Strain L2 Research Articles

Role of porous polymer carriers and iron-carbon bioreactor combined micro-electrolysis and biological denitrification in efficient removal of nitrate from wastewater under low carbon to nitrogen ratio

In the current research, a novel bioreactor composed of porous polymer carriers and iron-carbon (PPC@FeC) was established through bacterial immobilized technology. The influence of key factors was studied on the nitrate removal performance of the PPC@FeC bioreactor. The experimental results showed that the highest removal rate of nitrate (7.33 mg L−1 h−1) can be obtained with short hydraulic retention times (HRT = 2.0 h) and low carbon-to-nitrogen ratio (C/N = 2.0). The results of high-throughput sequencing revealed that Zoogloea sp. L2 was the dominant strain in bioreactor responsible for nitrate removal. Moreover, the SEM and XRD analyses elucidated that Fe2O3 was the final product produced by the interaction of FeC and strain L2. These findings showed that the PPC@FeC bioreactor successfully combined micro-electrolysis and biological denitrification, which exhibited great potential in removing nitrate effectively from wastewater under low C/N ratio and short HRT conditions.

Isolation and Evaluation of Probiotic Potential of Lactic Acid Strains From Healthy Equines for Potential Use in Salmonella Infection

The objective of the present study was to evaluate the probiotic properties, security and antibacterial ability in vivo of isolated strains from healthy equine. In the present study, two Pediococcus acidilactici (P1 and P2) and two Lactobacillus equi (L1 and L2) were isolated. All isolates were died when exposed to pH 2.0 for 3 hours but survived at pH 3.0 and pH 4.0 with differential survival rate, and there is a higher survival rate at pH 4.0. Similarly, the isolates showed different tolerance to bile. The viable bacteria count was sustained at high levels in a tolerance test with artificial gastrointestinal fluid. The isolates survived and grew at temperatures between 37 and 55°C but died at 65°C. Four strains exhibited inhibitory activity against pathogens, including Salmonella typhimurium (CVCC542), Escherichia coli (C83902), Staphylococcus aureus (BNCC186335), and Pasteurella multocida (clinical isolate). These isolates exhibited differential antibiotic susceptibility. In safety trials, all isolates were γ-hemolytic, and the oral toxicity of strains P1 (gavaged with 1 × 109 CFU/day) and L1 (gavaged with 1 × 109 CFU/day) were analyzed in mice. There were no effects on the overall health status of mice. There were no prominent differences in the incidence of bacteria translocation to blood, liver, and spleen. Mice gavaged with Pediococcus acidilactici P1 (1 × 108 CFU/day) or Lactobacillus equi L1 (1 × 108 CFU/day) as prevention showed lower rates of diarrhea and mortality after being challenged with Salmonella typhimurium (4 × 106 CFU signal dose, 0.1 mL by intragastric gavage). The results indicate that the isolated strains could act as potential probiotics, providing a new way to reduce salmonella infection, which merit future application studies.

Functional characterization of quorum sensing LuxR-type transcriptional regulator, EasR in Enterobacter asburiae strain L1.

Over the past decades, Enterobacter spp. have been identified as challenging and important pathogens. The emergence of multidrug-resistant Enterobacteria especially those that produce Klebsiella pneumoniae carbapenemase has been a very worrying health crisis. Although efforts have been made to unravel the complex mechanisms that contribute to the pathogenicity of different Enterobacter spp., there is very little information associated with AHL-type QS mechanism in Enterobacter spp. Signaling via N-acyl homoserine lactone (AHL) is the most common quorum sensing (QS) mechanism utilized by Proteobacteria. A typical AHL-based QS system involves two key players: a luxI gene homolog to synthesize AHLs and a luxR gene homolog, an AHL-dependent transcriptional regulator. These signaling molecules enable inter-species and intra-species interaction in response to external stimuli according to population density. In our recent study, we reported the genome of AHL-producing bacterium, Enterobacter asburiae strain L1. Whole genome sequencing and in silico analysis revealed the presence of a pair of luxI/R genes responsible for AHL-type QS, designated as easI/R, in strain L1. In a QS system, a LuxR transcriptional protein detects and responds to the concentration of a specific AHL controlling gene expression. In E. asburiae strain L1, EasR protein binds to its cognate AHLs, N-butanoyl homoserine lactone (C4-HSL) and N–hexanoyl homoserine lactone (C6-HSL), modulating the expression of targeted genes. In this current work, we have cloned the 693 bp luxR homolog of strain L1 for further characterization. The functionality and specificity of EasR protein in response to different AHL signaling molecules to activate gene transcription were tested and validated with β-galactosidase assays. Higher β-galactosidase activities were detected for cells harboring EasR, indicating EasR is a functional transcriptional regulator. This is the first report documenting the cloning and characterization of transcriptional regulator, luxR homolog of E. asburiae.

