The Potential Role of Chromophiles (Absorbtion) Fungi from Polluted Landfill by Tannery Effluent Challawa Industrial Estates Kano State of Nigeria

: The release of unprecedented tannery effluents into the environment as industrial wastes is one of the major causes of environmental pollution. Tannery waste containing heavy metals are usually disposed in landfills and streams in Challawa industrial estate Kano. In the present study tannery effluent discharge soil (polluted landfill)


Introduction
This paper focuses on the general ways in which microbes interact with metals.Some bacteria and fungi have evolved mechanisms to detoxify heavy metals, and some even use them for respiration.Microbial interactions with metals may have several implications for the environment.Microbes may play a large role in the biogeochemical cycling of toxic heavy metals also in cleaning up or remediating metalcontaminated environments.There is also evidence of a correlation between tolerance to heavy metals and absorption potential uptake capacity, a global problem currently threatening the treatment of infections in plants, animals, and humans.
Soil is an important system of terrestrial ecosystem.There is a direct impact of pollutants ion minerals, organic matter and microbial community of soil (Nagaraju et al., 2007).The discharged of industrial effluent especially without treatment may have profound influents on physicochemical and biological properties of soils related to soil fertility.A wealth of information on occurrence of changes in properties of soils due to discharge of effluent from other industries is available such as cotton ginning mill (Narasimba et al.,1999), sugar industry (Nagaraju et al., 2007), dairy waste water (David shyam babu, 2010) and dairy industry (Nizamuddin et al.,2008).Effluents from leather processing, a major industry that produces huge volume of waste water normally discharged to irrigate agricultural lands.This tannery waste water contains a very little amount of proteins except for the sludge waste that has nitrogenous compound from hides and skins of animals.Tannery effluent in the settling reservoir is usually drained to another temporary reservoir living the sludge in the main reservoir for a while and later became a solid waste.The effluent in the temporary reservoir is later released with contaminants into the land fill such as salts and chromium that might affect soil process and crop production (Alvarez-Bernal et al., 2006).During leather processing, the following steps are taken into recognizance, the chemicals use viz; lime, sodium sulphate, salt, solvents etc., are quite toxic; thus, remained one of the worst offenders of the environment (Kamini et al., 2010).

Figure 1. Macroscopic Mixed Culture of Fungi Isolates from Tannery Effluent
Tannery industries release effluents directly on the agricultural land or surface of water bodies which eventually leaches to ground water that lead to contamination of toxic metallic component.Thus, resulting in a sense of well documented problem in living beings (Zang and Li., 2011).Chromium exists in many oxidation states of which only Cr (VI) and Cr (III) ions are the most stable under environmental circumstances (Masood and Malik., 2011).Chromium (III) is required in human body, but in very small amounts and relatively immobile, slightly acidic to alkaline and chemically more stable than Cr (VI) and less bio available due to 50 its negligibility and permeable nature to bio membrane.Cr (VI) is highly mobile and water soluble when compare to Cr (III), whereas chromium is also used as a pigment.Hexavalent chromium can be harmful to human health and is toxic, mutagenic, teratogenic and carcinogenic (APHA et al., 1998).Chromates in soils have also been found to induce allergic reactions in some individuals.Due to those health and environmental issues, restrictions have been imposed on the use of certain chromium compounds in many countries.Conventional method for removing Cr (VI) from aqueous solution has been studied in detailed such as chemistry precipitation ion exchange, electrochemical treatment of membrane technologies thus, these methods are ineffective and uneconomical (Wong and Chen, 2006).Therefore, rapid and economical design technologies are needed to develop so as to remove heavy metals from industrials effluent.
The ultimate aim of this research is the removal of chromium, a heavy metal from tannery effluent, using the adsorptive abilities of either living or dead fungal mycelium.Such biological approach to metal ion recovery can be used to clean up effluents or to recover precious metal ion from solution.In both cases, it will be necessary to show that the use of fungal biomass can compete with physio-chemical methods that have been conclusively demonstrated in situ.

Research Problem
Heavy metals persist in soil and can be adsorbed in soil particles or leached into ground water.Human exposure to these metals through ingestion of contaminated food or uptake of drinking water can lead to their accumulation in humans, animals and plants (Khan, 2006).Recent research suggests that heavy metals induce tumor and mutation in animals at high concentrations (Degraeve, 1981).They are capable of causing genetic damage to germ cells of male and female animals including humans.They are regarded as cumulative toxins which through biomagnification in plants affect human health (Groten and Vanbladeren, 1994).Wastes containing heavy metals are usually disposed in landfills and streams in Kano.These streams are used in irrigation for the production of agricultural products (Carrots and vegetables) which in turn may cause ill health (cancer) to humans and also render the land devastated and unproductive for Agricultural activities (Gbolagunte et al., 2003).Proper treatment of this waste is extremely essential for the public to use this waste water for irrigation and other purposes.

