ABSTRACT
@#Aims: Mycorrhiza has an important role as a biocontrol agent. Its association with Phalaenopsis amabilis was molecularly identified through rDNA-ITS sequence analysis. The aims of the study were to identify molecular of orchids mycorrhiza isolate from native tropical orchids in Indonesia, conducted as one of native orchid conservation efforts in Indonesia. Methodology and results: One group of Ceratobasidium were isolated from the root of orchid plant in Yogyakarta based on morphological and microscopical analysis. The results of molecular analysis showed 600-750 bp of DNA products located on the ITS1-5.8S-ITS4 region. The sequenced products showed insertion and substitution occurances, which may result in strain diversity and possible variation. Reconstruction of phylogenetic trees using Maximum Parsimony and Bootstrap-1000 approach showed showed the Indonesian isolate is at the basal clade and already far apart from the other isolates. Conclusion, significance and impact of study: Isolate Ceratobasidium from Yogyakarta, Indonesia successfully isolated based on identification of rDNA-ITS sequences. Results of this study were expected to become the basic information in an effort of native orchid cultivation and protection against infectious diseases in Indonesia. The study was the first to report regarding Ceratobasidium isolated from native tropical orchids in Indonesia.
ABSTRACT
Ceratobasidium ramicola IBRLCM127, an endophytic fungus isolated from the rhizome of the local medicinal plantCurcuma mangga Valeton & Zijp, was found to possess significant anti-candidal activity. This fungal endophyte wascultivated in submerged fermentation system using yeast sucrose medium supplemented with host plant water extractand cultivated at 25°C, agitated at 120 rpm for 12 days. The ethyl acetate was used as a solvent to extract compoundsin the fermentative broth. The fungal ethyl acetate extract demonstrated significant inhibitory zones toward cells ofCandida albicans with minimum inhibitory concentration (MIC) value of 2.5 mg/ml, of which exerting yeastocidaleffect. The time–kill study conducted at three distinct ethyl acetate concentrations (half MIC, MIC, and 2 MICvalues) revealed that the growth of C. albicans cells was concentration-dependent. Yeastostatic activity was shownat lower concentration and yeastocidal activity was shown at higher concentration. The structural degeneration of theC. albicans cells after treated with ethyl acetate extract was observed under the scanning and transmission electronmicroscopes and the results exhibited various cell deformities including severe damage of the cell extracellularly andintracellularly which led to cell death beyond repair, thus suggesting that the extract could be a potential antifungalagent.
ABSTRACT
In this study， an endophytic bacteria strain BZJN1 was isolated from Atractylodes macrocephala， and identified as Bacillus subtilis by physiological and biochemical tests and molecular identification. Strain BZJN1 could inhibit the growth of mycelia of Ceratobasidium sp. significantly， and the inhibition rate was more than 70%. The mycelium growth deformity with bulge as spherical and partially exhaustible in apex or central with microscopic observation. The inhibitory rates under 3% and 6% concentrations of the cell free fermentation were 22.7% and 38.7% expectively. The field test proved that the control efficacy of treatment of 1×10⁸ cfu·mL⁻¹ is 75.27% and 72.37% after 10 and 20 days. All the treatments of strain BZJN1 was able to promote the growth of A. macrocephala， the treatment of 1×10⁸ cfu·mL⁻¹ could able to increase the yield to 14.1%.