Optimization of Culture Conditions for Enhanced Decolorization …
145
2 Materials and Methods
2.1 Dye Stuffs and Chemicals
Acid Blue 193 (AB 193) and Acid violet 90 (AV 90) commonly used in local textile
processing industries were obtained from Rajasthan Dye Chemical Ltd., Chennai,
India. Dyes were dissolved in double distilled water to prepare a stock concentration
(1000 mg L
−1 ) and solutions of the desired concentrations were obtained by successive dilutions. Media components and chemicals were purchased from Himedia Labs,
Bombay, India.
2.2 Sample Collection
Soil samples were collected from the textile industry at Tirupur, Tamil Nadu, India
and were stored at 4 °C until further process.
2.3 Screening and Identification of AB 193 and AV 90
Tolerant Fungi
The soil samples were serially diluted using sterile distilled water and from the 10
–2
to 10
–7 dilutions, 0.1 mL of sample was transferred onto Czapek-Dox agar plate
containing AB 193 and AV 90 (50 mg L
−1 ). Spread plate method was performed and
the plates were incubated at 30 ± 1 °C for 4 days. Fungal colonies were identified
using steriobinocular microscope. Fungi which showed decolorization in CzapekDox agar medium were screened further by transferring in a fresh Czapek-Dox agar
plates containing different dye concentrations (50 and 100 mg L
−1 ). Colonies were
selected on the basis of their ability to decolorize the dye on the plates. Isolated
colonies were then subsequently transferred to Czapek-Dox agar for further study.
Fungal strains with greatest dye tolerance capacity were identified by its different
biochemical characteristics and structural arrangements. Wet mount was prepared
by suspending culture in a few drops of lacto phenol cotton blue solution. The slides
were examined under high and low power magnification with the aid of a dissecting
microscope (Cappuccino and Sherman 2004).
145
2 Materials and Methods
2.1 Dye Stuffs and Chemicals
Acid Blue 193 (AB 193) and Acid violet 90 (AV 90) commonly used in local textile
processing industries were obtained from Rajasthan Dye Chemical Ltd., Chennai,
India. Dyes were dissolved in double distilled water to prepare a stock concentration
(1000 mg L
−1 ) and solutions of the desired concentrations were obtained by successive dilutions. Media components and chemicals were purchased from Himedia Labs,
Bombay, India.
2.2 Sample Collection
Soil samples were collected from the textile industry at Tirupur, Tamil Nadu, India
and were stored at 4 °C until further process.
2.3 Screening and Identification of AB 193 and AV 90
Tolerant Fungi
The soil samples were serially diluted using sterile distilled water and from the 10
–2
to 10
–7 dilutions, 0.1 mL of sample was transferred onto Czapek-Dox agar plate
containing AB 193 and AV 90 (50 mg L
−1 ). Spread plate method was performed and
the plates were incubated at 30 ± 1 °C for 4 days. Fungal colonies were identified
using steriobinocular microscope. Fungi which showed decolorization in CzapekDox agar medium were screened further by transferring in a fresh Czapek-Dox agar
plates containing different dye concentrations (50 and 100 mg L
−1 ). Colonies were
selected on the basis of their ability to decolorize the dye on the plates. Isolated
colonies were then subsequently transferred to Czapek-Dox agar for further study.
Fungal strains with greatest dye tolerance capacity were identified by its different
biochemical characteristics and structural arrangements. Wet mount was prepared
by suspending culture in a few drops of lacto phenol cotton blue solution. The slides
were examined under high and low power magnification with the aid of a dissecting
microscope (Cappuccino and Sherman 2004).