Rationale/Justification of This Research
Uncontrolled discharge of industrial effluent causes pollution of water by certain heavy metal ions and consumption of such contaminated water may lead to severe health problem.The metal ions may enter the food chain and become toxics in view of their high toxicity, environmental mobility, non-biodegradability and stability, their removal becomes an absolute necessity.
In recent years biosorption of heavy metals by microbial cells have been recognized as a potential alternative to the existing technologies for removing heavy metal from industrial effluent and accumulation of metals by microorganisms or their products have received attention as the metal ion concentration lower than 10 mg/l can thus be removed (Vasudevas et al., 2002).
Furthermore, in view of the increasing cost of using the existing technologies for bioremediation, using available agricultural waste materials is increasingly being considered.Thus, the use of modified rice husk, soya bean pod, ground/nut pod, and saw dust as materials for substitution of expensive, not easily available basal media is quite essential.The results of this research project will highlight the significance of bioremediation using media containing locally available wastes as an efficient means of removing toxic metals present in tannery effluent.

Research Aim and Objectives
The main purpose of this study is to assess the presence of chromium III, IV and Cr (VI) discharge from tannery effluent in Kano state of Nigeria as well as the presence of susceptible and 51 resistant microorganisms to chromium ions exposure in landfill abatement.
The specific objectives of this study are to: 1.
To Isolate and identify different fungi from tannery effluent and contaminated soil.

2.
To compare the growth of fungi isolated from contaminated soil and tannery effluent on both conventional and dried modified agricultural waste media.

3.
To determine the maximum tolerance level of these isolated fungi on different chromium salt concentrations using different media.

Research Questions
Does bio-absorption of tannery effluent containing Cr 6 + by filamentous fungi justifiable.
Is tannery effluent discharge on landfill abatement affect animals and human's health.
Why is it that Cr6+(Hexavalent) is so carcinogenic, teratogenic and mutagenic than those of Cr 4+ and Cr 3+ /total chromium?

Significance of the Study
Environmental pollution has become a major concern of developing countries in the last few decades.There is a growing sense of global urgency regarding the pollution of our environment by an array of chemicals used in various activities.Pollution of water and soil by heavy metals is an emerging problem in urban industrialized countries.Since the advent of development through mining and smelting, metallurgical industries, sewage, warfare, and tanning the survival of plants and animals are much affected (Ashraf, 2010).
The quality of life on earth is inextricably linked to overall quality in the environment.Currently there are two fundamental pollution related problems, the disposal of large quantities of wastes that are continually being produced and the removal of toxic compounds that have been accumulating at dump sites in the soil and in water system over the last few decades (Huppert and Sparks, 2006).

Literature Review Environmental Pollution
Environmental pollution has become a major concern of developing countries in the last few decades.There is a growing sense of global urgency regarding the pollution of our environment by an array of chemicals used in various activities.Pollution of water and soil by heavy metals is an emerging problem in urban industrialized countries.Since the advent of development through mining and smelting, metallurgical industries, sewage, warfare, and tanning the survival of plants and animals are much affected (Ashraf, 2010).
The quality of life on earth is inextricably linked to overall quality in the environment.Currently there are two fundamental pollution related problems, the disposal of large quantities of wastes that are continually being produced and the removal of toxic compounds that have been accumulating at dump sites in the soil and in water system over the last few decades (Huppert and Sparks, 2006).
Pollution is defined in various ways.It is considered as the release of unwanted substances to the environment by man in quantities that damage either the health or the resource itself.Environmental pollution caused by heavy metals is increasing along with the increase in the usage of chemicals in industry and agriculture.Such pollution is apparent in streams and lakes and in ground water which is replenished directly from surface water (Schell et al., 2006).

