Everett Peter Greenberg (born November 7, 1948) is an American

microbiologist A microbiologist (from Greek ) is a scientist who studies microscopic life forms and processes. This includes study of the growth, interactions and characteristics of microscopic organisms such as bacteria, algae, fungi, and some types of par ...

. He is the inaugural

Eugene Eugene may refer to: People and fictional characters * Eugene (given name), including a list of people and fictional characters with the given name * Eugene (actress) (born 1981), Kim Yoo-jin, South Korean actress and former member of the sin ...

and Martha Nester

Professor Professor (commonly abbreviated as Prof.) is an academic rank at universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who professes". Professor ...

Microbiology Microbiology () is the scientific study of microorganisms, those being unicellular (single cell), multicellular (cell colony), or acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, bacteriology, ...

at the Department of Microbiology of the

University of Washington The University of Washington (UW, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington. Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seat ...

School of Medicine A medical school is a tertiary educational institution, or part of such an institution, that teaches medicine, and awards a professional degree for physicians. Such medical degrees include the Bachelor of Medicine, Bachelor of Surgery (MBBS, MB ...

. He is best known for his research on

quorum sensing In biology, quorum sensing or quorum signalling (QS) is the ability to detect and respond to cell population density by gene regulation. As one example, QS enables bacteria to restrict the expression of specific genes to the high cell densities a ...

, and has received multiple awards for his work.

Early life and education

Greenberg was born in 1948 in

New York City New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the U ...

. When he was an infant, his family moved to

San Francisco San Francisco (; Spanish language, Spanish for "Francis of Assisi, Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the List of Ca ...

then to

Seattle Seattle ( ) is a port, seaport city on the West Coast of the United States. It is the county seat, seat of King County, Washington, King County, Washington (state), Washington. With a 2020 population of 737,015, it is the largest city in bo ...

, where he finished high school. He became interested in

biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditar ...

, especially

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

biology, after a field trip his biology teacher organized. Greenberg was determined to study biology after a year at Everett Junior College (now

Everett Community College Everett Community College (EvCC) is a public community college in Everett, Washington. EvCC educates more than 19,000 students every year at locations throughout Snohomish County, Washington, with most students and faculty at the main campus in E ...

), and, instead of the

which he thought was too big, opted for

Western Washington University Western Washington University (WWU or Western) is a public university in Bellingham, Washington. The northernmost university in the contiguous United States, WWU was founded in 1893 as the state-funded New Whatcom Normal School, succeeding a pri ...

in Bellingham,

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

in 1966. He graduated with a BA in Biology in 1970. He discovered his passion for

microbiology Microbiology () is the scientific study of microorganisms, those being unicellular (single cell), multicellular (cell colony), or acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, bacteriology, ...

during his

undergraduate Undergraduate education is education conducted after secondary education and before postgraduate education. It typically includes all postsecondary programs up to the level of a bachelor's degree. For example, in the United States, an entry-le ...

years, so despite initially planning to pursue

biochemistry Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology ...

for

postgraduate Postgraduate or graduate education refers to academic or professional degrees, certificates, diplomas, or other qualifications pursued by post-secondary students who have earned an undergraduate ( bachelor's) degree. The organization and str ...

study, he eventually went to the

University of Iowa The University of Iowa (UI, U of I, UIowa, or simply Iowa) is a public research university in Iowa City, Iowa, United States. Founded in 1847, it is the oldest and largest university in the state. The University of Iowa is organized into 12 coll ...

to conduct microbiology research, where he obtained his MSc in Microbiology in 1972. Greenberg then started his

PhD PHD or PhD may refer to: * Doctor of Philosophy (PhD), an academic qualification Entertainment * '' PhD: Phantasy Degree'', a Korean comic series * ''Piled Higher and Deeper ''Piled Higher and Deeper'' (also known as ''PhD Comics''), is a newsp ...

at the

University of Massachusetts Amherst The University of Massachusetts Amherst (UMass Amherst, UMass) is a public research university in Amherst, Massachusetts and the sole public land-grant university in Commonwealth of Massachusetts. Founded in 1863 as an agricultural college, it ...

, and received his PhD in 1977.

Career

After obtaining his

, Greenberg spent time at

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

for postdoctoral work. He joined the Department of

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to ...

as an assistant professor in 1979, and was promoted to

associate professor Associate professor is an academic title with two principal meanings: in the North American system and that of the ''Commonwealth system''. Overview In the '' North American system'', used in the United States and many other countries, it is ...

in 1984. Greenberg went to the Department of Microbiology of the

as a

professor Professor (commonly abbreviated as Prof.) is an academic rank at universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who professes". Professor ...

in 1988, and returned to

in 2005 when he joined the Department of Microbiology of the

as head of the department. Outside of academia, Greenberg was an associate editor of the ''

Annual Review of Microbiology The ''Annual Review of Microbiology'' is a peer-reviewed academic journal that publishes review articles about microbiology. It was first published in 1947 as the third journal title released by Annual Reviews. It covers significant developments ...

'' from 1991 to 2001.

Research

Before the 1960s and 70s,

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

were thought to be independent organisms that do not communicate with one another. The first indication of inter-bacterial communication was reported by Alexander Tomasz in 1965, who found ''

Streptococcus pneumoniae ''Streptococcus pneumoniae'', or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic conditions), aerotolerant anaerobic member of the genus Streptococcus. They a ...

