Memory of Germinant Stimuli in Bacterial Spores

ABSTRACT Bacterial spores, despite being metabolically dormant, possess the remarkable capacity to detect nutrients and other molecules in their environment through a biochemical sensory apparatus that can trigger spore germination, allowing the return to vegetative growth within minutes of exposure...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Shiwei Wang, James R. Faeder, Peter Setlow, Yong-qing Li
Formato:	article
Lenguaje:	EN
Publicado:	American Society for Microbiology 2015
Materias:	Microbiology QR1-502
Acceso en línea:	https://doaj.org/article/e7663a669ade473aa7de76e086e679c6
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:e7663a669ade473aa7de76e086e679c6
record_format	dspace
spelling	oai:doaj.org-article:e7663a669ade473aa7de76e086e679c62021-11-15T15:41:24ZMemory of Germinant Stimuli in Bacterial Spores10.1128/mBio.01859-152150-7511https://doaj.org/article/e7663a669ade473aa7de76e086e679c62015-12-01T00:00:00Zhttps://journals.asm.org/doi/10.1128/mBio.01859-15https://doaj.org/toc/2150-7511ABSTRACT Bacterial spores, despite being metabolically dormant, possess the remarkable capacity to detect nutrients and other molecules in their environment through a biochemical sensory apparatus that can trigger spore germination, allowing the return to vegetative growth within minutes of exposure of germinants. We demonstrate here that bacterial spores of multiple species retain memory of transient exposures to germinant stimuli that can result in altered responses to subsequent exposure. The magnitude and decay of these memory effects depend on the pulse duration as well as on the separation time, incubation temperature, and pH values between the pulses. Spores of Bacillus species germinate in response to nutrients that interact with germinant receptors (GRs) in the spore's inner membrane, with different nutrient types acting on different receptors. In our experiments, B. subtilis spores display memory when the first and second germinant pulses target different receptors, suggesting that some components of spore memory are downstream of GRs. Furthermore, nonnutrient germinants, which do not require GRs, exhibit memory either alone or in combination with nutrient germinants, and memory of nonnutrient stimulation is found to be more persistent than that induced by GR-dependent stimuli. Spores of B. cereus and Clostridium difficile also exhibit germination memory, suggesting that memory may be a general property of bacterial spores. These observations along with experiments involving strains with mutations in various germination proteins suggest a model in which memory is stored primarily in the metastable states of SpoVA proteins, which comprise a channel for release of dipicolinic acid, a major early event in spore germination. IMPORTANCE Cellular memory is defined as a sustained response to a transient environmental stimulus, and yet its generation and storage have not been described in bacterial spores. We demonstrate here that bacterial spores of multiple species retain memory of transient exposures to germinant stimuli that can result in altered responses to subsequent exposure. Memory was induced by activation of germinant receptors (GRs) or by GR-independent germinants and was accessed by both GR-dependent and GR-independent germinants. Analysis of effects on memory of exposure to GR-dependent and GR-independent germinants as well as in spores lacking various germination proteins suggests a model in which memory is stored primarily in metastable states of SpoVA proteins which comprise a channel for release of spore dipicolinic acid. Spore memory can also significantly reduce the concentration of nutrient germinants necessary to trigger germination, and this may be used to respond to low levels of nutrient germinants.Shiwei WangJames R. FaederPeter SetlowYong-qing LiAmerican Society for MicrobiologyarticleMicrobiologyQR1-502ENmBio, Vol 6, Iss 6 (2015)
institution	DOAJ
collection	DOAJ
language	EN
topic	Microbiology QR1-502
spellingShingle	Microbiology QR1-502 Shiwei Wang James R. Faeder Peter Setlow Yong-qing Li Memory of Germinant Stimuli in Bacterial Spores
description	ABSTRACT Bacterial spores, despite being metabolically dormant, possess the remarkable capacity to detect nutrients and other molecules in their environment through a biochemical sensory apparatus that can trigger spore germination, allowing the return to vegetative growth within minutes of exposure of germinants. We demonstrate here that bacterial spores of multiple species retain memory of transient exposures to germinant stimuli that can result in altered responses to subsequent exposure. The magnitude and decay of these memory effects depend on the pulse duration as well as on the separation time, incubation temperature, and pH values between the pulses. Spores of Bacillus species germinate in response to nutrients that interact with germinant receptors (GRs) in the spore's inner membrane, with different nutrient types acting on different receptors. In our experiments, B. subtilis spores display memory when the first and second germinant pulses target different receptors, suggesting that some components of spore memory are downstream of GRs. Furthermore, nonnutrient germinants, which do not require GRs, exhibit memory either alone or in combination with nutrient germinants, and memory of nonnutrient stimulation is found to be more persistent than that induced by GR-dependent stimuli. Spores of B. cereus and Clostridium difficile also exhibit germination memory, suggesting that memory may be a general property of bacterial spores. These observations along with experiments involving strains with mutations in various germination proteins suggest a model in which memory is stored primarily in the metastable states of SpoVA proteins, which comprise a channel for release of dipicolinic acid, a major early event in spore germination. IMPORTANCE Cellular memory is defined as a sustained response to a transient environmental stimulus, and yet its generation and storage have not been described in bacterial spores. We demonstrate here that bacterial spores of multiple species retain memory of transient exposures to germinant stimuli that can result in altered responses to subsequent exposure. Memory was induced by activation of germinant receptors (GRs) or by GR-independent germinants and was accessed by both GR-dependent and GR-independent germinants. Analysis of effects on memory of exposure to GR-dependent and GR-independent germinants as well as in spores lacking various germination proteins suggests a model in which memory is stored primarily in metastable states of SpoVA proteins which comprise a channel for release of spore dipicolinic acid. Spore memory can also significantly reduce the concentration of nutrient germinants necessary to trigger germination, and this may be used to respond to low levels of nutrient germinants.
format	article
author	Shiwei Wang James R. Faeder Peter Setlow Yong-qing Li
author_facet	Shiwei Wang James R. Faeder Peter Setlow Yong-qing Li
author_sort	Shiwei Wang
title	Memory of Germinant Stimuli in Bacterial Spores
title_short	Memory of Germinant Stimuli in Bacterial Spores
title_full	Memory of Germinant Stimuli in Bacterial Spores
title_fullStr	Memory of Germinant Stimuli in Bacterial Spores
title_full_unstemmed	Memory of Germinant Stimuli in Bacterial Spores
title_sort	memory of germinant stimuli in bacterial spores
publisher	American Society for Microbiology
publishDate	2015
url	https://doaj.org/article/e7663a669ade473aa7de76e086e679c6
work_keys_str_mv	AT shiweiwang memoryofgerminantstimuliinbacterialspores AT jamesrfaeder memoryofgerminantstimuliinbacterialspores AT petersetlow memoryofgerminantstimuliinbacterialspores AT yongqingli memoryofgerminantstimuliinbacterialspores
_version_	1718427737106939904

Memory of Germinant Stimuli in Bacterial Spores

Ejemplares similares