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Plant biostimulants (PBs) are used globally to increase crop yield and productivity. PBs such as (Serendipita indica) or algal extracts stimulate and accelerate plant physiological processes. The physiological, ecological, and biochemical effects of (Serendipita indica) or algal extracts individually and in combination on basil plant (Ocimum basilicum L.) were investigated. Macroalgae samples were collected from Abu Qir, Alexandria, Egypt. The growth parameters, chlorophyll index, and biochemical composition of basil were analyzed at 90th day. The (Chlorella vulgaris) + (Serendipita indica) (MI + F) treatment increased chlorophyll index by 61.7% (SPAD) compared to control. (Chlorella vulgaris) had the highest growth hormones, including GA3 at 158.2 ppb, GA4 at 149.1 ppb, GA7 at 142.6 ppb, IAA at 136.6 ppb, and TC at 130.9 ppb, while (Ulva lactuca) had the lowest. The MI + F treatment yielded the highest essential oil and antioxidant values. Treatment with (Chlorella vulgaris) increased S. indica colonization by 66%. In contrast, Ulva lactuca and (Padina Pavonica) inhibited S. indica colonization by 80% and 40%, respectively. (Ulva lactuca) and (Padina Pavonica) inhibited S. indica colonization by 80% and 40%, respectively. Combined treatments had a greater influence on basil performance than the individual treatments. The evidence of synergistic/additive benefits to plants performance due to the interactive effects of (Chlorella vulgaris) and (Serendipita indica) had been studied. Complementary modes of action between (Chlorella vulgaris) and (Serendipita indica), through their components newly emerging properties on basil, may explain observed synergistic effects. This study explores the potential of microbial-algal interactions, particularly (Chlorella vulgaris) and (Serendipita indica), as innovative plant biostimulants. These interactions demonstrate positive effects on basil growth, offering promise for more effective microbial-based formulations to enhance crop productivity and sustainability in agriculture. These novelties will help create a second generation of PBs with integrated and complementary actions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Microalgae-based biodiesel synthesis is currently not commercially viable due to the high costs of culture realizations and low lipid yields. The main objective of the current study was to determine the possibility of growing Nannochloropsis oceanica on Saccharomyces cerevisiae yeast wastewater for biodiesel generation at an economical rate. N. oceanica was grown in Guillard F/2 synthetic medium and three dilutions of yeast wastewater (1, 1.25, and 1.5%). Biodiesel properties, in addition to carbohydrate, protein, lipid, dry weight, biomass, lipid productivity, amino acids, and fatty acid methyl ester (FAMEs) content, were analyzed and the quality of the produced biodiesel is assessed. The data revealed the response of N. oceanica to nitrogen-deficiency in the three dilutions of yeast wastewater. N. oceanica in Y2 (1.25%) yeast wastewater dilution exhibited the highest total carbohydrate and lipid percentages (21.19% and 41.97%, respectively), and the highest lipid productivity (52.46 mg L -1 day -1 ) under nitrogen deficiency in yeast wastewater. The fatty acids profile shows that N. oceanica cultivated in Y2 (1.25%) wastewater dilution provides a significant level of TSFA (47.42%) and can be used as a feedstock for biodiesel synthesis. In addition, N. oceanica responded to nitrogen shortage in wastewater dilutions by upregulating the gene encoding delta-9 fatty acid desaturase (Δ9FAD). As a result, the oleic and palmitoleic acid levels increased in the fatty acid profile of Y2 yeast wastewater dilution, highlighting the increased activity of Δ9FAD enzyme in transforming stearic acid and palmitic acid into oleic acid and palmitoleic acid. This study proved that the Y2 (1.25%) yeast wastewater dilution can be utilized as a growth medium for improving the quantity of specific fatty acids and lipid productivity in N. oceanica that affect biodiesel quality to satisfy global biodiesel requirements.

