Antibacterial properties of chitosan isolated from the black soldier fly, Hermetia illucens

Insects are receiving wide attention as alternative food and feed resources, and for the production of useful by-products such as chitin, which can be converted into chitosan, a natural antibacterial agent. The larvae of Hermetia illucens, commonly known as Black Soldier Fly (BSF), can be reared on organic waste substrates and can be produced on a large scale. In this study, we focused on the antibacterial activity of chitosan obtained from BSF. Chitin from different growth phases of BSF was isolated using chemical treatments, characterized, and further synthesized into chitosan by deacetylation. The identities and structures of all isolated and synthesized compounds were verified using Fourier-transform infrared spectroscopy (FTIR). The antibacterial effect of BSF chitosan compounds against pathogenic bacteria were assessed with the determination of a minimum inhibitory concentration (MIC). Results showed that the chitin content increased gradually during the transition from larvae to adult BSF, with the highest amount obtained in the pupal stage. In the antibacterial susceptibility assay, Staphylococcus aureus was the most resistant to the action of BSF chitosan, with no significant effect exerted on its growth. For other species of bacteria, BSF chitosan could only restrict bacterial growth at concentrations of 0.25% or 0.5%, with the two most susceptible species being identified as Pseudomonas aeruginosa and Serratia marcescens. In conclusion, BSF chitosan exhibited antibacterial activity against different bacteria with varying sensitivities, in which the chitosan concentration was demonstrated to play an essential role

A new species of Haliotrema (Monogenea: Ancyrocephalidae (sensu lato) Bychowsky & Nagibina, 1968) from holocentrids off Langkawi Island, Malaysia with notes on the phylogeny of related Haliotrema species

Haliotrema susanae sp. nov. is described from the gills of the pinecone soldierfish, Myripristis murdjan off Langkawi Island, Malaysia. This species is differentiated from other Haliotrema species especially those from holocentrids in having a male copulatory organ with bract-like extensions at the initial of the copulatory tube, grooved dorsal anchors and ventral anchors with longer shafts. The maximum likelihood (ML) analysis based on partial 28S rDNA sequences of H. susanae sp. nov. and 47 closely related monogeneans showed that H. susanae sp. nov. is recovered within a monophyletic clade consisting of only species from the genus Haliotrema. It is also observed that H. susanae sp. nov. forms a clade with H. cromileptis and H. epinepheli which coincides with a similar grouping by Young based on solely morphological characteristics. The morphological and molecular results validate the identity of H. susanae sp. nov. as belonging to the genus Haliotrema

Ligophorus image data

Images of ventral and dorsal anchors of 530 specimens from 13 Ligophorus species

Monogenean anchor morphometry: systematic value, phylogenetic signal, and evolution

Background. Anchors are one of the important attachment appendages for monogenean parasites. Common descent and evolutionary processes have left their mark on anchor morphometry, in the form of patterns of shape and size variation useful for systematic and evolutionary studies. When combined with morphological and molecular data, analysis of anchor morphometry can potentially answer a wide range of biological questions. Materials and Methods. We used data from anchor morphometry, body size and morphology of 13 Ligophorus (Monogenea: Ancyrocephalidae) species infecting two marine mugilid (Teleostei: Mugilidae) fish hosts: Moolgarda buchanani (Bleeker) and Liza subviridis (Valenciennes) from Malaysia. Anchor shape and size data (n = 530) were generated using methods of geometric morphometrics. We used 28S rRNA, 18S rRNA, and ITS1 sequence data to infer a maximum likelihood phylogeny. We discriminated species using principal component and cluster analysis of shape data. Adams’s Kmult was used to detect phylogenetic signal in anchor shape. Phylogeny-correlated size and shape changes were investigated using continuous character mapping and directional statistics, respectively. We assessed morphological constraints in anchor morphometry using phylogenetic regression of anchor shape against body size and anchor size. Anchor morphological integration was studied using partial least squares method. The association between copulatory organ morphology and anchor shape and size in phylomorphospace was used to test the Rohde-Hobbs hypothesis. We created monogeneaGM, a new R package that integrates analyses of monogenean anchor geometric morphometric data with morphological and phylogenetic data. Results. We discriminated 12 of the 13 Ligophorus species using anchor shape data. Significant phylogenetic signal was detected in anchor shape. Thus, we discovered new morphological characters based on anchor shaft shape, the length between the inner root point and the outer root point, and the length between the inner root point and the dent point. The species on M. buchanani evolved larger, more robust anchors; those on L. subviridis evolved smaller, more delicate anchors. Anchor shape and size were significantly correlated, suggesting constraints in anchor evolution. Tight integration between the root and the point compartments within anchors confirms the anchor as a single, fully integrated module. The correlation between male copulatory organ morphology and size with anchor shape was consistent with predictions from the Rohde-Hobbs hypothesis. Conclusions. Monogenean anchors are tightly integrated structures, and their shape variation correlates strongly with phylogeny, thus underscoring their value for systematic and evolutionary biology studies. Our MonogeneaGM R package provides tools for researchers to mine biological insights from geometric morphometric data of speciose monogenean genera

