Biogenic Synthesis and Characterization of Silver Nanoparticles (AgNPs) Produced by Indigenous Microorganisms Isolated from Banana (Musa spp) Soils

This research focused on the screening of indigenous microorganisms isolated from banana soils for their capability to synthesize silver nanoparticles (AgNPs) extracellularly. Ninety-five isolates were screened for AgNP production. The cell-free extracts of these isolates were added to silver nitrate (AgNO3) aqueous solution and were observed for color changes from original pale yellow to dark brown. Ten isolates (3 bacteria and 7 fungi) were found capable of producing AgNPs. Bacterial isolates B2, B3, and B5 were molecularly identified as Bacillus aryabhattai, Priestia megaterium, and B. megaterium, respectively. The AgNPs produced by these bacterial isolates were circular and showed an absorbance peak at approximately 420 nm. On the other hand, the fungal isolates F2, F3, and F43 were molecularly identified as Penicilliumcitrinum, P. glaucoroseum, and P. oxalicum. The AgNPs produced by the Penicillium spp were aggregated, circular and showed absorbance peaks at 420 nm. The other four fungal isolates, F7, F24, F29, and F40, were identified as Aspergillus flavus, A. terreus, and A. japonicum (F29 and F40), respectively. The AgNPs produced by the Aspergillus spp. were circular and showed absorbance peaks between 420 nm and 450 nm. The continuous search for novel isolates that can carry out the biogenic synthesis of AgNPs remains the focus of nanotechnological research. This study confirms microorganisms of Bacillus, Penicillium, and Aspergillus genera can effectively biosynthesize AgNPs

Encapsulation of Bacteria-Derived Auxin, Cytokinin and Gibberellin and its Application in the Micropropagation of Coconut (Cocos nucifera L. var Makapuno)

Improved solubility of the PGR-loaded liposomes in aqueous solution was also observed. The PGR-loaded liposomes showed controlled-released behavior of the active component at pH 5.0 and 7.0. Higher stability of the encapsulated PGRs was observed at 0 -

A survey of lectin-like activity in Philippine marine invertebrates

Owing to their sugar-recognition specificities, lectins have now become useful tools in targeting carbohydrates on cell surfaces. Using an in vitro hemagglutination assay, we screened several marine invertebrates found in the Philippines to catalog new biosources for these lectins. We found fifty-nine (59) species showing lectin-like activity out of the 90 analyzed and described individual hemagglutination characteristics. Underscoring the diversity and abundance of marine lectin sources, this work hopes to provide valuable information relevant for “farming” novel lectins for biotechnology especially in developing nations with rich marine resource

DNA-based electrochemical nanobiosensor for the detection of Phytophthora palmivora (Butler) Butler, causing black pod rot in cacao (Theobroma cacao L.) pods

© 2019 Elsevier Ltd A nanobiosensor was developed for the electrochemical detection of Phytophthora palmivora, a notorious pathogen of cacao causing severe crop loss. Sandwich hybrids between two oligonucleotide probes and the genomic DNA of P. palmivora were prepared and electrochemically detected. The oligonucleotide probes were designed based on the ITS sequence of the P. palmivora field isolates. The detection of sandwich hybrids with P. palmivora genomic DNA and the selectivity of the nanobiosensor towards it compared to other cacao-associated fungal pathogens were demonstrated. The detection limit was determined to be at 0.30 ng DNA μL−1. Detection of P. palmivora DNA on cacao samples was also demonstrated. The result of the preliminary analysis on cacao pod samples shows the potential of the developed nanobiosensor for reliable and more cost-effective analysis of field samples