'' secretes a substance that allow other ''S. pneumoniae'' to take up foreign DNA. Then in 1970, John Woodland Hastings discovered that ''

Aliivibrio fischeri ''Aliivibrio fischeri'' (also called ''Vibrio fischeri'') is a Gram-negative, rod-shaped bacterium found globally in marine environments. This species has bioluminescent properties, and is found predominantly in symbiosis with various marine an ...

'' produced light and became

bioluminescent Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some b ...

under high

cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...

density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematicall ...

but not in diluted concentration, a phenomenon known as autoinduction. The molecule that ''A. fischeri'' secretes for autoinduction is called an

autoinducer Autoinducers are signaling molecules that are produced in response to changes in cell-population density. As the density of quorum sensing bacterial cells increases so does the concentration of the autoinducer. Detection of signal molecules by ba ...

, which was not identified until 1981. In 1985, Greenberg reported that, instead of a complex mechanism, the autoinducer simply passively diffuses from one bacterial cell to another, revealing one of the mechanisms of bacterial communication. He switched course after moving to the

, focusing on the luxR

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...

in ''A. fischeri''; the protein is a

transcription factor In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The fu ...

activated by the autoinducer. Research by Greenberg's team confirmed the

C-terminus The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein i ...

of luxR binds DNA while its

N-terminus The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...

binds the autoinducer. In a seminal article in 1994, Greenberg, together with Claiborne (Clay) Fuqua and Stephen Winans, at the time both from

, coined the term

to describe the behavior of autoinduced bioluminescence in ''A. fischeri'' and other bacterial

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

. Greenberg has also branched out from ''A. fischeri'', collaborating with Barbara Iglewski at the

University of Rochester The University of Rochester (U of R, UR, or U of Rochester) is a private university, private research university in Rochester, New York. The university grants Undergraduate education, undergraduate and graduate degrees, including Doctorate, do ...

to study quorum sensing in ''

Pseudomonas aeruginosa ''Pseudomonas aeruginosa'' is a common encapsulated, gram-negative, aerobic– facultatively anaerobic, rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, ''P. aer ...

'', the

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable d ...

of which is the primary cause of death in

cystic fibrosis Cystic fibrosis (CF) is a rare genetic disorder that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. Long-term issues include difficulty breathing and coughing up mucus as a result of frequent lung infections. ...

patients. The collaboration stemmed from Iglewski's discovery in 1991 of a ''P. aeruginosa''

gene In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

coding for a transcription factor protein that controls the expression of genes which, in turn, control its

virulence Virulence is a pathogen's or microorganism's ability to cause damage to a host. In most, especially in animal systems, virulence refers to the degree of damage caused by a microbe to its host. The pathogenicity of an organism—its ability to ...

. The closest relative of the transcription factor, in terms of protein sequence, was the luxR protein. This partnership led to the discovery of three quorum sensing signaling pathways in ''P. aeruginosa''. His research in quorum sensing led Greenberg to study the phenomenon of

biofilm A biofilm comprises any syntrophic consortium of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular ...

, which is a high-density cluster of

that attaches to each other and to surfaces and is embedded in an

extracellular matrix In biology, the extracellular matrix (ECM), also called intercellular matrix, is a three-dimensional network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide struc ...

. Notably, bacteria in biofilms are more resistant to

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy, ...

s than their free-living counterparts. In 1998, Greenberg, Iglewski, and J. William Costerton reported the link between quorum-sensing genes and biofilm formation, the first publication to show a genetic factor in biofilm structure. Over the next years, he kept studying biofilms and their effects on diseases, discovering that lungs of

patients are infected with biofilms, and that

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

is required for ''P. aeruginosa'' biofilm formation.

Personal life

Greenberg met his wife, Caroline Harwood, during his

years at the

. They started dating when he was a

postdoctoral researcher A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). The ultimate goal of a postdoctoral research position is to pu ...

, and were married in 1984. Harwood is currently also a

at the Department of

of the

Honors and awards

Fellow A fellow is a concept whose exact meaning depends on context. In learned or professional societies, it refers to a privileged member who is specially elected in recognition of their work and achievements. Within the context of higher education ...

of the

American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is an American international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsi ...

(1989) * Member of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, ...

(2002) *

Member Member may refer to: * Military jury, referred to as "Members" in military jargon * Element (mathematics), an object that belongs to a mathematical set * In object-oriented programming, a member of a class ** Field (computer science), entries in ...

of the

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nat ...

(2004) * Shaw Prize in Life Science and Medicine (2015) * Princess of Asturias Award for Technical and Scientific Research (2023) *

Canada Gairdner International Award The Canada Gairdner International Award is given annually by the Gairdner Foundation at a special dinner to five individuals for outstanding discoveries or contributions to medical science. Receipt of the Gairdner is traditionally considered a ...

(2023)

References

{{DEFAULTSORT:Greenberg, Everett Peter 1948 births Living people American microbiologists Everett Community College alumni Cornell University faculty University of Iowa faculty University of Washington faculty Western Washington University alumni University of Iowa alumni University of Massachusetts Amherst alumni Fellows of the American Academy of Arts and Sciences Fellows of the American Association for the Advancement of Science Members of the United States National Academy of Sciences Scientists from New York City