Morphological and structural response of Bacillus sp. SFC 500-1E after Cr(VI) and phenol treatment

PAULUCCI, NATALIA S.; AGOSTINI, ELIZABETH; FERNANDEZ, MARILINA; MORALES, GUSTAVO M.; REYNOSO, EUGENIA; GONZÁLEZ, PAOLA S.

JOURNAL OF BASIC MICROBIOLOGY

WILEY-V C H VERLAG GMBH

Año: 2020 p. 1 - 12

0233-111X

AbstractBacillus sp. SFC 500‐1E, a bacterial strain isolated from tannery sediments, isable to remove Cr(VI) and simultaneously tolerate high concentrations ofphenol. In this study, we used high‐resolution microscopies, fluorescencepolarization techniques, and several biochemical approaches to improve ourunderstanding about the adaptive mechanisms of this strain to survive in thepresence of Cr(VI) and phenol, both individually and simultaneously. Amongadaptive strategies developed by Bacillus sp. SFC 500‐1E, an increase inbacterial size, such as length, width, and height, and ultrastructural alterations,such as electron‐dense precipitates, the presence of exopolymers, and cell lysis,are noteworthy. The exopolymers observed were consistent with the extensivebiofilm formation and exopolysaccharides and extracellular protein quantifi-cation. At the cell membrane level, a rapid rigidity was induced in Cr(VI) +phenol treatment. This effect was counteracted after 16 h by changes at thelevel of phospholipids, mainly in the composition of fatty acids (FAs); inparticular, an increase in the unsaturated fatty acid/saturated fatty acid ratiowas detected. This study shows evidence of some adaptive responses displayedby Bacillus sp. SFC 500‐1E, which allows it to survive in stressful conditions.