Assessment of the Effect of Environmental Factors on the Antagonism of <i>Bacillus amyloliquefaciens</i>and <i>Trichoderma harzianum</i>to <i>Colletotrichum acutatum</i>

The effect of temperature (18°C - 30°C), water activity (0.85 - 1) and pH (4 - 9) was studied by dual culture technique on the antagonism of Bacillus amyloliquefaciens and Trichoderma harzianum to Colletotrichum acutatum, responsible of strawberry (Fragaria x ananassa (Weston) Duchesne ex Rozier) anthracnose. The antagonistic bacteria’s strains behave significantly and differently according to the parameters studied. These results reveal useful information about the applicability of their biocontrol in agricultural culture with the change of environmental factors.

Growth and Antagonism of <i>Trichoderma</i>spp. and Conifer Pathogen <i>Heterobasidion annosum</i>s.l. <i>in Vitro</i>at Different Temperatures

Variations in the radial growth rate of 24 isolates belonging to ten species of Trichoderma, three isolates of conifer pathogen Heterobasidion annosum s.s. and four isolates of H. parviporum were evaluated by incubation on a solid malt extract medium at a temperature of 4℃, 15℃ and 21℃. Trichoderma antagonism against Heterobasidion was investigated in dual culture in vitro. The slowest rate of growth was referable to all seven strains of Heterobasidion spp. All Heterobasidion spp. strains were overgrown by 63% of Trichoderma spp. strains after two weeks at 21℃ and by 33% of strains at 15℃. 21% of Trichoderma strains did not grow and only four strains belonging to T. koningii, T. viride and T. viridescens demonstrated the ability to completely overgrow Heterobasidion spp. after two weeks incubation at 4℃. According to the antagonistic efficiency, Trichoderma strains were divided into five groups with an Euclidean distance of 25. The groups contained isolates from different species. It was suggested that selected psychrotrophic fast growing T. viride, T. koningii and T. viridescens strains could be examined in different substrate conditions as suitable antagonist agents for the control of H. annosum and H. parviporum.

WORLD MILITARY SITUATION 2016: ANTAGONISM INTENSIFIES BUT CRISES REMAIN CONTROLLABLE

The world military situation in 2016was complex,military strategies of major countries undergoing profound readjustment,contest in emerging fields increasing and a new round of populism cropping up worldwide which resulted in'Black swan events'happening one after another,major-country contest and geopolitical conflicts piling up and local

Mutual antagonism of mouse-adaptation mutations in HA and PA proteins on H9N2 virus replication

Avian H9N2 viruses have wide host range among the influenza A viruses.However,knowledge of H9N2 mammalian adaptation is limited.To explore the molecular basis of the adaptation to mammals,we performed serial lung passaging of the H9N2 strain A/chicken/Hunan/8.27 YYGK3W3-OC/2018(3W3)in mice and identified six mutations in the hemagglutinin(HA)and polymerase acidic(PA)proteins.Mutations L226Q,T511I,and A528V of HA were responsible for enhanced pathogenicity and viral replication in mice;notably,HA-L226Q was the key determinant.Mutations T97I,I545V,and S594G of PA contributed to enhanced polymerase activity in mammalian cells and increased viral replication levels in vitro and in vivo.PA-T97I increased viral polymerase activity by accelerating the viral polymerase complex assembly.Our findings revealed that the viral replication was affected by the presence of PA-97I and/or PA-545V in combination with a triple-point HA mutation.Furthermore,the double-and triple-point PA mutations demonstrated antagonistic effect on viral replication when combined with HA-226Q.Notably,any combination of PA mutations,along with double-point HA mutations,resulted in antagonistic effect on viral replication.We also observed antagonism in viral replication between PA-545V and PA-97I,as well as between HA-528V and PA-545V.Our findings demonstrated that several antagonistic mutations in HA and PA proteins affect viral replication,which may contribute to the H9N2 virus adaptation to mice and mammalian cells.These findings can potentially contribute to the monitoring of H9N2 field strains for assessing their potential risk in mammals.