How siderophore production can influence the biocontrol activity of Aureobasidium pullulans against Monilinia laxa on peaches

In the present study Aureobasidium pullulans strains L1 and L8 were shown both in vitro and in vivo to compete for iron with Monilinia laxa through the secretion of siderophores (1.2 and 1.4 mg ml−1, respectively) and to prevent postharvest fruit decay of peaches. The two strains reduced mycelial growth and conidial germination of M. laxa specially in presence of lower iron concentrations (5 and 10 µg l−1 FeCl3), confirming a better efficacy when nutrients are scarce. In in vivo assay, A. pullulans L1 and L8 strains inhibited pathogen virulence, reducing by 83.5% and 84.4% on average respectively the peach lesion diameter for each tested iron solutions (5, 10, 20 µg l−1 FeCl3,). The highest iron solution slowed down the antagonists’ action and conversely increase the pathogen aggressiveness. Results shows that A. pullulans L1 and L8 strains compete with M. laxa for iron, so revealing new biocontrol aspects. Both strains showed the capability to decrease the accumulation of iron competing with some fungal pathogens and reducing their virulence. These results provide new perspectives for the use of biocontrol agents in agriculture.

The Influencing Factors of Bacillus megaterium Affect the Growth of the Antagonistic Strain and the Activities of Antibacterial Substances

164 strains of Antagonistic bacteria were isolated from 131 mature-period soil samples from eight counties in Bijie City, Guizhou Province, China. In this study, the antagonistic bacteria that inhibited Alternaria alternata were screened and isolated. In addition, the antagonistic strain L2 was identified as Bacillus megaterium. Influencing factors also demonstrated that the suitable conditions for the production of antibacterial substances by strain L2 are as follows: liquid volume 50 mL/500 mL at pH 7.0 and 30°C under oscillation culture conditions, with beef extract as the carbon, nitrogen source.

Biocontrol Activity and Plant Growth Promotion Exerted by Aureobasidium pullulans Strains

The most common leguminous plants’ diseases are caused by soil-borne pathogens leading to important economic losses worldwide. Strains L1 and L8, belonging to Aureobasidium pullulans species, were tested in vitro and in vivo as biocontrol agents (BCAs) against Rhizoctonia solani (Rs1) (AG-4) and as plant growth promoters (PGPs). The non-volatile metabolites produced by L1 and L8 strains inhibited the pathogen mycelial growth by 87.9% on average, with no significant differences between the two strains. The lower pathogen diametric growth inhibition was displayed by both yeasts’ volatile metabolites (VOCs) that significantly reduced the colony growth of R. solani, and similarly to the control, with an average of 10.5%. By in vivo assay, L1 and L8 strains showed the ability to control the pathogen virulence probably through the biofilm formation around the bean and soybean plant roots, as confirmed by scanning electron microscope (SEM) analysis. The spectroscopic analysis highlighted the composition of non-volatile compounds: complex carbohydrates (pullulan), degrading enzymes, siderophores and antifungals (aureobasidins). Moreover, the ability of L1 and L8 strains to stimulate the bean and soybean plant roots, stems, and leaves growth was investigated, showing that these yeasts could have an application not only as BCAs but also as plant growth biostimulator.

Lactobacillus delbrueckii is the key functional microorganism of natural fermented tofu sour water involved in the traditional coagulation of Chinese Huizhou Mao-tofu

