Duration Of Cultivation Research Articles

Research on the production of feed antibiotic «Kormogrizin» by a mutant strain of <i>Actinomyces griseus</i>

This article describes the method of obtaining the food antibiotic kormogrizin using a mutant strain of Actinomyces griseus. It is known that the scope of application of antibiotics in agriculture, medicine and food industry, fodder production is wide. Aerobic, anaerobic and facultative-anaerobic species of actinomycetes were isolated in the course of scientific research work on the production of kormogrizin in laboratory conditions. One of the peculiarities of the microorganisms Actinomyces griseus is that the vegetative cell TB 633 FU undergoes mutagenic changes in the logarithmic phase of growth. When conducting the research, the distance between the Petri dishes was 15 cm, and the BUF-15 lamp was used as an ultraviolet light source. In the research work, the activity of the fodder antibiotic was determined by the diffusion method, and it is also necessary to observe the temperature regime. In the next period of research, they controlled the sensitivity of microorganisms to antibiotics and placed them on paper discs. When the diameter of the inoculation zone of microorganisms was more than 25 mm, the sensitivity of the culture to antibiotics was high, and, accordingly, when the diameter of the inoculation zone was less than 10 mm, the level of sensitivity also decreased. The biological activity of antibiotics is determined by the diffusion method based on the comparison of growth inhibition. The requirements of the melting temperature and the seed medium were taken into account, and a sterile cylinder was used with the help of a stencil. Kormogrizin allows to increase the productivity of farm animals by 10-12%. Emphasis is placed on the main indicators of the antibiotic release process - temperature, duration of cultivation, pH of the medium. The relevance of this article is also high, as it is clear that the production of food antibiotics in laboratory conditions will contribute to the solution of important production and economic problems in the future.

Cellular Therapy with Autologous Mesenchymal Stromal Cells in Patients with Drug Resistant Pulmonary Tuberculosis

The objective: to evaluate the effectiveness of treatment with autologous mesenchymal stromal cells (MSCs) in patients with drug resistant pulmonary tuberculosis (DR TB).Subjects and Methods. 120 patients with drug resistant tuberculosis aged 18 to 61 years old were enrolled in the study. They all were treated at the Republican Scientific and Practical Center of Pulmonology and Phthisiology from 2009 to 2018. Against the background of anti-tuberculosis treatment, patients (60 people) from Main Group (MG) underwent bone marrow sampling and then intravenous administration of autologous MSCs.Results. The average dose of administered cells was 1x106 per kg of the patient body weight. The average duration of MSC cultivation made 35 days. Treatment effectiveness in MG made 90% versus 71% in Control Group (CG). All patients who were successfully cured of tuberculosis (TB) using autologous MSCs had no tuberculosis relapses during 5 years of follow-up. In Control Group, 8 (19%) cases of relapse were reported. In Main Group versus Comparison Group, the rates indicating healing of cavities and absence of relapse are statistically significantly better.Conclusion. The use of autologous MSCs in patients with drug resistant tuberculosis has shown its high effectiveness.

Культивирование Dunaliella salina на питательной среде из нейтрально-сульфитных щелоков

