African Journal of Biotechnology Vol. 4 (13), pp. 1548-1553, December 2005 Available online at http://www.academicjournals.org/AJB ISSN 1684–5315 © 2005 Academic Journals Review Bioremediation of textile effluent using Phanerochaete chrysosporium Asamudo, N. U.1, A.S. Daba2 and O.U. Ezeronye1* 1Department of Microbiology, Michael Okpara University of Agriculture, Umudike, Nigeria. 2Mubarak City for Scientific Research, Genetic Engineering Institute,New borg El Arab, P.O. Box 21934, Alexandra, Egypt. Accepted 5 October, 2005 Enormous volumes of effluent are generated at different stages of textile manufacturing, as a result of the use of copious amounts of chemicals and dyes. Several tons of textiles required to meet up with societal demands are produced daily in this industry. Effluent derived from the textile and dyestuff activities can provoke serious environmental impact in the neighboring receptor water bodies because of the presence of toxic reactive dyes, chlorolignin residues and dark coloration. Nature has demonstrated its capacity to disperse, degrade, absorb or otherwise dispose of unwanted residues in the natural sinks of the atmosphere, waterways, ocean and soil. It is realized however that this ability is not finite. The discharge of these waste residues into the environment eventually poison, damage or affect one or more species in the environment, with resultant changes in the ecological balance. The biological breakdown of the chlorolignin residues and the chromophoric groups responsible for the dark coloration of the textile effluent can be accomplished by the use of enzymes from the white rot fungus, Phanerochaete chrysosporium. The siderophores detected from the culture of the organism have been found useful in the decolourization and remediation of the effluent. This review summarizes the available information in the use of this fungus for bioremediation purposes and also assesses the current status of the technology. Key words: Bioremediation, textile effluent, Phanerochaete chrysosporium, white rot fungi, peroxidase enzymes. INTRODUCTION The world’s ever increasing population and her environment. progressive adoption of an industrial– based lifestyle has Textile effluents can seep into the aquifer and pollute inevitably led to an increased anthropogenic impact on the underground water, or where it is discharged without the biosphere. In textile production, opportunities exist for proper treatment into water bodies, the pollutants cannot the release into the ecosystem of potentially hazardous be confined within specific boundaries. They can compounds at various stages of the operation. These therefore affect aquatic life in enormous ways. Metallic pollutants are produced in an effort to improve human effluents can have ecological impacts on water bodies standard of living and fashion but ironically, their leading to increased nutrient load especially if they are unplanned intrusion into the environment can reverse the essential metals. These metals in effluent may increase same standard of living by impacting negatively on the fertility of the sediment and water column and consequently lead to euthrophication, which in open waters can progressively lead to oxygen deficiency, algal bloom and death of aquatic life (Purdom and Anderson, 1980). Water contaminated with metallic effluent can *Corresponding author. E-mail: [email protected]. cause several health problems. Lead for instance, can Asamudo et al. 1549 interfere with enzyme activities and formation of red compounds such as starch, cellulose, pectin, lignin, blood cells. It can affect nerves and brain at low lignocelluloses, which are characteristics of textile concentration. Heavy metals such as mercury, cadmium, effluent. It can also decolorize azo-tiphenyl methane dyes and chromium can bio-accumulate, and through the food by its lignin peroxidase enzyme. P. chrysosporium is chain, to toxic levels in man. Mercury can cause capable of producing extracellular enzymes such as numbness, locomotor disorders, brain damage, manganese peroxidase, effective in decolorization of convulsion, and nervous problems. Cadmium is textile effluent. This fungus appears to be the best responsible for kidney tubular impairment and candidate, so far studied, in textile effluent treatment in osteomalacia. Cadmium, zinc and manganese are situ. There is no doubt therefore, that if properly reported to affect ion regulation if present in sufficient harnessed, the fungus can be very useful in the treatment concentrations (Howells, 1990). Cadmium and and disposal textile and related effluents. manganese are also known to affect calcium metabolism, development and skeletal calcification as well as long term effect on spawning and recruitment of fish and other