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This paper examines the effects of poly (ethylene-co-vinyl acetate) (EVA) with 40% vinyl acetate content on thermal, mechanical, rheological, and morphological properties of polylactic acid (PLA) blends. Thermal analysis indicated improvement of crystallinity in the presence of more EVA. With 15% EVA, the impact strength of the binary blend increased significantly (37.80 KJ/m2) at an optimum elongation at break due to the compatibility of the blend and the formation of fibrils. In the presence of % EVA, complete phase separation with the formation of EVA droplets in the PLA continuous phase resulted in a reduction of impact strength and elongation at break. Changes in compatibility and morphology lead to variation in rheological properties. The complex viscosity (η*) decreased with increasing EVA content up to 10% EVA but slightly increased at 15% EVA due to optimum interphase interaction between components in the compatible blend. In the presence of more than 20% EVA, η* reduced again due to the occurrence of phase separation. The variations in the mechanical and rheological properties of PLA/EVA blends are directly related to the state of compatibility and morphology of the blends.

Data on the 16S rRNA gene amplicon sequences from Pteris vittata rhizosphere soils are reported. The following phyla were recorded in arsenic-rich soils: Actinobacteria (59%), Proteobacteria (26%), Chloroflexi (17%), and Acidobacteria (9%). Actinobacteria (45%), Proteobacteria (22%), Chloroflexi (10%), and Acidobacteria (11%) were in natural-mineral soils.

Enterobacter tabaci 4M9 (CCB-MBL 5004) was reported to have plant growth-promoting and heavy metal tolerance traits. It was able to tolerate more than 300 mg/L Cd, 600 mg/L As, and 500 mg/L Pb and still maintained the ability to produce plant growth-promoting substances under metal stress conditions. To explore the genetic basis of these beneficial traits, the complete genome sequencing of 4M9 was carried out using Pacific Bioscience (PacBio) sequencing technology. The complete genome consisted of one chromosome of 4,654,430 bp with a GC content of 54.6% and one plasmid of 51,135 bp with a GC content of 49.4%. Genome annotation revealed several genes involved in plant growth-promoting traits, including the production of siderophore, indole acetic acid, and 1-aminocyclopropane-1-carboxylate deaminase; solubilization of phosphate and potassium; and nitrogen metabolism. Similarly, genes involved in heavy metals (As, Co, Zn, Cu, Mn, Se, Cd, and Fe) tolerance were detected. These support its potential as a heavy metal-tolerant plant growth-promoting bacterium and a good genetic resource that can be employed to improve phytoremediation efficiency of heavy metal-contaminated soil via biotechnological techniques. This, to the best of our knowledge, is the first report on the complete genome sequence of heavy metal-tolerant plant growth-promoting E. tabaci.

The 16S rRNA gene amplicon sequence data from tailing and nontailing rhizosphere soils of Mimosa pudica from a heavy metal-contaminated area are reported here. Diverse bacterial taxa were represented in the results, and the most dominant phyla were Proteobacteria (41.2%), Acidobacteria (17.1%), and Actinobacteria (14.4%).

Globitermes sulphureus is a major pest in coconut plantations and also a secondary pest in the urban, suburban and rural areas of building structures, as well as in tropical agriculture areas. Although the literature revealed microbiome in termite guts, the bacterial community in G. sulphureus intestinal tracts remain largely unidentified. Here, we aimed to characterize the bacterial community associated with the worker and soldier castes of G. sulphureus using 16S metagenomic. The Illumina HiSeq 2500 sequencing machine was used to amplify the V3 and V4 regions of the 16S rRNA gene. The sequencing output was analyzed using Qiime pipeline v1.9.1. The result of the analysis showed that Spirochaetes, Fibrobacteres, Firmicutes, Proteobacteria, and Bacteroidetes were the dominant phyla that reside in the guts of the worker and soldier castes. We found that the worker and soldier castes shared similar bacterial phyla in their guts but different bacterial genera. Our findings provided a baseline information on microbial community inhabiting G. sulphureus guts up to the genus level for some phyla.

