Bacillus subtilis produces a wide array of extracellular metabolites that can inhibit the growth of bacteria and fungi or modify their behavior to attenuate the production of antibacterial products by potentially dangerous neighbors. We here propose to use the new technique of imaging mass spectrometry and classical analytical chemistry to systematically identify the extracellular metabolome of B. subtilis, with a focus on characterizing the interactive metabolome that is induced by other bacterial species. We will investigate the role these compounds play in two distinct outcomes of the interaction of B. subtilis with other species. The first is an impasse, in which B. subtilis forms closely abutting colonies with other species that produce a variety of antibacterial compounds (such as P. aeruginosa). The second, more frequent behavior is contact-dependent predation, in which B. subtilis moves towards, invades and destroys neighboring colonies, leading to death of the prey species and expanding the territory of the B. subtilis colony. These reproducible behaviors are conserved in different undomesticated B. subtilis strains. We will determine if these behaviors depend on the interactive metabolome and investigate the effects individual compounds have on target cell viability and behavior. We will further investigate the genetic requirements for interspecies interactions to identify stress responses, developmental and biosynthetic pathways that contribute to these distinct outcomes and we will use fluorescence microscopy to visualize the cellular consequences of interspecies interactions. These studies will illuminate the mechanistic basis for interspecies interactions and identify secondary metabolites that affect viability or behavior of other species that represent potential new antibacterial drugs.

Public Health Relevance

Bacteria produce many extracellular metabolites that mediate their interaction with other species, many of which have antibacterial and antifungal activities. We will here elucidate the chemical, genetic and cellular mechanisms by which these molecules allow Bacillus subtilis to interact with other bacterial species, producing outcomes ranging from coexistence to the invasion and destruction of neighboring colonies. Interspecies interactions are critical in medicine and the metabolites that facilitate destruction of other species represent promising new pharmaceutical leads.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI095125-02
Application #
8238306
Study Section
Special Emphasis Panel (ZRG1-GGG-B (03))
Program Officer
Korpela, Jukka K
Project Start
2011-03-07
Project End
2015-02-28
Budget Start
2012-03-01
Budget End
2013-02-28
Support Year
2
Fiscal Year
2012
Total Cost
$593,899
Indirect Cost
$197,714
Name
University of California San Diego
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
804355790
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Nonejuie, Poochit; Trial, Rachelle M; Newton, Gerald L et al. (2016) Application of bacterial cytological profiling to crude natural product extracts reveals the antibacterial arsenal of Bacillus subtilis. J Antibiot (Tokyo) 69:353-61
Hsu, Cheng-Chih; Dorrestein, Pieter C (2015) Visualizing life with ambient mass spectrometry. Curr Opin Biotechnol 31:24-34
Perera, Varahenage R; Newton, Gerald L; Pogliano, Kit (2015) Bacillithiol: a key protective thiol in Staphylococcus aureus. Expert Rev Anti Infect Ther 13:1089-107
Sahonero-Canavesi, Diana X; Sohlenkamp, Christian; Sandoval-Calderón, Mario et al. (2015) Fatty acid-releasing activities in Sinorhizobium meliloti include unusual diacylglycerol lipase. Environ Microbiol 17:3391-406
Luzzatto-Knaan, Tal; Melnik, Alexey V; Dorrestein, Pieter C (2015) Mass spectrometry tools and workflows for revealing microbial chemistry. Analyst 140:4949-66
Michelsen, Charlotte F; Watrous, Jeramie; Glaring, Mikkel A et al. (2015) Nonribosomal peptides, key biocontrol components for Pseudomonas fluorescens In5, isolated from a Greenlandic suppressive soil. MBio 6:e00079
Bleich, Rachel; Watrous, Jeramie D; Dorrestein, Pieter C et al. (2015) Thiopeptide antibiotics stimulate biofilm formation in Bacillus subtilis. Proc Natl Acad Sci U S A 112:3086-91
Perera, Varahenage R; Newton, Gerald L; Parnell, Jonathan M et al. (2014) Purification and characterization of the Staphylococcus aureus bacillithiol transferase BstA. Biochim Biophys Acta 1840:2851-61
Winnikoff, Jacob R; Glukhov, Evgenia; Watrous, Jeramie et al. (2014) Quantitative molecular networking to profile marine cyanobacterial metabolomes. J Antibiot (Tokyo) 67:105-12
Phelan, Vanessa V; Moree, Wilna J; Aguilar, Julieta et al. (2014) Impact of a transposon insertion in phzF2 on the specialized metabolite production and interkingdom interactions of Pseudomonas aeruginosa. J Bacteriol 196:1683-93

Showing the most recent 10 out of 36 publications