Industrialization
Since the beginning of the industrial revolution, pollution of the biosphere with toxic metals has accelerated dramatically.Increasing industrialization and population develops the standard of living, which results in highly contaminated atmosphere due to the drainage and wastage from these industries (Indus, 2007).
Rapid industrialization plays an important role in polluting the environment and causes severe degradation in pedosphere, hydrosphere and atmosphere.Water used in industries creates a waste that has potential hazard for our environment because of the introduction of 52 various contaminants such as heavy metals into soil and water resources (Rajamani et al., 1987).
Environmental contamination with metals through industrial wastes is one of the major health concerns of developing countries.Metal pollutants can easily enter the food chain if heavy metals contaminated soils are used for the production of crops.The accumulation of metals in an aquatic environment has direct consequences to man and ecosystem (Ahluwalia and Goyal, 2007).
The release of pollutants differs from industry to industry.The waste from the pulp industry mainly contain carbohydrates, textile industry contains dyes, plating industry contain nickel and leather tanning wastes contain mainly chromium, zinc, copper, suphides, carbonates, sodium and many other toxic organic compounds and inorganic compounds.

Tannery Effluent
The damage to the environment by the hazardous tannery effluent is an acute problem.The chrome tanning process results in toxic metals, especially chromium III passing to waste water and are not easily eliminated by ordinary treatment process.Tannery waste waters are mainly characterized by high salinity, high organic loading and specific pollutants such as chromium (Shrank et al., 2003).
Various chemicals used in tanning are lime, sodium carbonate, sodium bicarbonate, common salt, sodium sulphate, chrome sulphate, fat liquors, vegetable oils and dyes.The tannery waste water contains high concentrations of total dissolved solids, chromium, chloride, ammonia, nitrate and sulphates when the samples were collected from the outlets of the industry (Song et al., 2004).Besides these, chemicals such as zinc chloride, mercuric chloride and formaldehyde are used as disinfectants, sodium chloride in curing and as bleaching powder and sodium fluoride to prevent putrefaction, lime in liming, sodium sulphate, ammonium chloride, borax and hydrochloric acid in deliming, sodium for decreasing and basic or acidic dyes in leather finishing (Indus, 2006).
Tannery waste is always characterized by its strong colour (reddish dull brown), high BOD, high pH, and high dissolved solids.The other major chemical constituents of the waste from the tanning industry are sulphide and chromium.These chemicals mixed with water are discharged from the tanneries into polluted ground water permanently and thereby making it unfit for drinking, irrigation and general consumption.

Heavy Metals (Chromium)
Plants require certain elements for their normal growth, which are called essential elements (micro and macro elements).But there are also some elements which are not vital for plant growth.Such elements are called non-essential elements, which include heavy metals which cause toxicity to plants (Leta et al., 2004).
The contamination of the environment with heavy metals is a serious problem.Industrial activities and sewage sludge applications have largely contributed to the spread of these elements in the terrestrial environment (Leta et al., 2004).Heavy metals are ubiquitous environmental contaminants in an industrialized society.Concern over the possible health and ecosystem effects of heavy metals has increased in recent years (Indus, 2006).Tremendous increase in the use of heavy metals over the past decades has inevitability resulted in an increased flux of metallic substances in the environment.Some metallic ions accumulate poisonous substances that is capable of being assimilated and stored in the tissues of organisms causing noticeable adverse physiological effects (UNIDO, 2000).

Study Area and Samples Collection
The soils samples were collected from Gasau (A1) and Yankusa (A3) control site in Challawa industrial area, Kano State, Nigeria.A total of twelve samples were randomly collected from each site and were divided into two portions.Six for control land fill (Yankusa) while the other for polluted landfills (Gasau) samples.After the 53 removal of surface litter, 20gram of sample was collected from each of twelve sites at a depth of 10 -15cm using soils auger into clean polythene bags.All the samples were transported to National Research Institute for Chemical Technology (NARICT) Basawa Zaria, Nigeria for analysis.

Physiochemical Properties of Soil PH
Ten grams of the soil samples was taken and added to twenty-five ml of distilled water.The mixture was shaken intermittently for 30 minutes.The pH was then determined by using the pH meter in standard bulb solution (Nag, 2007).

