Biomass Activity Research Articles

Impact of Integration of FO Membranes into a Granular Biomass AnMBR for Water Reuse

The granular sludge based anaerobic membrane bioreactor (G-AnMBR) has gained emphasis in the last decade by combining AnMBR advantages (high quality permeate and biogas production towards energy positive treatment) and benefits of granular biomass (boosted biological activity and reduced membrane fouling). With the aim to further reduce energy costs, produce higher quality effluent for water reuse applications and improve system efficiency, a forward osmosis (FO) system was integrated into a 17 L G-AnMBR pilot. Plate and frame microfiltration modules were step by step replaced by submerged FO ones, synthetic wastewater was used as feed (chemical oxygen demand (COD) content 500 mg/L), with hydraulic retention time of 10 h and operated at 25 °C. The system was fed with granular biomass and after the acclimation period, operated neither with gas sparging nor relaxation at around 5 L.m-2.h-1 permeation flux during at least 10 days for each tested configuration. Process stability, impact of salinity on biomass, the produced water quality and organic matter removal efficiency were assessed and compared for the system working with 100% microfiltration (MF), 70% MF/30% FO, 50% MF/50% FO and 10% MF/90% FO, respectively. Increasing the FO share in the reactor led to salinity increase and to enhanced fouling propensity probably due to salinity shock on the active biomass, releasing extracellular polymeric substances (EPS) in the mixed liquor. However, above 90% COD degradation was observed for all configurations with a remaining COD content below 50 mg/L and below the detection limit for MF and FO permeates, respectively. FO membranes also proved to be less prone to fouling in comparison with MF ones. Complete salt mass balance demonstrated that major salinity increase in the reactor was due to reverse salt passage from the draw solution but also that salts from the feed solution could migrate to the draw solution. While FO membranes allow for full rejection and very high permeate purity, operation of G-AnMBR with FO membranes only is not recommended since MF presence acts as a purge and allows for reactor salinity stabilization.

Shift in the Mode of Carbon Cycling Recorded by Biomarkers and Carbon Isotopic Compositions in the Yanchang Formation, Ordos Basin: Autotrophy vs Heterotrophy.

Organic-rich shales and mudstones have long been investigated regarding the control of source, environment, climate, etc. on the enrichment of organic carbon. However, little is documented about how autotrophy and heterotrophy influence organic carbon cycling/export. Here, we show molecular and carbon isotopic compositional changes of the shale or mudstone source rocks from the Chang 3 to 7 members of the Yanchang Formation. The Chang 7 member source rocks have higher quality (480-500 mg/g) and total organic carbon (TOC) (15.3% on average) than other member source rocks; the sterane/hopane ratio and the δ13C of organic carbon and kerogen decrease from the Chang 3 to 7 members, but Δδ ([average δ13C of n-C17 + n-C18] - [average δ13C of pristane + phytane]) increases, and no aryl isoprenoids and C40 aromatic carotenoids (e.g., isorenieratane) were observed. These low maturity biomarker features suggest that there were no water stratification, photic zone euxinia (PZE), and no obvious change in the organic matter source, and the water column is generally anoxic. A comparison of the δ13C of Pr and Ph with the δ13C of the n-C17 and n-C18 alkanes reveals a shift in the mode of carbon cycling/export (autotrophy versus heterotrophy) in the Yanchang Formation and that there was dominant heterotrophic bacterial activity or bacterial biomass in the Chang 7 member. The TOC spike in the Chang 7 member may result from boosted carbon cycling/export that improves organic carbon preservation than other members. Possible external forcings on the shift are abundant hydrothermal- or volcanic-derived metal salts as electron acceptors in the palaeowater, which is a reasonable explanation for enhanced heterotrophic bacterial activity. This finding improves our understanding of heterotrophic bacterial activity control on organic matter (OM) preservation and may be a significant supplement for understanding the ecological or environmental forcings in the Yanchang Formation, Ordos Basin.

Control of Pre-formed Halogenated Disinfection Byproducts with Reuse Biofiltration.