Mao-tofu is traditionally coagulated by natural fermented tofu sour water (NFTSW), which contains large numbers of microorganisms from the environment. Nonetheless, the microorganisms accountable for coagulation require further analysis and characterization. Our aim was to evaluate the bacteria in NFTSW that carry out the traditional fermentation process of Mao-tofu by using polymerase chain reaction-denaturing gradient gel electrophoresis. Results show that Lactobacillus ultunensis, Enterococcus bulliens, Lactobacillus graminis, Lactobacillus delbrueckii, Lactobacillus delbrueckii subsp. lactis, and Lactobacillus mucosae are the primary bacteria involved in brewing. Furthermore, 6 types of lactic acid bacteria were sequestered from NFTSW by methodology dependent on culture and their acid-producing abilities were analyzed. The results indicated that strain L1, which was identified as Lactobacillus delbrueckii, produced the highest lactic acid content of 2.85 g/100 mL. Simulated coagulation further confirmed that strain L1 was preferable for Mao-tofu coagulation through the evaluation of textural properties, volatile flavour compounds, and sensory characteristics. The results suggested that Lactobacillus delbrueckii might be the core functional microorganism significantly contributing to flavor compound synthesis during the traditional production of Chinese Huizhou Mao-tofu. The research method we used in this investigation may encourage detection of the main microorganisms with different roles involved in other food fermentation processes.

Use of a probiotic mixture containing Bifidobacterium animalis subsp. lactis BB-12 and Enterococcus faecium L3 as prophylaxis to reduce the incidence of acute gastroenteritis and upper respiratory tract infections in children.

For healthy children, attending communities such as nurseries, kindergartens or schools, exposes them to the risk of acute gastroenteritis (AGE) and/or upper respiratory tract infections (URTIs). We therefore evaluated whether the use of a well-documented probiotic formula could act as prophylaxis for AGE and URTIs, reducing the risk of occurrence. In a randomized study, we tested a probiotic mixture containing Bifidobacterium animalis subspecies lactis BB-12 and Enterococcus faecium L3 on 94 healthy children, comparing the incidence and duration of episodes of AGE and the incidence of URTIs to those of a control group of 109 healthy, untreated subjects. In a subgroup consisting of 34 healthy, treated children, we also evaluated salivary IgA levels. The use of the probiotic formula significantly reduced the incidence and duration of episodes of AGE by 82% and 45%, respectively, and the incidence and duration of episodes of URTIs by 84% and 50%. Salivary IgA levels significantly increased three-fold after 90 days of probiotic treatment. The probiotic formula was well tolerated and no side effects occurred. According to our results, use of the probiotic strains BB-12 and L3 statistically reduced the risk of AGE and URTIs in healthy children and increased levels of salivary IgA.

The mixotrophic denitrification characteristics of Zoogloea sp. L2 accelerated by the redox mediator of 2-hydroxy-1,4-naphthoquinone

Denitrification in mixed culture system has been extensively researched to date, but few studies have focused on accelerating the process using redox mediators to promote electron transfer. Strain L2, an iron-reducing bacteria, can remove 75.44% of nitrate under temperature of 30.60 °C, pH of 6.75 and Fe2+ concentration of 27.86 mg·L−1. Additionally, the removal rate of nitrate reached 1.516 mg·L−1·h−1 in 8 h with the addition of 0.030 mmol·L−1 2-hydroxy-1,4-naphthoquinone (HNQ), which increased by 1.38 times than control group. Furthermore, analysis by fluorescence spectroscopy, flow cytometer and gas chromatography demonstrated that HNQ positively stimulated denitrification. This study provides a reference for enhancing denitrification in mixed culture and lays the foundation for the practical application of redox mediators in groundwater treatment.

Highly efficient nitrate and phosphorus removal and adsorption of tetracycline by precipitation in a chitosan/polyvinyl alcohol immobilized bioreactor.

Single denitrification using bacteria has been widely investigated, but few studies have focused on the simultaneous removal of nitrate, phosphorus. and tetracycline. Strain L2, an iron-reducing bacteria, was immobilized using chitosan/polyvinyl alcohol to simultaneously remove nitrate and phosphorus. The effects of carbon/nitrogen ratio (1:1, 1.5:1, and 2:1), initial Fe2+ concentration (0, 15, and 30mg·L-1), and HRT (2, 4, and 6h) were assessed in bioreactors and optimum conditions were established. Results showed that the nitrate and phosphorus removal efficiency reached 100.00% (2.697mg·L-1·h-1) and 81.93% (1.533mg·L-1·h-1) under the conditions of carbon/nitrogen of 2:1, Fe2+ concentration of 30mg·L-1 and HRT of 6h. The precipitation of bioreactor, which identified as FeOOH by XRD, had significant adsorption on tetracycline. The results of high-throughput sequencing indicated that strain L2 played a significant role in denitrification. This bioreactor provided effective method for the treatment of polluted water contaminated by nitrate, phosphorus, and tetracycline.

