Characterization of Hybrid Composites with Polyester Waste Fibers, Olive Root Fibers and Coir Pith Micro-Particles Using Mixture Design Analysis for Structural Applications.

In the present work, hybrid composites were developed by using polyester waste fibers along with natural origin materials: olive root fibers and coir pitch filler. Such composite panels can be used as a potential alternative for fiber glass sunshade panels and room dividers in buildings. Hybrid composites were fabricated by mixing polyester waste fibers and olive root fibers in different ratios (0:100, 33:67, 67:33 and 100:0). Coir pith micro-particles with an average size of 312 d.nm were used as filler in the polyester matrix at three different levels (0%, 5%, and 10%) of the overall matrix weight. Mechanical properties, e.g., tensile strength, flexural strength and impact strength, thermal properties, e.g., coefficient of linear thermal expansion, thermo-gravimetric analysis (TGA) and environmental properties, e.g., water absorption, loss of density after exposure to weathering were characterized. For comparison purposes, a commercially available fiber glass sunshades sample was also investigated. Mixture design analysis was used to optimize the ratio of all components in the composite. Graphical comparison of experimental results using regression models showed a high degree of correlation. An optimized formulation of composite with an objective of maximization of tensile strength, flexural strength, impact strength and minimization of water absorption, density loss, as well as coefficient of linear thermal expansion, was determined at 70.83 wt%, 15.15 wt%, and 14.01 wt% of polyester waste fibers, olive root fibers and coir pith micro-fillers, respectively. Overall, it can be concluded that the developed hybrid composites from waste fibrous materials can be used as a promising alternative and a value-added application in buildings and construction purposes.

Complete Genome Sequence of the Type Strain Pectobacterium punjabense SS95, Isolated from a Potato Plant with Blackleg Symptoms.

Pectobacterium punjabense is a newly described species causing blackleg disease in potato plants. Therefore, by the combination of long (Oxford Nanopore Technologies, MinION) and short (Illumina MiSeq) reads, we sequenced the complete genome of P. punjabense SS95T, which contains a circular chromosome of 4.793 Mb with a GC content of 50.7%.

Species Diversity of Dickeya and Pectobacterium Causing Potato Blackleg Disease in Pakistan.

Potato blackleg is caused by a diverse species of pectinolytic bacteria. In Pakistan, approximately 90% of the pathogens involved belong to Pectobacterium atrosepticum. Survey (2014 to 2017), sampling, and isolation from different potato growing areas of Punjab, Pakistan depicted an overall disease incidence of approximately 15%. Thirty-six pectinolytic strains confirmed through biochemical and pathogenicity testing were characterized via gapA gene to identify them at the species level. To further validate the identification, one strain from each species SS26 (P. atrosepticum), SS28 (Pectobacterium polaris), SS70 (Dickeya dianthicola), SS90 (Pectobacterium parmentieri), SS95 (Pectobacterium punjabense), and SS96 (Pectobacterium versatile) were selected for draft genome sequencing and multilocus sequence analysis of 13 housekeeping genes (fusA, rpoD, acnA, purA, gyrB, recA, mdh, mtlD, groEL, secY, glyA, gapA, and rplB). Phylogenetic analysis revealed considerable genetic diversity in the genus Pectobacterium. In silico DNA-DNA hybridization and average nucleotide identity values of the strains selected for genome sequencing were determined with other reference Pectobacterium and Dickeya strains. Moreover, all six representative strains were also phenotypically characterized on the basis of metabolism of different carbon sources. Overall, on the basis of genotypic and phenotypic characteristics, these 36 isolates were grouped into six species: P. atrosepticum, P. versatile, P. parmentieri, P. polaris, P. punjabense, and D. dianthicola.