Infection against infection: parasite antagonism against parasites, viruses and bacteria

Background:Infectious diseases encompass a large spectrum of diseases that threaten human health,and coinfection is of particular importance because pathogen species can interact within the host.Currently,the antagonistic relationship between different pathogens during concurrent coinfections is defined as one in which one pathogen either manages to inhibit the invasion,development and reproduction of the other pathogen or biologically modulates the vector density.In this review,we provide an overview of the phenomenon and mechanisms of antagonism of coinfecting pathogens involving parasites.Main body:This review summarizes the antagonistic interaaion between parasites and parasites,parasites and viruses,and parasites and bacteria.At present,relatively clear mechanisms explaining polyparasitism include apparent competition,exploitation competition,interference competition,biological control of intermediate hosts or vectors and suppressive effect on transmission.In particular,immunomodulation,including the suppression of dendritic cell(DC)responses,activation of basophils and mononuclear macrophages and adjuvant effeas of the complement system,is described in detail.Conclusions:In this review,we summarize antagonistic concurrent infections involving parasites and provide a funaional framework for in-depth studies of the underlying mechanisms of coinfeaion with different microorganisms,which will hasten the development of promising antimicrobial alternatives,such as novel antibaaerial vaccines or biological methods of controlling infeaious diseases,thus relieving the overwhelming burden of ever-increasing antimicrobial resistance.

‘Friendship Always,Antagonism Never’The launch of the Year of Russia marks a new chapter in a growing partnership between China and Russia

Most Chinese are at ease when talking about Russia. After all, past generations of Chinese were heavily influenced by things Russian-be it the language, folk songs, literature or food. This is easy to understand. China is Russia's largest neighbor and vice versa. The two countries are also important strategic partners. Joint efforts over the years have led to an unprecedented level of part-

Application of Silicon and Selenium in Rice for Reducing Cadmium Stress

Rice is an essential part of the human diet in most parts of the world;On the other hand,the industrialization of societies has led to pollution of the environment,including heavy metal contamination of soil and water,which negatively affects rice production and quality.Therefore,finding ways to increase the yield and quality of this strategic crop seems essential.Several studies have been conducted in recent decades to find effective and inexpensive solutions to reduce the adverse effects of heavy metals in rice fields.Due to the negative effect of cadmium pollution on rice quality and yield,the current study aimed to investigate cadmium absorption and transfer mechanisms in rice(from absorption by roots to loading in grains),and its effects on rice morphology,physiology,and biochemistry(such as biomass,nutrient absorption,antioxidant defenses).Also,rice’s natural mechanisms for detoxifying cadmium were discussed.This study also intended to identify the absorption and transfer pathways of silicon and selenium in rice,their roles in improving rice structures,and their antagonistic effects on reducing cadmium stress(absorption,transport,and toxicity of cadmium).

Interactions of cadmium and aluminum toxicity in their effect on growth and physiological parameters in soybean

The effect of Al and Cd on the growth, photosynthesis, and accumulation of Al, Cd and plant nutrients in two soybean genotypes were determined using hydroponic culture. There were six treatments: pH 6.5; pH 4.0; pH 6.5+1.0 μmol/L Cd; pH 4.0+1.0 μmol/L Cd; pH 4.0+150 μmol/L Al; pH 4.0+1.0 μmol/L Cd+150 μmol/L Al. The low pH (4.0) and Al treatments caused marked reduction in root length, shoot height, dry weight, chlorophyll content (SPAD value) and photosynthetic rate. Al-sensitive cv. Zhechun 2 accumulated comparatively more Al and Cd in plants than Al-tolerant cv. Liao 1. Compared with pH 6.5, pH 4.0 resulted in significant increase in Cd and Al concentration in plants. Combined application of Cd and Al enhanced their accu-mulation in roots, but caused a reduction in shoots. The concentrations of all 10 nutrients (P, K, Ca, Mg, Fe, Mn, Cu, Zn and B), except Mo were also increased when plants were exposed to pH lower than pH 6.5. Al addition caused a reduction in the con-centration of most nutrients in plant roots and shoots; but K, Mn and Zn in roots were increased. Treatments with Cd alone or together with Al reduced the concentrations of all the plant nutrients in plants. Al-sensitive genotype Zhechun 2 has lower nutrient concentration than Al-tolerant genotype Liao 1. The current findings imply that Al and Cd are synergistic in their effect on plant growth, physiological traits and nutrient uptake.

Synergistic and antagonistic interactions between potassium and magnesium in higher plants

Magnesium(Mg)affects various critical physiological and biochemical processes in higher plants,and its deficiency impedes plant growth and development.Although potassium(K)-induced Mg deficiency in agricultural production is widespread,the specific relationship of K with Mg and especially its competitive nature is poorly understood.This review summarizes current knowledge on the interactions between K and Mg with respect to their root uptake,root-to-shoot translocation and distribution in plants.Their synergistic effects on certain physiological functions are also described.The antagonistic effect of K on Mg is stronger than that of Mg on K in root absorption and transport within plants,indicating that the balanced use of K and Mg fertilizers is necessary for sustaining high plant-available Mg and alleviating K-induced Mg deficiency,especially in plant species with high K demand or in highavailable-K soil.The relationship between Mg and K in plant tissues may be antagonistic or synergistic depending on plant species,cell type,leaf age,source-and sink organs.There are synergistic effects of K and Mg on photosynthesis,carbohydrate transport and allocation,nitrogen metabolism,and turgor regulation.Definition of optimal K/Mg ratios for soils and plant tissues is desirable for maintaining proper nutritional status in plants,leading to a physiological state supporting crop production.Future research should concentrate on identifying the physiological and molecular mechanisms underlying the interactions between K and Mg in a given physiological function.

