Molecular Identification of Phytophthora sp. From Indonesian Cocoa Using Phylogenetic Analysis.

<b>Background and Objective:</b> Diseases caused by <i>Phytophthora</i> species cause widespread damage worldwide and are troubling cocoa farmers in Indonesia. The specific species causing disease in an area can be ascertained by characterizing its rDNA fragments. This study aimed to identify <i>Phytophthora</i> sp., samples from cocoa plantations in Southeast Sulawesi, Indonesia, based on phylogenetic analysis of rDNA fragments. <b>Materials and Methods:</b> Identification of rDNA fragments of <i>Phytophthora</i> sp., done by amplifying rDNA fragments using PCR (Polymerase Chain Reactions) techniques with the specific primer of <i>Phytophthora</i> (Phy-F and Phy-R) which can amplify regions of ITS1, 5.8S rRNA and ITS2. The rDNA fragments are then sequenced and analyzed using: The BLAST (Basic Local Alignment Search Tools) provided by NCBI (National Center for Biotechnology Information) via (www.ncbi.nlm.nih.gov/blast) to analyze the local alignment of DNA sequences with Genbank DNA data and Mega 7.0.26 software is used to construct the phylogenetic tree. <b>Results:</b> The DNA sequencing results showed the rDNA measuring 786 bp consisted of complete sequences of ITS 1 (210 bp), 5.8S rRNA (162 bp) and ITS 2 (414 bp). Based on phylogenetic tree analysis using the maximum likelihood method with 1000 bootstrap replications showed that the rDNA of <i>Phytophthora</i> sp., isolates and 29 comparator isolates formed 2 large groups. <i>Phytophthora</i> sp., formed a subgroup with <i>Phytophthora palmivora</i> with a bootstrap value of 99%. <b>Conclusion:</b> The type of <i>Phytophthora</i> spreading in cocoa plantations in Southeast Sulawesi, Indonesia, is 1 group with <i>Phytophthora palmivora</i>.

Characterization of Bacterial Cellulose Produced by Acetobacter xylinum Strain LKN6 Using Sago Liquid Waste as Nutrient Source.

<b>Background and Objective:</b> Bacterial Cellulose (BC) is an exopolysaccharide produced by bacteria with unique structural and mechanical properties and is highly pure compared to plant cellulose. This study aimed to produce novel bacterial cellulose using sago liquid waste substrate and evaluate its characteristics as a potential bioplastic.<b>Materials and Methods:</b> Production of BC by static batch fermentation was studied in sago liquid waste substrate usingAcetobacter xylinumLKN6. The BC structure was analyzed by Scanning Electron Microscopy (SEM) and Fourier Transform infrared spectroscopy (FT-IR). Mechanical properties were measured include tensile strength, elongation at break, elasticity (Young's modulus) and Water Holding Capacity (WHC). <b>Results:</b> The BC yield from sago liquid waste as a nutrients source was achieved 12.37 g L¹ and the highest BC yield 14.52 g L¹ in sago liquid waste medium with a sugar concentration of 10% (w/v) after 14 days fermentation period. The existence of bacterial cellulose is proven by FT-IR spectroscopy analysis based on the appearance of absorbance peaks, which are C-C bonding, C-O bonding, C-OH bonding and C-O-C bonding and represents the fingerprints of pure cellulose. The mechanical properties of BC from sago liquid waste were showed a tensile strength of 44.2-87.3 MPa, elongation at break of 4.8-5.8%, Young's Modulus of 0.86-1.64 GPa and water holding capacity of 85.9-98.6 g g¹. <b>Conclusion:</b> The results suggest that sago liquid waste has great potential to use as a nutrient source in the production of bacterial cellulose and BC's prospect as the bioplastic.