Productivity of fodder crops and their mixed planting depending on fertilizers and soil treatments

Relevance. The problem associated with the continuing decline in the yield of the main crops and soil fertility in most of the arable lands leads to the need of developing comprehensive measures, including the optimal selection of crops and methods of tillage and planting in order to increase the collection of plant protein and preserve soil fertility.Method. The work devoted to the study of the influence of tillage methods, mineral fertilizers and biological products on the productivity of forage crops and their mixed planting was carried out on the experimental fields of the Chechen Research Institute in 2019–2020 in the forest-steppe climatic zone. The experiment was multifactorial. Mineral fertilizers were used for crop rotation with a view to the planned yield. The biopreparation V417, created at the Institute of Agricultural Microbiology on the basis of the Bacillus subtilis strain, was used in the processing of seed material and crops during the period of intensive plant growth.Results. As a result of the research, it was revealed that each of the studied methods of tillage should correspond to the cultivated crop and the technology used. The introduction of mineral fertilizers provided an increase in the productivity of forage plants in their pure and mixed planting by 11–44%. The treatment of crops with biopreparation V417 reflected in the best way: an increase in yield was from 24 to 52%. At the same time, the highest yield of the green mass of 42.6 t/ha was obtained in a three-component mixture (wheat, peas, oats) in the variants where disking and chiseling were carried out. Mixed planting is a serious reserve for increasing the quantity and quality of plant products. It's feed productivity in the collection of dry matter and feed units was not inferior to pure planting of cereals, and in terms of the provision of 1 feed unit with digestible protein exceeded it by 3–14%.

Construction of a Mutant Bacillus Subtilis Strain for High Purity Poly-γ-Glutamic Acid Production

Purpose To construct a Bacillus subtilis strain for improved purity of poly-γ-glutamic acid. Results The construction of strain GH16 was achieved by knocking out five extracellular protein genes and an operon from Bacillus subtilis G423. Then we analyzed the protein content in the γ-PGA produced by the resultant strain GH16/pHPG which decreased by 6.08%. Subsequently the fla-che operon, PBSX and the yrpD, ywoF and yclQ genes were knocked out successively and the mutant strain GH17, GH18, and GH19 was obtained. Ultimately, the protein content was reduced by 43.9%. In addition, the polysaccharide content in the γ-PGA was decreased from 2.21–1.93% due to the epsA-O operon was knocked. Conclusion γ-PGA has potential applications as a drug carrier, sustained-releasing agent and medical composite in medicine. To our knowledge, this is the first report of engineered Bacillus subtilis strains which can produce γ-PGA with a purity higher than 97%. Our results confirmed that this upstream strategy significantly enhanced specific protein purity by the removal of extracellular protein genes in Bacillus subtilis, and it is promising in other protein purification.

The expediency of using a plant protection system using the microbiological fungicide BisolbiSan, W in the cultivation of winter wheat in the Southern natural and agricultural zone of the Rostov region

The authors analyzed the biological effectiveness of the integrated plant protection system formed when the microbiological fungicide BisolbiSan, Zh was included in the classical protection scheme adopted in the farms of the Rostov region. The biological effectiveness of the integrated protection system, including the fungicide BisolbiSan, was analyzed, the impact of the studied protection system on the yield, the quality of the grain obtained, the phytosanitary condition of the crop during the growing season on winter wheat crops of the variety Nakhodka with the use of a plant protection system, including the fungicide BisolbiSan, Zh. The fungicide BisolbiSan, containing a culture of rhizospheric bacteria Bacillus subtilis strain H-13, suppresses the germination of spores and mycelium growth of phytopathogenic fungi due to the multilateral action of bacterial metabolites, without causing the formation of resistance in pathogens. It was found that the protection system used practically does not cause a decrease in grain quality — in terms of the average protein and gluten content, the grain at the experimental site even slightly exceeds the grain obtained from the control site by 16.88% and 27.8%. With the cost of winter wheat grain of 1100 rubles/kg, an increase in the yield in the experiment of 3.8 kg/ha in relation to control and the cost of an experimental protection system in the amount of 3,357 rubles/ha, revenue amounted to 823 rubles/ha.

