Nitrification and dentrification in a eutrophic lake sediment bioturbated by oligochaetes

An Arthrobacter sp. capable of extensive nitrification was isolated from a eutrophic lake sediment employing inorganic salts medium with acetamide as the carbon source. This heterotrophic nitrifier was found to be closely associated with a Corynebacterium sp. both in growth and in nitrification. When the Arthrobacter sp. was jointly cultured with the Corynebacterium sp. in medium containing ammonium ion, acetate, and inorganic salts, the concentrations of nitrification products (nitrite and nitrate) increased approximately 10-fold. This stimulatory interaction was also determined in filter-sterilized sediment water samples amended with ammonium ion and acetate. Although both organisms failed to grow singly in media containing 1 mg/mL of nitrite N and of acetaldoxime N, they grew well in both media when cultured jointly. Nitrification, however, occurred only in the acetaldoxime medium. This is the first reported instance of mutualistic relationships in heterotrophic nitrification arid appears to be significant to our understanding of nitrogen transformation in lacustrine environments.

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Nitrogen dynamics in a eutrophic lake sediment

Hydrobiologia ◽

10.1007/bf00014726 ◽

1988 ◽

Vol 159 (2) ◽

pp. 177-188 ◽

Cited By ~ 12

Author(s):

K. R. Reddy ◽

R. E. Jessup ◽

P. S. C. Rao

Keyword(s):

Lake Sediment ◽

Eutrophic Lake ◽

Nitrogen Dynamics

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Response of Prokaryotes to TOC Contamination in Dianchi Lake Sediments

10.21203/rs.3.rs-18864/v1 ◽

2020 ◽

Author(s):

Cheng-Peng Li ◽

Ya-Ping Li ◽

Qing-Qing Huo ◽

Wei Xiao ◽

Yong-Xia Wang ◽

...

Keyword(s):

Lake Sediment ◽

Meta Analysis ◽

Eutrophic Lake ◽

Nucleotide Metabolism ◽

Microbial Consortia ◽

Dianchi Lake ◽

Strongly Correlated ◽

Eutrophic Lakes ◽

And Function ◽

Functional Profiles

Abstract Background: Explaining microbial consortia in sediments from the perspective of taxon, co-occurrence and function is the key to recover and maintain aquatic ecosystems. Trophic status was widely considered to be an important determinant of the lake sediment microbial community. However, little is known about the effect of a special eutrophic factor gradient on the prokaryotic community structure in situ. Within this context, we explored prokaryotic communities using an intensive field sampling from sediments in the Dianchi Lake, one of the most eutrophic lakes in China. Results: Microbial assemblages was strongly correlated with total organic carbon (TOC). Moreover, relatively high and low TOC shaped taxonomic and functional differences in microbial assemblages. The results identified the most abundant bacteria across all samples as Proteobacteria , Nitrospirae , Chloroflexi , Firmicutes , Ignavibacteriae , Actinobacteria , Bacteroidetes , Acidobacteria , Spiprochaetae and Latescibacteria . The dominant groups of archaea were Euryarchaeota , Woesearchaeota DHVEG-6 , Bathyarchaeota and WSA2 . Low TOC (LT) microbial assemblages displayed a major proportion of functional profiles related to some metabolisms such as carbohydrate metabolism, amino acid metabolism, energy metabolism, nucleotide metabolism and metabolism of cofactors and vitamins, membrane transport. These results illustrated that TOC concentration had obvious influence on the relative abundances of KEGG orthologs . Finally, the meta-analysis results highlight that most of network parameters of the LT community were significantly greater than those of other communities, which suggesting that the LT community was larger and more complex. Conclusion: TOC level might be a key determinant to shape taxonomic and functional construction of communities in Dianchi Lake sediment. LT community tended to establish a larger and more complex co-occurrence, which suggested that they may interact with each other strongly and exchange essential metabolites. Overall, this study could enhance our knowledge of microbial assemblages in eutrophic lake sediment and provide clues for the restoration and maintenance of sediment ecosystems.

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Numbers, activities, and diversity of autotrophic ammonia-oxidizing bacteria in a freshwater, eutrophic lake sediment

Canadian Journal of Microbiology ◽

10.1139/m91-143 ◽

1991 ◽

Vol 37 (11) ◽

pp. 828-833 ◽

Cited By ~ 46

Author(s):

W. T. Smorczewski ◽

E. L. Schmidt

Keyword(s):

Lake Sediment ◽

Environmental Changes ◽

Ammonia Oxidation ◽

Eutrophic Lake ◽

Ammonia Oxidizer ◽

Most Probable Number ◽

Ammonia Oxidizing Bacteria ◽

Ammonia Oxidizers ◽

Probable Number ◽

Nitrite Oxidizers

The microbiological and chemical potential for ammonia oxidation in a freshwater, eutrophic lake sediment was examined in relation to environmental changes caused by seasonal, dimictic circulation. Poulations of both ammonia and nitrite oxidizers as estimated by most probable number (MPN) were sustained throughout extended anaerobic summer intervals, with nitrite oxidizers outnumbering ammonia oxidizers by a factor ranging from 3.0 to 8.1. Ammonia oxidation potential on a per cell basis was affected by seasonal changes and was seen to decrease as oxygen was removed from the sediments. Pure-culture isolations from a positive MPN tube inoculated with oxygenated sediment and representing a single point in a seasonal cycle produced ammonia-oxidizing strains belonging to the genus Nitrosospira. These strains did not react with known ammonia-oxidizer serotypes and, therefore, extend the serological diversity of this group of bacteria. An immunofluorescence analysis of MPN tubes from sediment collected during a period of lake stratification revealed progressive changes in the diversity of the ammonia-oxidizer population. The genera Nitrosomonas, Nitrosolobus, and Nitrosospira, including the novel serotype of Nitrosospira isolated from the sediment a year earlier, were found to coexist in well-oxygenated sediment. This diversity was seen to disappear, with Nistrosomonas surviving, as anaerobic conditions persisted. Key words: ammonia oxidizers, lake sediments, nitrifiers, nitrification.

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