The effectiveness of cultivation of microalgae Dunaliella salina in the nutrient medium from neutral-sulfite alkalis obtained during the production of cellulose from birch wood, with additional sodium chloride addition was established. D. salina microalgae were isolated from the bottom sediment of the Koyash Lake of the Kerch Peninsula. It was shown that the physiological activity of microalgae was affected by the amount of sodium chloride introduced into the nutrient medium. When up to 5 % sodium chloride is added to the nutrient medium. D. salina microalgae exhibit halotolerant properties when up to 5 % of sodium chloride is added to the nutrient medium. With an increase in the amount of sodium chloride introduced up to 30 %, D. salina culture exhibits halophilic properties. The best kinetic characteristics of the growth of D. salina when cultivated in the nutrient medium from neutral sulfite alkalis were observed at halophilic physiological activity. The yield of biomass of D. salina microalgae when cultivated in the nutrient medium without and when 5 % sodium chloride was added to the nutrient medium from neutral-sulfite alkalis is higher compared to the addition of 15 and 30 % sodium chloride to the nutrient medium. However, the accumulation of protein has an opposite dependence, in particular, the protein content of the culture fluid, in which 15 and 30 % sodium chloride was applied is higher than that when 5 % sodium chloride was applied. With an increase in the duration of cultivation up to 240 hours, a decrease in the pH of the nutrient medium from 7.04 to 4.70 was observed, this was due to the assimilation by microalgae of mineral and organic-bound nitrogen present in the nutrient medium from neutral-sulfite alkalis. It was established that during cultivation microalgae assimilate both reducing substances and coloring substances present in the nutrient medium, which results in intensive cell growth. With an increase in the duration of cultivation of microalgae, an increase in the number of cells in the culture fluid to 4 ⋅ 106 cl/ml was observed, which at the same time synthesize the extracellular enzyme xylanase, which contributes to the additional formation of reducing substances in the nutrient medium due to the enzymatic hydrolysis of xylan. The obtained research results show the prospects of using neutral-sulfite alkalis in biotechnology in the cultivation of D. salina microalgae for the production of biological products. For citation: Iksanov R.A., Kanarsky A.V., Kanarskaya Z.A., Gеmatdinova V.M. Cultivation of Dunaliella salina Microalgae in the Nutrient Medium from Neutral-Sulfite Alkalis. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 6, pp. 162–175. (In Russ.). https://doi.org/10.37482/0536-1036-2023-6-162-175

The transformation and genome editing of Pisum sativum: protocols and their modifications

Pea (Pisum sativum) is an important agricultural crop and a model object in various fields of plant research. At the same time, the genetic modification of pea is still a difficult task, which, apparently, is associated with its low ability to regenerate. There are a lot of different pea transformation protocols, however, for most of them, the transformation efficiency, i.e. the number of transgenic plants per explant, is extremely low. In addition, none of the protocols known to us has demonstrated itself to be universal, i.e. suitable for all varieties and lines of peas. We searched for studies on the transformation and regeneration of peas and systematized the data obtained. The resulting database made it possible to identify the most effective protocols for the transformation and regeneration ofP. sativum, as well as to analyze statistically the general features of the methods used, such as the source of the explant, the composition of the culture media, the duration of cultivation, and so on. We assume that our system for the analysis of publications devoted toin vitrocell cultures can also be used for similar data on other plant species.
 This research was supported by the Sirius University of Science and Technology project: PBB-RND-2243.

Influence of liqorice growing on the salt composition of low-fertility soils of the Syrdarya region, Uzbekistan

The article describes the influence of licorice on hard-to-reclaim lands, in order to obtain valuable roots and improve soils. The creation of a salt regime of the soil on irrigated lands is achieved only through the implementation of a complex of reclamation and agrotechnical measures, and the most important is the cultivation of licorice. For a comprehensive study of the effect of licorice on soil properties, reference sections were laid in key areas up to the groundwater table, and areas with different durations of licorice cultivation were selected. The following types of work were carried out in the field: description of the soil and soil profile, moisture content of soils and soils, selection of soil samples. Under laboratory conditions, the composition of water-soluble salts was determined. When planting licorice from the first year, a decrease in salt content is observed, by the fourth year of growing licorice, the content of dense residue ranges from 0.735 to 0.890%, by the sixth year, the soil profile to the groundwater level (GWL) turned out to be slightly saline along the profile, the content of dense residue ranges from non-saline to moderately saline degree (0.270-1.200%). With an increase in the limitation period of cultivation in the soil under licorice, the content of the chlorine ion decreases. The degree of alkalinity is strongly influenced by the content of magnesium and sodium in the soil. According to the content of total alkalinity under cultures of different age of growing licorice, there are no special differences in the profile. With an increase in the prescription of licorice cultivation, the amount of toxic salts decreases.

Clonal micropropagation of some species of the genus Thymus L.