Biological Intelligence of Rare Earth Elements in Animal Cells

Recent progress in bioinorganic chemistry studies of rare earth elements (REE) in animal cells was outlined, and the definition of REE′s biological intelligence as well as their mechanism were also explained. The migration of REE from weathering rocks to the environment is accelerated by various anthropogenic activities, which can eventually result in the entrance of REE into animal and human bodies via food chain. REE can be found in body tissues such as brain, blood, muscle as well as bone. Based on their geochemical properties, REE in low dose show their unique biological intelligence by intervening in the process of signal transduction and its regulation, arteriosclerosis and blood clotting prevention, anticancer, and the promotion of cellular defense enzymes′ activities, nucleic acid metabolism enzymes as well as ATPases, etc. The meaning of REE′s biological intelligence refers to physicochemical properties-based capability to choose the targets (e.g., biometals) in biomolecules for the chelation or replacement of REE, and change the structures and functions of biomolecules, and consequently impact or control the biological functions or behaviors in living organisms. The regulation of various cellular processes caused by REE is mainly via antagonism or replacement of essential target biometals like calcium or via chelation of organic molecules, thereby embodying the unparalleled biological intelligence of REE. Additionally, the dosage effect of REE was also discussed from the angles of yin-yang dichotomy, bioavailability, entropy and evolution. In order to make full use of REE′s biological intelligence in the application for medicine, more detailed studies concerning dosage effect of REE and REE bioaccumulation in organisms should be conducted in future research.

Modeling and solution based on stochastic games for development of COA under uncertainty

Developing a course of action(COA) is a key step in military planning. In most extant studies on the COA development,only the unilateral actions of friendly forces are considered. Based on stochastic games, we propose models that could deal with the complexities and uncertainties of wars. By analyzing the equilibrium state of both opponent sides, outcomes preferable to one side could be achieved by adopting the methods obtained from the proposed models. This research could help decision makers take the right COA in a state of uncertainty.

A new Lactobacillus gasseri strain HMV18 inhibits the growth of pathogenic bacteria

To search for a new eco-friendly therapy for infectious disease caused by Escherichia coli,Staphylococcus aureus or Klebsiella oxytoca,we collected the vaginal swabs from healthy women,screened for Lactobacillus and found a strain repressing the growth of pathogenic bacteria.The new isolate was identified as L.gasseri by the colony morphology,Gram staining,biochemical reactions and confirmed by the 16 S rDNA sequencing.The HMV18 strain inhibited the growth of food-borne pathogens such as E.coli,S.aureus and K.oxytoca.The HMV18 strain was sensitive to penicillin,ampicillin,erythromycin,tetracycline and chloramphenicol.The HMV18 strain producedα-hemolysis.Pathological histology of the mice ileum showed that the mucosa,villi,lamina propria and crypt depth remained intact and there was no inflammation or hyperemia in the L.gasseri HMV18 gavaged group.L.gasseri HMV18 could not up-regulate inflammatory cytokines level of plasma.All the results suggested L.gasseri HMV18 is a candidate probiotic to be an additive for food preservation or drug to prevent food-borne diseases.

Mathematical rules for synergistic,additive,and antagonistic effects of multi-drug combinations and their application in research and development of combinatorial drugs and special medical food combinations

Multi-drug(or multi-element)combinations are often prescribed in the practice of clinical medicine and as foods for special medical purposes.The main motivations for these combinations are that most diseases contain multiple related targets and an appropriate combination can maximize benefits while minimizing adverse reactions.As such,it is especially important to derive mathematical models for their quantitative calculation.In this paper,we introduce mathematical rules for the synergistic,additive,and antagonistic effects of multi-drug combinations developed in our laboratory.We have established a“onebelt,one-line”model and provide examples of the quantitative calculation of the synergistic,additive,and antagonistic effects of a combination of multiple components.We also explain how to scientifically and precisely determine the intensity of these synergies,additions and antagonisms,as well as their corresponding dose ranges,thereby laying a solid theoretical foundation for market listing combinatorial drugs and foods for special medical purposes.