Disinfection byproduct (DBP) pre-formation is a major issue when prechlorination is used before or during advanced treatment of impacted drinking water sources. Control strategies for pre-formed DBPs before final disinfection, especially for currently nonregulated although highly toxic DBP species, are not yet established. This study evaluated the biodegradation potential of pre-formed DBPs, including haloacetonitriles (HANs), haloacetamides (HAMs), and haloacetaldehydes (HALs), during biofiltration with sand, anthracite, and biological activated carbon of three wastewater effluents under potable reuse conditions. Up to 90%+ removal of di- and trihalogenated HANs, HAMs, and HALs was observed, and removal was associated with active heterotrophic biomass and removal of biodegradable organic carbon. Unlike the microbial dehalogenation pathway of haloacetic acids (HAAs), removal of HANs and HAMs appeared to result from a biologically mediated hydrolysis pathway (i.e., HANs to HAMs and HAAs) that may be prone to inhibition. After prechlorination, biofiltration effectively controlled pre-formed DBP concentrations (e.g., from 271 μg/L to as low as 22 μg/L in total) and DBP-associated calculated toxicity (e.g., 96%+ reduction). Abiotic residual adsorption capacity in biological activated carbon media was important for controlling trihalomethanes. Overall, the toxicity-driving DBP species exhibited high biodegradation potential and biofiltration showed significant promise as a pre-formed DBP control technology.

Antibacterial and anti-biofilm activities of Disaspidin BB against Staphylococcus epidermidis.

Staphylococcus epidermidis infections are an important concern in worldwide, especially when associated with biofilms, and resistance of this agent to many drugs makes the situation even worse. We investigated the inhibitory effect of Disaspidin BB obtained from plant extracts and purifications on clinical S. epidermidis strains and their biofilms, and preliminarily investigated its mechanism of of its anti-biofilm activity. The broth dilution method was used to determine the minimum inhibitory concentrations (MIC) of Disaspidin BB on 11 clinical S. epidermidis strains (MIC value of 0.63 ~ 2.5 μg/ml). SEP-05 was found to be erythromycin-resistant (MIC value>8 μg/ml) and Disaspidin BB sensitive with an MIC value of 0.63 μg/ml. The time-kill curve assay indicated that the antibacterial activity of Disaspidin BB against SEP-05 with concentration dependence. The metabolic activity and total biomass of the drug-treated SEP-05 biofilm in each stage were significantly inhibited by the crystalline violet and XTT assay, and the scavenging effect of Disaspidin BB on SEP-05 biofilm was also confirmed by SEM observation. The results of real-time quantitative PCR showed that subinhibitory concentrations Disaspidin BB can inhibit biofilm formation by affecting the expression level of key genes (aap, atlE, icaA, luxS, recA) in SEP-05 biofilm formation. In addition, the content of polysaccharides, proteins and extracellular DNA in biofilm matrix after the intervention of Disaspidin BB was significantly reduced, and it was tentatively determined that the ability of SEP-05 biofilm formation and its stability were thus disturbed. The results show that Disaspidin BB has promising antibacterial effect on erythromycin-resistant S. epidermidis and significant scavenging effect on its biofilm, which provides a theoretical basis for the further development of BB as a new drug for the treatment of skin infections caused by S. epidermidis.

Listeria monocytogenes Biofilms Are Planktonic Cell Factories despite Peracetic Acid Exposure under Continuous Flow Conditions

Listeria monocytogenes biofilms are ubiquitous in the food-processing environment, where they frequently show resistance against treatment with disinfectants such as peracetic acid (PAA) due to sub-lethal damage resulting in biofilm persistence or the formation of secondary biofilms. L. monocytogenes serovar ½a EGD-e biofilms were cultivated under continuous flow conditions at 10 °C, 22 °C, and 37 °C and exposed to industrially relevant PAA concentrations. The effect of PAA on biofilm metabolic activity and biomass was monitored in real-time using the CEMS-BioSpec system, in addition to daily measurement of biofilm-derived planktonic cell production. Biofilm-derived planktonic cell yields proved to be consistent with high yields during biofilm establishment (≥106 CFU.mL-1). The exposure of biofilms to the minimum inhibitory PAA concentration (0.16%) resulted in only a brief disruption in whole-biofilm metabolic activity and biofilm biomass accumulation. The recovered biofilm accumulated more biomass and greater activity, but cell yields remained similar. Increasing concentrations of PAA (0.50%, 1.5%, and 4.0%) had a longer-lasting inhibitory effect. Only the maximum dose resulted in a lasting inhibition of biofilm activity and biomass-a factor that needs due consideration in view of dilution in industrial settings. Better disinfection monitoring tools and protocols are required to adequately address the problem of Listeria biofilms in the food-processing environment, and more emphasis should be placed on biofilms serving as a "factory" for cell proliferation rather than only a survival mechanism.

