Thermo-resistant enzyme-producing microorganisms isolated from composting

Organo-mineral fertilizers supplemented with biological additives are an alternative to chemical fertilizers. In this study, thermoresistant microorganisms from composting mass were isolated by two-step procedures. First, samples taken at different time points and temperatures (33 days at 52 ºC, 60 days at 63 ºC, and over 365 days at 26 ºC) were pre-incubated at 80 oC for 30 minutes. Second, the microbial selection by in vitro culture-based methods and heat shock at 60 oC and 100 oC for 2h and 4h. Forty-one isolates were able to grow at 60 °C for 4h; twenty-seven at 100 °C for 2h, and two at 100 °C for 4h. The molecular identification by partial sequencing of the 16S ribosomal gene using universal primers revealed that thirty-five isolates were from eight Bacillus species, one Brevibacillus borstelensis, three Streptomyces thermogriseus, and two fungi (Thermomyces lanuginosus and T. dupontii). Data from amylase, phytase, and cellulase activity assays and the enzymatic index (EI) showed that 38 of 41 thermo-resistant isolates produce at least one enzyme. For amylase activity, the highest EI value was observed in Bacillus licheniformis (isolate 21C2, EI= 4.11), followed by Brevibacillus borstelensis (isolate 6C2, EI= 3.66), Bacillus cereus (isolate 18C2, EI= 3.52), and Bacillus paralicheniformis (isolate 20C2, EI= 3.34). For phytase, the highest EI values were observed for Bacillus cereus (isolate 18C2, EI= 2.30) and Bacillus licheniformis (isolate 3C1, EI= 2.15). Concerning cellulose production, B. altitudinis (isolate 6C1) was the most efficient (EI= 6.40), followed by three Bacillus subtilis (isolates 9C1, 16C2, and 19C2) with EI values of 5.66, 5.84, and 5.88, respectively, and one B. pumilus (isolate 27C2, EI= 5.78). The selected microorganisms are potentially useful as a biological additive in organo-mineral fertilizers and other biotechnological processes.

Application of Livestock Slurry Significantly Influences Microbial Biosynthesis and Cumulative Respiration in Agricultural Grassland Soil

The long-term application of livestock slurry to intensive grassland soils may lead to positive effects, including an increase in soil organic matter and plant nutrient supply to soils. Further, there is increasing interest in the potential of biological slurry additives (mixtures of selected living or latent microorganisms added to slurry) to enhance soil fertility through mobilisation of key elements in slurry and soil. However, significant uncertainties remain surrounding the potential impacts of slurry amended with biological additives on carbon (C) partitioning within three pools: respired CO2, microbial biomass C (Cmic) and C retained in the soil, as well as composition of the microbial community in temperate grassland soils. We examined how slurry that has received a biological additive ultimately affects the partitioning of C within these pools and the composition of the soil microbial community, based on phospholipid fatty acid (PLFA) analysis. Four short-term incubations in which soil collected from a grassland field that has received livestock slurry treated with a commercial biological additive, alongside 14C-labelled carbohydrates of different complexity (14C-glucose, 14C-glucose 6-phosphate (G6P), and 14C-cellulose) were undertaken. Our results indicate that the addition of slurry to soil alongside carbohydrate compounds led to lower 14C biomass uptake and cumulative respiration of carbohydrate compounds, as well as greater residual 14C activities in soil, compared to the treatments in which slurry was not applied. A dominance of bacteria over fungi characterised soil microbial community composition in all treatments through time, with a prevalence of gram-negative over gram-positive bacteria. Our results also indicate that the addition of biological additives during slurry storage increased 14C biomass uptake following application of slurry to agricultural grasslands. Therefore, biological additives have the potential to create a favourable environment for maintaining and increasing soil fertility through modification of the microbial community associated with the slurry and influence of the soil microflora.

Preparation and application of a functional biological additive for quails based on microbial conversion of plant raw materials

When developing functional feed additives it is of interest to use microorganisms that have the ability to take root in the gastrointestinal tract of poultry and normalize its microflora to have a positive effect on the immune system. One of these bacteria is Propionibacterium shermanii, which has a fortifying, immunostimulating, antimutagenic effect, and can reduce the toxic effect of ultraviolet light and chemical compounds. Azotobacter vinelandii, which has probiotic fortifying, antibiotic properties, is effective as a stimulator of the development of the entire microbiota in a contaminated object, and recycles the formed ammonia in bird droppings, was chosen as another microorganism for creating the additive. The purpose of the research was to develop a functional biological additive based on probiotic microflora, using the by-products of crop processing in the formulations, and to select the norms for its introduction into the diet of quails. As a result of the research the technology of joint cultivation of Propionibacterium shermanii and Azotobacter vinelandii strains was developed, a universal starter culture was created that allows to ferment by-products of processing of plant raw materials, a functional additive with immunostimulating, vitamin and provitamin properties for quails has been obtained. The results of the production test confirmed the effectiveness of the developed additive in the diet of quails. Economic efficiency in the application of the proposed functional biological additive has been shown a reduction in feed consumption per 1 kg of live weight gain by 5,13 %. In addition, the economic effect of using the functional biological additive increases. Thus, the profit in the experimental group was 2738,34 rubles, which was 12,45 % higher than in the control group.