Evaluating effective Trichoderma isolates for biocontrol of Rhizoctonia solani causing root rot of Vigna unguiculata

The highly diverse genus Trichoderma has provided many formulations that are alternatives to the chemical pesticides in agriculture.The present study was undertaken to investigate the biocontrol potential of eight Trichoderma species,T.atrobrunneum,T.guizhouense,T.paratroviride,T.pyramidale,T.rufobrunneum,T.simmonsii,T.thermophilum and T.viridulum,against the phytopathogenic fungus Rhizoctonia solani.Trichoderma isolates were first evaluated in vitro by dual culture tests for their antagonism,mycoparasitic ability and antifungal activity against R.solani.Their growth promoting potential was further assessed in relation to phosphate solubilization,indole acetic acid and siderophore production.Five of the isolates were selected and evaluated for their abilities to prompt plant growth and to control R.solani infecting Vigna unguiculata(cowpea)seedlings in vivo.Two most effective isolates,T.guizhouense 9185 and T.simmonsii 8702,significantly(P<0.05)reduced the disease severity incidences(36.6 and 45.0%,respectively)and promoted plant growth,which have good prospects for application.

Isolation and Identification of Shoot-Tip Associated Endophytic Bacteria from Banana cv. Grand Naine and Testing for Antagonistic Activity against <i>Fusarium oxysporum</i>f. sp. <i>cubense</i>

Endophytic bacteria colonizing the shoot-tips of banana cv. Grand Naine were isolated and tested for the antagonistic activity against the Panama wilt pathogen Fusarium oxysporum f. sp. cubense (Foc). Pre-isolation, the suckers were given extensive disinfection treatments and the homogenate from the excised shoot-tip portion was plated on nutrient agar (NA) and trypticase soy agar (TSA). This yielded altogether 47 isolates: 26 on NA and 21 on TSA, respectively, from the 10 suckers collected during August to February. The number of bacterial isolates obtained per sucker varied from one to 15 based on colony characteristics registering up to 10 distinct species per shoot-tip based on 16S rRNA sequence analysis. The 47 isolates belonged to 19 genera and 25 species under the phylogenetic classes of Actinobacteria, α- and γ-Proteobacteria and Firmicutes. Actinobacteria constituted the predominant phylum (55% isolates) with the constituent genera of Arthrobacter, Brevibacterium, Corynebacterium, Curtobacterium, Kocuria, Kytococcus, Micrococcus, Naumanella, Rothia and Tessaracoccus spp. and an unidentified isolate belonging to the family Frankiaceae. Proteobacteria constituted the second major phylum (Brevundimonas, Enterobacter, Klebsiella, Pseudomonas, Serratia and Sphingomonas spp.) followed by Firmicutes (Bacillus and Staphylococcus spp.). Antagonistic activity of the endophytes against Foc was tested through agar plate assays (pit and spot applications on fungal lawn) employing potato dextrose agar and NA. Endophytic Pseudomonas aeruginosa (isolate GNS.13.2a) which was associated with a single sucker showed significant growth inhibition effect on Foc while Klebsiella variicola (GNS.13.3a) and Enterobacter cloacae (GNS13.4a) exhibited moderate inhibition. The study brings out considerable sucker to sucker variation in the associated cultivable endophytic bacteria in “Grand Naine” banana and identifies a few bacterial endophytes with biocontrol potential against the devastating Foc pathogen.

Bacteriocin-like inhibitory substance (BLIS) activity of Streptococcus macedonicus MBF10-2 and its synergistic action in combination with antibiotics

Objective: To characterize the bacteriocin-like inhibitory-substances(BLIS) activity of Streptococcus macedonicus MBF10-2 [named BLIS(MBF10-2)], a bacteriocinogenic strain isolated from an Indonesian tofu byproduct.Methods: BLIS(MBF10-2) was obtained by culturing the bacterium, and standard deferred antagonism assays were used to demonstrate its activity. The antibacterial testing of fractions collected by filtration using 3–30 kDa cut-off membrane sizes were carried out by performing well diffusion method.Results: The growth of Micrococcus luteus, Streptococcus pyogenes, Lactococcus lactis,Leuconostoc mesenteroides and Weissella confusa were inhibited by BLIS(MBF10-2).Interestingly, BLIS-containing fractions obtained from sequential application on ultrafiltration membranes indicated that this bacterium Streptococcus macedonicus MBF10-2 could produces at least two antimicrobial peptides activities, one of which is likely to be a lantibiotic peptide. Potential synergistic activity against certain Gram-positive(but not Gram-negative) species when partnered with antibiotics(ampicillin, tetracycline or kanamycin) were observed.Conclusion: Combination of some BLIS(MBF10-2) active fractions with antibiotics(ampicillin, tetracycline or kanamycin) could demonstrate synergistic activities against certain Gram-positive species.