GENERATION AND COMPOSITION OF TEXTILE aquatic lives. Any change in pH of water bodies as a EFFLUENTS result of influx of effluent, can cause serious change in water chemistry, which can affect resources especially The basic raw materials in textile are cotton, flax, jute, around the coastal areas. These effects on water bodies wool, silk and synthetic polymers fibers such as nylon, can be very significant. Dyes in water bodies also affect polyesters, polyethylene and rayon (Dara, 1993). The photosynthetic organisms and consequently impact cellulosic textiles are composed of pure cellulose and can negatively on the food chain. The reason for this global be categorized as: effect also lies in the weather systems and the biogeochemical cycling of elements, which aid in rapid 1. Natural cellulosic fibers, which include cotton, abaca, dispersal of the pollutants. coir, flax hemp, henequen, jute and sisal. Traditional methods for the clean up of pollutants 2. Man- made cellulosic fibers, which are usually involve, the removal of unwanted materials cuprammonium, polynosic and viscose. through sedimentation and filtration, and subsequent chemical treatments such as flocculation, neutralization Cotton (Gossypium spp) is a fiber crop, which belongs to and electro-dialysis before disposal. These processes the plant family, Malvaceae. It produces cotton lint, a may not guarantee adequate treatment of the effluent. white fiber used in the textile industries. Cotton fiber is a Moreover, they are often laborious and expensive, single plant cell. Its cross-section is oval, compared with considering the volume of wastes released during the the normal hexagonal plant cell. However, like small industrial production process. plant cells, cotton have a distinct cuticle, well-developed The past two decades have seen a tremendous primary and secondary walls and lumen. The cuticle is upsurge in the search for cost effective and the ‘skin’ of the cotton fiber. It is composed of a waxy environmentally sound alternatives to the conventional layer (cotton wax) only a few molecules thick. The inert methods for dealing with wastes. The technologies that nature of this cotton wax protects the rest of the fiber have emerged as most promising are those that closely against chemical and other degrading agents. Bleaching mimics the time tested, natural system that have restored during cotton finishing removes much of the cuticle or environments to their original status following undesirable wax (Gohl and Vilensky, 1987). This enables cotton to perturbations. In fact the self-restoring process in nature absorb moisture more quickly. Subsequently, laundering is what has actually given birth to the concept that the gradually removes most of the remaining cuticle. The self- cleansing ability of nature is infinite. Of all the primary cell wall, which is immediately underneath the technologies that have been investigated, bioremediation cuticle, is composed of very fine threads of cellulose, has emerged as the most desirable approach for cleaning called fibrils. The secondary cell wall forms the bulk of up many environmental pollutants in effluents. fiber. Concentric layers of the spiraling cellulosic fibrils Bioremediation uses living systems especially make up the secondary wall. Much of the strength and microorganisms to catalyze the degradation of wastes stability of the cotton fiber and hence, of yarn and fabrics, without disruption of the environment. Fungal systems are attributed to these spiral fibrils. The cotton polymer is appear to be most appropriate in the treatment of colored a linear cellulose polymer with repeating units of and metallic effluents (Ezeronye and Okerentugba, cellobiose, which consists of glucose. The polymer 1999). In the world of fungi, Phanerochaete consists of about 5000 cellobiose units (Gohl and chrysosporium has emerged a model system in textile, Vilensky, 1987). The fibers are resistant to alkalis and polycyclic aromatic hydrocarbon (PAH), and pulp and relatively unaffected by normal laundering. paper mill effluent remediation. P. chrysosporium is a Flax fiber is classified as a natural cellulose multi-fiber. basidiomycete fungus able to degrade complex ‘Linen’ is the term applied to the yarn spun from flax 1550 Afr. J. Biotechnol. fibers and to the cloth or fabric woven from this yarn. serious environmental pollution, sometimes to levels that Flax polymer is chemically the same as the cotton can threaten human health, livestock, wildlife, aquatic polymer both are cellulose polymers. Viscose is a man- lives and indeed the entire ecosystem. Every production made natural polymer of cellulose or regenerated process goes with wastes generation. Various treatment cellulose filament. Thus cotton, flax and viscose are all