The aim of the work was to study the influence of cultivation factors on the explants development to optimize the protocol of in vitro clonal micropropagation of four species of the genus Thymus L., valuable essential oil and medicinal plants. Conditions that ensure the production of up to 94.2 % of sterile explants were selected. It has been established that, when introduced into in vitro culture, it is advisable to use shoot tips and stem segments with a node (isolated from donor plants) and cultivate them in foil-covered test tubes. The optimal culture media for the first stage of micropropagation were determined: Murashige and Skoog (MS) medium with 1.0 mg/l benzylaminopurine (BAP) for Thymus serpyllum L. or MS with 1.0 mg/l kinetin and 1.0 mg/l gibberellic acids (GA3) for T. vulgaris L. ‘Gornyy Balzam’, T. × citriodorus (Pers.) Schreb. ‘Doone Valley’, T. caucasicus Willd. ex Ronniger. At the second stage of clonal micropropagation, it is advisable to cultivate T. caucasicus and T. serpyllum explants during 40 days, but T. vulgaris and T. × citriodorus – during 60 days. The maximum multiplication index at the recommended cultivation duration was obtained for T. × citriodorus (9.9) on MS medium without hormones, T. caucasicus (16.1) and T. vulgaris (10.0) – on MS medium with 1.0 mg/l kinetin., and T. serpyllum (6.8) on MS medium with 1.0 mg/l BAP. When comparing different culture vessels (tubes, jars and flasks), the effectiveness of jars was revealed. This type of culture vessels made it possible to increase the multiplication index up to 2.1–5.7 times. It was revealed that when microshoots of four thyme species were cultivated on MS medium with 1.0 mg/l IBA, the rooting rate reached 84.6–98.9 %. The frequency of adaptation ex vitro when using a mixture of peat and perlite (1:1) ranged from 62.8 to 89.5 %.

Total Content of Saponins, Phenols and Flavonoids and Antioxidant and Antimicrobial Activity of In Vitro Culture of Allochrusa gypsophiloides (Regel) Schischk Compared to Wild Plants.

Allochrusa gypsophiloides is a rare Central Asian species, a super-producer of triterpene saponins with pharmacological and technical value. In this work, a comparative evaluation of the in vitro culture of adventitious roots (ARs), in vitro adventitious microshoots (ASs), natural roots and aboveground parts of wild plants from Kazakhstan to define the total saponin (TS), phenol (TP) and flavonoid (TF) content, as well as antioxidant (AOA) and antimicrobial activity, is presented for the first time. In the AR culture, growth index (GI), TS, TP and TF were evaluated on days 25, 45 and 60 of cultivation on ½ MS medium without (control) and with auxin application. It was found out that TS and TF were higher in the in vitro AR culture. The amount of TP and TF are higher in the aerial part of vegetative plants with maximum AOA. The concentration of the extract required to inhibit 50% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical formation (ICO50) in extracts from natural material negatively correlated with TS, TP, TF and in the in vitro AR culture with TF. Control extracts from the in vitro AR culture with high TS levels showed growth-inhibitory activity against S. thermophillus, S. cerevisiae and C. albicans. The influence shares of medium composition factor, cultivation duration factor and their interaction with GI, TS, TP and TF were determined. The in vitro AR culture is promising for obtaining triterpene saponins TSR with high antibacterial and antifungal activity, and the in vitro ASs culture-for shoot multiplication with antioxidant properties.

The Effect of Sodium Chloride on Biomass Growth and Protein Synthesis during Cultivation of Dunaliella salina Microalgae on a Nutrient Medium from Beet Molasses

