Microbial Biology

University of California, Berkeley

About the Program

Bachelor of Science (BS)

The Department of Plant and Microbial Biology (PMB) offers an undergraduate major program in Microbial Biology, leading to a Bachelor of Science (BS) degree. Microbial biology focuses on small life forms such as microbes, viruses, and fungi that make up the majority of planetary biomass. Microbes play fundamental roles in maintaining biosphere health. They degrade environmental pollutants, supply essential nutrients and chemicals directly to multicellular organisms, and engage in numerous beneficial symbioses with higher organisms.

Admission to the Major

Advice on admission for freshmen and transfer students can be found on the Rausser College of Natural Resources Admissions Guide page or the college's Prospective Student website. Freshman students may apply directly to the major, or they may select the Rausser College of Natural Resource's undeclared option and declare the major by the end of their fourth semester. Transfer students may apply directly to the major through the UC application.

Information for current Berkeley students who would like to declare the major after admission, including information on a change of major or change of college, please see chapter 6 of the Rausser College of Natural Resources Undergraduate Student Handbook.

Research Opportunities

In addition to the Berkeley campus Undergraduate Research Apprenticeship Program (URAP), Rausser College students can also apply for the college's Sponsored Projects for Undergraduate Research (SPUR) program. For more information, please see the college's website.

Honors Program

Students with a GPA of 3.6 or higher may enroll in the Rausser College of Natural Resources Honors Program (H196) once they have reached upper division standing. To fulfill the program requirements, students work with a faculty sponsor to design, conduct, and report on an individual research project. For further information about registration for the honors symposium and the honors requirements, please see the college's website.

Other Major Program offered by the Department of Plant and Microbial Biology

Genetics and Plant Biology (Major only)

Visit Department Website

Major Requirements

In addition to the University, campus, and college requirements, listed on the College Requirements tab, students must fulfill the below requirements specific to their major program.

General Guidelines

  1. All courses taken to fulfill the major requirements below must be taken for graded credit, other than courses listed which are offered on a Pass/No Pass basis only. Other exceptions to this requirement are noted as applicable.

  2. A minimum cumulative grade point average (GPA) of 2.0 is required.

  3. A minimum GPA of 2.0 in upper division major requirements is required.

  4. At least 15 of the 36 required upper division units must be taken in the Rausser College of Natural Resources.

  5. A maximum of 16 units of independent study (courses numbered 97, 98, 99, 197, 198, and 199) may count toward graduation, with a maximum of 4 units of independent study per semester.

  6. No more than 1/3 of the total units attempted at UC Berkeley may be taken Pass/Not Pass. This includes units in the Education Abroad Program and UC Intercampus Visitor or Exchange Programs.

  7. A maximum of 4 units of physical education courses will count toward graduation.

For information regarding residence requirements and unit requirements, please see the College Requirements tab.

Lower Division Requirements

Reading and Composition Requirement

Students are required to complete the reading and composition requirement by the end of their sophomore year. 

Humanities & Social Sciences Requirement

Fifteen (15) units of coursework need to be taken from L&S breadth list, excluding biological and physical science courses. A maximum of 6 foreign language units can be used to fulfill the requirement.

MATH 10AMethods of Mathematics: Calculus, Statistics, and Combinatorics 14
MATH 10BMethods of Mathematics: Calculus, Statistics, and Combinatorics 14
General Chemistry
and General Chemistry Laboratory
Chemical Structure and Reactivity
and Organic Chemistry Laboratory
Chemical Structure and Reactivity
and Organic Chemistry Laboratory
General Biology Lecture
and General Biology Laboratory
BIOLOGY 1BGeneral Biology Lecture and Laboratory4
PHYSICS 8AIntroductory Physics4
Recommended, not required: PLANTBI 22

Upper Division Requirements 

Upper Division Core Requirements
MCELLBI 102Survey of the Principles of Biochemistry and Molecular Biology4
General Microbiology
and General Microbiology Laboratory
PLANTBI C112LGeneral Microbiology Laboratory2
PLANTBI C148Microbial Genomics and Genetics4
Upper Division Core Electives
Select two of the following:
PLANTBI C103Bacterial Pathogenesis3-4
or INTEGBI 118 Organismal Microbiomes and Host-Pathogen Interactions
or PB HLTH 162A Public Health Microbiology
PLANTBI 104LDiscovery-Based Research in Microbiology2
PLANTBI C110LBiology of Fungi with Laboratory4
PLANTBI 113California Mushrooms3
PLANTBI C114Introduction to Comparative Virology4
PLANTBI C116Microbial Diversity3
Biology of Algae
and Laboratory for Biology of Algae
PLANTBI 165Plant-Microbe Interactions3
ESPM 112Microbial Ecology3
or ESPM 131 Soil Microbiology and Biogeochemistry

Microbial Biology Concentrations

Option 1: Choose four courses from one of the concentrations below. One of the four courses may be selected from the upper division core electives list above, but may not be counted for both the upper division core elective requirement and your concentration.

