Inorganic polyphosphate in Bacillus cereus : Motility, biofilm formation, and sporulation

Abstract

Chains of inorganic polyphosphate (poly-P) with hundreds of Pi residues linked by phosphoanhydride bonds, as in ATP, are found in every bacterial, fungal, plant, and animal cell, in which they perform various functions. In the spore-forming Bacillus cereus, we have identified three principal enzymes and genes involved in the metabolism of poly-P, namely, (i) poly-P kinase (PPK), which synthesizes poly-P reversibly from ATP, (ii) exopolyphosphatase (PPX), which hydrolyzes poly-P to Pi, and (iii) poly-P͞AMP phosphotransferase (PAP), which uses poly-P as a donor to convert AMP to ADP, reversibly. In the null mutant of ppk, poly-P levels are reduced to <5% of the WT; in the ppx mutant, the PPK activity is elevated 10-fold, and the accumulation of poly-P is elevated Ϸ1,000-fold. All of the null mutants of ppk, ppx, and pap showed defects in motility and biofilm formation, but sporulation efficiency was impaired only in the ppx mutant. These enzymes and genes in B. cereus are nearly identical to those in the very closely related pathogen Bacillus anthracis, and, thus, they may provide attractive targets for the treatment of anthrax.polyphosphate kinase ͉ exopolyphosphatase ͉ polyphosphate͞AMP phosphotransferase

Nosocomial Bacteremia Caused by Biofilm-Forming Bacillus cereus and Bacillus thuringiensis

“…Bacillus cereus, a gram-positive, rod-shaped, spore-forming aerobe found commonly in soil and many other sources, is a cause thuringiensis isolated from clinical material other than feces and vomitus was commonly dismissed as a contamination. However, recent reports suggest that Bacillus species causes nosocomial bacteremia via catheter infection (6) and Bacillus species can form biofilm (7,8). Although bacterial biofilms are a common cause of persistent and chronic bacterial infections (9), it is not clear whether the Bacillus species that causes nosocomial bacteremia can also form biofilms.…”

Inorganic polyphosphate in the social life of Myxococcus xanthus : Motility, development, and predation

“…The pap gene that encodes PAP was first identified in A. johnsonii and later found in other bacteria that include P. aeruginosa (4, 13) and B. cereus (14). The level of activity in M. xanthus increases sharply after cells enter the stationary phase.…”

“…Among other poly P enzymes, poly P:AMP phosphotransferase (PAP), which uses poly P as a donor to convert AMP to ADP has been identified in Acinetobacter johnsonii (13). In Bacillus cereus, mutants are deficient in motility and biofilm formation (14).…”

Massive multiplication of genome and ribosomes in dormant cells (akinetes) of Aphanizomenon ovalisporum (Cyanobacteria)

“…Here we present evidence that phosphate is provided via the transformation of phosphate from its storage component (inorganic Poly-P bodies) in vegetative cells to enlarged pools of nucleic acids in akinetes. Inorganic Poly-P, a linear polymer of orthophosphate residues, is an essential energy source and a reservoir for metabolism and growth (Kornberg, 1995) and it has a role in regulation of fruiting body and spore development in Myxobacteria and sporulation in Bacillus (Shi et al, 2004). On the basis of cellular phosphor content of a single exponentially grown vegetative cell of A. ovalisporum (Hadas et al, 2002), the stored inorganic Poly-P should be sufficient for a 10-fold increase in the number of genome copies in an akinete relative to the vegetative cell it has differentiated from.…”