Using kale (Brassica oleracea var. acephala) as a phytoremediation plant species for lead (Pb) and cadmium (Cd) removal in saline soils

Ornamental kale (Brassica oleracea var. Acephala) is usually planted from early autumn until late winter. Since most of the plants used for phytoremediation cannot be grown during this time, kale can be a suitable option for phytoremediation and utilized during autumn and winter in urban landscape, especially in metropolitan areas where high levels of cadmium (Cd) and lead (Pb) pollutions exist. Kale growth in saline soil at different growth stages (germination and vegetative growth stages) was studied in this investigation. A factorial experiment based on completely randomized design (CRD) with four replications was used in this study. Treatments included three levels of sodium chloride (NaCl) (0, 30, and 60 mg/kg), four levels of Cd (0, 4, 8, and 16 mg/kg), and four levels of Pb (0, 1, 5, and 10 mg/kg). Results indicated that increase in Cd and Pb concentrations in the soil decreased fresh and dry weights of the plants. The results of the various growth stages revealed that under salinity stress, kale plants were able to absorb more Pb than Cd and effectively remediate Pb in polluted and saline lands. Cd accumulation in control treatment was 6.2% more than that in the saline treatments, whereas, Pb accumulation in the highest NaCl level, 60 mg/kg salinity treatment was 7.64% more than that of the control condition. Also, proline content of the plants was significantly increased under Cd and Pb stress. From the results of this study, it was concluded that using kale plant is recommended for phytoremediation of saline soils with 10 and 16 mg/kg Pb and Cd contents, respectively.     

Natural Food Selectivity Changes with Weights of Nile Tilapia,Oreochromis niloticus (Linnaeus), Reared in Fertilized Earthen Ponds

This work was carried out to study the relationship between fish weight and natural food selectivity of Nile tilapia, Oreochromis niloticus (Linnaeus) reared in earthen ponds without supplementary diet and to guide the adaptation of feeding and fertilization strategies. Fish were stocked (1.5 fish/m²) in four fertilized earthen ponds (0.1 ha) for 6 months. Fifty fish were sampled monthly to estimate individual total weight and length and evaluate stomach contents. Fish specimens were categorized into different weight classes: <25 g, 25–50 g, 50–75 g, 75–100 g, and 100–125 g. Overall, the 50–75 g weight class had the highest degree of stomach fullness. The intestinal length-fish length ratio was similar across all fish weights, ranging from 2.9–3.4. Likewise, the composition of food items found in fish stomach was ranked as phytoplankton > detritus > zooplankton. Phytoplankton contribution to gut content increased with increasing fish weight, while detritus and zooplankton contribution decreased. Zooplankton never exceeded 1% of total stomach contents. Cyanobacteria, Chlorophyceae, Bacillariophyceae and Euglenophyceae mostly represented the phytoplankton. Bacillariophyceae dominated the phytoplanktonic portion of stomach contents at small fish size (<75 g/fish), while Chlorophyceae is the dominant group at large fish size (> 75 g/fish). Fish could select Cyanobacteria and Euglenophyceae at all fish weights, meanwhile Chlorophyceae and Bacillariophyceae were eaten with slight selectivity at larger weights..     

Evaluations of Hilyses™, fermented Saccharomyces cerevisiae,on rainbow trout (Oncorhynchus mykiss) growth performance,enzymatic activities and gastrointestinal structure

This study examined the effects of Hilyses?, fermented Saccharomyces cerevisiae (S. cerevisiae), on rainbow trout growth performance, haematological parameters, digestive enzyme activities and gastrointestinal structure. Rainbow trout (mean weight 100–110 g) were fed dietary Hilyses? (5 g kg^?1) and control diet without Hilyses? for 50 days. Results of this study demonstrated that yeast supplementation in treatment group resulted in increased feed intake, followed by improved feed conversion ratio (FCR) and growth performance. Significant increases were also observed in trypsin and amylase activities in juvenile fish fed treatment diet. Light microscopy demonstrated that both groups of fish displayed normal morphology of proximal intestine and pyloric caeca. In yeast‐treated group, higher density of the goblet cells per villus in the proximal intestine was shown. No effects on haematological parameters and carcass chemical composition were noted. It is therefore possible to use fermented S. cerevisiae supplementation to significantly improve the gastrointestinal structure and growth performance in rainbow trout.     

Chronic effect after acute exposure to commercial petroleum fuels on physiological status of Nile tilapia, Oreochromis niloticus (L.)

Quantitative and qualitative analyses of bacterial flora associated with pond water, gills, and intestine of polycultured healthy common carp (Cyprinus carpio) and African catfish (Clarias gariepinus) were carried out and identified to species level where possible. Total viable bacterial counts in the pond water ranged from 9.2?±?5.5?×?10³ to 6.6?±?5.1?×?10⁴ colony-forming units (cfu)/mL; in the gill filaments of carp and catfish, 3.3?±?3.8?×?10⁶ to 7.9?±?5.6?×?10⁶ and 1.1?±?4.6?×?10⁵ to 2.3?±?5.2?×?10⁶ cfu/g, respectively; and in the intestine of carp and catfish, 1.4?±?2.9?×?10¹⁰ to 1.7?±?6.0?×?10¹¹ and 2.7?±?3.4?×?10¹⁰ to 1.0?±?4.5?×?10¹¹ cfu/g, respectively. Gram-negative rod-shaped bacteria dominated the populations: 90% in carp, 89% in catfish, 80% in water, and 86% in the total populations. Altogether, 14 bacterial species of 10 genera were identified in total populations. Pond water bacteria had a reflection on the bacterial composition of the gills and intestine of carp and catfish. Aeromonas hydrophila, Shewanella putrefaciens, Vibrio cholerae, Staphylococcus sp., and Vibrio vulnificus appeared as the common bacteria in the populations, where the first three were highly significantly abundant (P?<?0.0001). Moreover, A. hydrophila was the most significantly dominant bacteria (32%; P?<?0.005) among the total populations. Pantoea sp. and Pasteurella pneumotropica were present only in carp and catfish, respectively, but Corynebacterium urealyticum and Micrococcus sp. were present only in pond water.     

