SEBS Professors Study the Microbiology of Arsenic-Contaminated Agricultural Soils in the Mekong River and Red River Deltas

The research team of Max Häggblom, John Reinfelder, Vien Minh Duong and Hang Dam sampling soil cores in the Mekong Delta. Photo: courtesy of Max Häggblom and John Reinfelder.
The research team of Max Häggblom, John Reinfelder, Vien Minh Duong and Hang Dam sampling soil cores in the Mekong Delta. Photo: courtesy of Max Häggblom and John Reinfelder.
The research team of Max Häggblom, John Reinfelder, Vien Minh Duong and Hang Dam sampling soil cores in the Mekong Delta. Photo: courtesy of Max Häggblom and John Reinfelder.

Distinguished Professor Max Häggblom, chair of the Department of Biochemistry and Microbiology, and professor John Reinfelder, Department of Environmental Sciences, visited Vietnam to initiate collaborative research on microbial arsenic metabolism in rice paddy soils with investigators at Can Tho University, College of Agriculture and Hanoi University of Science and Technology, School of Biotechnology and Food Technology. The research was funded by an International Collaborative Research Grant from Rutgers Global.

Arsenic (As) contamination of groundwater is of serious concern in many regions of Southeast Asia, including Vietnam, and is linked to As contamination of paddy soils, which threatens the health of populations relying on rice as a staple crop. Rice consumption is a key pathway for the dietary intake of both essential trace elements and toxicants, including As which is harmful to human health.

Although generally present in the environment at low levels, As is actively metabolized by microorganisms, a process that has a strong impact on its mobility and bioavailability. Microbially mediated transformations modulate the toxicity of As and change its mobility and bioavailability, which in turn may affect its translocation and accumulation in plants. Hence, microbial transformations of As can have a direct effect on the nutritional quality of various crops, especially rice.

John Reinfelder team-teaching at Can Tho University and Hanoi University of Science and Technology. Photo: courtesy of Max Häggblom and John Reinfelder.
John Reinfelder team-teaching at Can Tho University and Hanoi University of Science and Technology. Photo: courtesy of Max Häggblom and John Reinfelder.

In pilot experiments, Häggblom and Reinfelder aim to cultivate and isolate As-respiring bacteria from agricultural soils in the Mekong and Red River watersheds to obtain site-specific reference strains for physiological characterization and for use in molecular monitoring of community dynamics and activity. With their collaborators, they will design a combination of greenhouse experiments and field site analyses comparing water management and rice cultivation methods to demonstrate the activity of As-reducing microbes under in situ conditions and determine how their abundance and activity are affected by changes in the redox environment and differences in site water and soil chemistry.

In addition to sampling of arsenic-agricultural soils in the Mekong River Delta and Red River Delta, Häggblom and Reinfelder presented research seminars and taught a short course on environmental microbiology and science for master’s and doctoral students, and early career scientists at Can Tho University and Hanoi University of Science and Technology.

This article was published by the SEBS/NJAES Newsroom on March 16, 2023.