Tarun Kumar Banerjee

Phytoremediation of the coalmine effluent.

Coal mine effluent was subjected to detoxification by phytoremediation using two macrophytes Azolla pinnata and Lemna minor. Both plants were kept separately in the effluents for 7 day. The initial concentration (mg L⁻¹) of eight metals: Fe, Mn, Cu, Zn, Ni, Pb, Cr and Cd investigated in the effluent were 22.91±0.02, 9.61±1.6, 2.04±0.23, 1.03±0.15, 0.86±0.19, 0.69±0.11, 0.18±0.007 and 0.06±0.008 respectively. The initial fresh biomass of each plant was 100g. After one week, metals removed in A. pinnata-phytoremediated effluent were in the order: Mn (98%)>Fe (95.4%)>Zn (95%)>Cu (93%)>Pb (86.9%)>Cd (85%)>Cr (77.7%)>Ni (66.2%) and metal decrease in L. minor-phytoremediated effluent were: Mn (99.5%)>Cu (98.8%)>Zn (96.7%)>Ni (94.5%)>Fe (93.1%)>Cd (86.7%)>Pb (84%)>Cr (76%). Due to metal toxicity the total chlorophyll and protein contents of L. minor decreased by 29.3% and 38.55% respectively. The decrease of these macromolecules in A. pinnata was 27% and 15.56% respectively. Also, the reduction in biomass of L. minor was greater than that for A. pinnata. Based on the finding we could suggest that both the plants are suitable for bioremediation of mine effluent at the contaminated sites. However, attention for quick disposal of these metal loaded plants is urgently required.

Histopathological changes induced by acute toxicity of mercuric chloride on the epidermis of freshwater catfish--Heteropneustes fossilis (Bloch).

The toxic effects of 0.3 ppm (96-hr LC50 value) of mercuric chloride solution on the epidermis of Heteropneustes fossilis at different time intervals have been studied. The epidermis reacts instantaneously by secreting a profuse amount of slime, especially due to hyperactivity of the goblet mucous cells which subsequently degenerate and get lost. Later, all other cell types also get entangled in the degenerative process. The damaged cells, especially the club cells, get sloughed at the surface, forming a thick crust of debris from the degenerating cells. Side-by-side regeneration of the epidermis also continues from the lower layers of the intact tissue with the addition of all the cell types. However, even before attaining maturity, these budding cells, especially the club cells, show signs of degeneration, their degeneration occurring faster than their regeneration. Thus most of the space left behind by the degenerated club cells gets quickly filled with haphazardly arranged polygonal epithelial cells, giving the epidermis an altogether different morphology.

Histopathology of respiratory organs of certain air-breathing fishes of India

Air-breathing fishes have evolved bimodal respiratory mechanisms for exploitation of water (through gills and highly vascularized skin) as well as atmospheric air (through aerial respiratory organs, ABO). Mucous cells in these respiratory organs of variously stressed fishes exhibit periodic fluctuations in their density and staining properties. The main types of damage in the gills include congestion of blood capillaries (BLCs), periodic lifting and sloughing of respiratory epithelia of the secondary lamellae causing haemorrhage, extensive fusion of secondary lamellae and hyperplasia of the respiratory epithelia due to uncontrolled regeneration leading to asphyxiation, altered excretion, and death of the fish. Haemolysis has also been observed following lead exposure. The damage in the ABO of Heteropneustes fossilis includes sloughing of the epithelial cells, leading to haemorrhage causing decreased red blood corpuscles density and degeneration of the secondary gill lamellae with reduced respiratory area. Subsequent hyperplasia of the respiratory epithelia and fusion of gill lamellae increase the respiratory barrier distance. The BLCs often bulge out and protrude into the lumen, bringing blood nearer to air. The ladder-like pillar cell (PLC)-BLC components of the gill lamellae frequently collapse. Damage to the ABO of Channa striata is less severe. Often haemorrhaging due to bursting of extensively stretched BLCs causes aerial respiratory failure. Chloride cells of the ABOs also show hyperplasia. While the highly mucogenic epidermis of C. striata shows less damage, the epidermis of Clarias batrachus and H. fossilis shows severe wear and tear, sloughing, and haemorrhage. Side-by-side regeneration continues, causing altered histomorphology of the epidermis. The different gland cells also show periodic fluctuations in their density and staining. The dermis also shows severe damage with loosening of their connective tissue fibres. These fibres give stronger reactions for sulfated mucin that not only retain additional water molecules for continuance of skin breathing, but also bind the toxic ambient pollutants.