Temperature
Ten grams of soil sample was taken and added to 25ml of distilled water and the mixture was shaken thoroughly for 20 minutes.The temperature was determined using the thermometer in solution (Aneja, 2007)

Organic matter
Two and a half grams of dried, sieved soil was taken into a pre-weighed crucible and ignited over a Bunsen burner to a bright red heat, stirring occasionally with a wire loop.The sample was heated for 15 minutes.Then it was allowed to cool in a desiccator and the weight of the soil was taken.The organic carbon content was calculated as follows: % Organic matter =   ℎ ℎ   100 (1)

Total Nitrogen
One and a half gram of crushed dried soil samples was poured into 300ml Kjelda flask along with 25ml of concentration.H2SO4 and 3g mixed catalyst.The sample was digested using Kjeldahl digestion apparatus until a clear green or whitish color was obtained.The digested solution was then diluted to 100ml with distilled water.Distillation was done adding 20ml of diluted digest into 500ml Kjeldahl flask containing anti -bumping chips and 40ml of 40% NaOH was slowly added by the side of the flask.A conical flask (250ml) containing a mixture of 50ml 2% boric acid and 4 drops of mixed indicator (Cresol/bromothymol) was used to trap the liberated ammonia.The distillate was then titrated with 0.1m HCL.The total nitrogen content was then calculated using: Where: M=Actual molarity of acid

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V=Titre volume of HCL used

Phosphorus
Fifty grams of the dried crushed soil was suspended and filtered through a nylon cloth into a glass beaker.Twenty-five ml of the filtrate was heated for 25 minutes with HNO3/HCL in a ratio of 3:1 (digestion).The mixture was dilute was diluted to the 100ml mark with distilled water.Fifteen ml of the diluted solution was then pipette into a cuvette and 1ml of the phosphate reagent was added to it and the reading taken using the phosphate meter (Nag, 2007).

Potassium
To determine the potassium content of soil samples fifty grams of the dried soil was suspended in 50ml of distilled water and filtered using nylon cloth.The filtrate (25 ml) was mixed with HNO3/HClO4 (ratio 2:1).The beaker containing the mixture was then placed on a hot plate and boiled until the solution became clear.This was then filtered using what man filter paper No.1 in a volumetric flask and the volume of the filtrate was made up to 100 ml by the addition of deionized water digested sample was stored in a sterile polyethylene bottle at room temperature for further analysis of the metal using atomic absorption spectrophotometer.

Total Chromium
Fifty grams of the dried crushed soil was suspended in 50ml distilled water in a beaker and was filtered through nylon cloth.Twenty-five ml of the filtrate was collected in a 400ml beaker and 10ml of concentrated H2so4 and 5ml of concentrated HNO3 were added to the filtrate in ratio3/1.The beaker containing the mixture was then placed on a hot plate for boiling until the solution becomes clear and then the solution was transferred by filtration through what man Filter paper No2 into a volumetric flask.The volume of the filtrate was made up to 50ml by adding deionized water.Digested sample were store in sterile polyethylene bottles at room temperature for further analysis of the metal using Flame Atomic Absorption Spectrometry, FAAS (Rani, 2003).After autoclaving all sterilized material dried in oven at 95°C.

Media preparation
Potato Dextrose Agar (PDA) media was used for fungal cultures revival.Potatoes (200g) were peeled, sliced and boiled and then sieved through a clean muslin cloth to get a broth in which agar (7.5) and dextrose sugar (7.5) was added.The media was then autoclaved for 30 minutes at 121°C (Iram et al., 2011).

Preparation of plates
Poured the media in Petri-dishes and allowed to solidify for 24 hours.To suppress the bacterial growth, 30 mg/lit of streptomycin was added in the medium.Once the agar was solidified, and then put plates in an inverted position for 24 hours at room temperature (Suhail et al., 2007).

55
Isolation and identification of fungi from soils and effluent samples Micro flora such as fungi populations of both soil and effluent samples were enumerated by serial dilution technique.10 g and 10 ml of each soil and effluent sample respectively were serially diluted and 0.1 ml was gradually spread with a spreader on potato dextrose agar medium for the growth of fungi.Smear of the isolated fungi was prepared in lactophenol cotton blue method.
Cultural characteristic such as colure, size of colonies of fungal isolates, size and shape of conidiophores/ fruiting bodies and conidia were measured and recorded.Fungal isolates were identified by matching these characteristics with that of Adawiah, (2008).

Metal tolerance test for fungi
Fungal strains including Aspergillus niger, Aspergillus Rhizopus nigricans and Penicillium sp were tested for their tolerance against different concentration of (CrSO4).Potato dextrose agar media was used for chromium sulphate tolerance experiment.The concentrations (0.0%, 0.1%, 0.5%, 1.0%, 1.5%, 2.0% and 4.00%) of Chromium sulphate) was used for the selection of fungi.Incubation was conducted at 32 o C for 7 days (Malik & Jaiswal, 2000).The growth was monitored by measuring the mycelia growth length of respective culture colony.Tolerance of fungi will be used for biosorption study using modified agricultural waste (Zafer et al., 2007).