Talus is a pivotal bone that assists in easy and correct locomotion and transfers body weight from the shin to the foot. Despite its small size, it is implicated in many clinical disorders. Familiarity with the anatomy of the talus and its anatomical variations is essential for the diagnosis of any disorder related to these variations. Furthermore, orthopedic surgeons must be fully aware by this anatomy during podiatry procedures. In this review, we attempt to present its anatomy in a simple, updated and comprehensive manner. We have also added the anatomical variations and some clinical points relevant to the unique and complex anatomy of talus. The talus has no muscle attachment. However, it does have many ligaments attached to it and others around it to keep it in place. Moreover, the bone plays a pig role in movements due to its involvement in many joints. Most of its surface is covered with articular cartilage. Therefore, its blood supply is relatively poor. This puts the talus at greater risk for poor healing as well as more complications in the event of injury than any other bone. We hope this review will make it easier for clinicians to pursue and understand the updated essential knowledge of one of the most complex bone anatomies that they need in their clinical practice., (© 2023. The Author(s), under exclusive licence to Japanese Association of Anatomists.)

Low-density polyethylene (LDPE) is broadly utilized worldwide, increasing more dramatically during the COVID-19 pandemic, and the majority ends up in the aquatic environment as microplastics. The influence of polyethylene microplastics (LDPE-MPs) on aquatic ecosystems still needs further investigation, especially on microalgae as typical organisms represented in all aquatic systems and at the base of the trophic chain. Thereby, the biological and toxicity impacts of LDPE-MPs on Chaetoceros calcitrans were examined in this work. The results revealed that LDPE-MPs had a concentration-dependent adverse effect on the growth and performance of C. calcitrans. LDPE-MPs contributed the maximum inhibition rates of 85%, 51.3%, 21.49% and 16.13% on algal growth chlorophyll content, φPSII and F v /F m , respectively. The total protein content, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities were significantly increased at 25 mg L -1 LDPE-MPs by 1.37, 3.52, 2.75 and 1.84 folds higher than those of the controls to sustain the adverse effects of LDPE-MPs. Extracellular polymeric substance (EPS) and monosaccharides contents of C. calcitrans were improved under low concentration of LDPE-MPs, which could facilitate the adsorption of MPs particles on the microalgae cell wall. This adsorption caused significant physical damage to the algal cell structure, as observed by SEM. These results suggest that the ecological footprint of MPs may require more attention, particularly due to the continuing breakdown of plastics in the ecosystem., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The research evaluates the spatio-temporal phytoplankton community structure and abundance along with the pollution sources and the lake bioenergy potential, primarily in order to better understand the interplay of the environmental factors affecting them in inland coastal waters. Burullus Lake, located in the north of the Nile Delta of Egypt, is selected as a case study area. Field investigations along with sampling of lake water from 55 sites in the period 20-25 September 2020 are performed. The physicochemical analysis is carried out for the lake water bathymetry, temperature (T°C), pH, salinities (total dissolved solids (TDS) and electric conductivity), and nutrient contents (nitrate, nitrite, ammonia, and phosphate). Phytoplankton identification and biological analysis are used to document the taxa and abundance along with their contents of chlorophyll-a, protein, carbohydrates, and lipids. Then, the trophic index (TRIX), along with the total phytoplankton biomass and the energy potentials, is estimated. Statistical analyses were appraised for the univariate summary statistics, correlation analysis, regression analysis, multivariate statistical analysis including principal component analysis (PCA), and