Biochemical Characterization of Cellulase From Bacillus subtilis Strain and its Effect on Digestibility and Structural Modifications of Lignocellulose Rich Biomass

Microbial cellulases have become the mainstream biocatalysts due to their complex nature and widespread industrial applications. The present study reports the partial purification and characterization of cellulase from Bacillus subtilis CD001 and its application in biomass saccharification. Out of four different substrates, carboxymethyl cellulose, when amended as fermentation substrate, induced the highest cellulase production from B. subtilis CD001. The optimum activity of CMCase, FPase, and amylase was 2.4 U/ml, 1.5 U/ml, and 1.45 U/ml, respectively. The enzyme was partially purified by (NH4)2SO4 precipitation and sequenced through LC-MS/MS. The cellulase was found to be approximately 55 kDa by SDS-PAGE and capable of hydrolyzing cellulose, as confirmed by zymogram analysis. The enzyme was assigned an accession number AOR98335.1 and displayed 46% sequence homology with 14 peptide-spectrum matches having 12 unique peptide sequences. Characterization of the enzyme revealed it to be an acidothermophilic cellulase, having an optimum activity at pH 5 and a temperature of 60°C. Kinetic analysis of partially purified enzyme showed the Km and Vmax values of 0.996 mM and 1.647 U/ml, respectively. The enzyme activity was accelerated by ZnSO4, MnSO4, and MgSO4, whereas inhibited significantly by EDTA and moderately by β-mercaptoethanol and urea. Further, characterization of the enzyme saccharified sugarcane bagasse, wheat straw, and filter paper by SEM, ATR-FTIR, and XRD revealed efficient hydrolysis and structural modifications of cellulosic materials, indicating the potential industrial application of the B. subtilis CD001 cellulase. The findings demonstrated the potential suitability of cellulase from B. subtilis CD001 for use in current mainstream biomass conversion into fuels and other industrial processes.

In Vitro Evaluation and Genome Mining of Bacillus subtilis Strain RS10 Reveals Its Biocontrol and Plant Growth-Promoting Potential

Recently, crop management has involved excessive use of chemical fertilizers and pesticides, compromising public health and environmental integrity. Rhizobacteria, which can enhance plant growth and protect plants from phytopathogen, are eco-friendly and have been attracting increasing attention. In the current study, Bacillus subtilis RS10 isolated from the rhizosphere region of Cynodon dactylon, inhibited the growth of indicator strains and exhibited in vitro plant growth-promoting traits. A whole-genome analysis identified numerous biosynthetic gene clusters encoding antibacterial and antifungal metabolites including bacillibactin, bogorol A, fengycin, bacteriocin, type III polyketides (PKs), and bacilysin. The plant growth-promoting conferring genes involved in nitrogen metabolism, phosphate solubilization, hydrogen sulfide, phytohormones, siderophore biosynthesis, chemotaxis and motility, plant root colonization, lytic enzymes, and biofilm formation were determined. Furthermore, genes associated with abiotic stresses such as high salinity and osmotic stress were identified. A comparative genome analysis indicated open pan-genome and the strain was identified as a novel sequence type (ST-176). In addition, several horizontal gene transfer events were found which putatively play a vital role in the evolution and new functionalities of a strain. In conclusion, the current study demonstrates the potential of RS10 antagonism against important pathogens and plant growth promotion, highlighting its application in sustainable agriculture.

