Publications of TBRI Researchers
Heavy metal pollution represents a health threat. Many fungal species are capable of tolerating various heavy metals, especially if they are isolated from a contaminated watercourse. One of the mechanisms by which fungi can sequester certain heavy metals is synthesizing stress proteins. The aim of this study is to investigate the production of metallothioneins in Aspergillus oryzae and Aspergillus clavatus exposed to environmentally relevant concentrations of Cd, Cu, Fe, and Zn at neutral, alkaline, and acidic pH conditions within 10 days. We determined the concentrations of these heavy metals in certain watercourses representing Behira and Giza governorates; also, we identified the most prevalent fungal species. We carried out a statistical correlation between different heavy metals and the isolated fungi. Then, in the laboratory, we exposed two of the most prevalent fungal species to the environmentally detected concentrations of the heavy metals and their doubles. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated that in A. oryzae, the metallothionein bands appeared in neutral medium containing Cd and Cu and in alkaline medium containing Cd and Zn, while in A. clavatus, no metallothionein bands appeared at all. In conclusion, metallothionein is a good indicator of pollution with Cd, Cu, and Zn in Aspergillus oryzae, and pH plays a central role in metallothionein production. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Schistosomiasis still affects a lot of people in many developing countries. Reducing the disease dissemination has been the target of various studies. As methyl gallate has antioxidant properties, it is assumed that it can be a good candidate for stimulating the immune response of snails. So, the aim of this work is to investigate the potential of using methyl gallate as an immunostimulant to Biomphalaria alexandrina snails in order to prevent the development of invading miracidia into infective cercariae. The infected snails were exposed to three concentrations of methyl gallate for two periods: 24 and 72 h. The results indicated that the most effective concentration was the lowest one: 125 mg/L of methyl gallate for 72 h, as it reduced both infection rate and mean number of shed cercariae. Also, it increased the total number of snails’ hemocytes in hemolymph, which were observed in head-foot region and digestive gland of treated snails surrounding degenerated sporocysts and cercariae. In addition, hydrogen peroxide showed its highest content in tissues of snails exposed to 125 mg/L of methyl gallate for 72 h. In conclusion, methyl gallate can be considered as one of the most promising immunostimulants of B. alexandrina snails against infection with Schistosoma mansoni. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.
Medicinal plants are still less expensive, safe to non-target organisms, and eco-friendly. The present work aims to evaluate the molluscicidal activity of the methanolic extract of Ziziphus spina-christi and Carica papaya seeds against Biomphalaria alexandrina snails. The half lethal concentrations (LC50) of Z. spina-christi and C. papaya were 108 and 138.5 mg/L, respectively after 24 h. LC10 of C. papaya created a pronounced induction in catalase (CAT) activity, while LC25 of Z. spina-christi and LC50 of C. papaya induced an inhibition in superoxide dismutase (SOD) level in treated snails. LC25 of Z. spina-christi caused the highest induction in total antioxidant capacity (TAC). Phagocytic indices values were the lowest in snails exposed to LC50 of both Z. spina-christi and C. papaya. Considerable changes in DNA patterns were observed in all treated groups by RAPD-PCR using six primers. The similarity indices of snails exposed to Z. spina-christi were higher than those exposed to C. papaya. Results showed no mortality in Daphnia magna individuals during the first 12 h of the experiment, while the extract of C. papaya seeds was more toxic on D. magna than Z. spina-christi after 24 h of the exposure. © 2020 John Wiley & Sons Ltd
The paper reports an assessment of the quality of some water courses located in three Egyptian governorates by investiga tion of organochlorine and organophosphorus pesticides residues, and the distribution of macroinvertebrates. Water and sediment samples were collected from the investigated sites in Giza, Qalubeya and Gharbeya governorates. The results showed that the total beta- hexachlorocyclohexane (β-HCH) was the highest in concentration amongst other organochlor ine pesticides in both Giza and Gharbeya governorates, and the total Dichlorodiphenyltrichloroethane (DDT) concentration was the highest in Qalubeya Governorate. In the organopho sphorus pesticides group, fenitrothion and fenamiphos showed the highest concentrations in all collected samples. In addition, gastropods were the dominant macroinvertebrates, and all sensitive organisms disappeared from all studied sites during all seasons indicating a poor water quality. The investigated watercourses are highly polluted with pesticides residues which have harmful consequences for both aquatic biodiver sity and human health.
The present work aims to assess the reprotoxicity in Biomphalaria alexandrina snails and developmental and hatchability alterations of their eggs after exposure to three phenolic compounds, viz., salicylic acid, benzoic acid and pyrogallol. The half lethal concentrations (LC50) of the three tested compounds were 574, 674 and 350 mg L−1, respectively after 24 h. The tested concentrations of all compounds showed a harmful effect on development and hatchability of eggs regardless of the age of embryos. Exposure of snails to sub-lethal concentrations of salicylic acid resulted in a significant reduction in their survival rate, and ½ LC50 of both benzoic acid and pyrogallol led to a sudden death of snails after the 1st week of the experiment. Therefore, the egg laying capacity showed a noticeable impairment throughout the whole experimental period. Moreover, the hermaphrodite glands of treated snails have mirrored the deleterious effects that occurred in the total reproductive rate. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.
