Bhavin Rawal's scientific contributions

Using Remazol Brilliant Blue R (RBBR), strains of terrestrial white rot (WRF) and marine fungi (MF) were screened for efficient decolorization. Dye degradation potential of selected strains was studied with chemically different dyes (azo, anthraquinone, heterocyclic, triphenylmethane). Irpex lacteus and Pleurotus ostreatus (WRF) efficiently degraded dyes from all groups whereas less efficient and selective degradations were observed with Dactylospora haliotrepha and Aspergillus ustus (MF). Seawater salinity often reduced decolorization efficiency of WRF but increased decolorization ability of MF. In soil /. lacteus removed 77 % of RBBR used at 150 |ig/g within 6 weeks. The work presents ftingi as suitable candidates to be applied to re-mediation of dye-contaminated water and soil.

The rate and efficiency of decolorization of poly R-478- or Remazol Brilliant Blue R (RBBR)-containing agar plates (200 microg x g(-1)) were tested to evaluate the dye degradation activity in a total of 103 wood-rotting fungal strains. Best strains were able to completely decolorize plates within 10 days at 28 degrees C. Irpex lacteus and Pleurotus ostreatus were selected and used for degradation of six different groups of dyes (azo, diazo, anthraquinone-based, heterocyclic, triphenylmethane, phthalocyanine) on agar plates. Both fungi efficiently degraded dyes from all groups. Removal of RBBR, Bromophenol blue, Cu-phthalocyanine, Methyl red and Congo red was studied with I. lacteus also in liquid medium. Within 14 days, the following color reductions were attained: RBBR 93%, Bromophenol blue 100%, Cu-phthalocyanine 98%, Methyl red 56%, Congo red 58%. The ability of I. lacteus to degrade RBBR spiked into sterile soil was checked, the removal being 77% of the dye added within 6 weeks. The capacity of selected white rot fungal species to remove efficiently diverse synthetic dyes from water and soil environments is documented.

Soil contaminated with the synthetic dye Remazol Brilliant Blue R (RBBR) was treated independently with the wheat straw-grown white rot fungus Irpex lacteus, a bacterial consortium isolated from a dye-polluted soil and a coculture comprising both I. lacteus and the bacterial consortium. Both I. lacteus and the coculture removed RBBR (decrease in absorbance at 578 nm) gradually during a 49-day incubation time to 76 and 78%, respectively. The bacterial consortium alone, however, decolorized RBBR starting after 14 days with a final RBBR removal of 89%. Using controls with heat-killed cultures almost no decolorization occurred. The decolorization by the coculture did not show an increased RBBR removal as compared to the individual cultures. This might be explained by the observation that I. lacteus inhibited growth of the bacterial consortium.

A first report on the occurrence of 22 species of filamentous fungi in the hypersaline (340 g I-1 salinity) Dead Sea is presented. Fungal species belonging to Zygomycotina (1 sp.), Ascomycotina (17 sp.) and Mitosporic fungi (4 sp.) were isolated from water samples of the Dead Sea. A new species Gymnascella marismortui Buchalo et al. has been found. Growth, enzyme (amylase, caseinase, urease, cellulase) activitites and dye degradation depending on salinity and temperature of some isolated fungi were studied. It was concluded that enzyme production and dye degradation decreased with increasing salinity and temperature. Most of the fungi isolated from the Dead Sea are known halotolerant soil inhabitants. The authors hypothesize that the obligate halophilic G. marismortui may represent an authentic inhibitant of the Dead Sea.