The variable salinity, climate, nutrient and anaerobic conditions of salt marshes gives them strong selective pressures on the microorganisms inhabiting them. In salt marshes, microbes play the main role in nutrient cycling and biogeochemical processing[1]. To date, the microbial community of salt marshes has not been found to change drastically due to human impacts, but the research is still ongoing[2]. Because of the major role of microbes in these environments, it is critical to understand the different processes performed and different microbial players present in salt marshes. Salt marshes provide habitat for chemo(litho)autotrophs, heterotrophs, and photoautotrophs alike. These organisms contribute diverse environmental services such as sulfate reduction, nitrification, decomposition and rhizosphere interactions.

Microbial Decomposition Activity within Salt Marshes

Another key process among microbial salt marshes includes microbial decomposition activity. Nutrient cycling in salt marshes is highly promoted by the resident community of bacteria and fungi involved in remineralizing organic matter. Studies on the decomposition of a salt marsh cordgrass, Spartina alterniflora, have shown that fungal colonization begins the degradation process, which is then finished by the bacterial community[3]. The carbon from Spartina alterniflora is made accessible to the salt marsh food web largely through these bacterial communities which are then consumed by bacteriovores[4]. Bacteria are responsible for the degradation of up to 88% of lignocellulotic material in salt marshes[4]. However, fungal populations have been found to dominate over bacterial populations in winter months[5].

Phaeosphaeria sp. on wheat. This fungus is of the same genus common to salt marsh cordgrass.

The fungi that make up the decomposition community in salt marshes come from the phylum ascomycota, the two most prevalent species being Phaeosphaeria spartinicola and Mycosphaerella sp. strain 2[3]. In terms of bacteria, the alphaproteobacteria class is the most prevalent class within the salt marsh environment involved in decomposition activity[3]. The propagation of Phaeosphaeria spartinicola is through ascospores that are released when the host plant is wetted by high tides or rain[6].

  1. ^ Yao, Zhiyuan; Du, Shicong; Liang, Chunling; Zhao, Yueji; Dini-Andreote, Francisco; Wang, Kai; Zhang, Demin (2019-03-06). "Bacterial Community Assembly in a Typical Estuarine Marsh with Multiple Environmental Gradients". Applied and Environmental Microbiology. 85 (6): e02602–18. doi:10.1128/AEM.02602-18. ISSN 0099-2240. PMC 6414364. PMID 30635381.
  2. ^ Bowen, Jennifer L; Crump, Byron C; Deegan, Linda A; Hobbie, John E (2009-08-01). "Salt marsh sediment bacteria: their distribution and response to external nutrient inputs". The ISME Journal. 3 (8): 924–934. doi:10.1038/ismej.2009.44. ISSN 1751-7362.
  3. ^ a b c Buchan, Alison; Newell, Steven Y.; Butler, Melissa; Biers, Erin J.; Hollibaugh, James T.; Moran, Mary Ann (2003-11). "Dynamics of Bacterial and Fungal Communities on Decaying Salt Marsh Grass". Applied and Environmental Microbiology. 69 (11): 6676–6687. doi:10.1128/AEM.69.11.6676-6687.2003. ISSN 0099-2240. PMID 14602628. {{cite journal}}: Check date values in: |date= (help)
  4. ^ a b Benner, Ronald; Moran, Mary Ann; Hodson, Robert E. (1986-01). "Biogeochemical cycling of lignocellulosic carbon in marine and freshwater ecosystems: Relative contributions of procaryotes and eucaryotes1". Limnology and Oceanography. 31 (1): 89–100. doi:10.4319/lo.1986.31.1.0089. ISSN 0024-3590. {{cite journal}}: Check date values in: |date= (help)
  5. ^ Newell, Steven Y.; Porter, David (2000), Weinstein, Michael P.; Kreeger, Daniel A. (eds.), "Microbial Secondary Production from Salt Marsh-Grass Shoots, and Its Known and Potential Fates", Concepts and Controversies in Tidal Marsh Ecology, Dordrecht: Springer Netherlands, pp. 159–185, doi:10.1007/0-306-47534-0_9, ISBN 978-0-306-47534-4, retrieved 2024-04-04
  6. ^ Newell, Steven Y.; Wasowski, Jennifer (1995). "Sexual Productivity and Spring Intramarsh Distribution of a Key Salt-Marsh Microbial Secondary Producer". Estuaries. 18 (1): 241–249. doi:10.2307/1352634. ISSN 0160-8347.