Revealing of multifunctional newly isolated Bacillus strains from Algerian wastes with high pectinase activity for sustainable biotechnological application

Pectinases, a group of enzymes that degrade pectin, are crucial in various industrial applications. This study aimed to isolate, characterize, and evaluate the multifunctional traits of pectinase-producing bacteria from partially decayed fruits and soil in Sidi Bel Abbes, Algeria. Out of 80 isolates screened on pectinase screening agar medium (PSAM), five Bacillus species demonstrated significant pectinase activity, with pectin degradation indices (PDI) of 6.9–7.9 and enzyme yields of 7.9–10 U/mL under submerged fermentation. Morphological, biochemical, and 16S rRNA gene analyses identified these strains as Bacillus amyloliquefaciens SL9, B. licheniformis SC3, B. mojavensis ST1, B. velezensis SPC3, and B. siamensis SL6. Besides pectinase production, these Bacillus spp. displayed plant growth-promoting traits (including nitrogen fixation, phosphate solubilization, siderophore production, and indole-3-acetic acid (IAA) synthesis) and antimicrobial activity against several phytopathogens. They also produced diverse extracellular enzymes and demonstrated tolerance to salinity, pH variation, and high temperatures underscoring their adaptability to challenging environments. These findings highlight the potential of these Bacillus spp. for industrial enzyme production, biocontrol, and sustainable agricultural applications, particularly in stress-prone conditions.