The use of amino sugars for assessing seasonal dynamics of particulate organic matter in the Yangtze River estuary

Stable carbon isotopic composition of amino sugars in heterotrophic bacteria and phytoplankton: Implications for assessment of marine organic matter degradation

“…Although the GlcN/GalN values (< 2) indicate that organic matter has undergone extensive microbial alteration, bacteria may still be undergoing active resynthesis. Compilation of data reported in previous studies reveals that GlcN/GalN values typically exhibit a narrow range (1–3) in marine organic matter samples (Niggemann and Schubert 2006; Kaiser and Benner 2009; Ren et al 2020). Especially in sediments, the GlcN/GalN values are generally < 2 and vary slightly.…”

“…It is uniquely derived from bacteria, especially Gram‐positive bacteria, and can therefore serve as a biomarker for bacterial organic matter (Kaiser and Benner 2008). Studies on the diagenetic state of organic matter based on amino sugars have been widely reported and involve different forms of organic matter in marginal seas and the open ocean (Niggemann and Schubert 2006; Kaiser and Benner 2009; Ren et al 2020). However, it is difficult to fully resolve the specific mechanisms of metabolic processing of organic matter solely from the analysis of amino sugar concentrations.…”

Evaluation of Sedimentary Organic Carbon Reactivity and Burial in the Eastern China Marginal Seas

“…The high mineralization efficiency during the OC sedimentation process may be responsible for this phenomenon. The low transfer efficiency of the BP has been confirmed by many studies, and during the settlement transport of materials, plankton-derived OC gradually transitions to bacterial sources (Legendre et al, 2015;Ren et al, 2020). On the other hand, the intrinsic rapid turnover of the surface sediments could also lead to the loss of OC bioreactivity.…”

“…The relatively high proportion of bacterial OC also indicates that the marine OC has undergone extensive heterotrophic processing. However, the bacterial detritus from sinking particles could also feed the benthic communities because the bacterial OC is not overly difficult to degrade (Kaiser & Benner, 2008;Ren et al, 2020). High primary production is usually coupled with active heterotrophic processes (Carlson et al, 1998;Obernosterer et al, 2008).…”

“…The carbon normalization index and abundance ratio established based on these molecules can indicate the reactivity and source of OC. With the heterotrophic processing of fresh plankton OC, amino sugars are preferentially removed, and the GlcN/GalN ratio will gradually decrease from >8 to <3 (Benner & Kaiser, 2003;Davis et al, 2009;Lehmann et al, 2020;Ren et al, 2019Ren et al, , 2020. In addition, MurA can serve as a molecular indicator of bacterial OC contribution due to its unique bacterial source (Bourgoin & Tremblay, 2010;Kaiser & Benner, 2008).…”