In vitro probiotic properties of Pediococcus pentosaceus L1 and its effects on enterotoxigenic Escherichia coli-induced inflammatory responses in porcine intestinal epithelial cells

This study aimed to evaluate in vitro probiotic characteristics of Pediococcus pentosaceus strain L1 from pickled radish and investigate its impacts on inflammatory responses in porcine intestinal epithelial cells (IEC) to enterotoxigenic Escherichia coli (ETEC) F4+. The abilities of P. pentosaceus L1 to tolerate gastrointestinal conditions and to antagonize ETEC F4+ growth were determined. Adhesion of P. pentosaceus L1 and its effect on ETEC F4+ adhesion to porcine IPEC-J2 IEC were evaluated. Furthermore, the effects of this strain on proinflammatory gene expression and cytokines/chemokine production in porcine IPEC-J2 IEC induced by ETEC F4+ were determined. P. pentosaceus L1 showed good tolerance to the medium adjusted at pH 2.5 and consequently supplemented with 0.3% oxgall. Reduction of ETEC F4+ growth in co-culture with L1 was found. Effective adhesion of L1 to porcine.IPEC-J2 IEC was observed under these conditions. P. pentosaceus L1 decreased the adhesion of ETEC F4+ to IPEC-J2 IEC and the extent of inhibition of ETEC F4+ adhesion depended on the timing of L1 addition. Further analysis revealed down-regulation of expression of ETEC F4+-induced proinflammatory genes encoding interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-8 (IL-8) in IPEC-J2 IEC. Expression of the genes involved in NF-κB pathway, including RELA and NFKB1, were also repressed, as was production of IL-6, TNF-α, and IL-8. These results indicate that P. pentosaceus L1 may have potential as a probiotic for control of ETEC infection in pigs.

Characteristics and in situ remediation effects of heavy metal immobilizing bacteria on cadmium and nickel co-contaminated soil.

Cadmium (Cd) and nickel (Ni) in soil have caused serious environmental problems and increased healthy risks to humans and biota, it is vital important and necessary to develop effective methods to resolve the combined contaminated problems. In this study, strains L5 and L6 with good heavy metal resistant and immobilizing capacities were isolated from Cd and Ni contaminated soil. Bacterial characteristic experiment illustrated that many functional groups (-OH, -NH2 and -COO et al.) were distributed on the surface of L5 and L6. Under the stress of heavy metals, bacterial appearances were distorted. The pot experiment indicated that the concentrations of HOAc-extractable Cd and Ni in soil reduced 6.26-15.33% and 13.31-19.53% with the inoculation of L5 and L6. In addition, the immobilization rates on Cd and Ni improved 61.27-128.50% and 23.69-39.66% with re-inoculation of strains L5 and L6 at 30 days, respectively. After inoculation of strains L5 and L6 for 60 days, the activities of FDA hydrolysis, acid phosphatase, urease, invertase and dehydrogenase in soil increased obviously. Furthermore, bacterial diversity indexes and community structure of soil were also improved. Thus, given the beneficial remediation effects of the isolated strains, L5 and L6 have great potentials for heavy metals contaminated soil remediation.

Uji Multilokasi Sepuluh Galur Padi Untuk Menghasilkan Varietas Unggul Baru

Reduced productive rice fields to non-paddy fields, most possible extension of the nationalrice cultivation area to the suboptimal lands reaching ± 91.9 million ha. Technologypackages that can be applied include the use of new improved rice varieties through theassembling of varieties that have high yield potential, resistant to suboptimal soil stress. Theobjective of the research is to produce new superior rice varieties that are available invarious environments. The study used a split-plot design, as the main plot is an environmentconsisting of rice paddies and gogo, as a subplot is the genotype of rice. The treatment ineach environment is prepared using the Randomized Complete Block Design (RCBD). Thetreatment consisted of 10 new rice strains and four varieties as a comparison. Variablesobserved (1) plant height; (2) the maximum number of shoots; (3) number of productiveshoots; (4) long panicle; (5) the number of grains per panicle; (6) the amount of graincontent of each panicle; (7) the number of empty grains per panicle; (8) weight of 1000grains of grain; (9) grain yield of each clump; (10) grain yield per hectare. Data wereanalyzed by variance if there was a difference between mean, median treatment, followed byLsd test at 5% level. The adaptability and yield stability of each strain was determined basedon the value of the coefficient of diversity (KK) (Francis and Kenneberg, 1978) in Syukur etal., (2012). The results showed that seven new rice strains had adaptations both planted asupland rice and lowland rice, namely strains B3, B4, F2, F3, H1, H4, and L2.

