Protozoan response to addition of the bacteria Mycobacterium chlorophenolicum and Pseudomonas chlororaphis to soil microcosms

2001 ◽  
Vol 33 (2) ◽  
pp. 126-131 ◽  
Author(s):  
R. Rønn ◽  
J. Grunert ◽  
F. Ekelund
Keyword(s):  
Pseudomonas Chlororaphis ◽  
Soil Microcosms ◽  
Mycobacterium Chlorophenolicum

Exemplar Abstract for Pseudomonas chlororaphis piscium Burr et al. 2010.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Pseudomonas Chlororaphis

Chemical stabilization of toxic metals in soil microcosms

2009 ◽  
Vol 17 (3) ◽  
pp. 483-494 ◽  
Author(s):  
Viktoria Feigl ◽  
Nikolett Uzinger ◽  
Katalin Gruiz
Keyword(s):  
Toxic Metals ◽  
Chemical Stabilization ◽  
Soil Microcosms

scholarly journals The occurrence and ecology of microbial chain elongation of carboxylates in soils

2021 ◽  
Author(s):  
Sayalee Joshi ◽  
Aide Robles ◽  
Samuel Aguiar ◽  
Anca G. Delgado
Keyword(s):  
Microbial Ecology ◽  
Anaerobic Metabolism ◽  
Chain Elongation ◽  
Soil Microcosms ◽  
Soil Microbial ◽  
Anaerobic Soils ◽  
Clostridium Kluyveri ◽  
Substrate Concentrations ◽  
Elongation Activity

AbstractChain elongation is a growth-dependent anaerobic metabolism that combines acetate and ethanol into butyrate, hexanoate, and octanoate. While the model microorganism for chain elongation, Clostridium kluyveri, was isolated from a saturated soil sample in the 1940s, chain elongation has remained unexplored in soil environments. During soil fermentative events, simple carboxylates and alcohols can transiently accumulate up to low mM concentrations, suggesting in situ possibility of microbial chain elongation. Here, we examined the occurrence and microbial ecology of chain elongation in four soil types in microcosms and enrichments amended with chain elongation substrates. All soils showed evidence of chain elongation activity with several days of incubation at high (100 mM) and environmentally relevant (2.5 mM) concentrations of acetate and ethanol. Three soils showed substantial activity in soil microcosms with high substrate concentrations, converting 58% or more of the added carbon as acetate and ethanol to butyrate, butanol, and hexanoate. Semi-batch enrichment yielded hexanoate and octanoate as the most elongated products and microbial communities predominated by C. kluyveri and other Firmicutes genera not known to undergo chain elongation. Collectively, these results strongly suggest a niche for chain elongation in anaerobic soils that should not be overlooked in soil microbial ecology studies.

scholarly journals Changes in Denitrifier Abundance, Denitrification Gene mRNA Levels, Nitrous Oxide Emissions, and Denitrification in Anoxic Soil Microcosms Amended with Glucose and Plant Residues

2010 ◽  
Vol 76 (7) ◽  
pp. 2155-2164 ◽  
Author(s):  
Sherri L. Henderson ◽  
Catherine E. Dandie ◽  
Cheryl L. Patten ◽  
Bernie J. Zebarth ◽  
David L. Burton ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Organic Carbon ◽  
Plant Residue ◽  
Plant Residues ◽  
Barley Plant ◽  
Mrna Levels ◽  
Soil Microcosms ◽  
Denitrification Gene ◽  
Gene Mrna ◽  
Amended Soil

ABSTRACT In agricultural cropping systems, crop residues are sources of organic carbon (C), an important factor influencing denitrification. The effects of red clover, soybean, and barley plant residues and of glucose on denitrifier abundance, denitrification gene mRNA levels, nitrous oxide (N2O) emissions, and denitrification rates were quantified in anoxic soil microcosms for 72 h. nosZ gene abundances and mRNA levels significantly increased in response to all organic carbon treatments over time. In contrast, the abundance and mRNA levels of Pseudomonas mandelii and closely related species (nirS P) increased only in glucose-amended soil: the nirS P guild abundance increased 5-fold over the 72-h incubation period (P < 0.001), while the mRNA level significantly increased more than 15-fold at 12 h (P < 0.001) and then subsequently decreased. The nosZ gene abundance was greater in plant residue-amended soil than in glucose-amended soil. Although plant residue carbon-to-nitrogen (C:N) ratios varied from 15:1 to 30:1, nosZ gene and mRNA levels were not significantly different among plant residue treatments, with an average of 3.5 � 107 gene copies and 6.9 � 107 transcripts g−1 dry soil. Cumulative N2O emissions and denitrification rates increased over 72 h in both glucose- and plant-tissue-C-treated soil. The nirS P and nosZ communities responded differently to glucose and plant residue amendments. However, the targeted denitrifier communities responded similarly to the different plant residues under the conditions tested despite changes in the quality of organic C and different C:N ratios.

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