การศึกษาสภาวะที่เหมาะสมต่อการผลิตสารทุติยภูมิ และประสิทธิภาพในการควบคุม โรคขอบใบแห้งของข้าวของแบคทีเรีย Bacillus amyloliquefaciens S20A1

บทคัดย่อ

An antagonistic bacteria Bacillus amyloliquefaciens S20A1 isolated from rice rhizosphere performed
the antagonistic activity chiefly by producing the effective secondary metabolites (SM) against
Xanthomonas oryzae pv. oryzae (Xoo). Maximum population and SM production of B. amyloliquefaciens
S20A1 achieved when culture in half yeast extract peptone broth (half YPB) incubated for 60 hours on the
rotary shaker with 150 rpm at 25±2°C. CFF of B. amyloliquefaciens S20A1 capable to inhibits various plant
pathogenic bacteria including Xoo, X. axonopodis pv. glycines (Xag) and X. campestris pv. campestris
(Xcc) with 37.82 mm, 30.86 mm and 34.68 mm of inhibition zone respectively. MIC of CFF was 20% for
Xag and Xcc and 10% for Xoo. Rice seedlings sprayed with 100% CFF after Xoo inoculation exhibited the
best disease reduction (68.56%) which better than treated with fresh cell and cell suspension of B. amyloliquefaciens S20A1 and chemical bactericide, gentamicin sulfate+copper hydroxychloride.
Culture medium and conditions obtained from this study can be used for cell mass and SM production of
B. amyloliquefaciens S20A1 by bioreactor Furthermore, this CFF can be an efficient eradicative agent to
control the bacterial blight of rice, leading to the bio-bactericide production