Kentucky State University
Microbial Characterization of Exiguobacterium Acetylicum SN, a New Strain of Soil Isolate from Capsicum-Grown Soil
Institution
Kentucky State University
Faculty Advisor/ Mentor
Narayanan Rajendran
Abstract
Soil bacteria are more common in natural habitats and represent a spectrum of complexity of bacterial community. By adopting different mechanisms such as preventing phytopathogens, many of them play vital roles in the biodegradation of major compounds as well as enhance the growth of many plants. In our earlier studies, Exiguobacterium acetylicum strain SN one of the leading soil bacteria was isolated from the capsicum-grown soil by the second author (mentor). In the present study, a partial characterization of this soil bacterium was carried out by using various microbiological methods. E. acetylicum SN is a yellowish, aerobic and motile bacterium. The straining technique proves it is a Gram positive bacterium. Based on the growth curve study in Nutrient Broth, the optimal growth of this strain was observed at 38-42 hours. The serial dilution and the spread plate techniques had yielded a frequency of the viable colony count at 2.7x109 CFU/mL. Based on the selective media analysis it was proved that this strain belongs to fermentative group and can ferment Glucose, Maltose and Sucrose, except Mannitol. Differential media analysis indicates that this bacterium can grow well in Nutrient Agar, and partially grow in Mannitol Salt Agar, and Kliger Iron Agar, but poorly grow in Eosin Methylene Blue Agar. Antibiotics such as Tetracycline, Kanamycin, Chloromphenicol, Neomycin, and Streptomycin exhibit variable growth inhibition against this bacterium after 24 hours. Novobicin showed higher growth inhibition than Erythromycin.
Microbial Characterization of Exiguobacterium Acetylicum SN, a New Strain of Soil Isolate from Capsicum-Grown Soil
Soil bacteria are more common in natural habitats and represent a spectrum of complexity of bacterial community. By adopting different mechanisms such as preventing phytopathogens, many of them play vital roles in the biodegradation of major compounds as well as enhance the growth of many plants. In our earlier studies, Exiguobacterium acetylicum strain SN one of the leading soil bacteria was isolated from the capsicum-grown soil by the second author (mentor). In the present study, a partial characterization of this soil bacterium was carried out by using various microbiological methods. E. acetylicum SN is a yellowish, aerobic and motile bacterium. The straining technique proves it is a Gram positive bacterium. Based on the growth curve study in Nutrient Broth, the optimal growth of this strain was observed at 38-42 hours. The serial dilution and the spread plate techniques had yielded a frequency of the viable colony count at 2.7x109 CFU/mL. Based on the selective media analysis it was proved that this strain belongs to fermentative group and can ferment Glucose, Maltose and Sucrose, except Mannitol. Differential media analysis indicates that this bacterium can grow well in Nutrient Agar, and partially grow in Mannitol Salt Agar, and Kliger Iron Agar, but poorly grow in Eosin Methylene Blue Agar. Antibiotics such as Tetracycline, Kanamycin, Chloromphenicol, Neomycin, and Streptomycin exhibit variable growth inhibition against this bacterium after 24 hours. Novobicin showed higher growth inhibition than Erythromycin.