Introduction. Currently, the applications of halophiles of the genus Halobacteriaceae are mainly limited to the use of β-carotene and hydrolases in the food and cosmetic industries. The expansion of halophile applications in biotechnology is based on the synthesis of effective and highly specific biocatalysts that can meet industrial needs. Halophiles are excellent sources of enzymes that are not only resistant to salt, but can also be effective in other extreme conditions. The resistance of halophiles to external factors is of increasing interest to them from biotechnologists, because they are the source of many BAS, and their habitat allows cultivation in non-sterile conditions. In this regard, it is of scientific and practical interest to determine the possibility of using D. salina bacteria in industry, which are recommended for wastewater treatment, expression of recombinant proteins, production of biofuels, production of natural polymer materials.Purpose. To study the effectiveness of cultivation of microalgae Dunaliella salina (D. salina) on a nutrient medium from molasses, experiments with additional addition of sodium chloride were carried out in this work.Materials and Methods. The review includes foreign articles published in English for the period 2010-2023. Search for scientific articles on suitable topics in the bibliographic databases Google Scholar, Scopus, Web of Science. When selecting publications for review, priority was given to highly cited sourcesResults. It was found that an increase in the cultivation temperature of microalgae from 5 to 25℃ favorably affects the growth characteristics of D. Salina culture: the specific growth rate increases, and the cell generation time decreases. When the content of sodium chloride in the nutrient medium is up to 5%, D. salina microalgae exhibit halotolerant properties. With an increase in the NaCl content in the nutrient medium up to 30%, D. salina culture exhibits halophilic properties. The best kinetic characteristics of the growth of D. salina culture are manifested with halophilic physiological activity. The yield of biomass of D. salina microalgae during cultivation on a nutrient medium without application and when introducing 5% sodium chloride into the nutrient medium from molasses is higher compared to the introduction of 15 and 30% sodium chloride into the nutrient medium. According to the results obtained, it can be said that an increase in the content of sodium chloride leads to an increase in the growth rate of the culture and the generation time, also in the values of 30% NaCl, a higher content of protein and β-fructosidase is manifested. With an increase in the duration of cultivation up to 240 h, a decrease in the pH of the nutrient medium from 7.04 to 4.70 is observed, which is due to the assimilation of mineral and organic nitrogen by microalgae. With an increase in the duration of cultivation of microalgae, there is an increase in the number of cells in the culture fluid up to 4 × 107 cl /ml, which at the same time synthesize the extracellular enzyme β-fructosidase, hydrolyzing sucrose.Conclusions. In view of the studies obtained, it is possible to indicate the possibility of using beet molasses as a source of carbon and substances that stimulate the growth of D.salina to produce biomass, protein substances and the enzyme β-fructosidase.

Medium and process optimizations for Euglena gracilis with high biomass production enriched with protein

Axenic Euglena cultures were grown under different LED conditions, medium compositions, and durations of cultivation to identify the factors involved in tuning Euglena biomass quality, especially protein and paramylon contents. Compositional analysis suggests that paramylon and protein concentrations in biomass can be tuned to different extents depending on medium and process conditions, including medium compositions, glucose concentrations, and illuminations of various LED spectra. Through the optimization of these parameters, the biomass productivities under specified conditions reached ~50–68 g/L. The protein-rich (>50 % dry basis) Euglena cultures can be produced with higher biomass productivities (38 g/L) under mixotrophic conditions with the presence of white and red LED lights and the modified medium composition. The cell morphology studies of Euglena cultures under various cultivation conditions indicate the correlation of slender cell-shape to the cell feature of high-protein contents in the biomass. The fresh cellular volumes and dry weights of paramylon-rich round-shaped cells were also estimated to be 5–9 times higher than those of protein-rich slender-shaped cells. The present study demonstrates an effective method to produce high-protein Euglena biomass with higher productivity in a shorter time.

Agro-Based Spent Mushroom Compost Substrates Improve Soil Properties and Microbial Diversity in Greenhouse Tomatoes

Spent mushroom compost (SMC) substrates are commonly used as growth media for greenhouse crops and horticulture production. This study aimed to investigate the responses of physiochemical soil properties, enzyme activities, and microbial community compositions to different cultivation durations and SMC soil treatments on tomatoes. The experiment included the following treatments: SMC substrate and the surrounding soil after planting at 1, 3, and 7 years and comparing control treatments including non-planting SMC substrates and continuous mono-cropping soil. The results revealed that the SMC substrates had higher contents of total N P and organic C nutrients than the surrounding soil treatments. The physicochemical soil properties and soil enzyme activities of the SMC substrates were significantly decreased with longer cultivation duration. Microbial alpha diversity was higher in the SMC substrates regardless of cultivation duration than in the control treatments. It was observed that many beneficial microbes, such as bacteria of the Deinococcus-Thermus, Halanaerobiaeota, and Nitrospirae phyla, and the fungi of the Basidiomycota, Mortierellomycota, and Chytridiomycota phyla were enriched in the SMC substrates. The SMC substrate and surrounding soil had enriched several potentially beneficial microorganism genera such as the bacterial Saccharimonadales, Gaiella, Bacillus, and the fungal Thermomyces, Kernia, and Mortierella. Therefore, the agro-based SMC substrate grooved cultivation system is recommended as an environmentally compatible practice for tomato growth in the greenhouse.