Results and Discussions
In trying to determine the physiochemical characteristics of the soil and the presence of chromium ions in environment due to their toxicity is of great concerned to public health and environment.The data showed the level at which the polluted landfill has been fully devastated due to the discharged of industrial chemical recipe.The unprecedented discharge of effluent containing chromium ions could be dully mitigated or resuscitated by the abating land through bioremediation process.
Discharge of tannery effluent containing chromium ion in to the environment can produce considerable modification of their microbial populations, reducing their activity and number in their consortia in a given habitat.The present study, is mainly focused on soil samples collected from control landfill (Yankusa), contaminated land fill (Gasau) respectively and tannery effluent from different sources of industrial discharge in to the soil.The emissions of effluent containing toxic chemical recipe have drastically rendered the virgin soil unproductive and devastated to plants and animals (Zafar et al., 2007).
Soil is a potent system of terrestrial system, and direct discharge of industrial tannery effluent especially that without treatment may have profound influence on physiochemical and biological properties of soil fertility (Narasimba et al., 2011).
Analysis of the soil and identification of fungi at the study site showed that the contaminated landfill soil differ from soil, from the control site as shown in table 1 plates 1 and 2. The contaminated soil is wet, dried and gummy with the upper portion having tanning debris while the control have dry, sandy mixed with silt and clay soil.The colors have always been the first parameter to be recognized in control and polluted landfill, due to contaminated waste water that affect the integrity of the land mass.Such colors were