Option 2: General Microbiology Concentration. Select any four courses from the concentrations below and/or the upper division core elective list above. Courses selected for Option 2 may not overlap with the courses used to fulfill the upper division elective requirement.

Host-Pathogen Interactions

PLANTBI 135Physiology and Biochemistry of Plants3
PLANTBI 150Plant Cell Biology3
PLANTBI 160Plant Molecular Genetics 13-4
or MCELLBI 140 General Genetics
PLANTBI 185Techniques in Light Microscopy3
BIO ENG 100Ethics in Science and Engineering 13-4
or ESPM 162 Bioethics and Society
INTEGBI 115Introduction to Systems in Biology and Medicine4
INTEGBI 119Evaluating Scientific Evidence in Medicine3
MCELLBI 104Genetics, Genomics, and Cell Biology4
MCELLBI 137LPhysical Biology of the Cell3
MCELLBI 150Molecular Immunology4
PB HLTH 150AIntroduction to Epidemiology and Human Disease4
PB HLTH 150BHuman Health and the Environment in a Changing World3
PLANTBI H196Honors Research - Plant and Microbial Biology3-4
or PLANTBI 199 Supervised Independent Study and Research

Evolution/Computational Genomics 

BIO ENG 131Introduction to Computational Molecular and Cell Biology4
BIO ENG 135Frontiers in Microbial Systems Biology4
BIO ENG 143Computational Methods in Biology 14
or MATH 127 Mathematical and Computational Methods in Molecular Biology
BIO ENG 144Introduction to Protein Informatics4
BIO ENG 144LProtein Informatics Laboratory3
COMPSCI 61AThe Structure and Interpretation of Computer Programs 24
COMPSCI 61BData Structures 24
INTEGBI 160Evolution 14
or INTEGBI 161 Population and Evolutionary Genetics
INTEGBI C166Biogeography4
MCELLBI 140General Genetics4
MCELLBI 143Evolution of Genomes, Cells, and Development3
PLANTBI H196Honors Research - Plant and Microbial Biology3-4
or PLANTBI 199 Supervised Independent Study and Research

Ecology & Environmental Microbiology 

PLANTBI C192Molecular Approaches to Environmental Problem Solving2
BIO ENG 100Ethics in Science and Engineering 13-4
or ESPM 162 Bioethics and Society
BIO ENG 135Frontiers in Microbial Systems Biology4
ESPM 134Fire, Insects, and Diseases in Forest Ecosystems3
INTEGBI 153Ecology3
INTEGBI 161Population and Evolutionary Genetics4
INTEGBI 162Ecological Genetics4
INTEGBI C166Biogeography4
PLANTBI H196Honors Research - Plant and Microbial Biology3-4
or PLANTBI 199 Supervised Independent Study and Research

Microbial Biotechnology 

BIO ENG 100Ethics in Science and Engineering 13-4
or ESPM 162 Bioethics and Society
MCELLBI 104Genetics, Genomics, and Cell Biology4
MCELLBI 137LPhysical Biology of the Cell3
MCELLBI 140General Genetics4
PLANTBI 122Bioenergy2
PLANTBI C124The Berkeley Lectures on Energy: Energy from Biomass3
PLANTBI 150Plant Cell Biology3
PLANTBI 170Modern Applications of Plant Biotechnology2
PLANTBI C192Molecular Approaches to Environmental Problem Solving2
PLANTBI H196Honors Research - Plant and Microbial Biology3-4
or PLANTBI 199 Supervised Independent Study and Research

College Requirements

Reading and Composition

In order to provide a solid foundation in reading, writing and critical thinking all majors in the College require two semesters of lower division work in composition. Students must complete a first-level reading and composition course by the end of their second semester and a second-level course by the end of their fourth semester.

