Member information

Find more information on the members of the Marine Natural Product Laboratory

Brad Haltli

Research Interests:
My research is focused on the discovery of novel bioactive natural products from marine microorganisms. Within this field I am interested in the biology, diversity and biogeography of prokaryotes from marine habitats. I am particularly interested in bacteria beloning to the bacterial class Actinomycetales. I am also interested in the genetic and biochemical processes involved in the production of natural products in marine microorganisms. In the Kerr research group I am responsible for directing mirobiology (bacteria)-related aspects of student projects.
Bachelor of Science, University College of the Cariboo (Thompson Rivers University), Kamloops, BC, Canada (1998).
Master of Science, Dalhousie University, Halifax, NS, Canada (2001)
Work Experience:
Research Scientist 1, Wyeth Research, Natural Products Discovery Research.  Pearl River, NY, USA, (2001-2008)
Research Manager, University of Prince Edward Island, Kerr Marine Natural Products Laboratory, Charlottetown, PE, Canada (2008 - )
Bacterial NP Discovery Group Leader, Nautilus Biosciences Canada Inc, Charlottetown, PE, Canada (2009-)
Peer-reviewed Publications

1.      Tangerina M.P., Correa H., Haltli B., Vilegas W., Kerr R.G. Bioprospecting from cultivable bacterial communities of marine sediment and invertebrates from the underexplored Ubatuba region of Brazil. Arch Microbiol. 2017 199: 155-169.
2.      McCauley E.P., Haltli B., Correa H., Kerr R.G. Spatial and temporal investigation of the microbiome of the Caribbean octocoral Erythropodium  caribaeorum. FEMS Micro Ecol. 2016 92: pii: fiw147. doi: 10.1093/femsec/fiw147.
3.      Robertson V.*, Haltli B.*, Overy D., Kerr R.G. Highly variable bacterial communities associated with the octocoral Antillogorgia elisabethae. Microorganisms 2016 4: pii:E23. doi: 10.3390/microorganisms 4030023.
4.      Pastrana-Camacho N., Suárez Z., Acosta-González A., Arango C., Haltli B., Correa H., Kerr R.G., Duque C., Diaz L.E. Bioprospecting for culturable actinobacteria with antimicrobial properties isolated from rivers in Colombian Orinoquia. Trop J Pharm Res. 2016 15: 1259-1265.
5.      Sommer B., Overy D.P., Haltli B., Kerr R.G. Secreted lipases from Malassezia globosa: recombinant expression and determination of their substrate specificities. Microbiology 2016 162: 1069-79.
6.      Herzog B., Overy D.P., Haltli B., Kerr R.G. Discovery of keratinases using bacteria isolated from marine environments. Syst Appl Microbiol. 2016 39: 49-57.
7.       Arens J.C., Haltli B., Kerr R.G. Draft Genome Sequence of Kitasatospora griseola Strain MF730-N6, a Bafilomycin, Terpentecin, and Satosporin Producer. Genome Announc. 2015  3: e00208-15.
8.      McCauley E.P., Haltli B., Kerr R.G. Description of Pseudobacteriovorax antillogorgiicola gen. nov., sp. nov., a bacterium isolated from the gorgonian octocoral Antillogorgia elisabethae, belonging to the family Pseudobacteriovoracaceae fam. nov., within the order Bdellovibrionales. Int J Syst Evol Microbiol. 2015 65: 522-30.
9.      Duncan K.R., Haltli B., Gill K.A., Correa H., Berrué F., Kerr R.G. Exploring the diversity and metabolic potential of actinomycetes from temperate marine sediments from Newfoundland, Canada. J Ind Microbiol Biotechnol. 2015 42: 57-72.
10.    Janso J.E., Haltli B.A., Eustáquio A.S., Kulowski K., Waldman A.J., Zha L., Nakamura H., Bernan V.S., He H., Carter G.T., Koehn F.E., Balskus E.P. Discovery of the lomaiviticin biosynthetic gene cluster in Salinispora pacifica. Tetrahedron. 2014 70: 4156-4164.
11.    Duncan K., Haltli B., Gill K. A., Kerr R.G. Bioprospecting from marine sediments of New Brunswick, Canada: exploring the relationship between total bacterial diversity and Actinobacteria diversity. Mar Drugs. 2014 12: 899-925.
12.    Correa H., Haltli B., Duque C., Kerr R.G. Bacterial communities of the gorgonian octocoral   Pseudopterogorgia elisabethae Microb Ecol. 2013 66: 972-85.
13.    Pike R.E., Haltli B., Kerr R. G. Description of Endozoicomonas euniceicola sp. nov. and Endozoicomonas gorgoniicola sp. nov., bacteria isolated from the octocorals Eunicea fusca and Plexaura sp., and an emended description of the genus Endozoicomona.  Int J Syst Evol Microbiol. 2013 63: 4294-4302.
14.    McCulloch M. W. B., Haltli B., Marchbank D. H., Kerr R. G. Evaluation of pseudopteroxazole and pseudopterosin derivatives against Mycobacterium tuberculosis and other pathogens. Mar Drugs. 2012 10: 1711-1728.
15.    McCulloch M.W.B., Berrue F., Haltli B., Kerr R.G. One-pot syntheses of pseudopteroxazoles from pseudopterosins: a rapid route to non-natural congeners with improved antimicrobial activity. J Nat Prod. 2011 74: 2250-2256.
16.    Jiang H., Haltli B., Feng X., Cai P., Summers M., Lotvin J., He M. Investigation of the biosynthesis of the pipecolate moiety of neuroprotective polyketide meridamycin. J Antibiot 2011 64: 533-538.
17.    Berrue F., Withers S. T., Haltli B., Withers J., Kerr R.G.  Chemical screening method for the rapid identification of microbial sources of marine invertebrate-associated metabolites.  Mar Drugs. 2011 9:  369-381.
18.    Liu H., Jiang H, Haltli B., Kulowski K., Muszynska E., Feng X., Summers M., Young M., Graziani E., Koehn F., Carter G. T., Min H.  Rapid cloning and heterologous expression of the meridamycin biosynthetic gene cluster using a versatile Escherichia coli-Streptomyces artificial chromosome vector, pSBAC. J Nat Prod. 2009 72 (3): 389-395.
19.    Ratnayake A. S., Haltli B., Feng X., Bernan V. S., Singh M. P., He H., Carter G.T.  Investigating the biosynthetic origin of the nitro group in pyrrolomycins. J Nat Prod. 2008 71 :  1923–1926.
20.    He M., Haltli B., Summers M., Feng X., Hucul J.A.  Isolation and characterization of the meridamycin biosynthetic gene cluster from Streptomyces species NRRL 30748.  Gene. 2006 377: 109-118.