Heat stress decreased transpiration but increased evapotranspiration in gerbera.

Heat stress is a major constraint for plant production, and evapotranspiration is highly linked to plant production. However, the response mechanism of evapotranspiration to heat stress remains unclear. Here, we investigated the effects of heat stress during two main growth stages on transpiration and evapotranspiration of gerbera. Two levels of day/night temperature were adopted during the vegetative growth stage (VG) and the flowering bud differentiation stage (FBD), namely control (CK; 28/18 °C) and heat stress (HS; 38/28°C) levels. The duration of HS was set as 5, 10, 15, and 20 days, respectively. At the beginning of HS, hourly transpiration was mainly inhibited near noon. With continuation of HS, the duration and extent of inhibition of hourly transpiration increased. Daily transpiration rate was also markedly reduced by HS during the VG (18.9%-31.8%) and FBD (12.1%-20.3%) stages compared to CK. The decrease in the daily transpiration rate was greater for longer duration of heat stress. This reduction of transpiration was the main contributor to stomatal limitation at the beginning of HS, while additional inhibition of root activity, leaf area, and root biomass occurred under long-term HS. The daily transpiration rate could not recover after the end of HS (so-called recovery phase), except when HS lasted 5 days during the VG stage. Interestingly, daily evapotranspiration during HS was substantially increased during the VG (12.6%-24.5%) and FBD (8.4%-17.6%) stages as a result of more increased evaporation (100%-115%) than reduced transpiration. However, during the recovery phase, the daily evapotranspiration was markedly decreased at the VG (11.2%-22.7%) and FBD (11.1%-19.2%) stages. Hence, we suggest that disproportionate variation of transpiration and evaporation during HS, especially at the recovery phase, should be considered in various evapotranspiration models and climate scenarios projections.

Assessment of Cultivation Parameters Influencing Polygalacturonase Production by Aspergillus sp. SO5 in Submerged Fermentation

Polygalacturonase represents an important enzyme of the pectinase consortium in the food and beverage industry. The present study aims to isolate, screen, and enhance physicochemical parameters for enzyme production under submerged fermentation. A total of 34 fungal strains were obtained from rotten fruits and 70.6 % of them are able to produce polygalacturonase by degrading pectin in pectin screening agar. The fungal isolate (SO5) that exhibited the greatest diameter of the hydrolysis zone (45.3 ± 0.04 mm) was selected for further study and later identified as Aspergillus sp. SO5, based on morphological characteristics using light microscopic observation. Several physicochemical parameters improved for pectinase production including incubation temperature, initial pH, agitation speed, inoculum density, and carbon and nitrogen sources. Under improved conditions, the polygalacturonase activity and fungal biomass increased up to 74.63 and 69.44 %, respectively. The finding also revealed that the improved physicochemical conditions enhance enzyme production and shorten the incubation period from 6 days to 5 days. HIGHLIGHTS This research paper highlighted the capability of indigenous fungus (Aspergillus) to produce polygalacturonase. The finding revealed that the improved physicochemical conditions including agitation speed, inoculum size, the concentration of pectin, and incorporation of yeast extract in the culture medium could enhance polygalacturonase production by up to 74.63 % (34.21 ± 0.49 U/mL). The improved physicochemical conditions not only enhance the polygalacturonase production but shorten the incubation period to obtain optimum enzyme production. GRAPHICAL ABSTRACT

Enhancing Soil Health Through Microbial Inoculation and Changing Cultivation Methods in Rice-Wheat Cropping System

India’s rice-wheat cropping system (RWCS) is going through a paradigm shift to address resource degradation and sustainability issues. The increasing level of soil degradation has made soil biological health an important aspect of managing the problems of RWCS through understanding the role of microbes in enhancing soil health and by increasing the adoption of conservation agriculture-based practices. Our two-year study revealed that soil biological health, as measured by soil acetylene reductase activity (ARA), soil chlorophyll, microbial biomass carbon (MBC), soil dehydrogenase enzyme activity, and soil alkaline phosphatase activity (APA), was significantly impacted by the rice and wheat cultivation methods. The system of rice intensification (SRI) and zero tillage wheat (ZTW) system had significantly higher values for all the studied microbial parameters. The application of Anabaena-Pseudomonas biofilm formulation along with 75% recommended dose of nutrients (RDN) (90 kg N/ha and 19.35 kg phosphorus (P/ha) significantly improved all studied microbial parameters in both rice and wheat. The microbial properties such as dehydrogenase enzyme activity, alkaline phosphatase activity and microbial biomass carbon (MBC) had significantly higher values in treatment with RDN over 75% RDN indicating the role of optimal fertilization in soil biological health maintenance. A significant improvement in ARA and soil chlorophyll in inoculated treatment showed superior performance of inoculated microbes over inherent soil microbes in nitrogen fixation. The study of a combination of different rice and wheat cultivation methods and their influence in the long run on soil biological health in RWCS emphasizes the need for soil biological health maintenance considering its significant role in the system’s sustainability.