Study on Anti-ship Missile Saturation Attack Model

Based on the analysis for the interception process of ship-to-air missile system to the anti-ship missile stream, the antagonism of ship-to-air missile and anti-ship missile stream was modeled by Monte Carlo method. This model containing the probability of acquiring anti-ship missile, threat estimation, firepower distribution, interception, effectiveness evaluation and firepower turning, can dynamically simulate the antagonism process of anti-ship missile attack stream and anti-air missile weapon system. The anti-ship missile's saturation attack stream for different ship-to-air missile systems can be calculated quantitatively. The simulated results reveal the relations among the anti-ship missile saturation attack and the attack intensity of anti-ship missile, interception mode and the main parameters of anti-air missile weapon system. It provides a theoretical basis for the effective operation of anti-ship missile.

Field Application of Non-Pathogenic <i>Verticillium dahliae</i>Genotypes for Regulation of Wilt in Strawberry Plants

Verticillium dahliae induced wilt disease in strawberry can cause severe yield losses and thus lead to inevitable negative economic impacts. Inoculation of plants with non-pathogenic strains of Verticillium was conducted as a biologic control agent (BCA) according to the concept that preoccupation of the ecologic niche rendered strawberry plants immune to infection with soil-borne pathogenic Verticillium. This concept was tested for economic viability in a field trial under commercial conditions. Results were reported for 2 years of field trials under practice conditions in two locations in Brandenburg, Germany. Inoculation was shown to have a positive effect of 20% of plants, while 30% of plants remain unaffected and of equally high vitality. However, 50%-0% of plants were impacted negatively, showing severe wilt symptoms up to total loss. The characteristic progression of wilt symptoms suggested an infestation caused by Phytophtora sp. and other pathogens. Further results showed that the main factor of the side effects was caused by different qualities of plant material in interaction to the inoculation with the BCA and only to a minor extent depended on pre-infestation of soils. We conclude that specific conditions, such as certified plant material or soil analysis for other pathogens besides Verticillium, avoided these side-effects relevant for commercial farming.

Soil Biological and Biochemical Responses to Cd Exposure

Heavy metals can stimulate the activity of soil enzymes in smaller amounts, but act as inhibitors if present in high concentrations. Natural and anthropogenic heavy metal contamination and its disturbances on soils can be evaluated by using enzymatic activities as sensors. To study the effects of Cd, soil added with known Cd concentrations (0, 10, 20, 50,100 and 200 mg/kg soil) were incubated for a period of 30 days at 28℃. At intervals of 0, 5, 10, 20 and 30 days samples were withdrawn for enzyme assays like dehydrogenase (DHA), catalase (CAT), phenol oxidase (PHE), and peroxidise (PER). In a separate experiment the effect of Cd on active microbial biomass carbon (AMBC), basal soil respiration (BSR), and metabolic quotient were studied. AMBC showed a reduction trend with increase in Cd concentration, and a maximum reduction of 47% was observed at 30th day for 200 mg/kg treatment. BSR also has got the same trend, with a maximum decrease of 42% at the 30th day. With the rate of Cd amendments and treatment period, DHA has shown an inhibition trend;whereas maximum decrease was observed for 200 mg/kg treatment at 30th day. CAT, PER, and PHE were found to be increased with Cd addition and remained at higher levels than in the control soil. These changes can be attributed to the effect of Cd on microbial activities. Based on cluster analysis, AMBC appears to be the sensitive indicators for the soil exposed to Cd contamination.

In Vitro Antagonistic Activity of Trichoderma harzianum and Bacillus amyloliquefaciens against Colletotrichum acutatum

Biological control of plant diseases makes extensive use of the antagonists. The effectiveness of the control depends on the choice of an effective antagonist strains from criteria of implying a good knowledge of biological peculiarities of the material used. In this study, the antagonistic activities of nine isolates of Bacillus amyloliquefaciens and one isolate of Trichoderma harzianum were tested in vitro against seven strains of Colletotrichum acutatum, the causal agent of strawberry anthracnose. It was found that T. harzianum and B. amyloliquefaciens strains showed the ability to inhibit the mycelial growth of the pathogen by dual culture technique by more than 50 percent. The nonvolatile substances produced by the antagonists showed high inhibition percentages that are more than 99 percent, meanwhile their volatile compounds inhibited the mycelial growth of C. acutatum strains with low inhibition percentages starting from 30 percent except the substances produced by B. amyloliquefaciens Bc2 that showed a high inhibition percentage of more than 70 percent.