Foreign LanguageEEP Majors only

The Foreign Language requirement is only required by Environmental Economics and Policy (EEP) majors. It may be satisfied by demonstrating proficiency in reading comprehension, writing, and conversation in a foreign language equivalent to the second semester college level, either by passing an exam or by completing approved course work.

Quantitative ReasoningEEP Majors only

The Quantitative Reasoning requirement is only required by Environmental Economics and Policy (EEP) majors. The requirement may be satisfied by exam or by taking an approved course.

Undergraduate Breadth

Undergraduate breadth provide Berkeley students with a rich and varied educational experience outside of their major program and many students complete their breadth courses in their first two years. Breadth courses are built into the Rausser College major requirements and each major requires a different number of breath courses and categories. The EEP major is the only college major that requires the entire 7 course breadth. Refer to the major snapshots on each Rausser College major page for for additional information. 

High School Exam Credit

Rausser College students may apply high school exam credit (Advanced Placement, International Baccalaureate, A-Level Exam) towards many College and Major Requirements. See AP Exam Equivalency Chart and Higher Level IB Exam Equivalency Chart in the Rausser College Student Handbook for more information.

Unit Requirements

Students must complete at least 120 semester units of courses subject to certain guidelines:

  • At least 36 units must be upper division courses, including a minimum of 15 units of upper division courses in the Rausser College. 
  • A maximum of 16 units of Special Studies coursework (courses numbered 97, 98, 99, 197, 198, or 199) is allowed towards the 120 units; a maximum of four is allowed in a given semester.
  • A maximum of 4 units of Physical Education from any school attended will count towards the 120 units.
  • Students may receive unit credit for courses graded P (including P/NP units taken through EAP) up to a limit of one-third of the total units taken and passed on the Berkeley campus at the time of graduation.

Semester Unit Minimum

All Rausser College students must enroll in at least 12 units each fall and spring semester.

Semester Unit Maximum

To request permission to take more than 20.5 units in a semester, please see the major adviser.

Semester Limit

Students admitted as freshmen must graduate within 8 fall/spring semesters at UC Berkeley. Students admitted as transfer students must graduate within 4 fall/spring semesters at UC Berkeley. Students who go on EAP and UCDC can petition for additional semesters. Summer session, UC Extension and non-UC study abroad programs do not count towards this semester limit. Students approved for double majors or  simultaneous degrees in two colleges may be granted an additional semester. Rausser College does not limit the number of total units a student can accrue.

Senior Residence Requirement

Once you achieve and exceed 90 units (senior status), you must complete at least 24 of the remaining 30 units in residence at the Rausser College of Natural Resources over at least 2 semesters. To count as residence, a semester must consist of at least 6 passed units taken while the student is a member of Rausser. At least one of the two terms must be a fall or spring semester. Senior residence terms do not need to be completed consecutively. All courses offered on campus for the fall, spring, and summer terms by Berkeley departments and programs and all Berkeley online ('W') courses count. Inter-campus Visitor, Education Abroad Program, UC Berkeley Washington Program, and UC Berkeley Extension units do not count toward this requirement.  Students may use Summer Session to satisfy one semester of the Senior Residence Requirement, provided that 6 units of coursework are completed.

Modified Senior Residence Requirement

Participants in a fall, spring or summer UC Education Abroad Program (UCEAP), Berkeley Summer Abroad, or the UC Berkeley Washington Program may meet a modified Senior Residence Requirement by completing 24 of their final 60 semester units in residence (excluding UCEAP). At least 12 of these 24 units must be completed after senior status is reached. International travel study programs sponsored by Summer Sessions and education abroad programs offered outside of the UC system do not qualify for modified senior residence.

Most students automatically satisfy the residence requirement by attending classes here for four years. In general, there is no need to be concerned about this requirement, unless students go abroad for a semester or year or want to take courses at another institution or through University Extension during their senior year. In these cases, students should make an appointment to see an adviser to determine how they can meet the Senior Residence Requirement.

