Enterobacter cloacae PNE2 As Promising Plant Growth Promoting Bacterium, Isolated From The Kadi Vegetable Market Waste, Gujarat

Abstract

Chemical fertilizer use in agricultural areas causes a variety of issues, including pollution, health risks, disruption of natural ecological nutrient cycles, and the loss of biological communities. In this case, chemical fertilizers, herbicides, and other supplements are replaced by plant growth promoting bacteria for sustainable agriculture. The present research work focus on the isolation of the plant growth promoting bacteria from the Kadi vegetable market waste. Derived from morphological, biochemical, and 16S rRNA gene sequence analysis the strain was identified as Enterobacter cloacae PNE2. The antibiotic susceptibility test indicated that the isolate was sensitive to all 22 antibiotics tested. The isolate Enterobacter cloacae PNE2 has multiple growth-promoting activities like N2 fixation, phosphate, solubilization, potassium solubilization, phytohormone (Indole-3-acetic acid) production, EPS production, biopolymer degradation, and also possesses good seed germination ability. Quantitative analysis of nitrite production revealed the isolate Enterobacter cloacae PNE2 produced 0.15±0.01 μg/ml nitrite. The Phosphate Solubilization Index (PSI) of the isolate was recorded 3.58±0.08 and the isolate released 278.34±0.56 μg/ml phosphate in Pikovskaya’s broth. The isolate Enterobacter cloacae PNE2 solubilized 32.66 mg/l potassium. The isolate Enterobacter cloacae PNE2 possesses IAA (48.49±0.05μg/ml) in presence of tryptophan and EPS (19.1±0.2 g/l) production ability. The isolate Enterobacter cloacae PNE2 was also found to degrade Cellulose, Pectin, and Xylan. Furthermore, the isolate Enterobacter cloacae PNE2 enhances seedling growth of Trigonella foenum graceum (fenugreek). Thus, the isolate Enterobacter cloacae PNE2 has significant plant growth promoting characteristics and can be applied in a bio-fertilizer formulation for sustainable agriculture.