56
observed to be brown and blue/black in their identity from control sample and contaminated site respectively (Dhungana and Yadav, 2009).WHO has reported colorless, dirty dark green and green appearance from tannery effluents in like manner.Thus, affect the color, appearance and permeability of the virgin soil when discharge.Obnoxious odor is also perceived and recognized within the affected area of effluent discharge compared with the reference soil sample as shown in table 2.
The mean pH values of the contaminated soil of (5.1) Daula was found to be acidic in comparison with (6.8) Yankusa control site as shown in table 2 has not been categorically in compliance with the WHO standard.Jyoshana and Narasimba (2007) reports show that discharge of effluent from tannery increased the soil pH slightly in comparison with the control soil pH 3.6 -7.2 and pH 6.8 -7.2 respectively.Variation in pH values of effluent waste to soils can alter the rate of biological reaction and survival of various microorganisms.Since the control landfill does not contained chemicals recipe.The organisms have been absolutely, sincerely and adequately maintaining their level of integrity in terms of improving the soil fertility for their survival as well as the life of plants and animals (Bannats et al., 2008).The varying pH could be attributed to the chemical discharge on landfill due to excessive use of NaOH, H2O2 and atomic stabilizer use during finishing processes.Nonetheless, in tanning process and in conjunction with environmental stresses have always been earmarked for contamination (Wood and Kellong, 2007).The soil samples collected from polluted sites were mostly affected by waste water irrigation due to the presence of heavy metal which affects the pH and might likely reduced the population densities of micro flora within a given habitat.
The mean temperature values of the contaminated land fill (Gasau) were (37 o C) in comparison with the reference soil sample (34.5 o C) Yankusa.The findings are in line with the study conducted by Nandakumar ( 2008).It appears the values falls within the permissible limit through which it might be that at the time the sample were collected at winter season, the reference water sample falls within the ambient temperature and other below.High temperature could be as a result of addition of warm water while low temperature could be attributable for the season of samples collection (winter).
Increase in temperature can cause change in the species in a given habitat.It could also reduce solubility of oxygen and amplified odor due to anaerobic and aerobic reaction respectively (Nandakumar, 2008).
The electrical conductivity of both contaminated and control soils were (0.65) and (1.27) µMhos cm -1 respectively.
Higher water holding capacities of the mean values were observed in contaminated soil than control, values were found to be (0.56) and 0.31mg/l respectively.Increased water holding capacity and decreased electrical conductivity in contaminated soil may be due to the accumulation of organic wastes such as amino acid residues and alkalis in tannery industries (Alvare Bernal, et al., 2006).
Mean soil texture values of (Gasau) contaminated soil in comparison with (Yankusa) control reference soil in terms of gram of sand, silt and clay were (52.75, 23.75, and 16.25), (74.5, 20.3 and16.25)respectively.The parameters like organic matter mean values were observed in contaminated soil higher than control values at (8.23) and 4.44mg/l respectively.This result is in accordance to the report of (Mohammed and Sani, 2006).Soil organic matter comprises of the following: Firstly, fresh plant and animal residues capable of rapid decomposition and loss of identity with simultaneous release of nutrient elements; secondly "Humus" which represents the vast bulk of having high adsorptive capacity for cat ions and capable of improving soil structure.In this current result, the Yankusa control land fill had little quantity of organic matter due to the high adsorptive capacity for cat ion, the synergy role plays by the plants and the microbes have well improved the soil structure.
On the other hand, where high quantity of organic matter is observed, it could be attributed to high concentration of chromium ions that affects the diversity of microbial activity in a given habitat.Some of these less tolerant 57 microorganisms could as will die in the process of struggling for survival.The dead of the organisms could be the reason for high quantity of organic matter in Gasau contaminated landfill; hence, there was no microbial activity within the catchment area of chromium ions disposal.Total nitrogen, phosphorus and potassium (NPK) in percentages were higher in all ramifications from contaminated land fill than the control soil except potassium content.The properties of contaminated soil sample were (0.718, 0.135 and 0.365%)) and 0.109%, 1.043and 0.063% respectively.However, this could be possibly explain that surface run-offs from agriculturally fertilized and neighboring lands, microbial interaction and synergy role play by the plants and the microbes in converting inorganic to organic compound (mineralization).This might have contributed significantly to the lesser amount of phosphate and nitrogen percentage present in the Yankusa control land fill in comparison with contaminated and deposited soil Gasau the higher area of devastated landfill abatement.Apart from potassium, this is exceptional.On the other hand, the essential elements that one would expect the assimilation should be in the order N > P > K, however, in this investigation, N < P > K.This might be related to the possible use of high amount of fertilizers during such periods by the neighboring farmers.In addition, surface run-offs could have added these nutrients during heavy rainfalls especially as this is the peak rainy season period in the area under study.Thus, there seems to be a low content of phosphate than nitrates.This might also be related to the fact that some aquatic photosynthetic microorganisms utilized phosphate while oxygen-depleted photosphorylation means of energy generation (Isabelle and walter, 1979).
The order of this trench N>P<K, nitrate might seem to be less abundant than phosphate, for which reason it may therefore be that nitrate could be said to be a limiting nutrient in the productivity of Challawa land fill Kano State Nigeria.