Bioassay analysis of efficacy of phytoremediation in decontamination of coal mine effluent

Phytoremediation efficacy of Lemna minor and Azolla pinnata in decontaminating metals from coal mine effluent (CME) was analyzed using bioassays. Catfish Heteropneustes fossilis were exposed to both the phytoremediated CMEs for the metal bioaccumulation analysis and biochemical alteration in seven vital tissues. Gross concentration of metals accumulated in liver, kidneys, air breathing organs (ABO), skin and muscle were greater in fish exposed to A. pinnata remediated CME (AP-CME) than those exposed to L. minor remediated CME (LP-CME). Total protein concentrations of all the tissues were greater in fish exposed to LP-CME than to AP-CME. Glycogen concentrations were greater in muscle, brain, ABO and skin of LP-CME exposed fish. In remaining tissues (liver, kidneys and gills) concentrations of glycogen were more in AP-CME exposed ones. Total lipid and total DNA concentrations were greater in most of the tissues of fish exposed to LP-CME than to AP-CME. The total RNA concentrations were elevated only in muscle, liver, kidneys and brain of LP-CME exposed fish; in rest of the tissues (gills, ABO and skin) it was greater in AP-CME exposed fish. The values of condition factor (K) and organosomatic index (OSI) of fish exposed to LP-CME and AP-CME were insignificant to those of wild fish. However, the improvements in the biomolecules concentration of tissues of fish exposed to either of the phytoremediated effluent were not equivalent to their concentration in the wild fish. Thus, decontamination of CME by either of these macrophytes was not complete and prolonged exposure of even phytoremediated CMEs exerts deleterious effects on the fish.

Functional organization of the skin of the ‘Green-puffer fish’Tetraodon fluviatilis (Ham.-Buch.) (Tetraodontidae, Pisces)

SummaryThe present study concerns the functional organization of the skin ofTetraodon fluviatilis. The epidermis consists of five different types of cells — the flask-shaped mucous cells, the eosinophilic granular cells, the sacciform granulated cells, the vesicle containing granulated cells, and the polygonal cells. A thin noncellular layer, the cuticle found on the surface of the skin, is probably secreted from the polygonal cells in the outermost layer of the epidermis. A,well-defined lymphatic plexus exists between the cells of the basal layer.Numerous triradiate calcareous spines are embedded within elastic connective tissue pockets in the thick dermis. These pockets are filled with an amorphous, acellular, PAS positive material, and are richly supplied with fine blood capillaries. A histomorphologic basis for the erection of the spines and various structural modifications in the skin facilitating its enormous stretching under inflated conditions of the fish are discussed.

Phytoremediation of the Toxic Effluent Generated During Recovery of Precious Metals from Polymetallic Sea Nodules

Recovery of metals from the polymetallic sea nodules at the pilot plant at National Metallurgical Laboratory, Jamshedpur, India has generated a highly toxic effluent. This effluent contains several metals like Mn, Cu, Zn, Fe, Pb, Cr, and Cd that pollute the neighboring water bodies when discharged. Hence detoxification of this effluent was practiced using two plants: Lemna minor and Azolla pinnata for 7 days. During investigation A. pinnata removed 96% of Mn, 97% of Cu, 98% of Zn, 70% of Fe, 96% of Pb, 93% of Cr, 78% of Cd, and was comparatively more effective than L. minor which removed 94% of Mn, 86% of Cu, 62% of Zn, 74% of Fe, 84% of Pb, 63% of Cr, 78% of Cd. During the 7 days of experiment chlorophyll content decreased by 51% and 59% in A. pinnata and L. minor respectively. Based on our findings we can suggest that these two plants have wide range of metal retention potentialities hence can be of routine use for purification of toxic effluents.