clustering techniques (both geographic position and the k-means clustering) which were conducted using the PAST 4.03 package. The geostatistical modeling of the ordinary kriging implemented in the ArcGIS 9.3 package was appraised for mapping the studied parameters. Results clarified ranges with wide variations for the water depth of 0.90-2 m (av. 130.5 cm), T°C of 26.6-30.20°C (av. 28.3 °C), alkaline pH of 7.78-8.92 (av. 8.6), and TDS of 0.3-17.09 (av. 4.33) gm/l. Ranges of nutrients (mg/l) are also widely varied with nitrates of 0.44-8.36 (av. 3.5), nitrites of 0.004-7.45 (av. 0.4), ammonia range of 0.03-8.54 (av. 1.4), and phosphate of 0.1-4.9 (av. 0.9). A much-diversified phytoplankton community showed maximum counts of 1005 × 10 3 units.l -1 to a minimum of 340 × 10 3 units.l -1 for a total of 145 taxa from 61 genera and six classes typically of freshwater forms. The largest biomass (3.06 × 10 -3 kg/m 3 ) and energy potential (19.87 × 10 -3 kWh/kg) marked the downstream area of the Brimbal Canal, followed by the area located in front of the eastern Burullus and El-Gharbiya drains, which exhibited 2.76 × 10 -3 kg/m 3 and 17.96 × 10 -3 kWh/kg, for the biomass and the energy potential, respectively. Geographic position and k-means clustering techniques distinguished three homogenous classes of marked intra-class variations. PCA analysis distinguished three principal components summed for about 95% of the variations. Intense environmental pollution at the drain downstream areas is indicated by many fish mortality occurrences that were related to the blooms of the toxic Microcystis aeruginosa among the cyanophyte species, and also due to the dominance of the Euglena spp. and Phacus spp. of the Euglenophyceae, which assimilate lots of organic matters in these areas. Lake water movement in the form of turbulent flows and mixing regimes is affected by wind direction and the amount of flows from the sea drains. The estuarine Nile canal has a great effect on the water's physicochemical properties, particularly the nutrient loads, inducing the phytoplankton composition and abundance, total biomass, and the biological contents hence the energy potential. Nutrient load from discharged water from drains was a major contributor to raising the total algae counts and their corresponding contents of the carbohydrates, lipids, proteins, and the chlorophyll-a, which arranged in decreasing order of influence. Phytoplankton dynamics are mostly linked to climatic, hydrologic fluctuation of the drain water flows, and hence, the associated nutrient load discharged from land use changes to fish farms and the related agricultural practices south of the lake. The adopted integrated analyses proved promising, which confirmed the combined effects of environmental factors on lake pollution and the bioenergy potentials., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In marine ecosystems, fluctuations in surface-seawater carbon dioxide (CO 2 ), significantly influence the whole metabolism of marine algae, especially during the early stages of macroalgal development. In this study, the response of the green alga Ulva fasciata for elevating ocean acidification was investigated using four levels of p CO 2  ~ 280, 550, 750 and 1050 µatm. Maximum growth rate (6.6% day -1 ), protein (32.43 %DW) and pigment (2.9 mg/g) accumulation were observed at p CO 2 -550 with an increase of ~2-fold compared to control. On the other hand, lipid and carbohydrate contents recorded their maximum production (4.23 and 46.96 %DW, respectively) at p CO 2 -750 while control showed 3.70 and 42.37 %DW, respectively. SDS-PAGE showed the presence of unique bands in response to p CO 2, especially at 550 µatm. Dominant associated bacteria was shifted from Halomonas hydrothermalis of control to Vibrio toranzoniae at p CO 2 -1050. These findings suggest that ocean acidification at 550 µatm might impose noticeable effects on growth, protein, pigments, and protein profile of U. fasciata, which could be a good source for fish farming. While, p CO 2 -750 was recommended for energetic purpose, due to its high lipid and carbohydrate contents., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors.)