The total chromium content of the contaminated soil was also much higher than that of the control as observed in table 2: with varying values ranging between (2.23m/l) from Yankusa control land full, (66.21mg/l) from Gasau dumpsite respectively.The study is in line with the result conducted earlier by (Ugoji and Aboaba, 2004).Total chromium implies chromium (II), chromium (III), chromate ion and chromium (VI) ion present in natural water or contaminated soil.Their present in a given habitat depend on interaction with microbes that led to the significantly differ in biological, geo chemical and toxicological properties (Sule and Ingle, 1996).Cr (III) over a narrow concentration range is considered essential for mammals, maintenance of glucose essential for mammals, lipid and protein metabolism at minimal level, whereas Cr (VI) is reported to have a toxic effect in human (Cotton et al., 1999).In this current investigation, tannery effluents discharged directly on land fill are usually found to contain higher values of chromium in comparison with the control land.According to Ugoji Aboaba, (2004), chromium ion in polluted land had higher concentration 89.30% against the lower values of 0.255mg/l in the control land.However, a possible explanation for its high level is as a result of the used chromium salt during tanning.This could be disastrous to the concept of a clean 58 environment.It may also enter the food chain through plants, animals as well as water source.Once it gets into food chains, biomagnifications and bioaccumulation of the metal in various living systems may take place.This result was in conformity with that of (Khan, 2006), in which they reported that bioaccumulation and biomagnifications could lead to toxic level of these metals in organism, even if exposure level is very low.This could also cause disruption in the ecological balance when in abundance.However, the said permissible limit for total chromium discharge in the stream or river for irrigation and domestic use should not exceed 0.05mg/l by (WHO, 1985).In contrast, it could be that the rural dwellers that leave within that vicinity are not guarantee of safety.High concentrations of chromium in drinking water can cause skin ulcer, allergic reactions, carcinogenic and mutagenic effect to humans (Matin and Ginswold, 2009).3, 4, 5. Plates 1 and 2 The fungal populations were relatively higher in control land fill by about four times than those of tannery waste polluted landfill and tannery waste effluent.The control soil sample contains the fungal population with 20.0 x 10 3 colony forming units (CFU/g) of the soil recorded in respect to soil with effluent discharges as against the tannery waste polluted landfill.The fungal population had 20.0 x 10 3 CFU/g being the highest from control soil followed by the average mean colony count of the three-tannery waste polluted landfill of 5.6 x 10 3 CFU/g; the least recorded was 4.6 x 10 3 CFU/ml by effluent waste.
The morphological and microscopic characteristics of fungal cultures isolated from soil samples with/without tannery industry effluents are listed in Table 3 (Appendix 1) on the basis of a comparison of these characteristics with those recorded by Adawiah (2008).Twelve isolates identified viz, A. niger, Aspergillus flavus, R. nigricans, Aspergillus fumigatus, Candida sp, Geotrichum sp, Penicillium notatum, Penicillium expansium, Coccidiodes immitis, Trichophyton schoenleinii, Paraccocidiodes bransilensis and Cephalosporum sp from the control land fill.The former two samples of tannery waste polluted landfill and tannery effluent waste had five each as seen in Table 4,5 and plate 2 respectively.Abundance and activities of micro flora in soil strata are controlled by the availability of water, nutrient, pH, concentration of metal ions, and hydrodynamic communication with the ground surface and so on.Environmental stresses brought about by the contamination could be a reason for the reduction in microbial species but increasing the population of few serving species.The soil samples collected from polluted sites were mostly affected by waste water irrigation due to the presence of heavy metal which affects the population densities of fungi.The differences between the sampled sites regarding their richness on microbial isolates appear to be closely linked to the degree of heavy metal pollution.Generally, pollution of soil and water by heavy metals may lead to a decrease in microbial diversity.This is due to the extinction of species sensitive to the stress imposed, and enhanced growth of other resistant species.The sources of pollutant as well as long period of exposure are also the important factors regulating stress and fungal adaptation.
Fungi isolates from polluted soil Gasau G1, G2 and Daula are shown in table 4 Aspergillus niger, Rhizopus nigricans and Penicillium sp were spotted in the entire polluted samples except Aspergillus flavus in Gasau G1 as seen in plates 1,2 and 6.Highest fungal count of 6.3x10 3 CFU/g from 59 Daula was twice that of G2 with 3.3x10 3 CFU/g being the least.The high fungal colony count found in Daula deposited site where agricultural activities are been practiced.This might not be surprised, because of the fact that most tanneries discharge their waste through different channels, with different tributaries containing different organic compounds that sustained the presence of fungal spores in waste water.However, the waste water contained available rich nutrients obtained from hides and skins of animals through different tributaries down the lower land fill of Daula deposited site might eventually contained more of the fungi than others.However, it served as a source of nutrient that sustained the existence of fungal species (Gbolagunte et al., 2003).