Observations of fine particulate matter (PM2.5) and meteorological parameter (temperature, relative humidity and wind speed) fluctuations during a high particulate event (HPE) in Sekolah Kebangsaan Bayan Lepas, Malaysia have been conducted for three days (48 hrs). Selected sample spot of collected PM2.5 particles with high concentration was chosen to investigate the physicochemical characteristics using Field Emission Scanning Electron Microscope coupled with Energy Dispersive X-ray (FESEM-EDX). The results show that the 24 h average concentration ± standard deviation of PM2.5 (81.87 μg m−3 ± 31.83) exceeded the limit suggested by Malaysia Ambient Air Quality Standard (MAAQS-2020) and United State Environmental Protection Agency (USEPA) which is 35 μg m−3. The diurnal variations of PM2.5 concentration fluctuated significantly during HPE. Results from Pearson correlation shows that relative humidity gives the most significant influence towards PM2.5 concentration (r = 0.410; p < 0.01) followed by wind direction (r = -0.306, p < 0.01), temperature (r = -0.262., p2.5 particles collected on a filter consist of two possible sources, natural and anthropogenic sources. The element components found in the natural particles were C, O, Na, Al, Si, S, K and Fe. The major components were C, O, Al, and Si with weight percentages were 18%, 39%, 9%, and 22%. Dominant elements in anthropogenic particles were C (41%) and a significant amount of K (3%) are found which considered as biomass burning soot. Besides that, the particles also consist of O, Na, Al, Si, and Cl. In summary, particles from natural and anthropogenic sources are dominant in the ambient PM2.5 during HPE.

Bacterial communities of blood cockles (Anadara granosa) collected from wet market across Penang, Malaysia, were examined using a cultivation method. This study aimed to describe the major abundance of blood cockle bacteria and its relationship with different sampling locations. 16S rRNA gene analysis and culturable bacterial numbers were found to be slightly different between samples in two different locations potentially due to management, handling, transport and storage practices by the farmers, distributors and retailers. Results from this study indicated that most of bacteria found were typically present in blood cockles. The results revealed that there were slight similarities between sampling times; and slight differences on bacterial numbers between two different sampling locations. Based on the results, the blood cockle microbial communities comprised of members of the genera Klebsiella and Bacillus, which are greatly predominant, with highly dynamic of bacterial communities. Other bacterial genera found were E.coli, Vibrio, Pseudomonas, Staphylococcus and Micrococcus. The overall data demonstrated dynamic bacterial communities in blood cockles (Anadara granosa) and its diversity.

Although freshwater biomes cover less than 1% of the Earth's surface, they have disproportionate ecological significances. Attempts to study the taxonomy and function of freshwater microbiota are currently limited to samples collected from temperate lakes. In this study, we investigated samples from the photic and aphotic of an aquaculture site (disturbed) of Temengor Lake, a tropical lake in comparison with the undisturbed site of the lake using 16S rRNA amplicon and shotgun metagenomic approaches. Vertical changes in bacterial community composition and function of the Temengor Lake metagenomes were observed. The photic water layer of Temengor Lake was dominated by typical freshwater assemblages consisting of Proteobacteria, Actinobacteria, Bacteroidetes, Verrucomicrobia, and Cyanobacteria lineages. On the other hand, the aphotic water featured in addition to Proteobacteria, Bacteroidetes, Verrucomicrobia, and two more abundant bacterial phyla that are typically ubiquitous in anoxic habitats (Chloroflexi and Firmicutes). The aphotic zone of Temengor Lake exhibited genetic potential for nitrogen and sulfur metabolisms for which terminal electron acceptors other than oxygen are used in the reactions. The aphotic water of the disturbed site also showed an overrepresentation of genes associated with the metabolism of carbohydrates, likely driven by the enrichment of nutrient resulting from aquaculture activities at the site. The results presented in this study can serve as a basis for understanding the structure and functional capacity of the microbial communities in the photic and aphotic zones/water layers of tropical man-made lakes.

