Influence of GIL 01 and GIL 16 tectiviral lysogeny on bacterial growth , 1 biofilm formation , and swarming motility of Bacillus thuringiensis

20 Bacillus thuringiensis is an entomopathogenic bacterium that has been used worldwide as an 21 efficient biopesticide. Despite that this bacterium is usually described as an insect pathogen, 22 its lifecycle in the environment is still largely unknown. B. thuringiensis belongs to the 23 Bacillus cereus group of bacteria, which has been associated with many mobile genetic 24 elements such as species-specific temperate or virulent bacteriophages (phages). Temperate 25 (lysogenic) phages are able to establish a long-term relationship with their host, providing, in 26 some cases, novel ecological traits to the bacterial lysogens. Therefore, this work focuses on 27 evaluating the potential influence of temperate tectiviruses GIL01 and GIL16 to the 28 development of different life traits of B. thuringiensis. For this purpose, a B. thuringiensis 29 serovar israelensis plasmid-cured (non-lysogenic) strain was used to establish bacterial 30 lysogens for phages GIL01 and GIL16 and, subsequently, the following life traits were 31 compared among the strains: kinetics of growth, metabolic profiles, antibiotics susceptibility, 32 biofilm formation, swarming motility and sporulation. The results revealed that GIL01 and 33 GIL16 lysogeny has a significant influence on bacterial growth, sporulation rate, biofilm 34 formation and swarming motility of B. thuringiensis. No changes in metabolic profiles or 35 antibiotics susceptibilities were detected. These findings provide evidence that tectiviruses 36 can have a putative role in B. thuringiensis lifecycle as adapters of life traits with ecological 37