Study Of Varying Ph Ranges On The Growth Rate Of Bacterial Strains Isolated From Plants

The effect of different pH ranges 3-10 was studied on the growth rate of six different bacterial strains, e.g. Escherichia coli, Klebsiella Pneumoniae, Bacillus cereus, Bacillus flexus, Brevibacterium borstelensis, Staphyllococcus scuiri, isolated from different hosts (Kinnow, Gada Dahi, Sweet orange, Musambi, and Bindweed). These bacterial endophytes were distinguished by the use of universal 16s rRNA primers based on morphological characters and biochemical tests as well as molecular approaches. The amplified PCR products were purified and sequenced from Mobix at Mc Master's University, Hamilton, Canada, and submitted to the NCBI database under accession (LT844655, MF966247, LT745986, LT745989, LT745979, and MF977365). The phylogenetic tree of isolated strains was constructed by MEGA 7.0 software. Gen 5 plate reader software was used to measure growth at O.D 600nm in 96 well plate for 24 hours at 30oC in EpochTM microplate spectrophotometer. According to the findings, Escherichia coli grew best in the pH ranges of 6, 7, and 8, but not in the pH range of 9. Similarly, Staphylococcus scuiri grew best in a pH range of 7 to 10, while pH 4 and 5 had no development. The typical growth pattern of Klebsiella pneumoniae was observed at pH 9 and 10, whereas growth was slower or limited in the other pH ranges. Whereas, Bacillus flexus and Bacillus cereus grew best at pH 6-9. Brevibacterium borstelensis, on the other hand, grew best at 4-9. These findings indicate that pH can play an important role in determining bacterial competition in host plants.