Influence of pH Variations on Biofilm Formation of Bacillus thuringiensiskurstaki HD1 on Polystyrene Surfaces

Biofilm formation enhances microbial survival, growth, nutrient access, biocide resistance, productivity, interactions, and stability. Bacillus thuringiensis kurstaki (Btk) HD1 is used as a biopesticide against lepidopterans (moths and butterflies). Thus, the objective of this paper is to evaluate the influence of pH variations on biofilm formation of Bacillus thuringiensis kurstaki HD1 on polystyrene surfaces across a range of pH levels from 1 to 14. The results demonstrated a clear pH-dependent trend in biofilm production. Biofilm formation was optimal between pH 4 and pH 9, with the highest production at pH 4. In contrast, extreme pH values (1, 10, 11, 12, 13, and 14) resulted in reduced biofilm formation. The study highlights the significant influence of pH on biofilm formation by Btk HD1, with optimal biofilm production occurring within a pH range of 4 to 9. These findings suggest that maintaining environmental pH within this range could enhance the efficacy and stability of Btk HD1 as a biopesticide.