Centennial scale temporal responses of soil magnetic susceptibility and spatial variation to human cultivation on hillslopes in Northeast China

Soil loss is a significant environmental issue that causes soil degradation and threatens national food security in the black soil region of Northeast China. The magnetic susceptibility (MS) technique is a promising method for evaluating soil loss and estimating soil redistribution. In this study, undisturbed soil samples were selected from four typical black soil cropland slopes with 110a, 60a, 30a, and 20a cultivated durations at 10 cm intervals from the surface to a depth of 50 cm to measure soil MS. Based on measurable magnetic indexes, a quantitative relationship between MS and cultivation duration was constructed. The results indicated that: (1) The MS showed an approximate trend, namely 110a < 60a < 20a < 30a < 0a, the longer the sloping land was cultivated, the smaller the MS. (2) The reduction rate of χlf on the surface and underlying soil ranged from 1.57 to 3.27 and was also enhanced in the topsoil. (3) The relative difference value of MS among cultivation durations were greater at the lower slope than at the upper and middle slopes for all selected slopes; however, all positions became nearly constant after 50a of cultivation; (4) MS values substantially correlated in power function with cultivation duration on the entire slope and on three slope positions with r2 values from 0.50 to 0.86 and root mean square error values from 0.21 to 0.41. Soil MS in croplands varied with cultivation duration and was directly proportional to the increase in cultivation duration, which was used to establish soil redistribution and erosion patterns. The results of this study demonstrate that MS is a credible index for quantifying soil loss during continuous tillage at the centennial scale.

The impact of ex situ cultivation on the genetic variation of endangered plant species – Implications for restoration

The ex situ cultivation of endangered plant species in botanic gardens reduces the loss of species and contributes to the preservation of genetic variation. However, ex situ cultivation may lead to changes of intraspecific variation, due to effects of bottlenecks, drift and interrupted gene flow.We applied molecular markers to compare genetic variation within and between ex situ and in situ populations of eighteen endangered plant species in order to analyse potential effects of ex situ cultivation on genetic variation.Genetic diversity varied strongly between species, but did not differ significantly between ex situ and in situ populations and was also not correlated with population size. However, genetic diversity of ex situ populations depended positively on the duration of cultivation. Furthermore, we observed a significant and mostly considerable genetic differentiation between ex situ and the respective in situ populations for all species, which tended to increase with the duration of ex situ cultivation.From our study, it can be concluded that ex situ cultivation does not necessarily result in a loss of genetic diversity and is therefore a well-suited approach to preserve intraspecific variation. However, our study also provided evidence for a potentially increasing genetic dissimilarity between ex situ and in situ populations during cultivation.Ongoing introduction of genetic material from in situ and a limited duration of ex situ cultivation are, therefore, essential prerequisites to avoid loss of genetic diversity as well as man-made differentiation under conditions of long-term ex situ cultivation.

Disparities in Cisplatin-Induced Cytotoxicity-A Meta-Analysis of Selected Cancer Cell Lines.

Cisplatin is a classic anticancer drug widely used as a reference drug to test new metal complex drug candidates. We found an unexpected diversity in cisplatin-related cytotoxicity values, expressed as IC50 (the half-maximal inhibitory concentration) in tumour cell lines, such as MCF-7, HepG2 and HeLa. We reviewed the data published from 2018 to 2022. A total of 41 articles based on 56 in vitro experiments met our eligibility criteria. Using a meta-analysis based on a random effect model, we evaluated the cytotoxicity of cisplatin (IC50) after 48- or 72-h cell exposure. We found large differences between studies using a particular cell line. According to the random effect model, the 95% confidence intervals for IC50 were extremely wide. The heterogeneity of cisplatin IC50, as measured by the I2 index for all cancer cell lines, was over 99.7% at culture times of 48 or 72 h. Therefore, the variability between studies is due to experimental heterogeneity rather than chance. Despite the higher IC50 values after 48 h than after 72 h, the heterogeneity between the two culture periods did not differ significantly. This indicates that the duration of cultivation is not the main cause of heterogeneity. Therefore, the available data is diverse and not useful as a reference. We discuss possible reasons for the IC50 heterogeneity and advise researchers to conduct preliminary testing before starting experiments and not to solely rely on the published data. We hope that this systematic meta-analysis will provide valuable information for researchers searching for new cancer drugs using cisplatin as a reference drug.

