บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Study of exo- beta -1,3-glucanase activity production by the yeast Pichia anomala in relation to its antagonistic properties against Botrytis cinerea on postharvest apples.

Grevesse, C.; Jijakli, M. H.; Lepoivre, P.;

Mededelingen - Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen, Universiteit Gent Year: 1998 Vol: 63 Issue: 4b Pages: 1685-1692 Ref: 23 ref.

1998

บทคัดย่อ

Study of exo- beta -1,3-glucanase activity production by the yeast Pichia anomala in relation to its antagonistic properties against Botrytis cinerea on postharvest apples.

The exo- beta -1,3-glucanase activity of P. anomala strain K, an antagonistic yeast of Botrytis cinerea (gray mold) on postharvest apples, was studied in a synthetic medium supplemented with either laminarin, B. cinerea cell wall preparation (CWP) or glucose. The highest enzyme activity was detected in culture media containing a cell wall preparation of B. cinerea as the sole carbon source whereas the lowest activity was observed in culture media supplemented with glucose. An exo- beta -1,3-glucanase purified to homogeneity from culture filtrates of strain K (paexg2), showed a stronger in vitro inhibitory effect on germ tube growth of B. cinerea than on conidial germination and induced morphological changes such as leakage of cytoplasm and cell swelling. An exo- beta -1,3-glucanase activity was detected on apples treated with strain K and was similar to paexg2 on the basis of mobility on native gel. Moreover, the addition of CWP to a suspension of P. anomala stimulated in situ exo- beta -1,3-glu

canase activity. Two genes coding for exo- beta -1,3-glucanase (PAEXG1 and PAEXG2) were found in strain K genome using PCR with degenerated primers designed on the basis of conserved amino acid regions found in exo- beta -1,3-glucanases of several fungi and on the N-terminal sequence of paexg2. Since strain K is diploid, the segregation of PAEXG1 and PAEXG2 alleles in 10 haploid segregants was studied by Southern blots in relation to their in vitro exo- beta -1,3-glucanase activity production and their protective activity against B. cinerea on apples. No relation was found between these properties and the segregation of PAEXG1 or PAEXG2 alleles showing that either strain K is homozygous at both loci and/or other genetic elements (genes or regulatory factors) determine them.