Breakthrough of Oscillatoria limnetica and microcystin toxins into drinking water treatment plants – examples from the Nile River, Egypt

The presence of cyanobacteria and their toxins (cyanotoxins) in processed drinking water may pose a health risk to humans and animals. The efficiency of conventional drinking water treatment processes (coagulation, flocculation, rapid sand filtration and disinfection) in removing cyanobacteria and cyanotoxins varies across different countries and depends on the composition of cyanobacteria and cyanotoxins prevailing in the water source. Most treatment studies have primarily been on the removal efficiency for unicellular Microcystis spp., with little information about the removal efficiency for filamentous cyanobacteria. This study investigates the efficiency of conventional drinking water treatment processes for the removal of the filamentous cyanobacterium, Oscillatoria limnetica, dominating the source water (Nile River) phytoplankton in seven Egyptian drinking water treatment plants (DWTPs). The study was conducted in May 2013. The filamentous O. limnetica was present at high cell densities (660–1 877 cells/mL) and produced microcystin (MC) cyanotoxin concentrations of up to 877 μg∙g-1, as determined by enzyme-linked immunosorbent assay (ELISA). Results also showed that conventional treatment methods removed most phytoplankton cells, but were ineffective for complete removal of O. limnetica. Furthermore, coagulation led to cell lysis and subsequent microcystin release. Microcystins were not effectively removed and remained at high concentrations (0.37–3.8 μg∙L -1) in final treated water, exceeding the WHO limit of 1 μg∙L-1. This study recommends regular monitoring and proper treatment optimization for removing cyanobacteria and their cyanotoxins in DWTPs using conventional methods.Keywords: cyanobacteria, removal, conventional drinking water treatmen

Selective inhibition of toxic cyanobacteria by β-carboline-containing bacterium Bacillus flexus isolated from Saudi freshwaters

AbstractA bacterial strain SSZ01 isolated from a eutrophic lake in Saudi Arabia dominated by cyanobacterial blooms, showed an antialgal activity against cyanobacteria species. Based on the analysis of the 16S rDNA gene sequence, the isolated strain (SSZ01) most likely belonged to the genus Bacillus with a 99% similarity to Bacillus flexus strain EMGA5. The thin layer chromatography (TLC) analysis of the ethyl acetate extract of this bacterium revealed that this strain can produce harmine and norharmane compared to different β-carboline analog standards. Harmine and norharmane were also detected in considerable amounts in bacterial growth medium, indicating a potential excretion of these compounds into the aquatic environment. The crude extract of Bacillus flexus as well as pure materials of harmine and norharmane inhibited the growth of tested species of cyanobacteria. However, the bacterial crude extract has a higher toxicity against tested species of cyanobacteria than harmine and norharmane. In addition, harmine was more toxic to cyanobacteria than norharmane. On the other hand, neither pure compounds of harmine and norharmane nor crude bacterial extract showed any antialgal activity against tested species of green algae. The results of the present study suggest that B. flexus SSZ01 or its crude extract containing harmine and norharmane could be a candidate for the selective control of cyanobacterial blooms without affecting other algal species

Occurrence and germination of dinoflagellate cysts in surface sediments from the Red Sea off the coasts of Saudi Arabia

AbstractThe distribution and abundance of dinoflagellate cyst assemblages were investigated in surface sediments from south-western Red sea coasts of Saudi Arabia at six sites during March 2010. A total of 19 taxa of dinoflagellate cysts were identified from all sites. The sampling sites showed a similar cyst assemblage, but they differed in total cyst abundance (3 to 4083 cysts g−1 dry weight). Cyst abundance was strongly correlated with sediment characteristics, the highest numbers being recorded in sediments with large contents of organic carbon, silt and clay. Cyst assemblages were dominated by cysts of potentially toxic species, including Cochlodinium polykrikos, Prorocentrum minimum, Dinophysis acuminata, Alexandrium catenella and Scrippsiella trochoidea. Most cysts germinated successfully at different rates at 15 and 25° C. This study suggests that surface sediments from all Saudi Red Sea coasts should be monitored for the presence of dinoflagellate cysts to give ample warning of the presence and abundance of toxic species in a given area

Optimization of growth and extracellular glucoamylase production by Candida famata isolate

Candida famata was isolated from traditional Moroccan sourdough. It exhibited high glucoamylase and biomass production. Starch induces high glucoamylase production C. famata with maximum glucoamylase activity at 5 g/L. Glucose stimulates good production in biomass but strongly inhibitsglucoamylase production. Among the sources of nitrogen tested, yeast extract and the (NH4)2HPO4 gave maximum glucoamylase and biomass after 72 h of incubation in liquid medium at 30°C, pH 5 and 105 rpm

