Bacillus mycoides JA20-1 was screened and identified as a biocontrol bacterium with a high capacity for producing volatile organic compounds(VOCs) in the laboratory. This strain had significant inhibitory effects on various postharvest disease pathogens in crops, such as Botrytis cinerea, as well as soil-borne disease pathogens in ginseng, such as Sclerotinia ginseng. In order to accelerate its industrialization process, in this study, single-factor experiments and response surface optimization methods were used. The fermentation medium and fermentation conditions in the shake flask of strain JA20-1 were systematically optimized by using cell production volume as the response variable. Meanwhile, the biocontrol effect of JA20-1 on B. cinerea of ginseng during the storage period was evaluated by using the method of fumigation in a dry dish in vitro. The results indicated that the optimal fermentation medium formulation for strain JA20-1 was as follows: 1% yeast paste, 1% soluble starch, 0.25% K_2HPO_4·3H_2O, and 0.2% NaCl. The optimal fermentation conditions in the shake flask were vaccination size of 3%, culture volume of 50 mL in a 250 mL Erlenmeyer flask, pH of 6.2, fermentation temperature of 34 ℃, shaking speed of 180 r·min~(-1), and incubation time of 18 hours. The bacteria count in the fermentation broth under these conditions reached 2.17 × 10~8 CFU·mL~(-1), which was 6.58 times higher than before. The average control efficacy of the fermentation broth on Botrytis cinerea of ginseng under in vitro fumigation reached 61.70% and 84.04% respectively, when 20 mL and 30 mL per dish were used. The research provided theoretical support and technical foundation for the development and utilization of Bacillus mycoides JA20-1 and the biocontrol of soil-borne diseases in ginseng and postharvest diseases in crops.
Botrytis/drug effects* ; Fermentation ; Panax/microbiology* ; Plant Diseases/prevention & control* ; Volatile Organic Compounds/metabolism* ; Bacillus/physiology* ; Pest Control, Biological/methods* ; Biological Control Agents/metabolism* ; Culture Media/chemistry*

To develop biocontrol agents for the control of kiwifruit bacterial canker, we isolated a strain CXG2-5 with inhibitory activity against Pseudomonas syringae pv. actinidiae (Psa), the pathogen of kiwifruit bacterial canker, from the rhizosphere soil of kiwifruit by the plate confrontation test. The strain was identified by morphological observation, physiological and biochemical tests, and molecular biological methods. The indoor control efficacy of the strain was determined by the inoculation of the strain into detached branches with wounds and into leaf discs by vacuum infiltration. The ability of the strain to expand and colonize leaf veins was determined by fluorescent labeling and scanning electron microscopy. Subsequently, the strain was prepared into microcapsules, the field control efficacy of which was evaluated. The strain CXG2-5 was identified as Pseudomonas benzenivorans. It demonstrated good antagonistic activity against Psa, with an inhibition zone diameter of 22 mm and an inhibition rate of 72.7%. The preventive effects of the strain on kiwifruit bacterial canker were better than the therapeutic effects on both detached branches and leaves, with the preventive effects reaching 65% and 92.4%, respectively. The control effect of microcapsules of this strain in the field reached 60.89%, which was slightly lower than that of 20% kasugamycin and higher than that of Bacillus subtilis wettable powder. In conclusion, strain CXG2-5 serves as a candidate for the control of kiwifruit bacterial canker, and the prepared microcapsules have good value for development and application.
Actinidia/microbiology* ; Plant Diseases/prevention & control* ; Pseudomonas syringae ; Pseudomonas/isolation & purification* ; Capsules ; Antibiosis ; Biological Control Agents ; Pest Control, Biological/methods*

