Implications of Heavy Metal Accumulation in Fish Feed, Water, Sediment, and Different Fish Species in a Polyculture System.

Heavy metal bioaccumulation in organisms is primarily a result of dietary uptake. The current study examines the concentrations of heavy metals (Pb, Cd, Cr, and Cu) in fish feed, water, sediment, and three fish species (Catla catla, Labeo rohita, and Cyprinus carpio) from different feeding zones in a polyculture pond system. Furthermore, associated human health risks were also evaluated. The fish samples (n = 25 for each species) were collected from 10 different fish ponds in the Kohat district, Pakistan. Heavy metals were determined using an atomic absorption spectrometer. Results revealed higher concentrations of heavy metals in sediment, followed by water. However, the concentration of heavy metals in fish feed was lower than the standard limits. In the case of fish, the bottom feeder (C. carpio) notably exhibited higher (P < 0.05) levels of heavy metals than the column feeder (L. rohita) and surface feeder (C. catla) fish. Moreover, in the liver of all fish species, the bioaccumulation of heavy metals was higher, followed by the gills. Principal component analysis (PCA) demonstrated a strong correlation of heavy metals in C. carpio gills, flesh, feed, and pond water, while the heavy metals in the liver correlated with the detected metals in sediment. The human health risk analysis shows that bottom feeder fish had higher estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) values (> 1). Consequently, the exposed population may experience adverse health effects. The findings of this study suggest that the bottom feeder (C. carpio) bioaccumulates a higher concentration of heavy metals than column (L. rohita) and surface feeder (C. catla) in the polyculture system.

Micro-synteny conservation analysis revealed the evolutionary history of bacterial biphenyl degradation pathway.

Phenolic compounds have been enlisted by the United States Environmental Protection Agency (USEPA) and the European Union (EU) as pollutants of priority concern. The biphenyl degradation pathway plays an essential role in prokaryote polychlorinated biphenyls degradation. Our understanding of prokaryotic pathways and their evolution has dramatically increased in recent years with the advancements in prokaryotic genome sequencing and analysis tools. In this work, we applied bioinformatics tools to study the evolution of the biphenyl degradation pathway focusing on the phylogeny and initiation of four representative species (Burkholderia xenovorans LB400, Polaromonas naphthalenivorans CJ2, Pseudomonas putida F1 and Rhodococcus jostii RHA1). These species contained partial or full concatenated genes from bph gene cluster (i.e. bphRbphA1A2A3A4BCKHJID). The aim was to establish this pathway's origin and development mode in the prokaryotic world. Genomic screening revealed that many bacterial species possess genes for the biphenyl degradation pathway. However, the micro-synteny conservation analysis indicated that massive gene recruitment events might have occurred during the evolution of the biphenyl degradation pathway. Combining with the phylogenetic positions, this work points to the evolutionary process of acquiring the biphenyl degradation pathway by different fragments through horizontal gene transfer in these bacterial groups. This study reports the first-ever evidence of the birth of this pathway in the represented species.

Epidemiology and molecular characterization of Theileria annulata in cattle from central Khyber Pakhtunkhwa, Pakistan.

Theileria annulata is a tick-borne hemoprotozoan parasite responsible for tropical theileriosis in the bovine population, which causes substantial economic losses to the livestock sector. The present study has investigated, characterized, and shaped epidemiologic and phylogenetic profiles of T. annulata infection in the cattle population of central Khyber Pakhtunkhwa, Pakistan. A total of 600 blood samples were collected from cattle. Microscopy and PCR (18S rRNA taxonomic marker) assays were performed to detect T. annulata infection in cattle from the study area. The overall relative prevalence rates of T. annulata in the examined cattle population were 12.8% (microscopy) and 23.7% (PCR). District-wise analysis (microscopy/PCR) showed that cattle from district Mardan were found more infected (16.0%/28.0%), as compared to cattle from district Charsadda (13.5%/25.5%) and district Peshawar (9.0%/17.5%). Based on host demographic and ecological parameters analysis, theileriosis was found to be higher in young, female, crossbred, freely grazing, tick-infested, and irregular/no acaricides treated cattle. The univariate logistic analysis showed that host age, tick infestation, acaricides use, and feeding method were significant risk factors (P<0.05) whereas multivariate analysis indicated that host age, gender, tick infestation, acaricidal application, and feeding method were potential risk factors (P<0.05) for tropical theileriosis in the cattle population. Phylogenetic and sequence analysis showed that T. annulata 18S rRNA isolates shared homology and phylogeny with other isolates from Asia and Europe. This study has addressed the epidemiology and phylogeny of T. annulata circulating in bovid in the study area where gaps were still present. These findings will serve as a baseline and will facilitate future large-scale epidemiological investigations on tropical theileriosis in the cattle population at a national level.

Fuel production from waste polystyrene via pyrolysis: Kinetics and products distribution.