Bacillus subtilis strain L1 promotes nitrate reductase activity in Arabidopsis and elicits enhanced growth performance in Arabidopsis, lettuce, and wheat.

Plant growth promoting rhizobacteria (PGPR) are a group of bacteria that promote plants growth in the rhizosphere. PGPRs are involved in various mechanisms that reinforce plant development. In this study, we screened for PGPRs that were effective in early growth of Arabidopsis thaliana when added to the media and one Bacillus subtilis strain L1 (Bs L1) was selected for further study. When Bs L1 was placed near the roots, seedlings showed notably stronger growth than that in the control, particularly in biomass and root hair. Quantitative reverse transcription polymerase chain reaction analysis revealed a high level of expression of the high affinity nitrate transporter gene, NRT2.1 in A. thaliana treated with Bs L1. After considering how Bs L1 could promote plant growth, we focused on nitrate, which is essential to plant growth. The nitrate content was lower in A. thaliana treated with Bs L1. However, examination of the activity of nitrate reductase revealed higher activity in plants treated with PGPR than in the control. Bs L1 had pronounced effects in representative crops (wheat and lettuce). These results suggest that Bs L1 promotes the assimilation and use of nitrate and plant growth.

Biodegradation of aliphatic and polycyclic aromatic hydrocarbons by the thermophilic bioemulsifier-producing Aeribacillus pallidus strain SL-1.

The utilization of thermophilic hydrocarbon-degrading microorganisms is a suitable strategy for improving biodegradation of petroleum hydrocarbons and PAHs, as well as enhancing oil recovery from high-temperature reservoirs. In this study, the thermophilic strain Aeribacillus pallidus SL-1 was evaluated for the biodegradation of crude oil and PAHs at 60°C. Strain SL-1 was found to preferentially degrade short-chain n-alkanes (<C17) and aromatic hydrocarbons from crude oil. The highest degradation rate of 84% was obtained with 1000mg/l naphthalene as sole carbon source. Additionally, the strain was able to degrade 80% of phenanthrene (200mg/l) and 50% of pyrene (50mg/l) within 5 days at 60°C. The SL-bioemulsifier produced by strain SL-1 was identified as a glycoprotein with stable emulsifying activity over a wide range of environmental conditions. Chemical composition studies exhibited that the SL-bioemulsifier consisted of polysaccharides (65.6%) and proteins (13.1%), among them, proteins were the major emulsifying functional substrates. Furthermore, the SL-bioemulsifier was able to enhance the solubility of PAHs. Thus, the bioemulsifier-producing strain SL-1 has great potential for applications in high-temperature bioremediation.

Antimicrobial assay of endophytic fungi from Rumex madaio and chemical study of strain R1

In order to search more antimicrobial natural products for new drug discovery, bioassay and chemical investigation of endophytic strains from Rumex madaio were carried out. Six fungal strains (numbered as L1, L6, L9, L10, R1, R2) were successfully isolated and their antimicrobial effects on three human pathogens, Escherichia coli, Staphyloccocus aureus and Candida albicans, were evaluated. The results indicated that ethyl acetate extracts of fermentation broth of these strains had no potent antimicorbial activity against E. coli and C. albicans while strains L1 and R1 had stronger inhibitory effects on S. aureus. On basis of morphological characteristics and 18S rRNA sequence analysis, strains L1 and R1 were respectively classified as Colletotrichum and Fusarium geni. The chemical study of strain R1 led to isolation of two known antimicrobial agents, dibutyl phthalate (1) and beauvericin (2).

Probiotic Properties of Lactobacillus paracasei subsp. paracasei L1 and Its Growth Performance-Promotion in Chicken by Improving the Intestinal Microflora.