Effect of pH on Potentially Toxic Trace Elements (Cd,Cu, Ni,and Zn) Solubility in Two Native and Spiked Calcareous Soils: Experimental and Modeling

The effect of soil pH on solubility of the potentially toxic trace elements (PTEs) [cadmium (Cd), copper (Cu), nickel (Ni), zinc (Zn)] was assessed using two native and spiked calcareous soils. Multiple PTEs solutions were added to soils and equilibrated (aged) for 40 days. Then, PTEs solubility was measured at different pH level (1–3 units below and above the pH of native soils). In native soils, all PTEs displayed a V-shaped pH-dependent solubility pattern with important releases at pH 4 and 10 (native soil 1) and 5 and 11 (native soil 2). In spiked soils, the general tendency for the pH where solubility started was in the order Cd > Ni > Zn > Cu. Solubility of added trace elements increased with a decrease in pH. Solubility of PTEs occurred at a lower pH in the soil with a higher carbonate content than the other soil (both native and spiked). In order to predict the effect of soil pH on solubility of PTEs, surface complexation and ions exchange models of PHREEQC program were used. The model simulated the PTEs solubility in soils very well. Comparison of experimental and simulated data indicated that ions exchange and surface complexation were the main mechanisms for predicting PTEs solubility in soils. Environmental implications concerning PTEs mobility might be derived from these findings.     

Evaluation of bermuda and paspalum grass types for urban landscapes under saline water irrigation

In the arid regions, turfgrass cover is an integral part of landscape to protect the soil from erosion, enhance the aesthetic value, and improve the microclimate. The salinity and the scarcity of fresh water of the arid region are the major challenging factors in turfgrass production. Therefore, the need for salt tolerant turfgrass with functional quality is necessary to improve the turf performance. The detrimental effects of salinity include growth suppression, and lowered osmotic potential ultimately leading to firing of the leaf blades. In this context, the study was undertaken to determine the relative salt tolerance and growth response of turfgrass genotypes in order to recommend turfgrass cultivars that can tolerate high salinity irrigation and maintain excellent visual and functional qualities under United Arab Emirates (UAE) condition. The paspalum cultivars maintained the highest succulence percentage compared to the bermudagrass cultivars under enhanced salinity levels. The shoots count, fresh weight (FW), and dry weight (DW) were found highest in paspalum types. The chlorophyll a, chlorophyll b and the total chlorophyll content was found higher in bermuda grass types under high salinity levels. The bermudagrass cultivars showed significantly higher carotenoids, anthocyanins and proline compared to the paspalum types under salt stress condition. In the case of princess 77 and Yukon, an inherently high amount of proline was recorded which confirmed an increase up to 10,000 ppm and drastically declined beyond this concentration. Sea Dwarf paspalum and Sea Isle 2000 maintained uniformity in the proline level at all levels of salinity without significant variation. These findings point to the fact that both paspalum and bermuda types exhibited varied responses to different physiological and biochemical parameters under the saline conditions. Paspalum types have an edge over the bermudagrass in terms of shoot density, which is a potential factor in determining the high-quality turfs. Bermudagrass types can be applied in lower salinity conditions based on the responses as evidenced from the present results.     

Effect of Soil Sample Size on Saturated Soil Hydraulic Conductivity

Saturated hydraulic conductivity (K_sat) is regarded as a key soil physical variable to determine soil infiltration rate, percolation depth and other hydrological processes. The purpose of this study was to determine the best soil sampling’s ring size for measuring K_sat. For this purpose, 25 rings with five different diameters (2, 3, 4, 5 and 6 inch) and with the same depth of 20 cm (five replicates) were hammered in close vicinity to each other into the ground of undisturbed loess deposits of a small farm to measure K_sat and bulk density. Hydraulic conductivity was measured at three constant loads of 22, 27 and 32 cm. The results showed that the ring with the internal diameter of 6 inches had the minimum variation coefficient and maximum K_sat for all the three hydraulic heads. In addition, the bulk density of this ring size was less than the other rings.     

Sequence and phylogenetic analysis of the non-structural 3A and 3B protein-coding regions of foot-and-mouth disease virus subtype A Iran 05

The A Iran 05 foot-and-mouth disease virus (FMDV) subtype was detected in Iran during 2005 and has proven to be highly virulent. This study was undertaken to focus on molecular and phylogenetic analysis of 3A and 3B coding-regions in the A Iran 05 field isolate. To assess the genetic relatedness of A Iran 05 isolate the nucleotide and predicted amino acid sequences of the 3AB region of type A FMDV isolates were compared with twenty previously described type A FMDV isolates. The phylogenetic tree based on the 672 bp 3AB gene sequences of type A FMDV from thirteen different locations clustered them into five distinct lineages. The A Iran 05 isolate clustered in lineage A along with four type A variants and was closely matched with viruses isolated in Turkey and Pakistan during 2005~2006. The number of protein sequence differences exhibited by each of the isolates revealed that A Iran 05 isolate contains three amino acid substitutions at positions 47 and 119 of 3A and 27 of the 3B coding region. The nucleotide identity between A Iran 05 and the other four isolates of lineage A was estimated to be 98%.