Morphological and biochemical characterization of bacterial isolates from diverse soil habitats in the Amhara region, Ethiopia.

Abstract

Soil harbors diverse microbial communities that play essential roles in ecosystem functioning; however, many microbial populations remain unexplored. In this study, bacterial isolates obtained from 11 selected soil sampling sites in the Amhara region of Ethiopia were characterized. A total of 104 morphologically distinct bacterial isolates were recovered using the serial dilution and spread plate techniques and were subsequently characterized based on their morphological and biochemical characteristics. Presumptive identification based on morphological and biochemical characteristics classified the isolates into nine bacterial genera. The Shannon diversity index (H' = 1.68) indicated moderate bacterial species diversity, whereas the Simpson diversity index (0.72) suggested a relatively even distribution of taxa within the sampled soils. The present study demonstrated that soil bacterial diversity was significantly and positively correlated with soil pH, total nitrogen (TN), and available phosphorus (AP). In contrast, organic carbon (OC), soil moisture, and temperature showed no significant association with bacterial diversity. Principal component analysis (PCA) explained 73 % of the total variation in the biochemical characteristics of the bacterial isolates. The high enzymatic activity and metabolic versatility exhibited by the isolates highlight their potential for various biotechnological applications, including bioremediation, industrial enzyme production, and agricultural biofertilizer development.