Enhancing Growth of Vigna radiata in the Presence of Pseudomonas aeruginosa Biopolymer and Metarhizium anisopliae Spores

Abstract

Exopolysaccharide producing Pseudomonas aeruginosa NCIM 2945 (PANCL) belonging to gamma-proteobacterium and entomopathogenic fungus Metarhizium anisopliae MCC 1129 (MAMCC) belonging to Ascomycota were studied for their morphological features biochemical characteristics and plant growth promotion ability. Optimum growth of PANCL was recorded after 24 h at temperature 30°C and pH 7.0. Gram-negative PANCL appeared as white in color, one mm size, circular, opaque, and nonconsistent elevated colonies with entire margin. It has utilized dextrose, fructose, maltose, and sorbitol as carbon source and produced acid in the medium. PANCL was sensitive to Polymyxin B (300 µgm/disc) followed by Neomycin (30 µgm/disc), Gentamycin (10 µgm/disc), and Chloramphenicol (30 µgm/disc). PANCL has secreted extracellular lipase, amylase, protease, and exopolysaccharides (EPS). Another fungal strain MAMCC sporulated after 168 h at temperature 30°C and pH 7.0. MAMCC has septate-white mycelium and bears dirty green colored spores. Growth of MAMCC was enhanced in the presence of Neem and Karela-Amla oil (0.1 mL each). Extracellular polysaccharide produced by PANCL and spores of MAMCC promoted growth of dicotyledon Vigna radiata (Mung) individually as well as in consortium. Considerable increase in dry weight of Vigna radiata was recorded. Thus, reported PANCL and MAMCC strains have promoted growth Vigna radiata and may be a solution for sustainable agriculture.