Biology

Microbiology

cells-molecules-physiologygenetics-developmentmicrobiology

Microbiology

The Microbiology Area is especially strong in teaching students superior lab technique. Classes involve many hours perfecting skills in the lab, and address a wide variety of microbiological topics, including ones of medical interest, ecological relevance, and prokaryotic diversity.

Larry Baresi - methane-producing bacteria

Professor
D.P.H. University of California, Los Angeles
email: larry.baresi@csun.edu
Phone: 818-677-3495
Fax: 818-677-2034 
Office: Magnolia Hall 4201
Website

I have three major research interests. The first is the exploration of methane producing bacteria as a unified physiological, biochemical, and genetic model system. I am also interested in isolation and identification of extremophiles for evolutionary purposes.  Finally, I work on the identification and isolation of environmentally important bacteria involved in the remediation of toxic wastes. These three groups of bacteria survive and grow in unusually "extreme" environmental habitats. Such habitats may place constraints of pH, salt, or temperature on the physiology of these organisms, forcing them to develop unique molecular solutions, which may be harnessed for technological applications. I'm currently developing a genetic vector capable of transferring DNA between methanogens and other bacteria. This work includes techniques of genetic transformation, gene manipulation, gene cloning, DNA isolation and purification, and other molecular genetic techniques. My primary effort on extremophiles is the isolation, identification, enzymology, and physiology of these unique organisms. Such studies will suggest how these organisms evolved, and how these organisms might be applied to existing or new industrial processes and the problems of toxic waste remediation.

David Bermudes - live bacteria as therapeutic delivery vectors

David BermudesAssistant Professor
Ph.D. Boston University
email: david.bermudes@csun.edu
Phone: 818-677-6062
Fax: 818-677-2034
Office: Magnolia Hall 4216
Website

Certain pathogenic bacteria such as Salmonella typhimurium have the innate ability to target and selectively replicate within solid tumors in a number of different animal species, including humans. Pathogenic bacteria can be genetically modified in order to eliminate debilitating aspects of their pathogenesis while retaining their ability to traverse the body and target tumors.  My laboratory is exploring a variety of mutations in Salmonella that decrease pathogenesis and/or increase their ability to colonize solid tumors in order to identify strains that have the potential to serve as anticancer agents in humans. In these studies, and in attempts to understand the fundamental nature of the bacterial physiology relating to tumor-targeting, we have identified spontaneous and genetically engineered mutations that have compensatory functions relating to their ability to exist under mammalian physiological conditions and may have the ability to enhance their antitumor effects.

Kerry Cooper - the pathogenesis and genetics of foodborne pathogens

Assistant Professor
Ph.D. University of Arizona, Tucson
email: kerry.cooper@csun.edu
Phone: 818-677-6147
Fax: 818-677-2034
Office: Eucalyptus Hall 2209
Website

The CDC estimates that there are 65 million foodborne illnesses in the United States every year. Bacterial foodborne pathogens are a diverse group, and have evolved to survive and flourish in a wide range of environments. My research involves a variety of different aspects including epidemiology, epigenetics, transcriptomics, proteomics, comparative genomics, host-microbe interactions, molecular biology, and genetics, with the ultimate goal of developing methods to prevent foodborne illness.

Gilberto Flores - microbial ecology

Assistant Professor
Ph.D. Portland State University
email: gilberto.flores@csun.edu
Phone: 818-677-4276
Fax: 818-677-2034
Office: Eucalyptus Hall 2208
Website

I am an interdisciplinary scientist who specializes in microbial ecology, exploring the diversity and function of microbial communities in a wide range of environments. I use a combination of cutting-edge molecular biology/bioinformatics tools (such as high-throughput sequencing and genomics) and more traditional microbiological techniques (e.g. cultivation, fluorescent microscopy) to address fundamental questions about the ecology and evolution of microorganisms. I have worked in a wide array of environments including deep-sea hydrothermal vents, terrestrial hot-springs, public restrooms and the human body. Currently, I am leading a project examining the temporal variability of the healthy human microbiome using undergraduate students as the study population. Other research interests include microbial oceanography, the pan-genome, geomicrobiology, systems biology, bioremediation and archaeal ecology.