Recommendations for growing young Australian red-clawed crayfish (Cherax quadricarinatus) in industrial conditions

The Australian thermophilic red-clawed crayfish (Cherax quadricarinatus) is characterized by a number of qualities that ensure its effective cultivation in commercial aquaculture. At the same time, the year-round cultivation of this species in natural reservoirs of Russia is limited by the seasonal course of temperatures. In this regard, the cultivation of tropical crayfish in certain periods of life in regulated conditions is a necessary stage of full-cycle technology. In particular, the successful maintenance of ARCC juveniles until they are transferred to natural conditions (after reaching a mass of 5 g) in installations with a controlled temperature regime is due to a number of factors. First of all, this is the planting density, which naturally depends on the area and capacity of installations with a closed water supply cycle, the size, mass and age characteristics of the object. The physiological and biological state of crayfish, the intensity and quality of feeding, and the duration of cultivation play an important role. The purpose of this work is to determine the main technological indicators of growing juveniles Australian red-clawed crayfish in industrial conditions up to 5 g. Data on the results of growing juveniles Australian red-clawed crayfish under controlled temperature conditions showed the main differences in mass indicators and survival of groups of juveniles Australian crayfish depending on the initial average weight, planting density, order of offspring. The terms of growing juveniles up to 5 g have been established, the feed costs for this period have been calculated, the chemical composition of the body of juvenile crayfish has been determined.

A novel hybrid bioprocess strategy addressing key challenges of advanced biomanufacturing.

Monoclonal antibodies (mAb) are commonly manufactured by either discontinuous operations like fed-batch (FB) or continuous processes such as steady-state perfusion. Both process types comprise opposing advantages and disadvantages in areas such as plant utilization, feasible cell densities, media consumption and process monitoring effort. In this study, we show feasibility of a promising novel hybrid process strategy that combines beneficial attributes of both process formats. In detail, our strategy comprises a short duration FB, followed by a fast media exchange and cell density readjustment, marking the start of the next FB cycle. Utilizing a small-scale screening tool, we were able to identify beneficial process parameters, including FB interval duration and reinoculation cell density, that allow for multiple cycles of the outlined process in a reproducible manner. In addition, we could demonstrate scalability of the process to a 5L benchtop system, using a fluidized-bed centrifuge as scalable media exchange system. The novel process showed increased productivity (+217%) as well as longer cultivation duration, in comparison to a standard FB with a significantly lower media consumption per produced product (-50%) and a decreased need for process monitoring, in comparison to a perfusion cultivation. Further, the process revealed constant glycosylation pattern in comparison to the perfusion cultivation and has strong potential for further scale-up, due to the use of fully scalable cultivation and media exchange platforms. In summary, we have developed a novel hybrid process strategy that tackles the key challenges of current biomanufacturing of either low productivity or high media consumption, representing a new and innovative approach for future process intensification efforts.

Mycobiota of the rhizosphere of vegetable and flower-ornamental crops in the conditions of Surgut