Background: The most common causes of re-dislocation after open reduction are inadequate exposure and failure to release the obstructing soft tissues inside and around the hip., Methods: This clinical study included 33 consecutive children (34 hips) who underwent a revision surgery after failed open reduction of developmental dysplasia of the hip (DDH)., Results: According to the McKay clinical criteria, the results were good in 28 cases (82.4%), fair in 4 cases (11.8%), and poor in 2 cases with re-dislocation (5.9%). Radiological results according to the modified Severin criteria were as follows: 28 hips (82.4%) were identified as category 2 (good), 4 hips (11.8%) category 4 (fair), and 2 hips (5.9%) category 5 (poor)., Conclusions: Revision surgery for DDH is demanding and the long-term consequences are usually serious, but stable, concentric reduction should be obtained either at the first or second open reduction by addressing the causes of failure. Failed acetabulum remodeling and technical errors with inadequate soft-tissue release were the most common causes of failure in the primary operation. Based on the results, the outcome of revision surgery after failed open reduction for DDH was good., Competing Interests: CONFLICT OF INTEREST: No potential conflict of interest relevant to this article was reported., (Copyright © 2020 by The Korean Orthopaedic Association.)

Enhanced visual counting technique coupled with combustion analysis and differential scanning calorimetry (DSC) was applied to assess microplastics (MPs) contamination in fish digestive tracts from Eastern Harbor, Egypt, to provide a simple and economic method for MPs assessment. This was the first study in Egypt to quantify MPs in fish. Plastic particles were detected in all fish samples, represented by seven thermoplastic polymers. The average number of MPs was at its highest level in Siganus rivulatus, Diplodus sargus, and Sardinella aurita (7527, 3593, and 1450MPs fish -1 , resp.) and the lowest in Sphyraena viridensis and Atherina boyeri (46 and 28MPs fish -1 , respectively). The average weight of MPs as measured by combustion ranged from 302mg kg -1 in S. rivulatus to 2mg kg -1 in Terapon puta., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Generation of biodiesel from microalgae grown in wastewater can offer a cost-effective approach, whilst wastewaters usually do not contain the optimum concentrations of the essential nutrients and carbon sources that result in lowering the productivities of biomass and lipid. This study aimed to overcome this limitation by manipulating wastewater with various concentrations of nutrients (NO 3 - , PO 4 3- , Cl - and SO 4 2- ) and three carbon sources either individually or in combination to cultivate Micractinium reisseri for biodiesel production. Initially, various dilutions of wastewater were tested and a concentration up to 75% of wastewater showed the highest biomass productivity (0.076 g L -1 d -1 ) and lipid productivity (0.014 g L -1 d -1 ). The optimum manipulating conditions for maximum lipid production and the highest productivity required 50% decrease in phosphorous from the concentration of the control medium and supplementation with 1.0 g L -1 of glucose. Under this condition, biomass and lipid productivities increased by 1.7 and 4-folds, respectively, compared to those observed in the control. Furthermore, phosphorous starvation condition in the presence of glucose significantly improved fatty acid profile in the biomass and biodiesel quality related parameters., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Behçet's disease (BD) is an autoimmune condition that involves multiple systems. The most common arterial manifestation in BD patients is pseudoaneurysm, which has higher frequency than aneurysm formation., Objectives: To clarify the importance of profunda femoris artery in BD pseudoaneurysm, and present a new method for identifying healthy segments for anastomosis., Methods: Fifteen patients presented at a vascular department with pseudoaneurysms of the common femoral (CFA) and superficial femoral artery (SFA), were diagnosed with BD and underwent surgical intervention at Kasr al Ainy hospitals over 2 years., Results: All patients were male. The patients ranged in age from 30 to 40 years (mean, 33.8±2.6 years). Mean duration of the disease was 5±3.4 years. Eight (53.3%) CFA graft interpositions, six (40%) mid SFA graft interpositions, and one (6.66) distal SFA graft interposition were performed. Eight (53.3%) of these operations were performed using Dacron graft and sartorius flap, three (20%) were performed with a polytetrafluoroethylene graft, and four (26.66) with a great saphenous vein graft. Two cases (13.33%) were accidentally discovered while four cases (26.66%) had short distance claudication, four cases (26.66%) had pain at rest, and five cases (33.33%) presented with pulsatile swelling correlated with pseudoaneurysm size (p = 0.005). Patients were followed-up over 1 year for new aneurysms and recurrence., Conclusions: Surgical repair with muscle flap coverage, with or without ligation of profunda femoris artery, does not affect prognosis. An alternative method for identifying healthy segments of femoral artery may be frozen section and examination of the artery to decrease the risk of recurrence at the site of anastomosis., Competing Interests: Conflicts of interest: No conflicts of interest declared concerning the publication of this article.