Resource-dependent foraging behaviour of grazers enhances effects of nutrient enrichment on algal biomass

Both the quantity and nutritional quality of food resources can strongly influence the foraging movements of herbivores, which in turn determine the strength of top-down control on primary producer biomass. Nutrient enrichment can alter the biomass and nutritional quality of primary producers, but the consequences for the foraging of herbivores and hence for top-down control are still poorly understood. In this study, we combined a two-factorial experiment (two nutrient levels × grazing by the freshwater gastropod Ancylus fluviatilis) with video analyses tracking grazers’ movements to investigate nutrient enrichment effects on spatial ranges of grazing activity and algal biomass removal. Natural stream biofilms were grown in phosphorus-enriched (P+) and phosphorus-poor flumes (P−) for two weeks before A. fluviatilis were added to the flumes and allowed to graze on biofilm for an additional 2 weeks. Total periphyton biomass was enhanced by P+ and reduced by grazer presence. However, the total grazer effect depended on the nutrient level: at the end of the experiment, on average 95% of algal cover were removed by grazing in the P− flumes versus 26% in the P+ flumes. Fast movements of A. fluviatilis were detected significantly more often in the P− treatment, whereas grazers were detected resting more often in the P+ treatment. Our results demonstrate that nutrient enrichment can increase primary producer biomass both directly and indirectly by limiting the foraging ranges of herbivores. The resulting feedback loop between reduced grazing activity and increased plant biomass might in turn exacerbate eutrophication effects on habitat structure.

Under-vine cover crops: Impact on physical and biological soil proprieties in an irrigated Mediterranean vineyard

Despite their potential benefits, cover crops in vineyards under to Mediterranean climate conditions are still not widespread, especially in the vine row. This under-vine space is normally kept weed-free through the application of herbicides and/or tillage. In this work, we evaluate the effect of a Trifolium fragiferum L. under-vine cover crop (UV) on soil quality, as reflected by a variety of physical, chemical, and biological soil indicators. 15 months after under-vine cover crop implementation, total (SOC) and particulate (POC) organic carbon storage, and soil aggregation (abundance (WSA) and mean weight diameter (MWD) of water stable aggregates) were compared with a control without cover (T) at 0–15 cm. In addition, for three consecutive years after under-vine cover crop implementation, the evolution of soil microbial communities was monitored through the determination of soil basal respiration, soil microbial biomass carbon and nitrogen (MBC and MBN), and community-level physiological profiles (CLPPs). The establishment of the under-vine cover crop resulted in higher values of SOC (27.78 Mg·ha−1 in UV vs. 20.71 Mg·ha−1 in T, +33%) and POC (4.75 Mg·ha−1 in UV vs. 2.73 Mg·ha−1 in T, +74%), as well as aggregation parameters (MWD: 1.82 µm in UV vs. 1.56 µm in T, +17% and WSA: 84.68% in UV vs. 71.58% in T, +18%). An evolution towards progressively greater values of biological activity (basal respiration) and microbial biomass was detected in under-vine cover crop soils as time elapsed. It was concluded that the Trifolium fragiferum L. under-vine cover crop led to soil quality improvement in our Mediterranean climate vineyard. Interestingly, this positive effect was noticed shortly after its implementation.