21.   Magarvey N. A., Haltli B., He M., Greenstein M. and Hucul J.A.  Biosynthetic pathway for mannopeptimycins, lipoglycopeptide antibiotics active against drug-resistant gram-positive pathogens. Antimicrob Agents Chemother. 2006 50: 2167-2177.

22.   Haltli B., Tan Y., Magarvey N.A., Wagenaar M., Yin X., Greenstein M., Hucul J.A., Zabriskie T.M. Investigating beta-hydroxyenduracididine formation in the biosynthesis of the mannopeptimycins. Chem Biol. 2005 12(11): 1163-1168. 
23.   Ritacco F. V., Haltli  B., Janso J. E., Greenstein M., Bernan V.S.  Dereplication of Streptomyces soil isolates and detection of specific biosynthetic genes using an automated Ribotyping instrument. J Ind Microbiol Biotechnol. 2003 30: 472-479.


Logan MacIntyre

Research Interests:







Work Experience:

Stacey Goldberg

Research Interests:

Advancement of molecular methods for identification of bromotyrosine alkaloid derivatives from marine sponges and assessment of their therapeutic potential.
Marine sponges provide unique and diverse niches for microbial communities, where bacterial symbionts can account for up to 60% of the mesohyl biomass. Since habitat diversity typically correlates with microbial diversity and in turn, chemical diversity, it is not surprising that marine sponges are known for their rich arsenal of bioactive secondary metabolites. A high percentage of these metabolites belong to an interesting family of brominated tyrosine derived alkaloids that display antimicrobial and cytotoxic properties. There is increasing evidence that the symbiotic microbes are the true producers of these secondary metabolites, rather than the invertebrate host. Since a great majority of sponge microbes do not remain viable in culture, access to their secondary metabolites is limited. Thus, new approaches are needed to address this major obstacle of sustainably fermenting bioactive metabolites. The objective of this research is to assess the microbial diversity of selected marine sponges and determine the ability of sponge-associated microbes to produce brominated bioactive compounds. This will be accomplished by combining conventional methods with novel molecular-based approaches to study key genes involved in the biosynthesis of brominated compounds. The origin of the genes will then provide evidence to determine the biosynthetic producers of these brominated bioactive metabolites.
Ph.D. University of Prince Edward Island, Canada  (Sept 2012 - Current)
Biomedical Sciences, Marine Natural Products
M.S. Johns Hopkins University, Maryland  (Sept 2002-Sept 2005)
B.S. Towson University, Maryland  (Sept 1996-Dec 2000)
Biology with Chemistry minor