Contribution of Ascorbate and Glutathione in Endobacteria Bacillus subtilis-Mediated Drought Tolerance in Two Triticum aestivum L. Genotypes Contrasting in Drought Sensitivity

We evaluated the effect of endobacteria Bacillus subtilis (strain 10–4) as a co-inoculant for promoting plant growth and redox metabolism in two contrasting genotypes of Triticum aestivum L. (wheat): Ekada70 (drought tolerant (DT)) and Salavat Yulaev (drought susceptible (DS)) in early stages of adaptation to drought (12% PEG–6000). Results revealed that drought reduced growth and dramatically augmented oxidative stress markers, i.e., hydrogen peroxide (H2O2) and lipid peroxidation (MDA). Furthermore, the depletion of ascorbate (AsA) and glutathione (GSH), accompanied by a significant activation of ascorbate peroxidase (APX) and glutathione reductase (GR), in both stressed wheat cultivars (which was more pronounced in DS genotype) was found. B. subtilis had a protective effect on growth and antioxidant status, wherein the stabilization of AsA and GSH levels was revealed. This was accompanied by a decrease of drought-caused APX and GR activation in DS plants, while in DT plants additional antioxidant accumulation and GR activation were observed. H2O2 and MDA were considerably reduced in both drought-stressed wheat genotypes because of the application of B. subtilis. Thus, the findings suggest the key roles in B. subtilis-mediated drought tolerance in DS cv. Salavat Yulaev and DT cv. Ekada70 played are AsA and GSH, respectively; which, in both cases, resulted in reduced cell oxidative damage and improved growth in seedlings under drought.

Rhizosphere Microbiomes of Potato Cultivated under Bacillus subtilis Treatment Influence the Quality of Potato Tubers

Plants serve as a niche for the growth and proliferation of a diversity of microorganisms. Soil microorganisms, which closely interact with plants, are increasingly being recognized as factors important to plant health. In this study, we explored the use of high-throughput DNA sequencing of the fungal ITS and bacterial 16S for characterization of the fungal and bacterial microbiomes following biocontrol treatment (DT) with Bacillus subtilis strain Bv17 relative to treatments without biocontrol (DC) during the potato growth cycle at three time points. A total of 5631 operational taxonomic units (OTUs) were identified from the 16S data, and 2236 OTUs were identified from the ITS data. The number of bacterial and fungal OTU in DT was higher than in DC and gradually increased during potato growth. In addition, indices such as Ace, Chao, Shannon, and Simpson were higher in DT than in DC, indicating greater richness and community diversity in soil following the biocontrol treatment. Additionally, the potato tuber yields improved without a measurable change in the bacterial communities following the B. subtilis strain Bv17 treatment. These results suggest that soil microbial communities in the rhizosphere are differentially affected by the biocontrol treatment while improving potato yield, providing a strong basis for biocontrol utilization in crop production.

Antibacterial Screening of Bacterial Isolates Associated with Mangrove Soil from the Ngurah Rai Mangrove Forest Bali

In this study we reported cultivation of bacteria associated with mangrove soil from the Ngurah Rai Mangrove Forest, Bali. Mangrove soil samples were serially diluted using sterile artificial seawater, spread onto Starch Casein M agar and incubated at 28oC for 28 days. Cultivation of mangrove soil samples yielded 165 bacterial colonies with 68 isolates were selected and purified based on different morphology. Of these 68 isolates, 22 isolates displayed antibacterial activities ranging from weak to strong inhibition against at least one of four bacterial indicators namely Staphyloccocus aureus, Streptococus mutans, Escherichia coli and Klebsiella pneumoniae using perpendicular streak method. Overall, 19 out of 22 bacteria isolates displayed weak antibacterial potential and two isolates exhibited moderate antibacterial activity. The isolate SA4 was the only bacterium with strong antibacterial potential with measured clear distance ≥ 10 mm against the four bacterial isolates. Sequence analysis based on 16S rRNA gene fragment assigned the isolate SA4 as Bacillus subtilis strain BIL/BS-168. Overall, this study confirmed the untapped potential of antibacterial activities from bacteria associated with mangrove soil.