Analysis of non-axenic biomasses for self-healing concrete

As an alternative to the usage of axenic bacteria to achieve microbially induced calcium carbonate precipitation (MICP), this study evaluates the usage of two non-axenic biomasses as self-healing agents. A fungi-based consortium (Yeast) and heterotrophic nitrifiers (HTN) were harvested from the incubation of agricultural side streams. The characteristics of the two biomasses were identified through flow cytometry, total suspended solids and volatile suspended solids tests. The incorporation of the biomasses into concrete was evaluated in terms of compressive strength, flow and healing ability. Self-healing ability was analyzed through microscope imaging on prismatic (60x60x220 mm) samples. Cracks were induced with a three-point bending test where the widths were controlled with an LVDT sensor. A curing period of 56 days was applied to the samples and visual inspection was conducted at the start and end of the healing period with an optical microscope. Results compare and discuss the differing effects of active and autoclaved biomasses on the concrete properties and crack closure.

Dendroclimatic studies of aspen growth in Moscow

This article presents the results of studying aspen (Populus tremula L.) growth in urbanized environment of Moscow metropolis with the help of dendrochronology method. Four significant correlation coefficients for data of two aspen chronologies and the group of forty-eight meteoparameters of current calendar year and the calendar year which was previous to the year of tree ring formation were established by the dendroclimatic method. According to the results of correlation calculation it was established that correlations sustainable for both considered chronologies as well as biologically interpretable ones between radial growth fluctuations and climatic data fluctuations are absent. It is due to the fact that the aspen trees on considered plots are in the conditions near the optimum zone and the factors, which are limiting radial growth size, change from year to year. One year one factor has strong deviation from optimal for species parameters, and another year it will be another factor. In this case the correlation analysis gives results about the lack of correlation, but it does not mean that climatic factors have no impact on tree ring formation. The absence of correlation, for instance, to the temperatures observed in May of the current year is important as this is a period of great cambium activity and assimilation biomass forming. So, the increase in temperature of this month, probably predicted with global warming, will not have a negative effect on aspen growth in the conditions of the studied stands.

Synergistic Effect of Bovine Cateslytin-Loaded Nanoparticles Combined With Ultrasound AgainstCandida AlbicansBiofilm

Purpose: To investigate the synergistic effect of bovine cateslytin-loaded nanoparticles (bCAT-NPs) combined with ultrasound against Candida albicans biofilm and uncover the underlying mechanism. Methods: bCAT-NPs were prepared by the double emulsion method, and toxicity was observed by the hemolysis ratio. The metabolic activity and viable cell biomass, morphology and membrane permeability of C. albicans biofilm were observed. The expression of ALS3 mRNA, the content of reactive oxygen species, was detected. Finally, bCAT structure was analyzed. Results & conclusion: The hemolysis ratio of the bCAT-NPs group was significantly lower than that of the bCAT group. bCAT-NPs combined with ultrasound significantly reduced biofilm metabolic activity, inhibited the formation of hyphae, decreased the expression of ALS3 mRNA and increased the intracellular reactive oxygen species content. In the in vivo experiments, the colony-forming units/ml in the ultrasound+bCAT-NPs group decreased, and a few planktonic fungal cells were observed.

Interaction Between Mycorrhizae and Organic Amendments to Improve Growth and Phosphorus Uptake in Brinjal

Phosphorus (P) is the second most important macronutrient both for plants and other living organisms. However, due to its fixation with soil collides; it becomes unavailable to plants and hence cannot enter the food chain. The effect of combination of mycorrhizae and different organic amendments on P uptake and plant growth of brinjal (Solanum melongena) was evaluated in a pot trial, conducted at wire house of Institute of Soil and Environmental Sciences, University of Agriculture Faisalabad. Each treatment was composed of one type of organic amendment (i.e. farmyard manure (FYM), biogas slurry (BGS), poultry manure and compost) at the rate of 1.5% w/w and mycorrhizae. Results showed that the combined application of mycorrhizae and organic amendment improved plant growth and enhanced P uptake. Improved root length, shoot height and leaf canopy was observed in FYM+mycorrhizae and BGS+mycorrhizae combinations. Similarly, enhanced P uptake improved photosynthetic activity and high biomass was observed in BGS+mycorrhizae combinations. The use of mycorrhizae and organic amendments appeared to be efficient in improving P uptake up to 53.45% and plant growth 64.32%. It is concluded that practicing this in the field can be cost effective approach and reduce environmental risk by reducing application of chemical fertilizers.

A device for assessing microbial activity under ambient hydrostatic pressure: The in situ microbial incubator (ISMI).

