scholarly journals Nematicidal Activity of Cyclopiazonic Acid Derived From Penicillium commune Against Root-Knot Nematodes and Optimization of the Culture Fermentation Process

2021 ◽  
Vol 12 ◽  
Author(s):  
Van Thi Nguyen ◽  
Nan Hee Yu ◽  
Yookyung Lee ◽  
In Min Hwang ◽  
Hung Xuan Bui ◽  
...  

Among 200 fungal strains isolated from the soil, only one culture filtrate of Aspergillus flavus JCK-4087 showed strong nematicidal activity against Meloidogyne incognita. The nematicidal metabolite isolated from the culture filtrate of JCK-4087 was identified as cyclopiazonic acid (CPA). Because JCK-4087 also produced aflatoxins, six strains of Penicillium commune, which have been reported to be CPA producers, were obtained from the bank and then tested for their CPA productivity. CPA was isolated from the culture filtrate of P. commune KACC 45973. CPA killed the second-stage juveniles of M. incognita, M. hapla, and M. arearia with EC50–3 days 4.50, 18.82, and 60.51 μg mL–1, respectively. CPA also significantly inhibited egg hatch of M. incognita and M. hapla after a total of 28 days of treatment with the concentrations > 25 μg mL–1. The enhancement of CPA production by P. commune KACC 45973 was explored using an optimized medium based on Plackett–Burman design (PBD) and central composite design (CCD). The highest CPA production (381.48 μg mL–1) was obtained from the optimized medium, exhibiting an increase of 7.88 times when compared with that from potato dextrose broth culture. Application of the wettable power-type formulation of the ethyl acetate extract of the culture filtrate of KACC 45973 reduced gall formation and nematode populations in tomato roots and soils under greenhouse conditions. These results suggest that CPA produced by P. commune KACC 45973 can be used as either a biochemical nematicide or a lead molecule for developing chemical nematicides to control root-knot nematodes.

2010 ◽  
Vol 22 (2) ◽  
pp. 281-296 ◽  
Author(s):  
M. Mašković ◽  
B. Jančić-Stojanović ◽  
A. Malenović ◽  
D. Ivanović ◽  
M. Medenica

2021 ◽  
Vol 166 ◽  
pp. 113488
Author(s):  
Agnese Spadi ◽  
Giulia Angeloni ◽  
Lorenzo Guerrini ◽  
Ferdinando Corti ◽  
Marco Michelozzi ◽  
...  

2021 ◽  
Vol 19 (1) ◽  
pp. 326-332
Author(s):  
Ana Paula Ferreirade Souza ◽  
Mateus Henrique Petrarca ◽  
Patrícia Aparecida de Campos Braga ◽  
Nadia Regina Rodrigues ◽  
Felix Guillermo Reyes Reyes

2013 ◽  
Vol 31 (No. 6) ◽  
pp. 627-632 ◽  
Author(s):  
O.G. Nagel ◽  
M.P. Molina ◽  
R.L. Althaus

We proposed an experimental design of a microbial bioassay of dichotomous response (positive or negative) using Bacillus subtilis BGA for the detection of sulfonamide residues. In the first stage, the bioassay response time was reduced to 6 h by increasing the spore concentration of B. subtilis. Then, the effects of spore, indicator, trimethoprim (TMP) concentration, and volume of the culture medium were examined with a Plackett Burman design (2<sup>4-1</sup>). Finally, the effect of TMP concentration on the method detection capabilities and specificity was analysed using a logistic model with interaction. The detection capabilities of sulfonamides in milk are close to the MRLs when using 500 mg/l of TMP in the culture medium of the bioassay. It is concluded that the experimental design techniques and a logistic regression model can be used to design successfully a dichotomous response bioassay.


2020 ◽  
Vol 45 (1-2) ◽  
pp. 25-38
Author(s):  
RENU KAUL ◽  
◽  
SANJOY ROY CHOWDHURY ◽  

Nematology ◽  
2001 ◽  
Vol 3 (4) ◽  
pp. 355-363 ◽  
Author(s):  
Ja-On Park ◽  
Krishnapillai Sivasithamparam ◽  
Emile Ghisalberti ◽  
Jaih Hargreaves ◽  
Walter Gams ◽  
...  

AbstractA strain of a Byssochlamys nivea, isolated from saline mud in Western Australia as a part of statewide survey of soil fungi for nematophagous activity, was evaluated for its effect on nematodes. Culture filtrate of the fungus grown on potato dextrose broth for 7 days caused structural changes in the cuticle, aggregation of individuals, and mortality of Caenorhabditis elegans. In addition, the culture filtrate completely inhibited hatching of C. elegans eggs. Exudates from agar colonies also caused cuticular disruption and mortality of C. elegans. The cuticular disruption observed, not reported in nematodes before, was initiated in the labial region and spread towards the posterior region of the nematode within 10 min of application. This reaction occurred only in live nematodes. Cuticular disruption and mortality caused by the culture filtrate varied according to growth conditions. The active compound(s) in the culture filtrate were thermostable (100°C for 1 h); however freezing the culture filtrate (-20°C for 2 days) eliminated the activities, as did dialysis (<14 000 molecular weight). Cuticular disruption and mortality were also observed when the nematode was exposed to culture filtrates of two other strains of B. nivea supplied by CBS, The Netherlands. The culture filtrate also inhibited in vitro growth of the plant-pathogenic fungi Fusarium oxysporum, Gaeumannomyces graminis var. tritici, Phytophthora cinnamomi, Pythium irregulare and Rhizoctonia solani.


Author(s):  
Graciella da Silva Campello ◽  
Renata Aguirre Trindade ◽  
Tatiane Vieira Rêgo ◽  
Janaína Fernandes de Medeiros Burkert ◽  
Carlos André Veiga Burkert

Abstract The main goal of this study was to investigate the immobilization of commercial ß-galactosidase from Kluyveromyces lactis (Lactozym®) on Eupergit® C. A Plackett-Burman design was proposed. The ionic strength and pH were the variables that presented significant effect (p<0.1) on immobilization. The increase in the ionic strength from 0.1 to 1.5 M and the increase in pH from 6.6 to 7.4 represented an increase of 28.56% and a reduction of 18.19% in the immobilization yield, respectively. At 25°C, pH 6.6, ionic strength of 1.5 M, immobilization for 8 h, 1 mM of divalent magnesium ion and 0.4 mL of enzyme added, reached 85% immobilization yield. The free and immobilized enzymes were characterized. pH and temperature profiles showed maximum activity at pH 6.6 and 45°C, for both free and immobilized enzymes. There was a gain in thermal stability with enzyme immobilization and there was an increase of about four times in the half-life of the immobilized derivative at 45°C (from 0.43 h to 1.78 h). This greater thermal stability was also made clear through the calculation of thermodynamic parameters (ΔH, ΔG and ΔS). Km values, 30.33 mM and 104.00 mM for free and immobilized enzymes, respectively, represented a reduction in substrate affinity after immobilization, possibly owing to stereo-conformational factors. In a batch reactor for lactose hydrolysis from cheese whey, an increase in lactose conversion with immobilization was observed at 40°C and 45°C (90.43% and 65.36%, respectively) in relation to the free enzyme (84.17% and 39.58%, respectively).


Sign in / Sign up

Export Citation Format

Share Document