The role of interleukins 4, 17 and interferon gamma as biomarkers in patients with Systemic Lupus Erythematosus and their correlation with disease activity

AbstractAim of the workThis work was designed to study the production of proinflammatory cytokines in SLE patients and their correlation with disease activity and study if they can be used as biomarkers for renal activity in lupus nephritis patients.Patients and methodsThis study was carried out on 70 subjects divided into two groups: Group I (SLE group) which included 40 SLE patients and Group II (Control group) which included 30 apparently healthy controls. The patients were subjected to full history taking and complete clinical examination. Assessment of disease activity in SLE patients by Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Sera of patients and controls were screened for the level of cytokine expression of T helper cells including interleukin 17 (IL-17), interleukin 4 (IL-4) and interferon gamma (IFN-γ).ResultsSerum levels of IL-4 were significantly lower while both IL-17 and IFN-γ were significantly higher in SLE patients than in the control group. The most powerful predictor and correlated cytokine with the SLEDAI in SLE patients was IL-17. Higher serum level of IFN-γ was associated with more pyuria and hematuria, while higher IL-17 was associated with more pyuria and proteinuria in SLE patients.ConclusionThe serum level of IL-17 and IFN-γ was proven to be significantly higher in SLE patients and can be used as biomarkers of renal activity

Design and Development of a Fuel Cell Car Prototype

A hydrogen vehicle is a vehicle that uses hydrogen as its on-board fuel for motive power. One of the ways to achieve it is by converting the chemical energy from the reaction between hydrogen and fuel cell to electrical energy. The purpose of this work is to design and develop a fuel cell car model by implementing polymer electrolyte membrane (PEM) types of fuel cell as the source of power to propel the prototype car. This fuel cell has capability to propel the electric motor by performing chemical reaction and converting chemical energy stored in hydrogen gas into useful electrical energy. In the developed fuel cell car prototype, PEM fuel cell alone is used as the power source for the electric motor without the aid of any other power source such as battery associated with it. Experimental investigations were carried out to investigate the characteristics of fuel cell used and the performance of the fuel cell car prototype. The power it develops, voltage, current and speed it produces under different load conditions are among the parameters that were investigated

Design and investigation of a fuel cell car prototype

A hydrogen vehicle is a vehicle that uses hydrogen as its on-board fuel for motive power. One of the ways to achieve it is by converting the chemical energy from the reaction between hydrogen and fuel cell to electrical energy. The purpose of this work is to design and develop a fuel cell car model by implementing polymer electrolyte membrane (PEM) types of fuel cell as the source of power to propel the prototype car. This fuel cell has capability to propel the electric motor by performing chemical reaction and converting chemical energy stored in hydrogen gas into useful electrical energy. In the developed fuel cell car prototype, PEM fuel cell alone is used as the power source for the electric motor without the aid of any other power source such as battery associated with it. Experimental investigations were carried out to investigate the characteristics of fuel cell used and the performance of the fuel cell car prototype. The power it develops, voltage, current and speed it produces under different load conditions are among the parameters that were investigated

The Development Of High Temperature Recirculating Pump (HTRP) For Energy Savings In An Incinerator.

Tremendous increase ingeneration of Municipal Solid Waste (MSW) has become a major concern for the Malaysian government as the country experiencing rapid development. It was estimated about 16000 tones/day MSW is produced at national level and in Kuala Lumpur alone about 2500 tones/day

The existence of Red Junglefowls (Gallus Gallus) in oil palm plantations in selected states in Malaysia and their morphological characteristics

An investigation was carried out to establish the existence of Red Junglefowl (Gallus gallus) populations in oil palm plantations and to study their morphological characteristics. This study which commenced from February to August in 2009 and 2010, took place in several oil palm plantations in the state of Johor, Selangor and Pahang, Malaysia. Twenty seven Red Junglefowls which comprised of seven adult males, six adult females, four juvenile males, three juvenile females, four male chicks and three female chicks were successfully captured throughout this study using the scoop netting method. The morphological study highly suggested the purity of the birds based on the characteristics exhibited. The birds were characterised by boat-shape body appearance, white or red ear lobe and slender greyish blue leg. Thus, this study offered some evidence that oil palm plantations are found to be suitable in sustaining and providing ample survivability for the species to exist in the future