This study was aimed to report data on the feasibility, safety, and effectiveness of endovascular procedures in a thromboangiitis obliterans diagnosed patients presenting with critical limb ischemia (CLI). Prospective study conducted on patients affected by Buerger's disease who presented to our center along 2 years. Clinical, radiological, and patient-based outcomes were recorded at 3, 6, and 12 months after the intervention. Total 39 patients were included in the study. Fifteen (38.5%) patients underwent percutaneous transluminal angioplasty, another 15 patients (38.5%) underwent follow-up on medical treatment, there are four other patients (10.3%) underwent surgical bypass, and five (12.8%) patients underwent lumbar sympathectomy. The 12 months' outcome showed 66.7% technical success in endovascular group with 46.7% patency rate ( p -value = 0.06), 86.7% limb salvage rate (LSR; p -value < 0.04), and 66.7% clinical improvement ( p -value = 0.005). The endovascular management of Buerger's disease is feasible, save, and effective with high rate of LSR and clinical improvement.

Background: Although the valgus subtrochanteric osteotomy is considered as a standard surgical treatment for coxa vara, there is no consensus on the optimal method of fixation and osteotomy technique. Fixation of the osteotomy has been achieved by various methods including external fixation and internal fixation with pins and cerclage and a variety of plates. The aim of this study is the evaluation of the results of developmental coxa treated by Y intertrochanteric valgus osteotomy fixed with a T-buttress plate compared with other methods of fixation in the literature., Methods: Eighteen corrective valgus intertrochanteric femoral osteotomies were performed in 18 patients (18 hips) for treatment of unilateral developmental coxa vara deformity and fixed with a T plate. There were 12 males and 6 females. The right hip was affected in 10 patients and the left hip in 8 patients. Clinically, patients were evaluated by Larson hip score. Radiographically, anteroposterior view of the pelvis and frog leg lateral views of the affected hip were taken preoperatively and compared with the findings at the final follow-up., Results: The average follow-up was 29 months (range, 24 to 36 months). Clinical results showed improvement of the mean Larson hip score from 57.8 to 97.0 (p < 0.001). Radiological results showed that all osteotomies were completely united in 2.4 months (range, 2 to 3 months) with the achievement of the planned correction angle. The average correction of Hilgenreiner's epiphyseal angle improved from 78.2° to 27.8° (p < 0.001) at the final follow-up. The femoral neck shaft angle was improved from 93.7° to 129.9° (p < 0.001) at the final follow-up. Shortening of the affected limb was corrected from 2.8 cm to 1.3 cm (p < 0.001) at the last follow-up. No major serious complications were recorded in the present study., Conclusions: Intertrochanteric valgus osteotomy of the proximal femur fixed with a T plate may be efficient for treatment of developmental coxa vara. With careful planning, it can result in a low complication rate and insignificant or minimal recurrence rate.

