Optical sorting and cultivation of denitrifying anaerobic methane oxidation archaea.

Xiaoqiong Qi,David M Carberry,Shihu Hu,Chen Cai,Halina Rubinsztein-Dunlop,Jianhua Guo,Zhiguo Yuan

doi:10.1364/boe.8.000934

Abstract

Denitrifying anaerobic methane oxidizing (DAMO) microorganisms play an important role in the global carbon and nitrogen cycles as they are able to mediate methane oxidation using nitrite/nitrate under anoxic conditions. However, the physiological properties of DAMO microorganisms remain poorly understood, partially since the organisms are difficult to isolate or cultivate in pure culture and partially because of their long cultivation time. In this study, DAMO cell sorting has been conducted by integrating optical tweezers within enclosed microfluidic chips. This integrated cell sorting method has high purity, low infection rates, and causes no discernable harm to cell viability. The purity of the sorted cells was controlled by the microfluidic chip structure design and operation, while the cell viability was verified by imaging the cultured DAMO archaea after 420 days.

Highlights

CH4 is a potent greenhouse gas with a global warming potential 25 times than that of CO2 over a span of 100 years [1]
Denitrifying anaerobic methane oxidizing (DAMO) microorganisms play an important role in the global carbon and nitrogen cycles as they are able to mediate methane oxidation using nitrite/nitrate under anoxic conditions
DAMO cell sorting has been conducted by integrating optical tweezers within enclosed microfluidic chips

Summary

Introduction

CH4 is a potent greenhouse gas with a global warming potential 25 times than that of CO2 over a span of 100 years [1]. Its emission and oxidation plays a critical role in global climate change. The discovery of denitrifying anaerobic methane-oxidizing (DAMO) microorganisms fundamentally changed our understanding of the methane cycle [3, 4]. DAMO bacteria have been reported to have the ability to biologically produce oxygen from nitrogen oxides, which may have had a considerable geochemical and evolutionary role on the early Earth [5]. The physiological properties of DAMO microorganisms remain poorly understood, partially since the organisms are difficult to isolate or cultivate as a pure culture. It is not known if DAMO microorganisms require a symbiotic relationship with other microorganisms, or whether other microorganisms hinder their doubling rate

Methods

Results

Conclusion