Microbes in the dark ocean are exposed to hydrostatic pressure increasing with depth. Activity rate measurements and biomass production of dark ocean microbes are, however, almost exclusively performed under atmospheric pressure conditions due to technical constraints of sampling equipment maintaining in situ pressure conditions. To evaluate the microbial activity under in situ hydrostatic pressure, we designed and thoroughly tested an in situ microbial incubator (ISMI). The ISMI allows autonomously collecting and incubating seawater at depth, injection of substrate and fixation of the samples after a preprogramed incubation time. The performance of the ISMI was tested in a high-pressure tank and in several field campaigns under ambient hydrostatic pressure by measuring prokaryotic bulk 3H-leucine incorporation rates. Overall, prokaryotic leucine incorporation rates were lower at in situ pressure conditions than under to depressurized conditions reaching only about 50% of the heterotrophic microbial activity measured under depressurized conditions in bathypelagic waters in the North Atlantic Ocean off the northwestern Iberian Peninsula. Our results show that the ISMI is a valuable tool to reliably determine the metabolic activity of deep-sea microbes at in situ hydrostatic pressure conditions. Hence, we advocate that deep-sea biogeochemical and microbial rate measurements should be performed under in situ pressure conditions to obtain a more realistic view on deep-sea biotic processes.

Active and smart biomass film containing cinnamon oil and curcumin for meat preservation and freshness indicator

Food safety issues caused by unrecognizable food spoilage threaten the health and lives of consumers. Simultaneously, petroleum-based plastic packaging films without degradability cause environmental pollution. Despite recent certain study progress in preparing biodegradable food packaging films, it is still significant and urgent to develop biomass food packaging films with favorable water resistance, mechanical strength, UV-barrier performance, antibacterial property, antioxidant activity and visual freshness indication performance at the same time. In this work, we fabricate an active and smart biomass composite film with favorable multifunctionality by incorporating the oxidized cellulose nanofiber (OCNF)-stabilized cinnamon oil (CNO) Pickering emulsion and curcumin (Cur) into gelatin/chitosan (GC) film matrix. The study results show that CNO Pickering emulsion droplets are uniformly distributed in the film matrix. Introducing Pickering emulsion reduces the film water absorption by 336.27% and promotes film antimicrobial activity. Moreover, the emulsion stabilizer OCNFs serve as nano-enhancers to increase film tensile strength by 1.4 MPa even if introducing CNO into the film matrix. Furthermore, Cur endows the film with colorimetric pH indication ability and increases the film antioxidant activity. The DPPH scavenging rates of film including Pickering emulsion and Cur maintain above 44% after 60-day storage, and its UV-barrier property increases by 65.5% at 400 nm compared with those of GC film. These results exhibit promising potential application of the prepared film in pork preservation and the visual pork freshness indicator by the film color changes. Thus, this work provides an attractive universal strategy to construct active and smart biomass composite film for meat packaging application.

TO THE QUESTION OF THE EFFECTS OF SHUNGHITES ON PLANT GROWTH AND DEVELOPMENT

The effects of shungite rocks (ShR) from Turastamozero (1, 5, 25, 100%), Nigozero (1, 5, 10, 25, 100%) and Zazhogino (1, 5, 100%) deposits added to growing substrate on wheat ( Triticum aestivum L.) and barley ( Hordeum vulgare L.) plant growth and development were studied. Silica sand was used as a control substrate for plant growing.Plants were grown in growth chambers at a temperature of 23°C or 15°C, PAR 200 µmol m -2 s -1 and irrigated with a complete or 25% nutrient solution. Salt stress was provided by irrigation with 1,68% NaCl solution for 3 days. Periodic drought conditions were simulated by watering plants every 2-3 days.The results of the experiments have shown that plant growth and development is affected not only by the concentration of ShR in the substrate, but also the type (deposit location) of the ShR. There was recorded positive effect of TurastamozeroShR at 1 and 25% concentrations on the photosynthetic activity and accumulation od plant biomass. ShR from Nigozero deposit at concentrations above 5% inhibited plant growth and development due to high acidity of the substrate. The effects of ZazhoginoShR on these processes at 1 and 5% concentrations were insignificant. The use of ShR as 100% substrate have shown that only ShR from Turastamozero deposit is suitable for plant growing. In the substrates containing 100% ShR from Nigozero and Zazhogino the seeds did not germinate.Under mineral nutrition deficiency, wheat plants in the substate with 1 and 5% TurastamozeroShRhad larger biomass compared to control plants. Under periodic drought stress, the use of 1 and 5% ShR from all three deposits led to an increase of root biomass of barley, however, plant biomass was higher than the control only when 1% TurastamozeroShR was used. No positive effect of ShR on plant tolerance to salt and chilling stress was found. Based on our own results and literature data, we analyzed the hypothetical reasons of direct and indirect effects of ShR on plant growth and development. It is concluded that the practical use of ShR requires great care and further study, since without understanding the mechanisms of their effects on plants it is impossible to ensure their effective use in order to control growth, development and productivity. It is also obvious that the general term “shungite” is not Applicable in plant physiology and crop science as ShR from different deposits and mixed with other substrates in the fertilizing compositions can have very different, even opposing effects on plants.