Concatenation of MAFFT-aligned DNA sequences for 13 Ligophorus species

This file contains concatenated multiple sequence alignments of 18S rRNA, ITS-1 and 28S rRNA sequences (in this order) for 13 Ligophorus species. Multiple sequence alignment was performed using MAFFT (version 7). Alignment parameters: Q-INS-i iterative refinement method; 1PAM/k=2 nucleotide scoring matrix; gap opening penalty = 1.53. The sequences were manually concatenated from trimmed MAFFT-alignments

Landmark coordinate data of ventral and dorsal anchors of 13 Ligophorus species

The file contains landmark coordinate data of ventral and dorsal anchors of 530 specimens from 13 Ligophorus species. Data generated from Ligophorus Image Data using TPSDIG2

Assembling of Ag and Au nanoparticles mediated by terpyridine-based oligomers: Relationship between morphology and spectral characteristics

This work is aimed at the preparation and morphological and spectroscopic characterization of the interphase nanocomposite (NC) two-dimensional (2D) self-assembled systems of Ag and Au nanoparticles (NPs). The NPs were functionalized with the following ligands with terpyridine end-groups: 2,2′:6′,2′′-terpyridine (tpy), 4'-(2-thienyl)-2,2':6',2''- terpyridine (T-tpy), α,ω-bis(terpyridyl)-2,2'-bithiophene (tpy-2T-tpy) and α,ω-bis(terpyridyl)- 2,2':5',2''-terthiophene (tpy-3T-tpy). The morphological analysis of transmission electron micrographs proves the preservation of the average interparticle distance in closely spaced NP pairs, independent of the ligand. The value of the total average interparticle distance increases in the order: tpy < T-tpy < tpy- 2T-tpy < tpy-3T-tpy, while the average occupied area fraction in the same order decreases. The morphological descriptors (i.e. interparticle distance and occupied area fraction) were found to correlate with the shift of the SPE (surface plasmon extinction) maxima of NCs (tpy > T-tpy > tpy-2T-tpy > tpy-3T-tpy). The results show that the shift of SPE band maximum depends on the degree of surface plasmon delocalisation rather than on the value of the average interparticle distance in closely spaced NP pairs. The smaller are the islands formed by closely..

Maximum likelihood tree of 13 Ligophorus species

This file contains the inferred maximum likelihood tree of 13 Ligophorus species (Figure 3 in Khang et al. (2016)). The tree was inferred using the IQ-tree pipeline. Parameters: DNA substitution model: GTR + G; 10 000 bootstrap replicates; mid-point rooting

R scripts and associated data files

This file contains R scripts and associated data files for reproducing the analyses in Khang et al. (2016). Note: The authors of the geomorph package has recently informed me (21 January 2016) that changes to the latest version (3.0.0) have rendered some arguments in the gpagen function obsolete. To ensure smooth running of the script, please install geomorph version 2.1.1. as in Khang et al. (2016). Updates to monogeneaGM are forthcoming and will be announced in the PeerJ reader comment section