Lake Idku, northern Egypt, receives large quantities of drainage water from four main discharging drains. Ecological and biological status of Lake Idku has been monitored during (autumn 2012 to summer 2013) to examine the lake water quality and eutrophication level in response to the quality as well as the source of the discharging water. Discrete water samples were collected from the lake body and the drains. Chemical analyses revealed an excessive nutrient load goes into the lake. A range of 1.4-10.6 mg nitrites/L was determined for drain waters, however a sudden increase was observed in lake and drain water samples of up to 84 and 74.5 mg/L, respectively. Reactive silicate ranged between 2.9 and 4.8 mg/L; while inorganic phosphate fluctuated between 0.2 and 0.43 mg/L. Transparency varied from 45 cm to 134 cm with better light conditions at drain sites. Biological results indicated a hyper-eutrophic status for the lake with a range of chlorophyll-a varied from a minimum of 39.9 μg/L (at Idku Drains) and a maximum of 104.2 μg/L (at El-Khairy drain). Phytoplankton community structure revealed higher abundance at lake sites compared with the drains. Maximum phytoplankton density was detected during summer with the dominance of Bacilariophyceae (e.g. Cyclotella meneghiniana, Cyclotella comate, Melosira varians) followed by Chlorophycean taxon (e.g. Scenedesmus dimorphus, S. bijuga and Crucigenia tetrapedia). Five indices were applied to evaluate the water quality of the lake. Diversity Index (DI) indicated slight to light pollution along all sites; while Sapropic Index (SI) indicated slight pollution with acceptable oxygen conditions and an availability of sensitive species. Palmer Index (PI) gave a strong evidence of high organic pollution at some sites in the lake, while Generic Diatom Index (GDI) revealed that levels of pollution varied from average to strong. Trophic Index (TI), suggest that there are an obvious signs of eutrophication in the lake., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Antioxidant activity and mineral composition were evaluated seasonally from spring to autumn 2010 in the three common seaweeds Ulva lactuca Linnaeus (Chlorophyta), Jania rubens (Linnaeus) J.V. Lamouroux and Pterocladia capillacea (S.G. Gmelin) Bornet (Rhodophyta). The antioxidant activity was measured with β-carotene, total phenol content and DPPH (2,2-diphenyl-1-picrylhydrazyl). Seaweeds were collected from the rocky site near Boughaz El-Maadya Abu-Qir Bay of Alexandria, Egypt. The results showed maximum increase of β-carotene in P. capillacea during summer. A significant increase in total phenolic content at P ⩽ 0.05 was found in the red alga (J. rubens) during summer. Also, U. lactuca showed the maximum antioxidant scavenging activity especially during summer. Minerals in all investigated samples were higher than those in conventional edible vegetables. Na/K ratio ranged between 0.78 and 2.4 mg/100 g, which is a favorable value. All trace metals exceeded the recommended doses by Reference Nutrient Intake (RNI). During summer season, it was found that Cu = 2.02 ± 0.13 and Cr = 0.46 ± 0.14 mg/100 g in U. lactuca and Fe had a suitable concentration (18.37 ± 0.5 mg/100 g) in P. capillacea. The studied species were rich in carotenoids, phenolic compounds, DPPH free radicals and minerals, therefore, they can be used as potential source of health food in human diets and may be of use to food industry.

This is an investigation concerned with studying the possible adaptive response of four different unicellular algae, Anabaena PCC 7120, Oscillatoria angustissima, Scendesmus obliquus and Chlorella vulgaris, to the toxin of Microcystis aeruginosa (Kützing). The effects of four different concentrations, 25, 50, 100 and 200 μg mL-1 of microcystins crude extract of M. aeruginosa, on both intra and extra-cellular polysaccharide levels, in log phase, of the four tested algae were studied. The obtained results showed differential increase in the production levels for both intra and extra-cellular polysaccharides by the tested algae, compared with the control. S. obliquus and C. vulgaris showed a resistance to crude toxin higher than Anabaena PCC 7120 and O. angustissima. The highly production of polysaccharides by green algal species under this toxic stress indicated the involvement of these polysaccharides in protecting the algal cells against toxic species and, reflect the biological behavior of particular algal species to the environmental stresses.