Fusarium head blight (FHB), caused by Fusarium graminearum, not only leads to severe yield losses but also poses a threat to food safety due to the mycotoxins produced by the pathogen. Since this disease is preventable but not curable, the current control mainly relies on chemical fungicides, the long-term use of which may lead to pathogen resistance and environmental pollution. To develop green control methods, we screened 13 biocontrol strains from the rhizosphere soil of wheat, among which strain No. 12 (identified as Pythium aphanidermatum) showed significant antifungal effects. In the plate confrontation test, this strain reduced the colony diameter of the pathogen by 69.2% (1.47 mm vs. 4.78 mm in the control group), with an inhibition rate of 77% (P < 0.01). Microscopic observation revealed obvious deformations in the pathogen hyphae, suggesting a lysing effect. The coleoptile experiment further confirmed that the pre-treatment with this strain reduced the incidence rate to 0. These findings provide new candidate strains for the biocontrol of FHB and offer a scientific basis for reducing the use of chemical fungicides and promoting sustainable agricultural development.
Triticum/growth & development* ; Fusarium/growth & development* ; Plant Diseases/prevention & control* ; Soil Microbiology ; Pest Control, Biological/methods* ; Pythium/physiology* ; Biological Control Agents ; Rhizosphere ; Fungicides, Industrial

Peach brown rot, caused by Monilinia fructicola, is one of the most serious peach diseases. A strain belonging to the Actinomycetales, named Streptomyces blastmyceticus JZB130180, was found to have a strong inhibitory effect on M. fructicola in confrontation culture. Following the inoculation of peaches in vitro, it was revealed that the fermentation broth of S. blastmyceticus JZB130180 had a significant inhibitory effect on disease development by M. fructicola. The fermentation broth of S. blastmyceticus JZB130180 had an EC₅₀ (concentration for 50% of maximal effect) of 38.3 µg/mL against M. fructicola, as determined in an indoor toxicity test. Analysis of the physicochemical properties of the fermentation broth revealed that it was tolerant of acid and alkaline conditions, temperature, and ultraviolet radiation. In addition, chitinase, cellulase, and protease were also found to be secreted by the strain. The results of this study suggest that S. blastmyceticus JZB130180 may be used for the biocontrol of peach brown rot.
Ascomycota/pathogenicity* ; Bacterial Proteins/metabolism* ; Cell Wall/metabolism* ; Cellulase/metabolism* ; Chitinases/metabolism* ; Fermentation ; Fruit/microbiology* ; Pest Control, Biological/methods* ; Phylogeny ; Plant Diseases/prevention & control* ; Prunus persica/microbiology* ; Siderophores/metabolism* ; Streptomyces/physiology*

In recent years, root rot diseases of Chinese herbal medicine have been posing grave threat to the development of the traditional Chinese medicine industry. This article presents a review on the occurring situation of the root rot disease, including the occurrence of the disease, the diversity of the pathogens, the regional difference in dominant pathogens,and the complexity of symptoms and a survey of the progress in bio-control of the disease using antagonistic microorganisms. The paper also discusses the existing problems and future prospects in the research.
Animals ; Antibiosis ; Bacteria ; growth & development ; Fungi ; physiology ; Nematoda ; growth & development ; Pest Control, Biological ; methods ; Plant Diseases ; microbiology ; parasitology ; prevention & control ; Plant Roots ; microbiology ; parasitology ; Plants, Medicinal ; microbiology ; parasitology

A type of entomopathogenic fungus of soil in Citrus grandis 'tomentosa' production base was isolated and identified with morphological and molecular biological methods, including pathogenesis, spore characteristic and ITS sequence analysis were conducted. The results showed that eighteen entomopathogenic fungi strains were isolated from the Tenebrio molitor infected in the soil samples, which were identified as Metarhizium anisopliae var. anisopliae. Based on results above, we concluded that there was quantity of Metarhizium resources in this area. These provided the useful information for controlling some pests of C. grandis by using these strains of fungus.
Animals ; Citrus ; parasitology ; Metarhizium ; isolation & purification ; physiology ; Pest Control, Biological ; methods ; Soil Microbiology

GAP production of medicinal plants needs diseases' green control during their cultivation processes. In this article, The authors summarized the achievements in cultural control and biological control to crops' diseases, taking the characteristics of medicinal plants into account, we put out the notion of the green control to medicinal plants' diseases, and indicated that the green control for medicinal plants' diseases should combine with cultural control, modem phytopathology methods, biological control and essential pesticides, besides, we introduced some suggestions and the prospect, to provide a reference for green control of medicinal plants' diseases in their GAP production.
Agriculture ; methods ; Pest Control, Biological ; methods ; Plant Diseases ; microbiology ; parasitology ; prevention & control ; Plants, Medicinal ; chemistry ; growth & development ; microbiology ; parasitology

