Novel cereal bran based low-cost liquid medium for enhanced growth, multifunctional traits and shelf life of consortium biofertilizer containing Azotobacter chroococcum, Bacillus subtilis and Pseudomonas sp

• Published in: Journal of microbiological methods 2024-07, Vol.222, p.106952, Article 106952
• Main Authors: Akashdeep, Kumari, Suman, Rani, Neeraj
• Format: Article
• Language: English
• Subjects: And wheat bran; Azotobacter - growth & development; Bacillus subtilis - growth & development; Consortium biofertilizer; Culture Media - chemistry; Dietary Fiber; Edible Grain - growth & development; Edible Grain - microbiology; Fertilizers; Low-cost bioformulation; Microbial Viability; Oryza - growth & development; Oryza - microbiology; Pseudomonas - growth & development; Rice
• ISSN: 0167-7012; 1872-8359; 1872-8359
• DOI: 10.1016/j.mimet.2024.106952

The present study was carried out to valorise cereal (rice and wheat) bran for the development of low-cost liquid consortium bioformulation. Different concentrations of bran-based liquid media formulations were evaluated for the growth of consortium biofertilizer cultures (Azotobacter chroococcum, Bacillus subtilis and Pseudomonas sp.). Among the bran-based formulations, wheat bran-based formulation WB5, exhibited the highest viable cell of 10.68 ± 0.09 Log10 CFU/ml and 12.63 ± 0.04 Log10 CFU/ml for Azotobacter chroococcum and Bacillus subtilis whereas for Pseudomonas sp., rice bran based bioformulation RB5 recorded maximum viability (12.71 ± 0.05 Log10 CFU/ml) after 72 h of incubation. RB51RB1: 1:10 (Rice bran: distilled water)RB2: 1:10 (Rice bran: distilled water)RB3: 1:10 (Rice bran: distilled water)RB4: 1:10 (Rice bran: distilled water)RB5: 5:10 (Rice bran: distilled water)1 and WB52WB1: 1:10 (wheat bran: distilled water)WB2: 2:10 (wheat bran: distilled water)WB3: 3:10 (wheat bran: distilled water)WB4: 4:10 (wheat bran: distilled water)WB5: 5:10 (wheat bran: distilled water)2liquid formulations were further optimized for enhanced shelf life using 5, 10 and 15 mM of trehalose, 0.05 and 0.1% carboxymethyl cellulose, and 0.5 and 1.0% glycerol. Following the peak growth at 72 h of incubation, a gradual decrease in the viable population of consortium biofertilizer cultures was observed in all the liquid formulations. The WB5 and RB5 formulations with 15 mM trehalose and 0.1% CMC, not only recorded significantly highest cell count of consortium biofertilizer cultures, but also maximally supported multi-functional traits i.e., phosphate and zinc solubilization, ammonia and IAA production up to 150 days. Further evaluation of seedling emergence and growth of wheat (PBW 826) under axenic conditions recorded WB5 amended with 15 mM trehalose-based consortium bioformulation to exhibit maximum emergence and growth of wheat seedlings. This low-cost liquid formulation can be used for large-scale biofertilizer production as a cost-effective liquid biofertilizer production technology. [Display omitted] •Semi-synthetic media for commercial biofertilizer production is highly expensive.•Agro-industrial by-products for stable and economical means is also a major concern.•Developed cereal bran (rice and wheat) based liquid medium.•Enhanced growth and shelf life of consortium biofertilizer.•Cost-effective and eco-friendly alternative to synthetic media.