Grade Requirements

  • A 2.0 UC GPA is required for graduation.
  • A 2.0 average in all upper division courses required of the major program is required for graduation.
  • A grade of at least C- is required in all courses for the major

Student Learning Goals

Learning Goals for the Major

Students should be able to do the following:

  1. Demonstrate a solid grasp of the fundamentals of biology, chemistry, and math that are necessary for understanding the more advanced concepts that are presented in upper division major coursework.
  2. Have the skills to evaluate scientific information as a result of receiving adequate training in statistics, computational biology and genomics.
  3. Have an understanding and appreciation of microbial diversity in various ecosystems.
  4. Have an understanding of the importance of microbes as related to biotechnology and human health.
  5. Have an understanding of the scientific method and the microbial research process.
  6. Demonstrate proficiency in scientific writing and presentation.
  7. Have exposure to an undergraduate research experience. The goal is to give every microbial biology undergraduate the opportunity to do research in either a laboratory or field research setting. This experience would include reading and evaluating primary literature, critical thinking and the development of a hypothesis to test and other aspects of the scientific method including data analysis, as well as oral and written presentation of their research.
  8. Appreciate the relationship between a microbial biology major and the community at large.

Major Map

Major Maps help undergraduate students discover academic, co-curricular, and discovery opportunities at UC Berkeley based on intended major or field of interest. Developed by the Division of Undergraduate Education in collaboration with academic departments, these experience maps will help you:

  • Explore your major and gain a better understanding of your field of study

  • Connect with people and programs that inspire and sustain your creativity, drive, curiosity and success

  • Discover opportunities for independent inquiry, enterprise, and creative expression

  • Engage locally and globally to broaden your perspectives and change the world

  • Reflect on your academic career and prepare for life after Berkeley

Use the major map below as a guide to planning your undergraduate journey and designing your own unique Berkeley experience.

View the Microbial Biology Major Map PDF.


In the Rausser College of Natural Resources, we provide holistic, individual advising services to prospective and current students who are pursuing major and minors in our college. We assist with a range of topics including course selection, academic decision-making, achieving personal and academic goals, and maximizing the Berkeley experience.

If you are looking to explore your options, or you are ready to declare a major, double major, or minor, contact the undergraduate advisor for your intended major or minor. Visit our website to explore all of our advising services.

Undergraduate Adviser, Microbial Biology
Patricia Helyer
260 Mulford Hall


Microbial Biology

Faculty and Instructors

+ Indicates this faculty member is the recipient of the Distinguished Teaching Award.


Barbara Baker, Adjunct Professor. Biochemistry, genetics, signal transduction, plant and microbial biology, biolomolecular mechanisms of plant resistance to microbial disease, plant pathogen recognition, plant resistance to pathogen diseases, tobacco mosaic virus, agriculture and crops.
Research Profile

Benjamin Blackman, Assistant Professor. Evolution, adaptation, domestication, phenotypic plasticity, flowering time, evo-devo, genomics, plant biology.

Rachel B. Brem, Associate Adjunct Professor. Genetics of regulatory variation.
Research Profile

Steven Brenner, Professor. Molecular biology, computational biology, evolutionary biology, bioengineering, structural genomics, computational genomics, cellular activity, cellular functions, personal genomics.
Research Profile

Thomas D. Bruns, Professor. Microbial biology, plant biology, fungi, nucleic acid sequences, basidomycetes, ectomycorrhizal fungi communities.
Research Profile

John Coates, Professor. Environmental microbiology, Bioremediation, alternative energy production, biogeochemistry.
Research Profile

Devin Coleman-Derr, Assistant Adjunct Professor. Plant, Microbiome, Environmental Stress, Drought, Sorghum.
Research Profile

+ Lewis J. Feldman, Professor. Microbial biology, plant biology.
Research Profile

Robert L. Fischer, Professor. Plant and microbial biology.
Research Profile

Jennifer C. Fletcher, Adjunct Professor. Molecular biology, genetics, gene regulation, stem cells, plant development.
Research Profile

Michael Freeling, Professor. Genetics, genomics, plants, trends in evolution.
Research Profile

N. Louise Glass, Professor. Biofuels, biotechnology, fungal genetics, fungal cell biology.
Research Profile

Britt Glaunsinger, Associate Professor. Virology, gene expression, herpesvirus.
Research Profile

Igor V. Grigoriev, Adjunct Professor. Genomics, fungi, algae, eukaryotes, computational biology, bioinformatics, genome annotation.
Research Profile

Sarah Hake, Adjunct Professor.

Frank Harmon, Associate Adjunct Professor.

