germination bioassay and greenhouse pot experiments. The highest colony-forming units (cfu) 8.58 and 8.87 log cfu mL⁻¹, respectively, at 48 h of growth were recorded in MSGW and MSGW with yeast extract 0.04%. Seed bioassay results revealed that A. rugosum grown on MSGW stimulated the root and shoot elongation of maize (Zea mays L.) and pai tsai (Brassica chinensis L.). Pai tsai recorded significantly higher dry matter production when treated with A. rugosum and chemical fertilizers than control. The MSGW is a suitable culture medium for A. rugosum growth, and it is comparable to commercial media when tested for agricultural production.