The paper presents the results of a study of the mycobiota of the control soil and the rhizosphere of 11 vegetable and 6 flower-ornamental plant species. Flower cultures are represented by Gauston ageratum, double-feathered cosmea, erect marigolds and thin-leaved marigolds, hybrid petunia and brilliant sage. Closed-ground vegetable crops are cucumber, tomato, hot pepper and Bulgarian pepper; open-ground vegetable crops are seed peas, radish, garlic, potatoes, sorrel, dill and curly parsley. During the year of the research, fertilizers were not introduced into the soil. Most vegetable crops were grown continuously for several years, flower crops during the year. In the mycocoenoses of the rhizosphere of most vegetable crops, toxin-forming species of the genus Penicillium are abundant: P. citrinum, P. citreonigrum and P. polonicum. The toxin-forming agent P. citrinum was found in the mycobiota of the control soil and the rhizosphere of most vegetable and flower-ornamental crops. In the structure of the mycobiota of the control soil, mycocoenoses of the rhizosphere of some vegetable crops such as seed peas, curly parsley, Bulgarian pepper and in the mycobiota of the rhizosphere of flower-ornamental crops, saprotrophic micromycetes with a noticeable abundance of cosmopolite Aspergillus phoenicis (from the A. niger group) are abundant in mycocoenoses of the rhizosphere of the double-feathered cosmea, hybrid petunia, marigolds erect and Bulgarian pepper. According to the research results, it can be concluded that the formation of the species composition of the mycobiota of the rhizosphere of vegetable and flower-ornamental crops is influenced by the type of plant, conditions and duration of cultivation. In the future the author is going to study the species composition of the mycobiota of the rhizosphere depending on the duration of plant cultivation, the expansion of their assortment, as well as the effect of fertilizers on the species composition of the soil mycobiota.

Optimum parameters of deoxynivalenol synthesis by micromycete F. graminearum on grain substrates

Today, fusariotoxins play an increasingly important role in the pathology of farm animals, among which deoxynivalenol plays an important role. Deoxynivalenol (DON) is one of the most common fusariotoxins. It affects the health of animals that consume contaminated feed, and can lead to various metabolic disorders, disrupting the body's homeostasis. One of the main effects of deoxynivalenol is that it stimulates the production of anti-inflammatory cytokines, which in turn causes the acute phase of inflammation in animals. In addition, deoxynivalenol leads to a decrease in appetite and can cause hypophagia in animals, which in turn leads to a decrease in daily gains. The direction of the conducted research is aimed at identifying the optimal substrate for the synthesis of deoxynivalenol and its maximum accumulation by the fungus F. graminearum, and also established the optimal parameters for the synthesis of mycotoxin (cultivation temperature, substrate humidity, cultivation period). Grains of the following crops were used as substrates: wheat, rice, corn, barley, oats, rye, millet, millet, peas, soybeans, sunflower, mustard, rapeseed, buckwheat, and flax. Deoxynivalenol in samples was determined by thin-layer chromatography. The production of deoxynivalenol was studied in the temperature ranges of 4, 17, 24, and 28 °C; humidity of the substrate in the range from 14–90 % and the duration of cultivation from 1 to 4 weeks. The mycotoxin-producing activity of the fungus F. graminearum isolate 195/1 was largely determined by the studied parameters. The maximum amount of deoxynivalenol was produced at a temperature of 24 ºС, a substrate humidity of 50%, and a duration of cultivation of 24 days. Of the tested substrates, rice was the best for deoxynivalenol production. The obtained results serve as a basis for possible prediction of feed contamination with deoxynivalenol and, in general, will allow to optimize measures to combat mycotoxicosis and thus minimize the possible risks of mycotoxin poisoning of people and animals.

Aggregate pore structure, stability characteristics, and biochemical properties induced by different cultivation durations in the Mollisol region of Northeast China

Long-term cultivation tends to cause thinning and even partial disappearance of Mollisols, which largely limits the sustainable development of agriculture. Cultivation duration greatly affects soil pore structure and biochemical properties of Mollisols. This study aims to elucidate the response of aggregate pore structure, stability, and biochemical properties of soil during degradation under long-term cultivation in Mollisols. The study involved four croplands with different cultivation durations (20, 40, 60, and 100 years; designated as AL20, AL40, AL60, and AL100, respectively) and one undisturbed forest land (FR). Samples were collected from three soil depths (0–20, 20–40, and 40–60 cm). Pore structure and biochemical properties were analyzed by X-ray Computed Tomography (CT) and standard method. As a result, the aggregate stability and biochemical properties of soil showed different degrees of degradation with the extension of cultivation duration. The mean weight diameter, soil organic carbon, total nitrogen, and microbial biomass carbon followed the order of AL20 > FR > AL40 > AL60 > AL100, while the soil bulk density exhibited an opposite trend. FR and AL20 showed significant differences from other sites (P < 0.05). The CT results revealed that total porosity and pore number approximately decreased with cultivation duration, with their maximum appearing in FR and minimum occurring in AL100. The pore shape and pore size of aggregates were dominated by elongated pores (> 65%) and porosity > 100 µm, respectively, both of which declined with increasing cultivation duration. Similarly, the fractal dimension and connectivity were the highest in FR. These results demonstrated that the pore structure of soil aggregates tended to be "simplified" with increasing cultivation duration. Soil structure index, which varied significantly with cultivation duration, was used to comprehensively evaluate the soil structure. The results provide important insights into soil structural degradation caused by long-term cultivation.