One of the most common compounds in pesticide formulations, plastics, and papers is 4-nonylphenol (4-NP). It is contained in agricultural, industrial, and wastewater effluents, which when discharged into surface waters affect aquatic fauna. Therefore, the present study aimed to use Biomphalaria alexandrina snails to evaluate the chronic toxicity of 4-NP. Its concentrations in collected water samples from Giza Governorate ranged from 400 to 1600 μg/l. Based on these environmentally relevant concentrations, laboratory experiments were carried out using standard 4-NP to investigate the effect of three concentrations; namely 400, 750, and 1600 μg/l. Survival rate of the exposed snails to 4-NP concentrations was affected after 4 weeks. Reproduction of the exposed snails to 4-NP concentrations was lower than that of the control at 30 °C, while the exposed snails to 400 μg/l of 4-NP showed maximum reproduction at 15 °C. The lowest hatchability percentage was recorded with egg masses laid by the exposed snails to 400 and 1600 μg/l of 4-NP at 15 and 30 °C, respectively. Furthermore, the results showed fluctuated levels of progesterone, estradiol, and testosterone depending upon the concentration and the temperature, which played a key role in determining the degree of 4-NP toxicity.
Several formulated mixtures of pesticides are widely used in modern agriculture. Nevertheless, the agriculture runoff causes a serious damage to the aquatic ecosystem. Therefore, the present study aims to use B. alexandrina snails as bioindicators for 30 g/l lambda-cyhalothrin and 17 g/l acetamiprid as a formulated mixture insecticide. Results showed that it has a molluscicidal activity against snails at LC50 7.9 mg/l. The hatchability percent of both treated 1-day-aged and/or 3-day-aged groups were less than that of the control group. The sublethal concentrations of the tested insecticide caused a remarkable abnormal necrosis in male and female gametogenic cells, besides a severe damage in both secretory and digestive cells. The results of SDS-PAGE protein profiles of treated snails showed that the least number of protein bands was noticed in snail groups that subjected to LC10 (6.6 mg/l) and LC25 (7.2 mg/l) concentrations when compared to control protein fractions. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
Biological assessment is considered a useful tool for assessing the ecological status of the aquatic ecosystems. Therefore, the goal of the present study was to use phytoplankton and macroinvertebrates as biological tools for ecological assessment of the River Nile around Gizert El-Warrak. A total of 33 phytoplankton species were recorded at the studied stations; these include 16 species of Chlorophyta, 5 Cyanophyta and 12 Bacillariophyta species. All investigated stations were characterized by high organic pollution according to Palmer′s index. Trophic state index showed a hyper-eutrophic status in stations S1, S2, S4, S6 and S8 and an eutrophic status in stations S3, S5 and S7.Gastropoda and Oligochaeta were the most dominant of macroinvertebrates taxa recorded 50.8 and 24.6% of all biota, respectively. Diversity Index (H′) ranged between (1.14-2), which indicated that the structure of macroinvertebrate habitats was poor. Moreover, Evenness Index (J) ranged between (0.016 – 0.043), which indicated that individuals were not distributed equally. The values of biotic index (HBI) depending on macroinvertebrates categories showed that the River Nile’s water quality is fairly poor with significant organic pollution. © 2018, Egyptian Society for the Development of Fisheries and Human Health. All rights reserved.
Contamination of aquatic ecosystems by heavy metals is considered one of the most major threats of the aquatic life. So, the present work aims to investigate the accumulation and tolerance of Ceratophyllum demersum plant to different concentrations of Pb+2, Al+3 and Cd+2 during four treatment periods for 16 days. Results indicated that the highest tolerance percentage of C. demersum was (96.26 %) of Pb at 10 mg L-1 after 4 days; whereas the highest tolerance percentage values were (95.89 % and 80.84 %) at 3 mgL-1 of Al and at 0.1 mg L-1 of Cd after 8 days, respectively. C. demersum accumulated the highest amount of Pb (17029.19 μg g-1) at 50 mg L-1 after 12 days, followed by Al amount which was (2893.04 μg g-1) at 9 mg L-1 after 8 days and the highest accumulation value of Cd was (521.28 μg g-1) at 0.5 mg L-1 after 4 days. Metal accumulation in C. demersum showed at a descending order as follow; Pb >Al >Cd and it was significantly increased with increasing the concentration and treatment period. In addition, results showed that the maximum BCF value of Cd in C. demersum at low concentration was (1295.37) after 12 days of the treatment. Therefore, C. demersum is considered a hyperaccumulator species for cadmium. © 2018, Egyptian Society for the Development of Fisheries and Human Health. All rights reserved.
Effects of sub-acute exposure of pesticide aronil (propanil) on haematology and serum biochemistry of Oreochromis niloticus juvenile was investigated in the present study. Sub-acute doses (0.21 mg/l, 0.43 mg/l and 0.83 mg/l) were derived from 1/20, 1/10 and 1/5 of the 96h LC50 (4.17 mg/l) of aronil, in which fish specimens were exposed for eight weeks. Control group was exposed to dechlorinated tap water. Haematology and serum biochemistry of fish were examined at week 2, 6 and 8 of aronil exposure. Significant and dose dependent decreases in red blood cell, haemoglobin and haematocrit were observed in aronil exposed fish compared to the control. White blood cell, mean cell haemoglobin and mean cell haemoglobin concentration of the control were significantly lower compared to the exposed fish groups. Neutrophil and lymphocyte percentages were elevated significantly in 0.83 mg/l exposed fish when compared to other exposed fish and the control at the eight week. Basophils, eosinophils and monocytes were not observed in aronil exposed fish. Significant and dose dependent increases in glucose, protein, aspartate aminotransferase, alanine aminotransferase and triglyceride were observed in aronil treated fish with reference to the control while insignificant changes in cholesterol level was observed in the exposed fish compared to the control. Aronil pesticide induced stress and had toxic effect on O. niloticus. Use of the pesticide aronil should be regulated especially in farm lands along the coast and riversides to avoid the influx of pesticides into the aquatic ecosystems. © 2018, Egyptian Society for the Development of Fisheries and Human Health. All rights reserved.