A novel procedure to detect low molecular weight compounds released by alkaline ester cleavage from low maturity coals to assess its feedstock potential for deep microbial life

Abstract

. (2009): A novel procedure to detect low molecular weight compounds released by alkaline ester cleavage from low maturity coals to assess its feedstock potential for deep microbial life. -Organic Geochemistry, 40, 2, 175-183, DOI: 10.1016/j.orggeochem.2008 A novel procedure to detect low molecular weight compounds released by alkaline ester cleqavage from low mature coal to assess its feedstock potential for deep microbial life.Centre for Geosciences AbstractIn recent years the widespread occurrence of microorganisms was demonstrated in deep marine and terrestrial sediments. With this discovery inevitably the question of the potential carbon and energy sources for this deep subsurface microbial life arises. In the current study a new method for the investigation of low molecular weight (LMW) organic acids linked to the kerogen matrix is presented. These LMW organic acids form a potential feedstock for deep microbial populations. Twelve coal samples of different maturity (vitrinite reflectance (R 0 ) of 0.28 to 0.80%) from several coal mines on the North and South Island of New Zealand (NZ) were examined to assess the amount of bound LMW organic acids. Formate, acetate and oxalate were detected in significant amounts whereas the amounts of these compounds decrease with increasing maturity of the coal sample. This decrease of LMW

Sulfate reduction controlled by organic matter availability in deep sediment cores from the saline, alkaline Lake Van (Eastern Anatolia, Turkey)

“…When looking at the pore water DOC composition of both sites ( Table 1 ) it becomes obvious that the DOC in AR pore water is dominated by high molecular weight OM (biopolymers, humic substances and building blocks) accounting in total for 91% of the DOC, whereas LMW OM accounts for only 9% in AR pore water. In contrast, the HMW fraction of pore water DOC samples from NB accounts for only 75%, but the LMW fraction, which is considered a potential substrate for microbes (Glombitza et al, 2009), accounts for 25%, including 0.6% LMW acids which are absent at AR ( Table 1 ). We thus suggest that availability of labile OM in the pore water plays a more important role in controlling microbial activity in Lake Van than sedimentary OM content.…”

IODP Expedition 337: Deep Coalbed Biosphere off Shimokita – Microbial processes and hydrocarbon system associated with deeply buried coalbed in the ocean

“…Despite the biogeochemical significance of hydrocarbon reservoirs for the global carbon cycle (Head et al, 2003;Jones et al, 2008), there have been no studies of coal layers that are deeply buried in the subseafloor, mainly because of the safety regulations related to hydrocarbon gasrelated hazards during non-riser-type drilling. In continental sediments, large quantities of gaseous hydrocarbons and their derivatives (e.g., H 2 , organic acids) are potentially generated via thermogenic and/or biogenic degradation processes of deeply buried organic matter such as lignite coals (e.g., Jones et al, 2008;Glombitza et al, 2009;Strąpoć et al, 2008Strąpoć et al, , 2011. Such diagenetic products are potential nutrient and energy sources that support energy-yielding redox reactions mediated by deep subseafloor microbial communities.…”

Expedition 337 summary

“…Previous studies of terrestrial coal deposits suggest that microorganisms play important ecological roles in coal diagenesis, producing substantial quantities of coalbed methane and secondary products (e.g., Brown et al, 1999;Detmers et al, 2001;Shimizu et al, 2007;Krüger et al, 2008;Strapoc et al, 2008;Jones et al, 2008;Fry et al, 2009;Glombitza et al, 2009;Orem et al, 2010;Ünal et al, 2012). The microbial communities in terrestrial coal habitats are phylogenetically diverse, despite often having low cell densities (<10 6 cells/cm 3 ).…”