In the present study polystyrene waste (PS) was collected from a drop off site in a local market and pyrolyzed at heating rates of 5, 10, 15 and 20 °C/min and temperature range 40-600 °C under nitrogen condition. The apparent activation energy (Ea) and pre-exponential factor (A) were determined using 6 different kinetic methods. Activation energy and pre-exponential factor were found in the range of 82.3 - 202.8 kJmol-1 and 3.5 × 106-7.6 × 1014 min-1 respectively. The results demonstrated that the calculated values of Ea and A vary with fraction of conversion, heating rates and the applied model. Moreover, pyrolysis of waste polystyrene was carried out in an indigenously manufactured furnace at temperatures ranging from 340 to 420 °C. The composition of liquid and gaseous fractions was determined using gas chromatography-mass spectrometry. Temperature and reaction time were optimized and the results revealed that temperature of 410 °C and exposure time of 70 min are the best conditions for maximum fuel oil production. Methane and ethane were found as the main products in the gas phase constituting about 82% of the gaseous fraction. The liquid products composed of broad range of C2 - C15 hydrocarbons depending on the pyrolytic parameters. A comparison of the composition of pyrolysis oil with standard parameters of diesel, gasoline and kerosene oil suggested that pyrolysis oil from polystyrene waste holds great promise for replacing fuel oil.

Genome-wide identification, evolution and expression analysis of cyclic nucleotide-gated channels in tobacco (Nicotiana tabacum L.).

Tobacco (Nicotiana tabacum) serve as the top leading commercial, non-food, and model crop worldwide. Cyclic nucleotide-gated channels (CNGCs) are ligand-gated, calcium-permeable, divalent, cation-selective channels, involved in important biological functions. Here, we systematically characterized thirty-five CNGC genes in the genome of Nicotiana tabacum, and classified into four phylogenetic groups. Evolutionary analysis showed that NtabCNGC family of N. tabacum originated from the parental genome of N. sylvestris and N. tomentosiformis, and further expanded via tandem and segmental duplication events. Tissue-specific expression analysis showed that twenty-three NtabCNGC genes are involved in the development of various tobacco tissues. Subsequent RT-qPCR analyses indicated that these genes are sensitive towards external abiotic and biotic stresses. Notable performances were exhibited by group-I and IV CNGC genes against black shank, Cucumber mosaic virus, Potato virus Y, cold, drought, and cadmium stresses. Our analyses also suggested that NtabCNGCs can be regulated by phosphorylation and miRNAs, and multiple light, temperature, and pathogen-responsive cis-acting regulatory elements present in promotors. These results will be useful for elaborating the biological roles of NtabCNGCs in tobacco growth and development.

Comprehensive genomic analysis of the CNGC gene family in Brassica oleracea: novel insights into synteny, structures, and transcript profiles.

BACKGROUND: The cyclic nucleotide-gated ion channel (CNGC) family affects the uptake of cations, growth, pathogen defence, and thermotolerance in plants. However, the systematic identification, origin and function of this gene family has not been performed in Brassica oleracea, an important vegetable crop and genomic model organism. RESULTS: In present study, we identified 26 CNGC genes in B. oleracea genome, which are non-randomly localized on eight chromosomes, and classified into four major (I-IV) and two sub-groups (i.e., IV-a and IV-b). The BoCNGC family is asymmetrically fractioned into the following three sub-genomes: least fractionated (14 genes), most fractionated-I (10), and most fractionated-II (2). The syntenic map of BoCNGC genes exhibited strong relationships with the model Arabidopsis thaliana and B. rapa CNGC genes and provided markers for defining the regions of conserved synteny among the three genomes. Both whole-genome triplication along with segmental and tandem duplications contributed to the expansion of this gene family. We predicted the characteristics of BoCNGCs regarding exon-intron organisations, motif compositions and post-translational modifications, which diversified their structures and functions. Using orthologous Arabidopsis CNGCs as a reference, we found that most CNGCs were associated with various protein-protein interaction networks involving CNGCs and other signalling and stress related proteins. We revealed that five microRNAs (i.e., bol-miR5021, bol-miR838d, bol-miR414b, bol-miR4234, and bol-miR_new2) have target sites in nine BoCNGC genes. The BoCNGC genes were differentially expressed in seven B. oleracea tissues including leaf, stem, callus, silique, bud, root and flower. The transcript abundance levels quantified by qRT-PCR assays revealed that BoCNGC genes from phylogenetic Groups I and IV were particularly sensitive to cold stress and infections with bacterial pathogen Xanthomonas campestris pv. campestris, suggesting their importance in abiotic and biotic stress responses. CONCLUSION: Our comprehensive genome-wide analysis represents a rich data resource for studying new plant gene families. Our data may also be useful for breeding new B. oleracea cultivars with improved productivity, quality, and stress resistance.