Effect of Biochar on Rhizosphere Soil Microbial Diversity and Metabolism in Tobacco-Growing Soil

In this study, four different biochar application rates and a control were set up using indoor potted tobacco, to study the effects of biochar on the microbial diversity and metabolism of tobacco-growing soil. The five treatments were as follows: control—0% biochar (w/w) + 26 g fertilizer/pot; biochar treatments—1% biochar (w/w) + 26 g fertilizer/pot, 2% biochar (w/w) + 26 g fertilizer/pot, 3% biochar (w/w) + 26 g fertilizer/pot, and 4% biochar (w/w) + 26 g fertilizer/pot. We found that biochar increases the microbial diversity of soils and simultaneously changes the microbial community structure. Under the influence of biochar, soil urease activity increased by 18%, invertase activity increased by 23.40%, polyphenol oxidase activity increased by 59.50%, and catalase activity increased by 30.92%. Biochar also significantly increased the microbial biomass carbon and nitrogen content of the soil. Soil microbial biomass nitrogen had a positive correlation on bacterial diversity, with the highest coefficient, while soil microbial biomass carbon had a positive correlation on fungal diversity, with the highest coefficient. The microbial diversity and metabolic capacity of soil are improved under the influence of biochar, and soil enzyme activity and microbial biomass carbon and nitrogen have positive impacts on soil microbial diversity.

Native Bacillus subtilis Strains Efficiently Control Lupin Anthracnose Both under Greenhouse and in Field Conditions

Colletotrichum acutatum is the cause of lupin anthracnose in the Andean zone. The pathogen affects the crop throughout its entire production cycle, causing losses of up to 100%. In previous studies, native strains of B. subtilis (CtpxS1-1; CtpxS2-1 and CtpxZ3) from the province of Cotopaxi reduced anthracnose infections in seed and seedlings. This study evaluated the potential biological control of these strains by using two lupin anthracnose susceptible cultivars under greenhouse conditions and in the field. Plants of I-451 Güaranguito and I-450 Andino cultivars were treated with active biomass from each B. subtilis strain. Pre-inoculated plants that received a bacterial concentration of 1 × 109 colony-forming units per milliliter (CFU/ml) showed a reduction by ten times in the stem lesion diameter when compared with plants artificially infected with the pathogen alone in greenhouse evaluations. Sequential applications of antagonists every two-week allow for quantifying their biocontrol efficiency under field conditions. A significant (P

Effects of Bacillus subtilis and Pseudomonas fluorescens as the soil amendment

The application of soil beneficial bacteria (SBB) in agriculture is steadily increasing as it provides a promising way to replace chemical fertilisers and other supplements. Although the role of SBB as a biofertiliser is well understood, little is known about the response of soil physiochemical properties via the change in soil enzymatic activities with SBB growth. In this study, sterilised bulk soil was inoculated with Bacillus subtilis (BS) and Pseudomonas fluorescens (PF), which exhibit excellent characteristics in vitro for potentially improving soil quality. It is found that the contents of bioavailable nitrogen and ammonium in soil inoculated with SBB increased significantly, up to 34% and 57% relative to a control. This resulted from the enhancement of soil urease activity with BS and PF treatments by approximately 90% and 70%, respectively. The increased soil urease activity can be explained by the increased microorganism activity evident from the larger population size of BS (0.78–0.97 CFU mL−1/CFU mL−1) than PF (0.55–0.79 CFU mL−1/CFU mL−1) (p < 0.05). Results of principal component analysis also reinforce the interaction apparent in the significant relationship between soil urease activity and microbial biomass carbon (p < 0.05). Therefore, it can be concluded that the enhancement of soil enzymatic activities induced bulk soil fertility upregulation because of bacterial growth. These results demonstrate the application of SBB to be a promising strategy for bulk soil amendment, particularly nutrient restoration.