Discovering the roles of subsurface microorganisms: Progress and future of deep biosphere investigation

Abstract

The discovery of the marine "deep biosphere"-microorganisms living deep below the seafloor-is one of the most significant and exciting discoveries since the ocean drilling program began more than 40 years ago. Study of the deep biosphere has become a research frontier and a hot spot both for geological and biological sciences. Here, we introduce the history of the discovery of the deep biosphere, and then we describe the types of environments for life below the seafloor, the energy sources for the living creatures, the diversity of organisms within the deep biosphere, and the new tools and technologies used in this research field. We will highlight several recently completed Integrated Ocean Drilling Program Expeditions, which targeted the subseafloor deep biosphere within the crust and sediments. Finally, future research directions and challenges of deep biosphere investigation towards uncovering the roles of subsurface microorganisms will be briefly addressed.

Genome guided investigation of antibiotics producing actinomycetales strain isolated from a Macau mangrove ecosystem

“…This phenomenon can be explained due to frequent genetic exchanges between different species of bacteria 40 , 41 . Therefore, the search for new ecosystems in largely unexplored areas and unusual environments has become vital for the discovery of novel compounds and bacteria 42 . In our study, plant samples were collected from a mangrove ecosystem, at a tidal swamp in a tropical delta, and showed high potential for the discovery of new natural products.…”

Diversity and Metabolic Potentials of Subsurface Crustal Microorganisms from the Western Flank of the Mid-Atlantic Ridge

“…Oceanic crust microbiology has long been ignored and is not well studied due to technical constraints; however, the crust has been assumed to harbor active microorganisms that may significantly contribute to global biogeochemical cycles and weathering of the seafloor landscape ( Schrenk et al, 2010 ; Wang et al, 2013 ). Several lines of evidence have revealed the presence of microorganisms in this dark, oligotrophic biosphere ( Fisk et al, 1998 ; Cowen et al, 2003 ; Santelli et al, 2008 ; Lever et al, 2013 ); however, some fundamental questions remain, including (1) how much microbial biomass is present in the oceanic crust, (2) where do the microorganisms originate, and (3) what are their metabolic functions.…”

Functional genomic analysis of Hawaii marine metagenomes

“…Since they have to adapt to various environmental differences such as temperature, pressure and light intensity, the biodiversity makes most of the marine microorganisms not identified yet, including many typical extreme environmental microorganisms [2,3]. The genomic research on marine microorganisms can not only help to understand the origin, evolution, diversity and adaptation of lives to complex and extreme environment, but also have important implications for biosynthesis and the application of synthetic biology to energy, pharmacy and environmental management.…”