Work Experience:
Bermuda Institute of Ocean Sciences, St. George’s, Bermuda
Phytoplankton Ecology Lab – Marine Particle Imaging Lab
Research Technician (Jul 2010 –May 2012)
Responsibilities: Managed the Flow Cytometry Facility (MARPIL), through which every project in the Phytoplankton Ecology Lab (and other labs) was executed. In less than 2 years, became an expert in operating and troubleshooting the BD Influx flow cytometer and cell sorter and developed optimal efficiency for completing enumeration and 90-99% pure sorting of oceanic samples (phytoplankton, heterotrophic bacteria, and eukaryotes). As a Scientist on the R/V HSBC Atlantic Explorer (research vessel), executed Conductivity, Temperature, Depth (CTD) deployment, stable isotope incubations, and filtrations of ocean water samples. Solely responsible for converting MARPIL into a mobile ‘at sea’ lab on cruises lasting 5 – 17 days, for a total of 2 months at sea. This accomplishment placed me in a category of one of a few other scientists in the world who have been able to achieve a fully functioning flow lab at sea.
Meso-Scale Discovery, Maryland
Critical Reagents Group
Research Associate (Jan 2009-Jul 2010)
Responsibilities: Contributed to the development of sandwich based ELISA “type” assays, utilizing MSD proprietary Electro-chemiluminescence (ECL) and multi-array technologies, which are used by research laboratories and drug development companies around the world to analyze disease states through the characterization and quantification of biomarkers. Responsible for assessing and optimizing the critical reagents used to develop MSD assays that provided highly sensitive, quantified, reproducible results. Maintained inventory, proper handling and storage of critical reagents utilized for assays. •
Aeras Global TB Vaccine Foundation, Maryland
Immunology Vaccine Assessment Group
Research Specialist (Dec 2005-Dec 2008)
Responsibilities: Supervised the Vaccine Assessment group devoted to assessment of Tuberculosis vaccine studies using a variety of in vitro immunoassays, and executed analysis of multi-color flow cytometry data. Focused on looking for poly-functionality of cells and correlations with protection of TB. Successfully accelerated the validation and qualification of human Intracellular cytokine assay for use in Pre-clinical and Phase I clinical trials according to GLP regulations, and was responsible for writing qualified standard operating procedures (SOP) required for maintaining quality control of the assays.
Johns Hopkins University, Maryland
Cancer Research Department
Senior Lab Technician Jun 2002-Dec 2005
Responsibilities: Supported clinical oncology trials for AML/CML, Multiple Myeloma, and Hodgkins Lymphoma, where patients received GM-CSF producing vaccines. Processed clinical blood samples using density-gradient centrifugation (ficoll), isolated plasma and PBMC’s, and used cells in a variety of assays to assess immune response to vaccines.

Goldberg S., Mueller S., Brichetti J., Sadoff J. Cryo-preserved Whole Blood (WB) for use in Cell Mediated Immunity (CMI) Assays, Poster on behalf of Aeras Global TB Vaccine Foundation. TB Vaccines for the World Conference, Atlanta, GA (2008).

Casey, J.R., Aucan J.P., Goldberg S.R., Lomas M.W. Changes in partitioning of carbon amongst autotrophic pico- and nanoplankton groups in response to changes in the North Atlantic Oscillation. Deep Sea Research II: Topical Studies in Oceanography (Feb 2013).

Goldberg, S. Advancement of molecular methods for identification of bromotyrosine alkaloid derivatives from marine sponges and assessment of their therapeutic potential. Graduate Studies and Research Days, AVC, University of Prince Edward Island (2013). Gold Prize Award.

Hope Igboeli

Research Interests:
Work Experience:

Doug Marchbank

Research Interests:
My research is primarily focused on the discovery and development of natural products with a range of applications in human health and wellness. Our team utilizes a LC/MS-based metabolomics approach to profile microbial extracts and identify potentially novel compounds through statistical analysis. This work also includes purification and structure elucidation of natural products and characterization of their properties. My efforts are also focused on the synthesis of natural product analogues to expand our knowledge of structure-activity relationships and develop new lead compounds. As a senior chemist with Nautilus Biosciences, I am interested in the development of organic UV filters, biosurfactants, antimicrobials, and antioxidants.
PhD, University of Prince Edward Island (2013)
BSc (Hons) in Chemistry, University of Prince Edward Island (2008)
Work Experience:
Research Manager, Chemistry Department, University of Prince Edward Island (2015 - present)
Senior Scientist, Nautilus Biosciences Canada Inc., Charlottetown, PE, Canada (2015 - present)
Research Assistant, Agriculture and Agri-Food Canada, Lethbridge, AB, Canada (2014 - 2015)
Postdoctoral Fellow, University of Prince Edward Island (2013)
McCulloch, M.W.B.; Haltli, B.H.; Marchbank, D.H.; Kerr, R.G. Evaluation of pseudopteroxazole and pseudopterosin derivatives against Mycobacterium tuberculosis and other pathogens. Mar. Drugs 2012, 10, 1711-1728.
Marchbank, D.H.; Berrue, F.; Kerr, R.G. Eunicidiol, an anti-inflammatory dilophol diterpene from Eunicea fusca. J. Nat. Prod. 2012, 75, 1289-1293.
Marchbank, D.H.; Kerr, R.G. Semisynthesis of fuscoside B analogues and eunicosides, and analysis of anti-inflammatory activity. Tetrahedron 2011, 67, 3053-3061.

Leon Liang

Research Interests:
Secondly metabolite induction of microbial; biological screening methods; Organic synthesis.

2011-2013 Chemical Engineering, Hainan University

2013-present (transfer) Chemistry(Undergraduate), UPEI

Work Experience:
CHEN Da, JIA Chun-man, ZHANG Chun-yan, ZHANG Qi, CAO Li, SUN Lu, LIANG Li-bang. Synthesis of γ-Nitro Ester Compounds by Solvent-free Ball-milling Method[J]. Fine Chemicals, 2014, 31(1): 124-128.