Acinetobacter spp. are found in all environments on Earth due to their extraordinary
capacity to survive in the presence of physical and chemical stressors. In this study, we
analyzed global gene expression in airborne Acinetobacter sp. strain 5-2Ac02 isolated
from hospital environment in response to quorum network modulators and found that
they induced the expression of genes of the acetoin/butanediol catabolism, volatile
compounds shown to mediate interkingdom interactions. Interestingly, the acoN gene,
annotated as a putative transcriptional regulator, was truncated in the downstream
regulatory region of the induced acetoin/butanediol cluster in Acinetobacter sp. strain
5-2Ac02, and its functioning as a negative regulator of this cluster integrating quorum
signals was confirmed in Acinetobacter baumannii ATCC 17978. Moreover, we show
that the acetoin catabolism is also induced by light and provide insights into the light
transduction mechanism by showing that the photoreceptor BlsA interacts with and
antagonizes the functioning of AcoN in A. baumannii, integrating also a temperature
signal. The data support a model in which BlsA interacts with and likely sequesters
AcoN at this condition, relieving acetoin catabolic genes from repression, and leading to
better growth under blue light. This photoregulation depends on temperature, occurring
at 23◦C but not at 30◦C. BlsA is thus a dual regulator, modulating different transcriptional
regulators in the dark but also under blue light, representing thus a novel concept. The
overall data show that quorum modulators as well as light regulate the acetoin catabolic
cluster, providing a better understanding of environmental as well as clinical bacteria.
Para citar este articulo: Tuttobene MR,
Fernández-García L, Blasco L,
Cribb P, Ambroa A, Müller GL,
Fernández-Cuenca F, Bleriot I,
Rodríguez RE, Barbosa BGV,
Lopez-Rojas R, Trastoy R, López M,
Bou G, Tomás M and Mussi MA
(2019) Quorum and Light Signals
Modulate Acetoin/Butanediol
Catabolism in Acinetobacter spp.
Front. Microbiol. 10:1376.
doi: 10.3389/fmicb.2019.01376