[Lead adsorption by Trametes gallica, Bacillus cereus, and their co-immobilized biomaterial].

Taking Trametes gallica mycelium pellets, Bacillus cereus, and their co-immobilized biomaterial as bio-adsorbents, this paper studied their Pb2+ adsorption under effects of different contact time, medium initial pH value and Pb2+ concentration, and bio-adsorbent concentration, and compared the infrared spectra of the bio-adsorbents before and after Pb2+ absorption. The Pb2+ adsorption efficiency of the bio-adsorbents was the highest when the bio-adsorbent concentration was 2 g x L(-1), initial pH was 5.0, initial Pb2+ concentration was 50 mg x L(-1), and contact time was 1 h, with the Pb2+ biosorption rate being 71.7% for the mycelium pellets of T. gallica, 91.0% for B. cereus, and 96.9% for the co-immobilized biomaterial. The infrared spectra of the bio-adsorbents were mainly consisted of the absorption zones of protein, carbohydrates, and sulphur- and phosphors-based groups, suggesting that hydroxyl, carboxyl, and sulphur- and phosphate-based groups played important roles in the Pb2+ adsorption by the bio-adsorbents.

[Biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5].

With a shaker, this paper studied the characteristics of the biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5 under different adsorption time, initial pH, and temperature, as well as the desorption and recycling use of the dyes. The biosorption of crystal violet and malachite green by R. graminis Y-5 had the peaks (93.8% and 87.7%, respectively) at pH 7.0, dye concentration 50 mg x L(-1), 150 r x min(-1), 30 degrees C, and lasting 10 hours. After desorption, the biosorption rate of crystal violet and malachite green by R. graminis was 85.5% and 78.5%, respectively, indicating that the biosorption of crystal violet and malachite green was reversible, and the recycling use of the dyes by R. graminis was quite good, i. e., the dyes were renewable and could be recycled. Biosorption could be the mechanism of the decolorization of the dyes. The dyes were mostly adsorbed on the R. graminis surface -OH. The adsorption process was fast, efficient, and reversible, suggesting that R. graminis had a high potential for waste water treatment.

[Induce of laccase from Trametes gallica and its degradation on neutral dyes and organophosphorus pesticides].

The characteristics of the induction of laccase in Trametes gallica under different initial cultural pH, incubation time by different inducers were discussed, as well as the effects of temperature, pH and time on laccase degradation of six dyes and four organophosphors. The results showed that RB-bright blue, ABTS and o-toluidine affected the production of laccase at different levels, and ABTS was the best inductive agent in our test conditions, whose optimal initial pH and incubation time were 4.0 and 13 days, respectively. The appropriate reaction temperature of the laccase produced was 38 degrees C, and it got a good stability, for it could retain 78.6% of the enzyme activity after 20 min holding at 40 degrees C. Mediated by ABTS, the optimal temperature for laccase to degrade the six types of neutral dyes could be divided into two cases, that was 30 degrees C (neutral black, neutral bordeaux, neutral pink, methyl orange) and 60 degrees C (neutral dark yellow, cresol red), the optimal pH were 6.0 (neutral black), 2.0 (neutral bordeaux, neutral pink) and 4.0 (methyl orange, neutral dark yellow, cresol red), respectively, while the optimal times separately were 6 h (methyl orange, neutral dark yellow, cresol red), 12 h (neutral pink) and 24 h (neutral bordeaux). And using the same inductive agent, the best temperature for laccase to degrade dimethoate, chlorpyrifos, trichlorfon and parathion-pyridazine was 25 degrees C, the suitable time was 9 h, and the optimal pH was 10.0 for dimethoate, chlorpyrifos and parathion-pyridazine, and 8.0 for trichlorfon.