First report of Xanthomonas sacchari isolated from sugarcane with leaf scald disease in Tucuman

MIELNICHUK, N; BIANCO, MI; TOUM, L; YARYURA, P M; CASTAGNARO, AP; VOJNOV, AA

Parana

Congreso; LIV Reunion Anual Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular; 2018

Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular

Xanthomonas sacchari is a closely related bacterium to Xanthomonas albilineans, the causal agent of sugarcane leaf scald disease. It is unknown if X. sacchari is able to infect sugarcane. Recently, two strains of X. sacchari (named Xs14 and Xs15) were isolated from sugarcane with leaf scald disease. Our goal is to analyse key virulence factors and to assess pathogenicity of X. sacchari. First, exopolysaccharide (EPS) and biofilm characteristics were analysed in media with different carbon source (glucose: GLU; sucrose: SUC). EPS yield was determined as dry weight after KCl/ETOH precipitation. Relative EPS-Xs14 production in GLU and SUC was 100% and 70% respectively. On the other hand, EPS-Xs15 relative production was 38% in GLU and 34% in SUC. Low shear rate viscosity (LSRV) was calculated with a Brookfield viscometer. LSRV of EPS-Xs14 and EPS-Xs15 obtained in GLU were significantly higher (P