Rachel Mackelprang - environmental metagenomics

Rachel MackelprangAssistant Professor
Ph.D. University of Washington
Email: rachel.mackelprang@csun.edu
Phone: 818-677-4589
Fax: 818-677-2034
Office: Eucalyptus Hall 2207
Website

I am a genomicist focused on environmental metagenomics. Microbes are the engines that power fundamental biogeochemical cycles. Large-scale anthropogenic alterations in the environment are predicted to greatly affect microbial life, altering the balance of these cycles in the biosphere. While most microbes in the environment are recalcitrant to culturing, metagenomics provides access to the genomes of "inaccessible" organisms by isolating and sequencing all DNA from a particular environment. I am interested in leveraging ultra high-throughput sequencing, bioinformatic analysis, and microbiology-based approaches to study microbial community response to human-caused environmental perturbations and determine the impact of microbes on biogeochemical cycles. Current study systems include the thawing permafrost, the Gulf of Mexico Deepwater Horizon oil spill, and the great prairie of the Midwestern United States.

Sean Murray - bacterial cell cycle

Associate Professor
Ph.D. Yale University, 2003
email: sean.murray@csun.edu
Phone: 818-677-2950
Fax: 818-677-2034
Office: Eucalyptus Hall 2205
Website

The dimorphic bacterium Caulobacter crescentus is a model organism for studying the bacterial cell cycle. Its asymmetric cell division results in one swarmer and one stalked cell progeny. Motile swarmer cells can not undergo DNA replication until they differentiate into stationary stalked cells. If sufficient nutrients are available, swarmer cells eject their polar flagellum and build a stalk (with adhesive at its end; for attaching to a surface near nutrients) at the same pole formerly occupied by the flagellum. Stalked cells are competent for DNA replication and cell division. During cell division, a flagellum is placed at the pole opposite that of the stalk. Caulobacter's obligate cell cycle is controlled by oscillating master regulators that control different genetic modules in space and time. As a result of this carefully orchestrated process, a flagellum is synthesized only when needed (just prior to cell division) and is placed at the pole opposite that of the stalk. Likewise, a new stalk is synthesized only at the pole previously occupied by a flagellum. Our lab studies the roles of lipid biosynthesis in this process, using pharmacological, genetic, and molecular approaches. Only by further elucidating the control mechanisms of bacterial cell division can we advance the development of new antimicrobial compounds. Lipid biosynthesis is essential for cell viability and bacterial fatty acid synthetic enzymes have been suggested as antibiotic targets. In fact, compounds specific to bacterial fatty acid biosynthetic compounds have been generated. Most previous studies on bacterial lipid metabolism have focused on E. coli, a gamma-proteobacteria. Caulobacter in contrast, as an alpha-proteobacteria, is closely related to human pathogenic bacteria, such as Brucella and Rickettsia.

Michael Summers - genetics of cyanobacterial metabolism and differentiation

Michael SummersProfessor
Ph.D. University of California, Davis
email: michael.l.summers@csun.edu
Phone: 818-677-7146
Fax: 818-677-2034
Office: Eucalyptus Hall 2213
Website

My laboratory focuses on the problem of how bacteria regulate adaptive alterations of their cell morphology and physiology in response to environmental changes. I use Nostoc punctiforme for these studies. This filamentous cyanobacterium can differentiate from normal vegetative cells into nitrogen fixing heterocysts, resistant akinetes, or motile hormogonia, that move by gliding motility. Our research focuses on identification of genes involved in cellular differentiation of akinetes. Akinetes are resting cells capable of surviving long periods of desiccation and cold that differentiate from normal vegetative cells due to low light or phosphate starvation.

Paul Tomasek - molecular evolution and biochemistry of biodegradation by bacteria

Associate Professor
Ph.D. University of Minnesota
Website

My research interests center around the bacterial biodegradation of toxic compounds such as pesticides and other organic compounds that are not readily degraded in the environment. We identify bacteria with new biodegradation capabilities and study both the biodegradation enzymes and the structure and regulation of the corresponding genes. We routinely conduct enzyme purification and characterization studies and employ various molecular biological techniques to isolate and characterize biodegradation genes. Currently we are studying the degradation of multi-ring aromatic compounds, chlorinated aromatic compounds, and neurotoxic insecticides with particular emphasis on the ring-fission dioxygenases or hydrolases involved in the initial breakdown or detoxification of these compounds.

CROSS-AREA FACULTY, LECTURERS & RESEARCH SCIENTISTS

Cheryl Hogue

Vergine Madelian

Mary-Pat Stein