Blue-green algae (cyanobacteria) constitute the greater part of the phytoplankton. Microcystis aeruginosa is amongst the most ubiquitously distributed cyanobacterial species, and almost invariably produces cyclic heptapeptide toxins called microcystins (MCs). The present study was designed to investigate the phenological and liver antioxidant profiles of the Nile tilapia Oreochromis niloticus chronically exposed to toxic live M. aeruginosa cells. Fish were grown in the absence and presence of M. aeruginosa in three different concentrations for seven days, and subsequently reared for another 30 days in the absence of the cyanobacteria. While cyanobacteria did not cause any fish mortality, there was a progressive development of yellowish discolouration in the livers of exposed fish. In the livers, the activities and levels of superoxide dismutase (SOD), lactate dehydrogenase (LDH), glutathione (GSH), and lipid peroxidation products like malondialdehyde (MDA) were elevated in response to the concentration of M. aeruginosa. Moreover, DNA fragmentation and DNA-protein crosslinks were measured. These parameters can thus be considered potential biomarkers for the fish exposure to M. aeruginosa. The present study sheds light on cyanobacterial blooms like health, environmental, and economic problem, respectively.

Phytoplankton assemblages and species succession along Lake Burullus (Southern Mediterranean) is expressed as carbon biomass (mg cm3) using a standard spreadsheet based on the species cell volume cell(-1) carbon relationship. High Chl a levels were measured (maximum 85-126 mg m(-3)) reflecting a dense phytoplankton population (up to 8.3 x 10(3) cell ml(-1) and 5.5 x 10(3) mg cm(-3)) throughout the lake body with maximum concentrations at the western sector of the lake (S1). Adiverse phytoplankton community was determined. Cell count data revealed the dominance of a mixed phytoplankton taxa, however biomass data indicates over-dominance of Bacillariophyceae (up to 98%). Good correlation (r = 0.73, p < 0.05) was found between Chl a and carbon biomass with various cell carbon/Chl a ratio according to variations in community structure. Bacillariophyceae were the most dominant, particularly at the middle (S2) and the western parts (S1) during periods of high nutrient (silicate) and good weather conditions (during spring/summer months). Chlorophyceae were abundant with Scenedesmus sp. mostly dominant, particularly at P-rich sites. Dinoflagellates peaked only during calm and high light summer months (May-July) being at a maximum level at S1. Euglenophyceae were less contributed to total phytoplankton abundance and peaked only; as a transition stage; at S1 during Jannuary and March (winter months). Cyanophyceae were numerous along with maximum peak at S2 affected by the southern drains. Excessive nutrient enrichment into the lake alters the existent structure of phytoplankton community. The water quality index indicated a poor water quality status of the lake.This may led to increase the possibility of toxic algal blooms to invade the lake ecosystem and, in turn, affect the lake fish yield.

Cyanobacterial blooms exert negative impacts on fisheries and water management authorities. Recently, it has gained global attention, as elevated earth warming and environmental pollution are accelerating algal growth. Oreochromis niloticus (O. niloticus) is a worldwide and the most commonly cultured fish in Egypt. The biological interaction of the living organisms to the surrounding environment must continuously be assessed to predict future effects of the ongoing hazards on fish. The study was designed to examine the possible biological and biochemical response of O. niloticus exposed to different concentrations of microcystins crude extract (containing microcystin-LR). Three equal groups of O. niloticus were assigned for intraperitoneal injection of three different doses: 100, 200, and 400 μg m(-1) dried aqueous microcystins extract, for 10 days. Clinical, condition factor (K) and hepatosomatic index (HIS) were estimated. Biochemical alterations were evaluated via lipid peroxidation, DNA fragmentation assay and electrophoretic analysis of fragmented DNA using agarose gel electrophoresis. The results showed that there were discernible behavioral and clinical alterations. Significant differences in K and HIS were observed between treatments. Also, significant elevations were observed in lipid peroxidation level and in the DNA fragmentation percentage in the exposed fish to the doses of 200 and 400 μg m(-1) of microcystins crude extract. The current study addresses the possible toxic effects of microcystins crude extract to O. niloticus. The results cleared that microcystins crude extract (containing MC-LR) is toxic to O. niloticus in time- and dose-dependent manners.