Authors: Ismaila A. Jimoh, Erik G. Søgaard, Svetlana N. Rudyk and Sergey V. Kucheryavskiy
Abstract: In this study, spectroscopy and image analysis have been employed to characterize the difference between pure strains of Clostridium tyrobutyricum and the strains adapted to salinity and temperature for microbial enhanced oil recovery purposes. The pure strain and adapted bacteria strains have been metabolically characterized by gas production, pH and morphologically by FT-IR spectroscopy and image analysis. The result of FT-IR analysis was able to distinguish the adapted strains from the pure strain based on cell content. Further results from multivariate data analysis using PCA method showed that the morphological and physiological changes were induced with increasing salt concentration that correlates with gas production and change in pH. It was found that the adaptation probably occurred due to the formation of bacterial clusters at extremely high salinity. High density of bacteria cells occurring as single cells and rod like shape were found in low to medium salinity in contrast to high salinity where the proportion of bacteria cells were found in clusters, round shaped but with decreasing cell density. The shifts in the morphological as well as the physiological composition of the bacterial assemblage in the media allow for a clear subdivision into different salinity groups.
Keywords: Adaptation, FT-IR spectroscopy, image analysis, salinity