Lactobacillus paracasei subsp. paracasei L1 was previously isolated from sweet potato sour liquid. This bacterial species specifically binds onto starch granular surfaces, triggering the enzymatic hydrolysis of raw starch. We investigated the functional and safety properties of strain L1 in vitro to establish its probiotic potential, and analyzed its effect on growth performance and intestinal microflora of chicken in feeding experiments. The optimal growth conditions of strain L1 included low pH and high concentrations of bile salts and NaCl. Its 1-, 2-, and 24-h autoaggregation values were 15.8 ± 1.2%, 20.4 ± 2.3%, and 47.2 ± 0.8%, respectively, with the surface hydrophobicity value at 560 nm of 38.1 ± 2.7%. Further, its adhesion rate to Caco-2 cells was 22.37 ± 1.44%. Strain L1 was resistant to erythromycin and azithromycin, but sensitive to other antibiotics tested. For the feeding experiments, 240 chickens with similar weights were randomly divided into a control (C) group and strain L1 (L) group and fed for 8 weeks. Strain L1 promoted the weight gain of chickens in L group. A significant increase in the population size of the two phyla and 23 genera in the small intestine was observed in the presence of strain L1 (P < 0.05), with 0 phyla and 4 genera showing significant increase in the cecum (P < 0.05). In the small intestine, the abundance of six functional genes at Kyoto Encyclopedia of Genes and Genomes (KEGG) level 2 and 49 genes at KEGG level 3 was significantly increased in group L (P < 0.05), with lesser changes noted in the cecum. An increase in the metabolic pathway functions, including enzyme families and the digestive system, was observed in the intestinal microbiota in the L group compared to the C group. However, the other metabolic pathway functions, including metabolism of fatty acid biosynthesis, as well as metabolism of glycerolipids and propanoate, increased in the cecal microbiota of the L group relative to the C group. These changes are most likely related to the changes in the gut microbiota composition. Collectively, strain L1 supplementation may promote growth performance and improve the intestinal microflora in chicken although further studies are needed to confirm this.

CARACTERIZACIÓN DE BACTERIAS RIZOSFÉRICAS DE SUELO CIRCUNDANTE A UNA PLANTA RECICLADORA DE PLOMO (Pb)

The aim of this research was to isolate and characterize rhizosphere bacteria of huizache ( Acacia farneciana ) and mesquite ( Prosopis glandulosa ), predominant vegetation surrounding a lead (Pb) recycling company. Bacteria were evaluated on their tolerance to Pb(NO 3 ) 2 ,andtheircapacity to produce indole-acetic acid (IAA) and siderophores using Salkowski and chrome azurol S (CAS) agar medium techniques, respectively. The bacterial isolates were identified through the 16S rRNA gene. Ten bacterial strains tolerated concentrations between 0.6 and 1.8 mM of Pb (NO 3 ) 2 , of which seven strains had IAA production of up to 60 μg/mL and five strains showed siderophore production. Qualitatively, the bacterial strains L2, L48 and L67 presented a more intense orange halo than the bacterial strains L138 and L23, which indicates a positive reaction of siderophores production. Additionally, the siderophores production of the hydroxamate type produced by the bacterial strains L2, L48, L67, L138 and L23 was variable, between 0.02 and 0.054 μg/mL. The results of this research allow concluding that there are bacterial strains around the lead (Pb) recycling company with a high potential for phytoremediation processes.

An emerging problem affecting apple production: Neofusicoccum parvum. Aureobasidium pullulans L1 and L8 strains as an alternative control strategy

Aureobasidium pullulans strains L1 and L8 were used as an alternative strategy against Neofusicoccum parvum, pathogen of apple wood and fruit. Both strains displayed a great ability to reduce pathogen conidia germination of almost 50% and totally stop its sporification in wood of ‘Gala’ and ‘Fuji’ apple cultivars. In addition, by in vitro tests the antagonistic activity displayed by non-volatile metabolites produced by both yeasts was highlighted by 70% of reduction of the pathogen mycelial growth. On apple fruit, the pathogen severity was reduced by 66% and 50% in ‘Gala’, and 70% and 60% in ‘Fuji’ by L1 and L8 respectively. In wood, no statistical differences were observed between L1, L8 and the control, except for ‘Fuji’ wood, where L8 strain displayed a wood lesion reduction of 23% with respect to the untreated control. Infrared analysis showed how the presence of both strains on woody tissues helped preserving cellulose content, preventing in this way the faster wood degradation by the pathogen. In addition, L1 and L8 simply colonized the wood surface, probably displaying an endophytic attitude, an essential requirement for controlling N. parvum in field.

Screening, Isolating, and Identifying Antagonistic Bacterium from the Rhizosphere Soil of Alternaria Brown Spot

Alternaria brown spot is a serious agricultural fungal disease that consistently leads to serious economic losses in commercial crop fields worldwide. Antagonistic bacteria were isolated from 131 mature-period soil samples from eight counties in Bijie City, Guizhou Province, China. In this study, the antagonistic bacteria that inhibited Alternaria alternata were screened and isolated. In addition, the antagonistic strain L2 was identified as Bacillus megaterium.