Activation of soil enzymes by addition of artificial root exudate combinations

2020 ◽  
Author(s):  
Diane Hagmann ◽  
Jennifer Krumins ◽  
Bhagyashree Vaidya ◽  
Nina Goodey
Keyword(s):  
Amino Acids ◽  
Microbial Community ◽  
Organic Acids ◽  
Enzymatic Activity ◽  
Root Exudates ◽  
Soil Microbial Community ◽  
Soil Function ◽  
Soil Enzymatic Activity ◽  
Soil Microbial ◽  
Barren Soil

<p>In vegetated soils,plants naturally release root exudates, consisting of sugars, organic acids, and amino acids, into the soil increasing soil enzymatic activity.  Liberty State Park, located in Jersey City, New Jersey, is an industrial brownfield contaminated with heavy metals and organic pollutants.  Some sites have soils that function poorly, as indicated by low soil enzymatic activity, and do not support plant growth.  This study will determine whether different combinations of artificial root exudates increase soil enzymatic activity in these contaminated and low functioning soils. Different combinations of sugars, organic acids, and amino acids and will be added to barren, poorly functioning soil.  Three soil enzymatic activities will be examined at several time points over 120 days to assess the impacts of different combinations of root exudates on soil function. Further, soil microbial community composition will be determined to examine whether different artificial exudate solutions result in changes in soil microbial community.  Preliminary results suggest that the combination of sugars, organic acids, and amino acids greatly increased phosphatase, cellobiohydrolase, and L-leucine amino peptidase activity over time in poorly-functioning, barren soil from Liberty State Park. The other combinations (sugars and organic acids, sugars and amino acids, organic acids and amino acids) also increase the three enzyme activities more than the individual groups. Dormant microbes in barren soil can possibly be revived with the addition of artificial root exudates to mimic the presence of plants in revitalizing the microbial communities and improving soil function. </p>

Do diverse mixtures of cover crop residues alter the soil microbial community and increase soil function?

2020 ◽  
Author(s):  
Xin Shu ◽  
Yiran Zou ◽  
Liz Shaw ◽  
Lindsay Todman ◽  
Mark Tibbett ◽  
...  
Keyword(s):  
Microbial Community ◽  
Soil Respiration ◽  
Cover Crops ◽  
Soil Microbial Community ◽  
Cover Crop ◽  
Crop Residues ◽  
Soil Health ◽  
Soil Function ◽  
Soil Microbial ◽  
Quaternary Mixture

<p>Cover crops are a contemporary tool to sustainably manage agricultural soils by boosting fertility, suppressing weeds and disease, and benefiting cash crop yields, thus securing future food supply. Due to the different chemical composition of crop residues from different plant families, we hypothesised that a mixture of cover crop residues may have a greater potential to improve soil health than the sum of the parts. Our experiment focused on the impact of four cover crops (clover, sunflower, radish and buckwheat) and their quaternary mixture on soil respiration and the soil microbial community in an 84-day microcosm experiment. On average adding cover crop residues significantly (P < 0.001) increased soil respiration from 29 to 343 µg C g<sup>-1</sup> h<sup>-1</sup> and microbial biomass from 18 to 60 µg C g<sup>-1</sup>, compared to the unamended control during 84 days’ incubation. Cover crop addition resulted in a significant (P < 0.001) alteration of the soil microbial community structure compared to that of the control. The quaternary mixture of cover crop residues significantly (P = 0.011) increased soil respiration rate by 23.79 µg C g<sup>-1</sup> h<sup>-1</sup> during the period 30 to 84 days after residue incorporation, compared to the average of the four individual residues. However, no significant difference in the size of the microbial biomass was found between the mixture and the average of the four individuals, indicating the mixture may invest resources which transit dormant microbial species into a metabolically active state and thus boost microbial respiration. Analysis of similarity of microbial community composition (ANOSIM) demonstrated the mixture significantly (P = 0.001) shifted microbial community structure away from buckwheat (R = 0.847), clover (R = 0.688), radish (R = 0.285) and sunflower (R = 0.785), respectively. This implies cover crop residues provide a niche specialization and differentiation on a selection of microbial communities that favour certain plant compounds. While applying cover crop residues has positive impacts on soil function, we found that applying a mixture of cover crop residues may provide greater potential to select for microorganisms or activate dormant microbial species which result in higher soil function. The outcome of this study will help seed suppliers to design, and farmers to select, novel cover crop mixtures which enhance soil function synergistically, leading to a greater potential to sustainably improve soil health.</p>

scholarly journals Functional Diversity of Soil Microbial Communities in Response to the Application of Cefuroxime and/or Antibiotic-Resistant Pseudomonas putida Strain MC1

2018 ◽  
Vol 10 (10) ◽  
pp. 3549 ◽  
Author(s):  
Kamila Orlewska ◽  
Anna Markowicz ◽  
Zofia Piotrowska-Seget ◽  
Joanna Smoleń-Dzirba ◽  
Mariusz Cycoń
Keyword(s):  
Amino Acids ◽  
Microbial Community ◽  
Pseudomonas Putida ◽  
Carboxylic Acids ◽  
Functional Diversity ◽  
Soil Microbial Community ◽  
Carbon Substrate ◽  
Antibiotic Resistant ◽  
Soil Microbial ◽  
Catabolic Activity