Results of mycotoxicological studies of the influence of sanitary and hygienic conditions on the synthesis of deoxynivalenol by the micromycete F. graminearum on various grain substrates

Today, fusariotoxins play an increasing lyimportant role in the pathology of farm animals, among which deoxynivalenol plays an important role. Deoxynivalenol (DON) is one of the most common fusariotoxins. It affects the health of animals that consume contaminated feed, and can lead to various metabolic disorders, disrupting the body's homeostasis. One of the main effects of deoxynivalenol is that it stimulates the production of anti-inflammatory cytokines, which in turn causes the acute phase of inflammation in animals. In addition, deoxynivalenol leads to a decrease in appetite and can cause hypophagia in animals, which in turn leads to a decrease in daily gains. The direction of the conducted research is aimed at identifying the optimal substrate for the synthesis of deoxynivalenol and its maximum accumulation by the fungus F. graminearum, and also established the optimal parameters for the synthesis of mycotoxin (cultivation temperature, substrate humidity, cultivation period). Grains of the following crops were used as substrates: wheat, rice, corn, barley, oats, rye, millet, peas, soybeans, sunflower, mustard, rapeseed, buckwheat, and flax. Deoxynivalenol in samples was determined by thin-layer chromatography. The production of deoxynivalenol was studied in the temperature ranges of 4, 17, 24, and 28 °C; humidity of the substrate in the range from 14–90% and the duration of cultivation from 1 to 4 weeks. The mycotoxin-producing activity of the fungus F. graminearum isolate 195/1 was largely determined by the studied parameters. The maximum amount of deoxynivalenol was produced at a temperature of 24 ºС, a substrate humidity of 50%, and a duration of cultivation of 24 days. Of the tested substrates, rice was the best for deoxynivalenol production. The obtained results serve as a basis for possible prediction of feed contamination with deoxynivalenol and, in general, will allow to optimize measures to combat mycotoxicosis and thus minimize the possible risks of mycotoxin poisoning of people and animals. Key words: F. graminearum, grain substrates, deoxynivalenol, cultivation temperature, substrate humidity, duration of cultivation.

Divergent accumulation of microbial and plant necromass along paddy soil development in a millennium scale

Plant inputs and their subsequent microbial transformations drive the formation and accumulation of soil organic carbon (SOC). Rice paddy is more conducive to SOC accumulation than uplands, primarily because of predominant anaerobic conditions. However, the role of microbes and plants in the buildup of SOC under prolonged rice cultivation has not been well explored in the literature. In a millennium-scale paddy soil chronosequence, we used amino sugars (AS) and lignin phenols (LN) as tracers to investigate microbial and plant-derived necromass changes and evaluated their contributions to SOC accumulation with increasing rice cultivation duration. Across the 1000-year rice cultivation process, AS and LN contents increased with SOC accumulation. Soil pH and salinity are considered to play vital roles in regulating the retention of AS and LN. In contrast to the control of soil enzyme activity on LN accrual (e.g., peroxidase), the microbial biomass and fungi-to-bacteria ratio greatly affected AS accumulation in paddy soil. The components of AS and LN also changed with time, exhibiting a significant accumulation of galactosamine and cinnamyl phenol units in the late stage. Long-term rice cultivation is more conducive to the accumulation of bacterial residues. AS demonstrated a greater contribution to SOC than LN compounds within 100 years, whereas the contribution of LN ultimately exceeded AS in the late stage. Concurrently, we found a higher degree of oxidative lignin degradation in younger soils and reduced degradation with increasing duration of rice paddy cultivation. The accumulation of microbial necromass is more than plant necromass in the early stage, and it is the opposite in the late stage. Our results are critical to understand the formation and sequestration processes of SOC in paddy soils.