In this study, microbial community dynamics were assessed within a simple in vitro model system in order to understand those changes influenced by diet. The abundance and diversity of bacteria were monitored within different treatment slurries inoculated with salmon faecal samples in order to mimic the effects of dietary variables. A total of five complete diets and two ingredients (plant meal) were tested. The total viable counts (TVCs) and sequencing data revealed that there was very clear separation between the complete diets and the plant meal treatments, suggesting a dynamic response by the allochthonous bacteria to the treatments. Automated ribosomal intergenic spacer analysis (ARISA) results showed that different diet formulations produced different patterns of fragments, with no separation between the complete diets. However, plant-based protein ingredients were clearly separated from the other treatments. 16S rRNA Illumina-based sequencing analysis showed that members of the genera Aliivibrio, Vibrio and Photobacterium became predominant for all complete diets treatments. The plant-based protein ingredient treatments only sustained weak growth of the genus Sphingomonas. In vitro based testing of diets could be a useful strategy to determine the potential impact of either complete feeds or ingredients on major fish gastrointestinal tract microbiome members.

We investigated the changes in the faecal microbial population of the hindgut of farmed Atlantic salmon fed two commercial diets (A and B) over a 10-month period. At each sampling round, hindgut contents of 40 fish (20 per diet) were pooled according to diet and cultivated on selective agar. The functional status of all microbiota was assessed against 48 substrates using the PhPlate generalized microplate, which also yielded a metabolic capacity (MC) value for each microbiota. Virulence gene profiles of each microbiota were also investigated. The number of different bacterial groups between two diets varied slightly and increased as water temperature peaked at 18.5°C during summer. This however, was associated with an increase in Vibrio numbers and a decrease in lactic acid bacterial numbers. A shift in the functional status of gut microbiota was observed as temperature increased, which was coupled with a decrease in the MC-value of the microbiota in both diets. Of the 35 virulence genes tested from total DNA extract of the microbiota, only cdt and east1 were detected. Results indicate that temperature is the main driver of changes to the gut microbiota in farmed Tasmanian Atlantic salmon receiving these two diets.

To better understand salmon GI tract microbial community dynamics in relation to diet, a feeding trial was performed utilising diets with different proportions of fish meal, protein, lipid and energy levels. Salmon gut dysfunction has been associated with the occurrence of casts, or an empty hind gut. A categorical scoring system describing expressed digesta consistency was evaluated in relation to GI tract community structure. Faster growing fish generally had lower faecal scores while the diet cohorts showed minor differences in faecal score though the overall lowest scores were observed with a low protein, low energy diet. The GI tract bacterial communities were highly dynamic over time with the low protein, low energy diet associated with the most divergent community structure. This included transiently increased abundance of anaerobic (Bacteroidia and Clostridia) during January and February, and facultatively anaerobic (lactic acid bacteria) taxa from February onwards. The digesta had enriched populations of these groups in relation to faecal cast samples. The majority of samples (60–86%) across all diet cohorts were eventually dominated by the genus Aliivibrio. The results suggest that an interaction between time of sampling and diet is most strongly related to community structure. Digesta categorization revealed microbes involved with metabolism of diet components change progressively over time and could be a useful system to assess feeding responses.&nbsp

Aims: The relationship of Atlantic salmon gastrointestinal (GI) tract bacteria to environmental factors, in particular water temperature within a commercial mariculture system, was investigated. Methods and Results: Salmon GI tract bacterial communities commercially farmed in south-eastern Tasmania were analysed, over a 13-month period across a standard commercial production farm cycle, using 454 16S rRNA-based pyrosequencing. Faecal bacterial communities were highly dynamic but largely similar between randomly selected fish. In postsmolt, the faecal bacteria population was dominated by Gram-positive fermentative bacteria; however, by midsummer, members of the family Vibrionaceae predominated. As fish progressed towards harvest, a range of different bacterial genera became more prominent corresponding to a decline in Vibrionaceae . The sampled fish were fed two different commercial diet series with slightly different protein, lipid and digestible energy level; however, the effect of these differences was minimal. Conclusions: The overall data demonstrated dynamic hind gut communities in salmon that were related to season and fish growth phases but were less influenced by differences in commercial diets used routinely within the farm system studied. Significance and Impact of the Study: This study provides understanding of farmed salmon GI bacterial communities and describes the relative impact of diet, environmental and farm factors.