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*

OBJECTIVETo propose a new method for acquiring pulmonary function parameters based on measurement of volume changes of thoracic impedance.

METHODSWe studied the relationship between the volume changes of thoracic impedance and pulmonary function parameters during forced breathing based on bioimpedance measurement, and developed an instrument for measuring thoracic impedance. Using this instrument and a MRI spirolab III lung function test instrument, both based on flowmeter measurement, we measured such pulmonary function parameters including forced vital capacity (FVC), forced expiratory volume in one second/FVC (FEV1/FVC), and peak expiratory flow in 10 healthy volunteers and compared the measurement results.

RESULTSThe differences in the parameters measured using the two instruments were all within two folds of the positive and negative standard deviations of the average values, demonstrating good consistency in the measurement between the two methods.

CONCLUSIONSThe measurement results of the bioimpedance-based instrument we developed show good consistency with those by the commercially available pulmonary function test instrument.

Adult ; Electric Impedance ; Forced Expiratory Volume ; Humans ; Peak Expiratory Flow Rate ; Respiratory Function Tests ; methods ; Thorax ; physiology ; Vital Capacity ; Young Adult

Objective To propose a new method for acquiring pulmonary function parameters based on measurement of volume changes of thoracic impedance. Methods We studied the relationship between the volume changes of thoracic impedance and pulmonary function parameters during forced breathing based on bioimpedance measurement, and developed an instrument for measuring thoracic impedance. Using this instrument and a MRI spirolab III lung function test instrument, both based on flowmeter measurement, we measured such pulmonary function parameters including forced vital capacity (FVC), forced expiratory volume in one second/FVC (FEV1/FVC), and peak expiratory flow in 10 healthy volunteers and compared the measurement results. Results The differences in the parameters measured using the two instruments were all within two folds of the positive and negative standard deviations of the average values, demonstrating good consistency in the measurement between the two methods. Conclusions The measurement results of the bioimpedance-based instrument we developed show good consistency with those by the commercially available pulmonary function test instrument.

Objective To propose a new method for acquiring pulmonary function parameters based on measurement of volume changes of thoracic impedance. Methods We studied the relationship between the volume changes of thoracic impedance and pulmonary function parameters during forced breathing based on bioimpedance measurement, and developed an instrument for measuring thoracic impedance. Using this instrument and a MRI spirolab III lung function test instrument, both based on flowmeter measurement, we measured such pulmonary function parameters including forced vital capacity (FVC), forced expiratory volume in one second/FVC (FEV1/FVC), and peak expiratory flow in 10 healthy volunteers and compared the measurement results. Results The differences in the parameters measured using the two instruments were all within two folds of the positive and negative standard deviations of the average values, demonstrating good consistency in the measurement between the two methods. Conclusions The measurement results of the bioimpedance-based instrument we developed show good consistency with those by the commercially available pulmonary function test instrument.