Microbial Treatment and Oxidative Stress in Agricultural Plants

Abstract

Anthropogenic factors expose agricultural plants to abiotic and biotic stresses, one of which is oxidative stress. Oxidative stress changes cell metabolism, as well as inhibits plant growth and development. Microbial treatment is an environmentally safe method of oxidative stress prevention. The research objective was to study the antioxidant activity of microflora native to coal dumps in order to combat the oxidative stress in crops.
 The study featured microorganisms isolated from technogenically disturbed soils. Pure bacterial cultures were isolated by deep inoculation on beef-extract agar. A set of experiments made it possible to define the cultural, morphological, and biochemical properties of cell walls. The antioxidant activity and the amount of indole-3-acetic acid were determined on a spectrophotometer using the ABTS reagent and the Salkowski reagent, respectively. The isolated microorganisms were identified on a Vitek 2 Compact device. The biocompatibility of strains was tested by dripping, while the increase in biomass was measured using a spectrophotometer.
 The study revealed ten microbial strains with antioxidant activity ranging from 67.21 ± 3.08 to 91.05 ± 4.17%. The amount of indole-3-acetic acid varied from 8.91 ± 0.32 to 15.24 ± 0.69 mg/mL. The list of microorganisms included Klebsiella oxytoca, Enterobacter aerogenes, Pseudomonas putida, and Bacillus megaterium. The consortium of P. putida and E. aerogenes demonstrated the best results in antioxidant activity, indole-3-acetic acid, and biomass. Its ratio was 2:1 (94.53 ± 4.28%; 15.23 ± 0.56 mg/mL), while the optical density was 0.51 ± 0.02. Extra 2% glycine increased the antioxidant activity by 2.34%, compared to the control. Extra 0.5% L-tryptophan increased the amount of indole-3-acetic acid by 3.12 mg/mL and the antioxidant activity by 2.88%.
 The research proved the antioxidant activity of strains isolated from microflora native to coal dumps. The consortium of P. putida and E. aerogenes (2:1) demonstrated the best results. Further research will define its ability to reduce oxidative stress in plants.

Peptides of Yeast Saccharomyces cerevisiae Activated by the Aquatic Extract of Atriplex sibirica L.

“…The general formula of antiviral peptides includes hydrophobic amino acids (isoleucine or leucine) and cationic amino acids (arginine or lysine). In addition, they are characterized by a short sequence (5–50 amino acid residues), a positive charge, and amphiphilic nature. , PTS3.1 and PTS2.3 peptides differ from other test specimens by their substantial amino acid content, such as leucine 14%, arginine 14%, and lysine 14% (PTS3.1), and lysine 11%, arginine 11%, and lysine 22% (PTS2.3). In view of this, these peptides may have antiviral activity.…”

“…In view of this, these peptides may have antiviral activity. Antitumor activity is characteristic of the peptides, which contain leucine, arginine, glutamine acid, glycine, isoleucine, lysine, and asparagine. − The peptide PTS3.3 with a high level of glutamine acid (22%) and glycine (11%) may potentially have antitumor activity, and the presence of arginine (22%) may also indicate antimicrobial activity. The peptide PTS3.4, containing arginine (14%), glutamine (14%), and glycine (14%), can hypothetically be characterized as antitumor, and the presence of serine (43%), allows for some antidiabetic effects.…”

“…Peptides comprising tryptophan, tyrosine, histidine, and proline are powerful antioxidants. The hydrophobic amino acids (leucine or valine) present in the peptide structure also affect the antioxidant activity of peptides and their ability to inhibit lipid peroxide oxidation. , Among the peptides in the test sample, two peptides have a relatively high concentration of these amino acids: PTS2.4 (histidine content 13% of the amino acid sum, proline 13%, leucine 13%) and PTS3.1 (leucine content 14%, proline 14%). This indicates the antioxidant activity of these peptides.…”

The biopotential of extremophilic microorganisms isolated from Kuzbass for protection and growth stimulation of oat (Avena sativa L.)

“…The subject matter of the investigation comprised extremophile microorganisms Leclercia sp., Sphingomonas paucimobilis, and Lactobacillus plantarum, which were isolated from natural sources during the initial stage of the research [12], as well as a consortium based on them in a ratio of 2:1:1 [13].…”