Cefuroxime (XM), the most commonly prescribed antibiotic from the cephalosporin group, may cause changes in the structure of the soil microbial community, and these changes may also be reflected in the alteration of its functionality. Therefore, due to the lack of studies on this topic, the scope of this study was to assess the functional diversity and catabolic activity of the microbial community in soil treated with XM (1 mg/kg and 10 mg/kg soil) using the community-level physiological profile (CLPP) approach during a 90-day experiment. In addition, the effect of antibiotic-resistant Pseudomonas putida strain MC1 (Ps) was also evaluated. The resistance/resilience concept and multifactorial analysis were used to interpret the data. The results showed that the introduction of XM and/or Ps into the soil caused changes in the catabolic activity and functional diversity of the microbial community. A decrease in the values of the CLPP indices (i.e., microbial activity expressed as the average well-color development (AWCD), substrate richness (R), the Shannon-Wiener (H) and evenness (E) indices and the AWCD values for the six carbon substrate groups) for the XM-treated soil was generally detected up to 30 days. In turn, at the same time, the activity measured in the Ps-inoculated soil was higher compared to the control soil. A stimulatory effect of XM at 10 mg/kg (XM10) and XM10+Ps on the utilization pattern of each substrate group was found at the following sampling times (days 60 and 90). The AWCD values for the utilization of amines, amino acids, carbohydrates, carboxylic acids, miscellaneous compounds and polymers for these treatments were found to be up to 2.3-, 3.1-, 2.3-, 13-, 3.4- and 3.3-fold higher compared to the values for the nontreated control, respectively. The resistance of the CLPP indices and the AWCD values for the carbon substrate groups were categorized as follows: E > H > R > AWCD and amino acids = carbohydrates > polymers > amines > miscellaneous > carboxylic acids, respectively. The results suggest a low initial resistance of the soil microbial community to XM and/or Ps, and despite the short-term negative effect, the balance of the soil ecosystem may be disturbed.

scholarly journals Selected amino acids uptake by microorganisms in soil of differently managed mountain meadows

2011 ◽  
Vol 59 (1) ◽  
pp. 263-268
Author(s):  
Valerie Vranová ◽  
Ladislav Holík ◽  
Michael Pöschl ◽  
Klement Rejšek ◽  
Pavel Formánek
Keyword(s):  
Amino Acids ◽  
Microbial Community ◽  
Microbial Biomass ◽  
Glutamic Acid ◽  
Soil Microbial Community ◽  
Test Method ◽  
Soil Microbial ◽  
Experimental Stand ◽  
Mountain Meadows

This work was aimed at determination of the effect of 13 years abandonment of previously long-term mown mountain meadows on uptake of L-glutamic acid (14CO2H[14CH2]2[NH2]14CO2H) and L-alanine (14CH314CH[NH2]14CO2H) by microbial community of Ap horizon (3–13 cm). The study plots has been located near to the experimental stand “Bílý Kříž“ which is located in the Moravian-Silesian Beskids Mountains (N 49°30’17”, E 18°32’28”), on a slope with an elevation of 825–860 m a. s. l. and southeast orientation, and soil classified as an Oxyaquic Hapludalf. The study was performed to test method for measurement of 14C-labelled amino acids uptake by soil microbial community and to increase knowledge on particular processes of N-transformation in soil of these ecosystems. The results obtained in this work showed that 13 years abandonment of mountain meadow did not significantly (P > 0.05) influence rate of glutamic acid or alanine uptake by soil microbial community. Further research including determination of amino acids use by soil microbial biomass with expression of their partitioning between production of new microbial biomass and energy metabolism is necessary.

Winter effect on soil microorganisms under different tillage and phosphorus management practices in eastern Canada

2015 ◽  
Vol 61 (5) ◽  
pp. 315-326 ◽  
Author(s):  
Yichao Shi ◽  
Roger Lalande ◽  
Chantal Hamel ◽  
Noura Ziadi
Keyword(s):  
Microbial Community ◽  
Enzymatic Activity ◽  
Soil Microbial Community ◽  
Mycorrhizal Fungi ◽  
Soil Microorganisms ◽  
Management Practices ◽  
Phospholipid Fatty Acid ◽  
P Fertilization ◽  
Soil Microbial ◽  
Winter Conditions

Determining how soil microorganisms respond to crop management systems during winter could further our understanding of soil phosphorus (P) transformations. This study assessed the effects of tillage (moldboard plowing or no-till) and P fertilization (0, 17.5, or 35 kg P·ha−1) on soil microbial biomass, enzymatic activity, and microbial community structure in winter, in a long-term (18 years) corn (Zea mays L.) and soybean (Glycine max L.) rotation established in 1992 in the province of Quebec, Canada. Soil samples were collected at 2 depths (0–10 and 10–20 cm) in February 2010 and 2011 after the soybean and the corn growing seasons, respectively. Winter conditions increased the amounts of soil microbial biomasses but reduced the overall enzymatic activity of the soil, as compared with fall levels after corn. P fertilization had a quadratic effect on the amounts of total, bacterial, arbuscular mycorrhizal fungi phospholipid fatty acid markers after corn but not after soybean. The soil microbial community following the soybean and the corn crops in winter had a different structure. These findings suggest that winter conditions and crop-year could be important factors affecting the characteristics of the soil microbial community under different tillage and mineral P fertilization.

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