Fungal isolates from different tannery effluent viz; Mario Jose, Mahazah and Fata are shown in Table 5: Aspergillus niger, Penicillium sp and Rhizopus nigricans were spotted in all ramification of the tanneries except Aspergillus fumigatus in Fata effluent.High fungal count of 6.30 x10 3 CFU/ml was found in Fata followed by Mahazah with 4.30x10 3 CFU/ml and least was obtained in Mario Jose with 3.20x10 3 CFU/ml.High count of fungal in Fata could possibly be explained by the poor treatment of the waste.In a situation where there is remnant of organic debris from hides and skins of animals in the effluent, it might probably be a clue of improper treatment of effluent waste through negligence checkup of some physicochemical parameters viz; Total suspended solid, total dissolve solid and total solid of the effluent before discharge into the land fill.Thus, this determined the said purity of waste water to be bacteria or fungi free; hence, their existence is due to the remnant of organic debris from hides and skins of animals.On the other hand, Mario Jose had the least colony count of 3.20x 10 3 CFU/ml, it is possible that the effluent treatment has always been thoroughly ascertained before discharge in to land fill.
Tolerance of fungal isolates to different chromium sulphate concentration as shown in table 6 plate 3, 4 and 5 reveals all the fungal isolates tested tolerated chromium at 0.1% concentration of 0.5% inhibited A.fumigatus, C. immitis, T. schoenleinnii P. brasiliensis e.tc.While Geotrichium sp was inhibited at 0.5% concentration.The tolerance of the fungi isolated and characterized from land fill and waste water, three common and dominant chromium sulphate solution tolerance fungi isolated belonged to the genera of A. niger, R. nigricans and Penicillium sp.They were spotted for tolerance of chromium sulphate concentration of 4.0%.as seen in plate 6 Since it is obvious that fungi may have adaptive advantage to chrome environment than bacteria, then our bioremediation effort may focus more on the use of these favorable fungi.An area of fungi biotechnology currently in vogue is the use of fungal biomass to adsorb metal ions from solution (Gadd, 1990).The intention is the removal of pollutant heavy metals from effluents and landfill soils using adsorptive abilities of either living or dead fungal mycelium.Such biological approach to metal ion recovery can be used to clean up polluted effluents or recover precious metal ions from solution.In such a case, it will be necessary to show that the use of fungal biomass could be favorably competed with physic-chemical methods so as the investigator would rather come to a conclusion for tracing the precise fungi for adsorptive ability of chromium ion.
The issue in this study is that since these fungi were tolerant of the chrome environment to the extent that they were, their possible viability in the landfill is highly likely.Therefore, if made to grow abundantly (with the aid of suitable substrates) in the landfill, the tendency of extensive adsorption of the chromium to their surfaces is high, since fungal surface contains metal binding ligands such a chitin, amino group, sulfurhydryl group etc. this can prevent further migration of contaminants.The process may not only be that of sorption; it may in fact be complexing -either way, the union becomes nonreactive or inert, thereby allaying the fears of where to disposed the supposedly toxic adsorbed metal.Microorganisms can remove toxic metals and metalloids from contaminated water and waste stream by converting them into forms that are precipitated or volatilized from 60 solution (Suresh Kuma et al., 1998).Accumulation of metals by microorganisms or their products has been used for some time, but has received more attention in recent years because of its potential application in both environmental protection and recovery of precious and strategic metals (Gadd and Rome, 1988).
Reason for varying the concentrations of the chromium solution in this study is that of toxicity which is well known to be limiting as shown in table 6 plates 3,4 and 6.Microbial growth actually, will be influenced by the presence or absence of toxic or inhibitory materials (Skladamy and Metting Jr, 1993).It is important to remember that inhibition or toxicity is often a result of high contaminant concentrations and not merely due to their presence.Certain chemicals may only inhibit the growth of a given species, whereas other compounds may actually be lethal at the same concentration.For bio-treatment to be successful, concentration of toxic chemicals must be carefully evaluated even when they are the target contaminants.That is what this study has addressed.
Effect of pH and Temperature on tolerance of fungal isolates at 1% chromium concentration as shown table 7: The best mycelia growth of the 3 test fungi was obtained at pH 5.0.There was no growth by any of the fungi at pH 3.0.The best mycelia growth of the 3 test fungi was obtained 32 o C and there was no growth by any of the fungi at 23 o C. The measurement of pH and temperature in industrial effluent are the major physical parameter that influences the growth and activity of the existing microbial diversity in their consortia within a given habitat.The possible explanation could be attributed to where the study was conducted.However, in the tropic the temperature differences are always maintained within the mesophilic range while in the temperate region they are maintained at psychrophilic range.In current investigation, successful soil bioremediation relies on identifying and maintaining a suitable pH for microbial biodegradation of the dominants of interest.The three fungi of interest in this study grew optimally at pH 4-5 at 32 o C in four days.Soil and ground water remediation occur at a pH of 5 or less (Skladamy and Metting jr, 1993), which provides the optimum environment for the growth of these three fungi, if the process would require that the microbial biomass should maintain its viability under normal conditions or prescribes by the company or investigators either in sachet powder or in liquid form.

Conclusion
Three fungi viz; Aspergillus niger, Rhizopus nigricans and Penicillium sp.out of the four and three if possible in tannery waste polluted soil and tannery waste, tolerated chrome solution of up to 4.0% concentration, while the other Aspergillus fumigatus, Candida sp. and Geotrichium sp.only tolerated up to 0.5% and 1.0% respectively all at an optimum pH and temperature of 4-5 and 32 o C respectively in 4 days.The relatively higher tolerance of the three-tannery waste/ landfill fungi opens up their favorable potential for cell surface adsorption of the chromium metal, away from the environment, substituting this cheaper and cleaner biological remediating method for the costlier and not too environment friendly physicochemical methods.

Figure 5 .
Figure 5. Picture showing growth tolerant of Penicillium sp after exposure to different concentration CrSO4 at A=0.0%; B=0.1%