Combined use of microbial consortia isolated from different agricultural soils and cyclodextrin as a bioremediation technique for herbicide contaminated soils

Abstract

The phenylurea herbicide diuron is persistent in soil, water and groundwater and is considered to be a highly toxic molecule. The principal product of its biodegradation, 3,4-dichloroaniline, exhibits greater toxicity than diuron and is persistent in the environment. Five diuron degrading microbial consortia (C1C5), isolated from different agricultural soils, were investigated for diuron mineralization activity. The C2 consortium was able to mineralize 81.6% of the diuron in solution, while consortium C3 was only able to mineralize 22.9%. Isolated consortia were also tested in soil slurries and in all cases, except consortium C4, DT (the time required for the diuron concentration to decline to half of its initial value) was drastically reduced, from 700 days (non-inoculated control) to 546, 351, and 171 days for the consortia C5, C2, and C1, respectively. In order to test the effectiveness of the isolated consortium C1 in a more realistic scenario, soil diuron mineralization assays were performed under static conditions (40% of the soil water-holding capacity). A significant enhancement of diuron mineralization was observed after C1 inoculation, with 23.2% of the herbicide being mineralized in comparison to 13.1% for the control experiment. Hydroxypropyl-β-cyclodextrin, a biodegradable organic enhancer of pollutant bioavailability, used in combination with C1 bioaugmentation in static conditions, resulted in a significant decrease in the DT (214 days; 881 days, control experiment). To the best of our knowledge, this is the first report of the use of soil-isolated microbial consortia in combination with cyclodextrins proposed as a bioremediation technique for pesticide contaminated soils.

Effects of perennial aromatic grass species richness and microbial consortium on soil properties of marginal lands and on biomass production

“…Growth of roots help in uptake of more water and nutrients from soil and in turn the root and shoot biomass improves fertility of soils (Khan et al, 2019; Ma, Rajkumar, & Freitas, 2009; Oves, Khan, & Zaidi, 2013). Use of microbes (consortium) with diverse physiological traits have been recommended for soil management and plant growth (Awasthi, 2019; Awasthi et al, 2014; Brenner, You, & Arnold, 2008; Villaverde, Rubio‐Bellido, Lara‐Moreno, Merchan, & Morillo, 2018). In this study, therefore, we used mixture of three bacterial species, that is, Bacillus paramycoides , Bacillus paramycoides , and Pseudomonas protegens .…”

Biodegradation of atrazine, glyphosate and pendimetaline employing fungal consortia

“…Fungal respiratory activity was evaluated in microcosms, using the principle of Bartha's respirometric method with modifications (Villaverde et al, 2018). The microcosms consisted of sealed and sterilized 600 mL glass jars containing 30 mL 0.50 mol L -1 KOH solution in a sterile 50 mL beaker; 100 g sterile soil artificially contaminated with atrazine, Research, Society and Development, v. 9, n. 11, e1549119679, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i11.9679 glyphosate and pendimethalin at concentrations zero and 50 μg mL -1 ; 1 mL fungal spore suspension and sterile ultrapure water to maintain moisture.…”

A Path Forward: Promoting Microbial-Based Methods in the Control of Invasive Plant Species

“…Several studies have explored the role of particular microbes for biocontrol or plant protection services. However, there have only been limited investigations into field-scale investigations and utilization of a consortia approach to either control invasive plants, or benefit native plants to shift competitive outcomes when threatened with invasive plants [ 79 , 125 , 126 , 127 , 128 ]. Here, we advocate for additional research to advance sustainability and an integrated microbiological approach to help suppress invasive plant fitness as a potential additional tool for land managers.…”