Paper mill effluent decolorization by fifty streptomyces strains.

Area of Science:

• Microbiology
• Environmental Biotechnology
• Bioremediation

Background:

• Paper mill effluent from semichemical alkaline pulping of wheat straw presents a significant source of industrial pollution.
• The colored compounds in this effluent, primarily high- and medium-molecular-weight substances, pose environmental challenges.
• Actinomycetes are known for their diverse metabolic capabilities, including the degradation of complex organic compounds.

Purpose of the Study:

• To investigate the potential of actinomycete strains for decolorizing paper mill effluent.
• To identify specific actinomycete strains capable of efficient effluent decolorization.
• To analyze the changes in effluent composition following microbial treatment.

Main Methods:

• Isolation and screening of fifty actinomycete strains from lignocellulosic substrates.
• Cultivation of selected Streptomyces strains in a liquid medium with paper mill effluent.
• Quantification of decolorization levels and analysis of effluent fractions using gel permeation chromatography and thin-layer chromatography.

Main Results:

• Four Streptomyces strains (UAH 15, UAH 23, UAH 30, UAH 51) demonstrated significant effluent decolorization.
• Achieved decolorization levels ranged from 60% to 65% with strains UAH 30 and UAH 51 showing distinct decolorization patterns.
• Gel permeation chromatography indicated a reduction in high- and medium-molecular-weight compounds, suggesting their role in effluent color.

Conclusions:

• Actinomycetes, particularly Streptomyces strains, are effective agents for the biological treatment of paper mill effluent.
• Microbial decolorization primarily targets the high- and medium-molecular-weight fractions responsible for the effluent's color.
• Further research into low-molecular-weight compounds is needed to address residual coloration.