Dr. James Maki
Dr. James MakiMarquette University

Wehr Life Sciences, 407

MilwaukeeWI53201United States of America
(414) 288-7311


Microbial ecology



B.S. 1975, Whitworth College, Spokane, WA
Ph.D. 1982, University of Wisconsin-Milwaukee
Postdoctoral Fellow, University of Washington, Seattle, WA
Research Associate, Harvard University, Cambridge, MA

Research Interests

Microbial Ecology

The research in my laboratory involves the study of microorganisms and their interactions with their biotic and abiotic environments. These studies generally use a combination of molecular techniques and traditional culture/enrichment microbiology to examine microbial and/or gene diversity, abundance and activity.

We continue to examine microbial communities in anaerobic digesters in collaboration with colleagues in the Department of Civil, Construction and Environmental Engineering at Marquette. The goals of this research are to enhance methane production and to determine the identity of beneficial microorganisms that can be used in bioaugmention to significantly shorten new digester startup times and/or to aid the recovery of stressed digesters. Anaerobic digestion is a microbial community interrelated process that breaks down organic matter ultimately resulting in the production of biogas, containing methane. Methane is produced by archaea known as methanogens and we are using a variety of molecular techniques to determine their abundance, activity and diversity in different anaerobic biomass. However, they are not the only microorganisms involved in the organic breakdown, so we have been developing molecular methods to analyze the members of the microbial community participating in the steps preceding methane production.  The information we are obtaining will be used to design anaerobic cultures that can bioaugment a variety of different digester situations.

Additional research involves the role of microbial biofilms in biofouling by larval and adult zebra (Dreissena polymorpha) and quagga (D. bugensis) mussels. The zebra and quagga mussels are bivalves that invaded the North American Great Lakes sometime in the mid-to-late 1980s and have since spread through interconnected waterways across much of the United States. Both animals represent potentially expensive fouling problems to industrial and municipal concerns. Our field studies have shown that the effect of natural biofilms on zebra mussel larval attachment varies between the substrata that the biofilms develop on. On one substratum biofilms stimulated larval attachment while on another they had no effect. Laboratory studies showed that natural biofilms could also influence the byssal thread reattachment of young adult mussels. Additional experiments demonstrated that monospecies bacterial biofilms on specific substrata and in some cases the cell-free extracellular polymers of these biofilms inhibited reattachment of young adult mussels. The research is focused on the study of the extracellular polymers of these bacteria. The goal is to determine if natural products can be isolated from the bacteria that either stimulate or more importantly inhibit attachment of zebra and/or quagga mussels.

We are also doing research on the microbiome of rice plants, particularly those bacteria that are considered plant growth promoting and are found either on the root surface (rhizoplane) or inside the plant itself (endophytic).

We also study biofilm formation by oral microorganisms and its control in collaboration with investigators from the Marquette University School of Dentistry. The goal is to find better methods to prevent infection and re-infection of teeth and tissues.

Selected Publications

Bhattad, U., K. Venkiteshwaran, J.S. Maki & D.H. Zitomer (2017) Biochemical methane potential assays and anaerobic digester bioaugmentation using freeze dried biomass. Environmental Science: Water Research & Technology 3: 1152-1161

Bhattad, U., K. Venkiteshwaran, K. Cherukuri, J.S. Maki & D.H. Zitomer (2017) Activity of methanogenic biomass after heat and freeze-drying in air. Environmental Science: Water Research & Technology 3: 462-471

Morris, R.L., V.P. Tale, P.P. Mathai, D.H. Zitomer & J.S. Maki (2016) mcrA gene abundance correlates with hydrogenotrophic methane production rates in full-scale anaerobic waste treatment systems. Letters in Applied Microbiology 62: 111-118.

Rittschof, D., C. Chai, S.L.M. Teo & J.S. Maki (2015) Fouling and its next generation management: a perspective. Journal of Agricultural and Marine Sciences 19: 16-23.

Ventkiteshwaran, K., B. Bocher, J. Maki & D. Zitomer (2015) Relating anaerobic digestion microbial community and process function. Microbiology Insights 8(S2): 37-44.

Mathai, P.P., D.H. Zitomer & J.S. Maki (2015) Quantitative detection of syntrophic fatty acid degrading bacterial communities in methanogenic environments. Microbiology 161: 1189-1197.

Bocher, B.T.W., K. Cherukuri, J.S. Maki, M. Johnson & D.H. Zitomer (2015) Relating methanogen community structure and anaerobic digester function. Water Research 70: 425-435.

Tale, V.P., J.S. Maki & D.H. Zitomer (2015) Bioaugmentation of overloaded anaerobic digesters restores function and archael community. Water Research 70: 138-147.

Morris, R.L., Schauer-Gimenez A.E., Bhattad U., Kearney C., Struble C.A., Zitomer D.H., & J.S. Maki. (2014) Methyl coenzyme M reductase (mcrA) gene abundance correlates with activity measurements of methanogenic H2/CO2 enriched anaerobic biomass. Microbial Biotechnology 7: 77-84

Maki, J.S. (2013) Bacterial intracellular sulfur globules: structure and function. Journal of Molecular Microbiology and Biotechnology 23: 270-280.

Chen, C.-L., J.S. Maki, D. Rittschof, & S.L.-M. Teo. (2013) Early marine bacterial biofilm on a copper-based antifouling paint. International Biodeterioration & Biodegradation 83: 71-76.

Selected Presentations

Mathai, P.P., C.M. Brown, D.H. Zitomer, J.S. Maki, & M.J. Sadowsky (2016) Identification of microbial communities indicative of process imbalance in methanogenic reactors. 52B. ISME 16, August 21-26, 2016, Montreal, Canada

Walsh, M. A.D. Kappell, K. Shelledy, J. Maki, & K.R. Hristova (2016) The invader invaded: antibiotic resistant bacteria and genes in Lake Michigan mussel microbiomes. 250A. ISME 16, August 21-26, 2016, Montreal, Canada.

Kappell, A.D., M.J. Walsh, K. Paavola, T. Metcalf, J.S. Maki & K.R. Hristova (2016) Transfer of antibiotic resistance between bacteria within quagga mussels. Sunday 191, ASM Microbe 2016, June 16-20, Boston, MA.

Kavouras, J.H., & J.S. Maki (2015) Biofilms and their role in the reattachment of quagga mussels. 36, 7th ASM Conference on Biofilms, October 24-29, 2015, Chicago, Ill.

Mathai, P.P., M. Martin, K. Venkiteshwaran, D.H. Zitomer & J.S. Maki (2015) Syntrophic microbial communities drive functional resilience in anaerobic reactors in response to organic overload perturbations. 2643. 115th General Meeting of the American Society for Microbiology, May 30 – June 2, New Orleans, LA.

Mathai, P.P., K. Venkiteshwaran, B.T. Bocher, D.H. Zitomer & J.S. Maki (2014) Quantitative significance of syntrophic propionate degrading bacteria in anaerobic digestion process. 2307. 114th General Meeting of the American Society for Microbiology, May 17-20, Boston, MA

Mathai, P.P., & J.S. Maki (2013) Quantitative detection of syntrophic fatty-acid degrading bacteria in anaerobic environments. 113th General Meeting of the American Society for Microbiology, May 18-22, Denver, CO

Current Students

Nasim Maghboli Balasjin (co-mentored with Dr. Michael Schlappi)

Dr. Maki is NOT currently accepting new Ph.D. students into his lab

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Department of Biological Sciences

Wehr Life Sciences, 109
1428 W. Clybourn St.
Milwaukee, WI 53233

(414) 288-7355

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