Industrial polluted soil borne fungi decolorize the recalcitrant azo dyes Synozol red HF-6BN and Synozol black B.

Today's world needs to control the industrial pollution through smarter ways. Presently, we observed the capacity of soil borne fungi to digest Synozol Red HF-6BN and Synozol Black B. Initially, 86 fungal strains were isolated from soil samples randomly collected from industrial sites. Among these, 31 isolates were capable of dye decolorization on solid media, with SN12f and SN13a isolates showed the highest decolorization capacity. The dye decolorization by both strains was higher (80-95%), when incubated for 120 h under optimized conditions of pH, concentration, nutrient source and temperature. The dye (Synozol red HF-6BN and Synozol black B) decolorization by SN12f isolate was maximum (˃90%) at pH7, whereas the SN13a decolorized 90% of Synozol red HF-6BN and 89% of Synozol black B at pH3. The SN13a and SN12f isolates at 40 mg/L showed de-colorization of 94.71%, 81.4% (for Synozol red HF-6BN) and 90.5%, 84.4% (Synozol black B), respectively. Our isolates also mitigated the toxic effect of azo dyes on the growth of phosphate solubilizing soil bacteria. In fact, the untreated effluent showed toxic effects on the growth of beneficial bacterial by developing zone of inhibition (16.5 mm around Aeromonas spp., 14.5 mm around Sallmonella while 14.25 mm around Citrobacter spp). However, the fungal treated dye was unable to develop zone of inhibition. Laccase activity was positive for both of fungal isolates after incubation on Bassnell Hass Medium (0.0733 U/mL for SN12f and 0.0439 U/mL SN13a). Using molecular approaches (ITS region), SN12f was identified as Aspergillus nidulans, while SN13a as Aspergillus fumigatus. The current study showed that local fungal flora can reclaim the contaminated soils and support the agro-friendly micro-flora.

Efficacy of Fungi in the Decolorization and Detoxification of Remazol Brilliant Blue Dye in Aquatic Environments.

Industrial effluents result in water pollution and affect the biological activity of aquatic and terrestrial life. In this study, efficient fungal strains were isolated from the aquatic environment and identified as Aspergillus fumigatus (SN8c) and Aspergillus terreus (SN40b). The isolates were selected based on their potential to efficiently decolorize and detoxify Remazol brilliant blue (RBB) dye, which is extensively used in different industries. Initially, a total of 70 different fungal isolates were screened. Among these, 19 isolates demonstrated dye decolorization capabilities, and SN8c and SN40b revealed the highest decolorization capabilities in liquid medium. The maximum estimated decolorization for SN8c was 91.3% and for SN40b, 84.5% at 40 mg/L of RBB dye in the presence of glucose (1 gm/L), after 5 days of incubation at different levels of pH, temperature, nutrient source, and concentration. RBB dye decolorization using SN8c and SN40b isolates was at a maximum of 99% at pH 3-5, whereas minimum decolorization was recorded as 71.29% and 73.4% SN8c, respectively, at pH 11. The maximum decolorization of the dye was 93% and 90.9% in a defined glucose concentration of 1 gm/L, and a 63.01% decrease was recorded in the decolorization activity at a low level of glucose concentration (0.2 gm/L). Finally, the decolorization and degradation were detected using UV spectrometry and HPLC. Toxicity tests of pure dye and treated dye samples were checked against the seed germination of different plants and the larvae mortality of Artemia salina. This study revealed that indigenous aquatic fungal flora can recover contaminated sites and support aquatic and terrestrial life.