In recent years, the soil borne disease of medicinal plants becomes severely during the process of cultivation and directly endangered the production and quality of raw materials used in traditional Chinese medicine (TCM). The chemical pesticides have been constantly used to prevent and control the soil borne disease, but only a few are effective. Meanwhile, the excessive uses of chemical pesticides also lead pesticide residues in TCM, which often exceed limit of the standard, and harm the human health and cause environmental pollution. Therefore, biological control has become a hot research point for its environmental advantages. This paper mainly discussed the mechanisms of different species of microorganisms, which could control the soil borne disease of medicinal plants, from the following aspects: improving host plants' nutrient absorption, the nutrient and space competition with the pathogenic bacteria, changing the morphology and anatomical structure of roots, adjusting the host plants' endogenous hormones, restoring the balance of host rhizosphere soil microecology and activating the host plants' defense system etc. Then put forward the prospect of biocontrol agents in the future.
Medicine, Chinese Traditional ; Pest Control, Biological ; methods ; Plant Diseases ; prevention & control ; Plants, Medicinal ; Soil Microbiology

cry1Ah1, one of holo-type cry genes, cloned in this laboratory from Bacillus thuringiensis strain has been patented in China, and it encoded a protein with strong insecticidal activity against certain lepidopteran insect pests, such as Chilo suppressalis. cry1Ah1 gene is exhibiting good application prospects. In order to improve the expression level of cry1Ah1 gene in rice, and investigate the effect of codon usage preference of gene expression, we designed five different optimized schemes for cry1Ah1 insecticidal critical fragment in accordance with bias of rice codon, to improve G+C content, removed the shear signal and unstable factors. Optimized cry1Ah1 genes were transformed into Escherichia coli Rosetta (DE3) respectively, and 65 kDa polypeptides was expressed normally in inclusion body separately. All of these expressed polypeptides showed insecticidal activity against 2nd-instar larvae of Plutella xylostella and neonate of Chilo suppressalis. After transformation with modified cry1Ah1 genes into Var nippobare, the transgenic rice seedlings were detected by PCR, the positive rate containing target gene was more than 87%. Afterwards, the results of real-time RT-PCR and ELISA assay indicated that the highest expression level of five modified cry1Ah1 genes was that using the highest frequent codons. Average expression amount of Cry1Ah1 polypeptides was 0.104% of total soluble proteins from the positive transgenic rice.
Animals ; Bacillus thuringiensis ; genetics ; metabolism ; Bacterial Proteins ; biosynthesis ; genetics ; Cloning, Molecular ; Codon ; genetics ; Endotoxins ; biosynthesis ; genetics ; Hemolysin Proteins ; biosynthesis ; genetics ; Insecticides ; Lepidoptera ; Oryza ; genetics ; Pest Control, Biological ; methods ; Plants, Genetically Modified ; genetics ; Recombinant Proteins ; biosynthesis ; genetics

In order to explore the environmental pest management method of Dorysthenes hydropicus, three strains of entomopathogenic nematodes, viz. Heterorhabditis bacteriphora (H06), Steinernema scapterisci (SS), S. carpocapsae (All) were used on larvae of Dorysthenes hydropicus, with treatments of 0, 5 000 and 10 000 nematodes each larva. The result showed that these three strains viz. All, H06 and SS had high lethal effects on the larvae. Lethal rates had dose-effects relationship with inoculation amounts. High dose treatments resulted in high mortalities and led to quick death, especially in the treatment of H06. Treatment of H06 with 10 000 nematodes per larva resulted in 100% mortality after inoculated 4 days. Different strains of these nematodes had various lethal characters, H06 with only one peak mortality, the larvae died quickly after inoculated, while All and SS with 2 peak mortalities, there was a stable stage with low mortality between the 2 peak mortalities. Entomopathogenic nematodes could be used as a hopeful method for controlling of Dorysthenes hydropicus in fields.
Animals ; Larva ; parasitology ; Moths ; growth & development ; parasitology ; physiology ; Nematoda ; physiology ; Pest Control, Biological ; methods