Russell L. Jones, Professor. Plant and microbial biology.
Research Profile

Cheryl Kerfeld, Associate Adjunct Professor. Bacterial microcompartments, bioinformatics, photosynthesis, synthetic biology, Structural Biology, carboxysome, cyanobacteria, photoprotection.
Research Profile

Arash Komeili, Associate Professor. Microbiology, Biomineralization, bacterial organelles, Magnetic Nanoparticles.
Research Profile

Peggy G. Lemaux, Cooperative Extension Specialist.

Jennifer Lewis, Assistant Adjunct Professor. Plant-pathogen interactions, plant immunity, type III effector proteins.
Research Profile

Steven E. Lindow, Professor. Microbial ecology, microbial biology, plant biology, plant frost control, bacterial plant diseases, plant disease epidemiology.
Research Profile

Sheng Luan, Professor. Microbial biology, plant biology.
Research Profile

Sheila Mccormick, Adjunct Professor. Molecular biology, genetics, pollen, plant reproduction.
Research Profile

Anastasios Melis, Professor. Photosynthesis, Metabolic Engineering, bioenergy.
Research Profile

Krishna K. Niyogi, Professor. Genetics, plant and microbial biology, algae, photosynthesis, antioxidants.
Research Profile

Markus Pauly, Professor. Cell walls, extracellular matrix, plants, polysaccharides, carbohydrates, lignin, nucleotide sugars, analytical carbohydrate chemistry, plant genomics, enzyme biochemistry.
Research Profile

Daniel A. Portnoy, Professor. Mammalian cells, molecular and cellular basis of microbial pathogenesis, defense against infection, listeria monocytogenes, cell biology of infection, mechanisms of secretion.
Research Profile

Peter Quail, Professor. Plant biology, plant and microbial biology.
Research Profile

Kathleen Ryan, Associate Professor. Bacterial cell cycle regulation, signal transduction, and regulated proteolysis.
Research Profile

Henrik Scheller, Adjunct Professor. Biofuels, polysaccharides, plant cell walls, biochemistry, plant biotechnology, glycosylation.
Research Profile

Kimberly Seed, Assistant Professor. Interactions between bacteria and their viral predators (bacteriophages).
Research Profile

Chris Somerville, Professor. Biochemistry, biotechnology, bioenergy, cell biology, biofuels, cell walls, polysaccharides, cellulose, arabidopsis, cellulose synthase.
Research Profile

Shauna Somerville, Professor. Powdery mildew disease, cell wall integrity sensing, plant-fungal interactions, plant cell walls.
Research Profile

Chelsea Specht, Associate Professor. Molecular evolution, adaptation, plant systematics, evolution of development (evo-devo), evolution of form and function, plant morphology, comparative phylogenetics, floral developmental evolution, diversification rates.
Research Profile

Brian J. Staskawicz, Professor. Biotechnology, plant and microbial biology.
Research Profile

Zinmay Sung, Professor. Plant biology, plant and microbial biology.
Research Profile

Michiko Taga, Assistant Professor. Molecular biology, genetics, microbial biology, chemical biology, cofactors, nutrient exchange, microbial communities.
Research Profile

John Taylor, Professor. Evolution, fungi, phylogenomics, mycology, population genomics.
Research Profile

Norman Terry, Professor. Phytoremediation, Bioremediation, environmental cleanup, soil and water, plant biology, microbial biology.
Research Profile

Matthew Traxler, Assistant Professor.

John Vogel, Adjunct Professor.

Mary Wildermuth, Associate Professor. Plant-pathogen interactions.
Research Profile

Patricia Zambryski, Professor. Microbial biology, plant biology, plant intercellular communication via plasmodesmata, Agrobacterium, bacterial type IV secretion.
Research Profile

Daniel Zilberman, Associate Professor. Developing science and tech solutions at the food, energy, and water nexus for under-resourced communities.

Emeritus Faculty

Bob B. Buchanan, Professor Emeritus. Biotechnology, environmental policy, plant biology, thioredoxin.
Research Profile

Andrew Jackson, Professor Emeritus.

Contact Information

Department of Plant and Microbial Biology

111 Koshland Hall

Phone: 510-642-9999

Visit Department Website

Department Chair

John D. Coates

312G Energy Biosciences

Phone: 510-643-8455


Associate Chair

Sheng Luan

451 Koshland Hall

Phone: 510-642-6306


Undergraduate Advisor

Patricia Helyer

260 Mulford Hall

Phone: 510-643-9479


Graduate Advisor

Lyn Rivera

111C Koshland Hall

Phone: 510-642-5167


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