Lipids in the skin of a cat-fish Heteropneustes fossilis (Bloch) (Heteropneustidae, Pisces)

SummaryLocalization and characterization of different lipids in the cellular constituents of the skin of Heteropneustes fossilis has been made using several histochemical techniques.High contents of cholesterol, its esters and phospholipids have been correlated with the metabolically active state of the basal cells undergoing cell proliferation and differentiation.The polygonal cells in the outermost layer of the epidermis, though rich in phospholipid contain small amounts of cholesterol and its esters. This has been correlated with the metabolically less active state of these cells.Neutral lipids and phospholipids in the polygonal cells of the outermost layer may contribute to the contents of surface slime and act as an efficient barrier for the penetration of water through the skin.The deposits of neutral lipids in the subcutis may provide energy during the period of fasting, act as a barrier for water diffusion through the skin and serve as shock absorbing pads protecting the fish from mechanical injury.

Evaluation of pollution of Ganga River water using fish as bioindicator.

Ganga River, life line of millions of people got heavily polluted due to uncontrolled anthropogenic activities. To monitor the effect of pollution of the river on its aquatic life, a field study was conducted by analyzing the different biomarker enzymes and biochemical parameters in the various tissues (muscles, liver, gills, kidney, brain, and skin) of the Indian major carp Labeo rohita collected from the River Ganga from different study sites of Varanasi district. Activities of antioxidant enzymes, e.g., superoxide dismutase, catalase, and level of lipid peroxidation were found to be higher in the fish collected from the river showing pollutant-induced oxidative stress in the fish. Disturbed health status of the river fish was also manifested by increased activities of aspartate amino transferase, alanine amino transferase, and alkaline phosphatase. Concentration of nutritionally important biomolecules (proteins, lipids, and moisture) and energy value were also found to be significantly lower in the tissues of the River fish indicating its decreased nutritional value due to oxidative stress caused by different pollutants.

Impact of Sodium Arsenite on Certain Biomolecules of Nutritional Importance of the Edible Components of the Economically Important Catfish C. batrachus (Linn.)

The toxicity of sublethal concentration (1 mg/L; 5% of 96hLC50 value) of sodium arsenite (NaAsO2) for 60 days on certain biomolecules (proteins, lipids, and water) of five vital organ systems (muscles, liver, brain, skin, and gills) of Clarias batrachus were analyzed to evaluate the damage rendered to the food value of the fish. Arsenic disturbs the equilibrium existing between these nutritionally important macromolecules in all the organ systems. These tissues showed marked fluctuations in their protein (1.56 ± 0.79% in gills to 4.46 ± 1.54% in muscles), lipid (1.79 ± 0.89% in skins to 4.81 ± 1.15% in brain tissue) and water contents (65.84 ± 1.01% in brain to 78.66 ± 0.37% in gills).

The histochemistry of urea-unmasked glycosaminoglycans int he skin of the eel, Anguilla japonica

SummaryIn the connective tissues of the dermis and subcutis of the eel skin, the histochemistry of urea-unmasked glycosaminoglycans has been studied by means of combined staining and enzyme digestion procedures. The staining procedures employed were alcian blue (AB) pH 1.0, AB pH 2.5, aldehyde fuchsin (AF), periodic acid-Schiff (PAS), AB pH 2.5-PAS, high iron diamine (HID) and low iron diamine (LID) methods, whereas the enzymes used were Streptomyces and testicular hyaluronidases, chondroitinases ABC and AC and keratanase. The results obtained have shown that a substantial amount of dermatan sulfate and a relatively small amount of hyaluronic acid, chondroitin, chondroitin sulfate A and/or C were the glycosaminoglycans involved in the connective tissues of the eel skin and that the tissues were devoid of keratan sulfate.