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Animal manure, a sustainable alternative to chemical fertilizers, is rich in beneficial microorganisms capable of improving soil structure, nutrient availability, and crop yield. Understanding the bacteriological characteristics of these manures is crucial for optimizing their agricultural application while minimizing potential pathogenic risks. The study was conducted to investigate the microbial composition and plant growth-promoting potential of ruminant and non-ruminant animal manures to enhance soil fertility management. The research aimed to isolate and identify bacteria present in animal manures using phenotypic and molecular methods, evaluate their PGP traits, and assess their effects on the germination and growth performance of Telfairia occidentalis (fluted pumpkin). A total of twenty-four manure samples from ruminant and non-ruminant animals were collected
from different farms in Benin City, Edo State, Nigeria. Standard microbiological procedures were used for isolation, enumeration, and biochemical identification of bacterial isolates. Phenotypic characterization involved Gram staining and biochemical assays such as oxidase, indole, catalase, urease, citrate utilization, and triple sugar iron tests. Molecular identification was performed using 16S rRNA gene sequence analysis. Pathogenicity tests, including gelatin liquefaction, DNase, lipase, and hemolysin assays, were conducted to assess the virulence potentials of isolates. The isolates were also screened for plant growth-promoting traits such as indole-3-acetic acid (IAA) and ammonia production. In addition, the impact of different manure treatments on Telfairia occidentalis was evaluated through germination rate, vine length, leaf area, chlorophyll content and biomass yield. The results revealed that the heterotrophic bacterial count ranged from 13.30 × 10⁵ cfu/g in nonruminant manure to 27.80 × 10⁵ cfu/g in mixed manure, while the coliform count varied between6.40 × 10⁴ cfu/g and 13.69 × 10⁴ cfu/g, indicating a higher microbial load in the mixed manure samples. Six major bacterial species were identified Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica and Bacillus velezensis with E. coli showing the highest frequency of occurrence (25%). Molecular characterization further revealed Pseudomonas aeruginosa strain PA3 (88.5% identity), Escherichia coli strain NCCP 15734 (92.1%), Bacillus velezensis strain UA0297 (97.3%) and Klebsiella pneumoniae strain BUH3 (96.8%). Most isolates demonstrated positive results for plant growth-promoting xv traits such as nitrogen fixation, Indole Acetic Acid (IAA) and ammonia production. Growth trials on Telfairia occidentalis showed that plants treated with mixed manure had the best performance, with an average vine length of 76.05 cm, leaf number of 33, and leaf length of 25.13 cm by weekeight, compared to control plants with 55.13 cm vine length and 20 leaves. These findings confirm that animal manures, particularly mixed manure, significantly enhanced plant growth and soil microbial quality and therefore can serve as biofertilizers for sustainable agriculture and improved crop productivity
from different farms in Benin City, Edo State, Nigeria. Standard microbiological procedures were used for isolation, enumeration, and biochemical identification of bacterial isolates. Phenotypic characterization involved Gram staining and biochemical assays such as oxidase, indole, catalase, urease, citrate utilization, and triple sugar iron tests. Molecular identification was performed using 16S rRNA gene sequence analysis. Pathogenicity tests, including gelatin liquefaction, DNase, lipase, and hemolysin assays, were conducted to assess the virulence potentials of isolates. The isolates were also screened for plant growth-promoting traits such as indole-3-acetic acid (IAA) and ammonia production. In addition, the impact of different manure treatments on Telfairia occidentalis was evaluated through germination rate, vine length, leaf area, chlorophyll content and biomass yield. The results revealed that the heterotrophic bacterial count ranged from 13.30 × 10⁵ cfu/g in nonruminant manure to 27.80 × 10⁵ cfu/g in mixed manure, while the coliform count varied between6.40 × 10⁴ cfu/g and 13.69 × 10⁴ cfu/g, indicating a higher microbial load in the mixed manure samples. Six major bacterial species were identified Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica and Bacillus velezensis with E. coli showing the highest frequency of occurrence (25%). Molecular characterization further revealed Pseudomonas aeruginosa strain PA3 (88.5% identity), Escherichia coli strain NCCP 15734 (92.1%), Bacillus velezensis strain UA0297 (97.3%) and Klebsiella pneumoniae strain BUH3 (96.8%). Most isolates demonstrated positive results for plant growth-promoting xv traits such as nitrogen fixation, Indole Acetic Acid (IAA) and ammonia production. Growth trials on Telfairia occidentalis showed that plants treated with mixed manure had the best performance, with an average vine length of 76.05 cm, leaf number of 33, and leaf length of 25.13 cm by weekeight, compared to control plants with 55.13 cm vine length and 20 leaves. These findings confirm that animal manures, particularly mixed manure, significantly enhanced plant growth and soil microbial quality and therefore can serve as biofertilizers for sustainable agriculture and improved crop productivity
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