Rensselaer Polytechnic Institute | About RPI | Academics | Research | Student Life | Admissions | News & Events
Rensselaer Polytechnic Institute Department of Biological Sciences
Biology Faculty
* * * *
Department of Biological Sciences
1W14 Jonsson-Rowland Science Center
Rensselaer Polytechnic Institute
110 Eighth Street
Troy, NY 12180-3590

Phone: (518) 276-6446
Fax: (518) 276-2344

* * *
Biology Home Undergraduate Graduate Faculty Research News and Events Contacts
Henry L. Ehrlich

Professor Emeritus

Education and Training

B.S. Harvard College, Cambridge, MA
Biochemical Sciences

M.S. University of Wisconsin, Madison
Agricultural Bacteriology

Ph.D. University of Wisconsin, Madison
Major: Agricultural Microbiology; Minor: Biochemistry

Dr. Ehrlich joined the Biological Sciences Department faculty of RPI at the rank of Assistant Professor in 1951.  He attained the rank of Professor Emeritus in 1994.  He has continued as an active retiree.  He is a fellow of the American Academy of Microbiology and the American Association for the Advancement of Science.  He is included in the listings of Marquis Whos’sWho in America and Marquis Who’s Who in the World.  He is a member of the Interdisciplinary Committee of the World Cultural Council (Consejo Cultural Mundial), and an honoree of the 11th Int Symp Water/Rock Interactions, 1994, Saratoga Springs, NY.  

Dr. Ehrlich’s professional activities include Editor-in-Chief, GEOMICROBIOLOGY JOURNAL 1983-1995; Co-Editor-in-Chief 1995-present; Editorial Board Member: Applied and Environmental Microbiology; Applied Microbiology and Biotechnology; Editorial Board member, Applied and Environmental Microbiology and Applied Microbiology and Biotechnology; Former Editorial Board Member, Journal of Industrial Microbiology; Director and Treasurer, International Symposia on Environmental Biogeochemistry, Inc. 1973-1999; Former Member of the Membership Committee of the American Academy of Microbiology; chairman, Eastern New York Branch, American Society for Microbiology;  Past Industrial Consultant to E.I. DuPont de Nemours & Co., Gorham International; Genetics Institute, and other occasional consultancies. Dr. Ehrlich has prepared a 5th edition of his book, Geomicrobiology, with Dianne K. Newman of MIT as co-author, which is in press with the Taylor & Francis Group LLC.


Tel: (518) 276-8428
Fax: (518) 276-2344

Office: Science Center 1W14

Rensselaer Polytechnic Institute
110 8th Street
Troy, NY 12180

Research Interests

Geomicrobiology:  Bacterial oxidation of Mn(II) and reduction of Mn(IV) associated with marine ferromanganese concretions and in freshwater environments; bacterial oxidation of arsenic(III); bacterial reduction of Cr(VI); bacterial interaction with bauxite; bioleaching of ores, including metal sulfides, bauxite, and others.

Since 1959, Dr. Ehrlich’s research interests have centered on geomicrobiology. Research in his lab has dealt with bacterial oxidation of Mn(II) and reduction of Mn(IV), in particular as it applies to the development and fate of marine ferromanganese concretions and the possible bacterial origin of Mn(IV) oxide in calcareous deposits along the western shore of the Dead Sea. In addition, he and his collaborators have studied the activity of Mn(II)-oxidizing and Mn(IV)-reducing bacteria isolated from samples collected by Woods Hole Oceanographic Institution at the site of hydrothermal vents at the Galapagos Rift and the East Pacific Rise, and from some freshwater environments. The manganese-oxidizing bacteria that were isolated from the marine hydrothermal vent samples differed in their mechanism of action on Mn(II) from those that were isolated from marine ferromanganese concretions.

Other research in Dr. Ehrlich’s lab has dealt with the bacterial oxidation (bioleaching) of various metal sulfides (minerals and ores), bacterial oxidation of arsenite, and bacterial reduction of Cr(VI). The most recent work dealt with the interaction of bacteria associated with bauxite ore from three different sites: one in Australia, another in Amazonia, and a third on the island of Jamaica. Among the bacteria associated with these ores were some that under anaerobic conditions, extensively mobilized ferric iron in the ore by reducing it to ferrous iron, and to a much lesser extent solubilized ‘silica’ in the ore. The bacteria also mobilized small amounts of aluminum when they caused a drop in pH of the culture medium to below ~4.5. In collaboration with Prof. Teofilo Abrajano, a member of the Earth & Environmental Sciences Department at RPI, he is pursuing  a study to determine the mechanism whereby the bacteria mobilize the ferric iron below the surface of intact pisolithic (pea-sized ore) bauxite.

Selected Publications

Ehrlich, H.L. 2008. Are gram-positive bacteria capable of electron transfer across their cell wall without an externally available electron shuttle? Geobiology 6:220–224.

Ehrlich, H.L.  2006.  Geomicrobiology: relative roles of bacteria and fungi as geomicrobial agents. In: Gadd GM, ed.  Fungi in Biogeochemical Cycles.  Cambridge, UK: Cambridge University Press, pp 1-27.

Yan B, Abrajano T, Newville M, Sutton S, Sturchio NC, Ehrlich H. 2004.   Anaerobic bacterial reduction of ferric iron in pisolites.  In: Wanty RB, Seal, RR II, eds. Water-Rock Interaction: 11th Int  Symp Water-Rock Interaction, Vol 2.  Leiden, Netherlands: AA Balkama Publ, pp 1165–1169.

Ehrlich, H.L. 2002.  How microbes mobilize metals in ores: A review of current understandings and proposals for further research.  Minerals & Metallurgical Processing 19:220-224.

Ehrlich, Henry L. 2002. Geomicrobiology, 4th edition. New York: Marcel Dekker, 768 pp.

Ehrlich, Henry L. 2001. Bacterial oxidation of As(III) compounds. In: Frankenberger WT Jr, ed. Environmental Chemistry of Arsenic. New York: Marcel Dekker, pp. 313-327.

Ehrlich, HL. 2000. Biogenesis of ocean manganese nodules and the possibility of processing them by bioleaching. Minerals & Metallurgical Processing 17: 121-128. 

Ehrlich, H.L.and L.M. Wickert. 1997. Bacterial action on bauxites in columns fed with full-strength and dilute sucrose mineral salts medium. In: L. Lortie, P. Bedard, and W.D. Gould, eds. Biotechnology and the Mining Environment. SP97-1. Proc., 13th Annu. Meet. BIOMINET. CANMET, Ottawa, Canada, pp. 73-89.

Ehrlich, H.L., L.M. Wickert, D. Noteboom, and J. Doucet. 1995. Weathering of pisolitc bauxite by heterotrophic bacteria.  In: T. Vargas, C.A. Jerez, J.V. Wiertz, and H. Toledo, eds. Biohydrometallurgical Processing, Vol. 1. University of Chile, Santiago, Chile, pp. 395-403.

Ehrlich, H.L. 1993. Electron transfer from acetate to the surface of MnO2 particles by a marine bacterium. J. Ind. Microbiol. 12:121-128.

Ehrlich, H.L., Salerno JC. 1990.  Energy coupling in Mn2+ oxidation by a marine bacterium.  Arch. Microbiol. 154:12-17.

Rensselaer Polytechnic Institute Department of Biological Sciences