Effects of substrate quality on carbon partitioning in a temperate grassland soil as influenced by microbial activity

Using organic amendments, including livestock slurry, in intensively managed agricultural grasslands may potential lead to multiple benefits, including plant nutrient supply to soils and long-term accumulation of soil organic matter. There is increasing interest in the extent to which biological slurry additives (mixtures of selected living or latent microorganisms added to slurry) are able to enhance soil fertility through mobilisation of key elements in the slurry and in the soil. However, little is known about the impacts of slurries amended with biological additives on carbon (C) partitioning within three pools: respired CO2, microbial biomass C (Cmic) and C retained in the soil. We report data from incubation experiments in which soils received livestock slurry treated with a commercial biological additive, alongside 14C-labelled carbohydrates of different lability (14C-glucose, 14C-glucose 6-phosphate (G6P), and 14C-cellulose). The aim of this experiment was to understand how slurry that has received a biological additive ultimately affects the partitioning of C within these pools, alongside how slurry additives influence soil microbial biomass and the priming effect (PE) in soil. The addition of slurry alongside carbohydrates to soil resulted in lower 14C biomass uptake and greater residual 14C activities in soil, as well as to lower cumulative respiration and PE, compared to the corresponding carbohydrate-only treatments. Competition in the soil between the indigenous microbial community and the microbial community associated with slurry is proposed to account for the apparent suppression of biomass uptake of added C-substrate and of cumulative respiration. Our findings also seem to indicate that the addition of a biological additive to slurry resulted in higher cumulative CO2 efflux from soil compared to the unamended slurry, both for glucose and G6P treatments. This suggests that biological slurry additives may have the potential to reduce the suppressive effect of slurry microorganisms on native soil microorganisms.

Dual sensor measurement shows that temperature outperforms pH as an early sign of aerobic deterioration in maize silage

High quality silage containing abundant lactic acid is a critical component of ruminant diets in many parts of the world. Silage deterioration, a result of aerobic metabolism (including utilization of lactic acid) during storage and feed-out, reduces the nutritional quality of the silage, and its acceptance by animals. In this study, we introduce a novel non-disruptive dual-sensor method that provides near real-time information on silage aerobic stability, and demonstrates for the first time that in situ silage temperature (Tsi) and pH are both associated with preservation of lactic acid. Aerobic deterioration was evaluated using two sources of maize silage, one treated with a biological additive, at incubation temperatures of 23 and 33 °C. Results showed a time delay between the rise of Tsi and that of pH following aerobic exposure at both incubation temperatures. A 11 to 25% loss of lactic acid occurred when Tsi reached 2 °C above ambient. In contrast, by the time the silage pH had exceeded its initial value by 0.5 units, over 60% of the lactic acid had been metabolized. Although pH is often used as a primary indicator of aerobic deterioration of maize silage, it is clear that Tsi was a more sensitive early indicator. However, the extent of the pH increase was an effective indicator of advanced spoilage and loss of lactic acid due to aerobic metabolism for maize silage.

THE POSSIBILITY OF USING PECTIN OF CONIFEROUS TREES AS STRUCTURE-FORMING

In recent years, the demand for food has sharply increased in functional ingredients, especially in pectin. At present, there is no production of pectin substances in the Russian Federation, and the demand for them is satisfied, mainly due to the use of imported pectin. At the same time, the country has prerequisites for its own production of pectin from non-traditional types of raw materials, for example, bark of coniferous trees, which in the form of waste is produced in large quantities when processing wood in the timber, woodworking and pulp and paper industries, and goes to incineration, although its can be used to obtain such a valuable substance as pectin. The article considers the possibility of using pectins from the bark of coniferous trees in the production of fruit and vegetable nectars with pulp as a biological additive that improves the consistency of the product. To confirm this, VNII researchers of conservation technology conducted studies to test pectin from the bark of spruce and larch on their structure-forming ability. For this purpose, experimental samples of fruit and vegetable nectars with pulp were made: apricot, quince, cherry, redcod, plum and carrot, obtained on the basis of fruit and vegetable purees, as well as the calculated amount of sugar syrup with a certain concentration, with the addition of pectin from the spruce bark and larch, and for comparison samples with the addition of ordinary apple pectin. Pectin was added as a 10% solution in an amount of 9.0% of the total weight of nectar (in terms of dry pectin – 0.9%), which allowed to provide a homogeneous, non-dissolving consistency of nectars.