BECAS
MORELLI Matias Nicolas
artículos
Título:
Sclerotium oryzae biocontrol in flooded rice fields with floating microcarrier technology: The effect of chitosan molecular weight
Autor/es:
MORELLI, MATIAS NICOLAS; OSVALDO SPONTÓN ; SANTIAGO, LILIANA G; LEONARDI, RODRIGO JORGE; HEINRICH, JOSUÉ MIGUEL
Revista:
Pest Managment Science
Editorial:
John Wiley and Sons Ltd
Referencias:
Lugar: CHICHESTER; Año: 2021 vol. 77 p. 5228 - 5235
ISSN:
1526-498X
Resumen:
BACKGROUND: Biocontrol strategies are of significant concern for their application in crops. Various green practices have beendesigned, but almost all of them had delivery constraints. In particular, to design biocontrol strategies against Sclerotiumoryzae in flooded rice fields, the active agent should be retained on the plant leaves by spreading application, neverthelessthe direct application onto the water produces the biocontrol agent dilution. An effective delivery model was needed. This workaimed to evaluate the effects of chitosan molecular weight on the formation of positively charged Pseudomonas fluorescens?chitosan complex as a floating microcarrier against Sclerotium oryzae. To this end, three different sizes of chitosan [molecularweights (MWs) 20 000, 250 000, and 1 250 000 g mol−1] at different pH values (4, 6, and 7) were tested. The electrostatic interaction was analyzed through ζ-potential measurement. An adjustment of the experimental values was carried out for makingpredictions. The bacteria antifungal activity into the carrier with different chitosan MWs was analyzed.RESULTS: Our results suggest that it is possible to form a bacteria?chitosan complex with a net positive charge under conditionthat improve bacteria incorporation to the microcarrier technology without harming bacteria viability and antifungal activity.Thus, high chitosan MW (1 250 000 g mol−1) at pH 6 is preferable for microcarrier technology.CONCLUSION: Our findings provide relevant information about bacteria?chitosan interaction and may be useful in biocontrolprograms that involved these two components as well as situations in which bacteria adsorption to an anionic carrier or anionicsurface is desirable
