Panus tigrinus as a potential biomass source for Reactive Blue decolorization: isotherm and kinetic study

Background: Textile and dye industries pose a serious threat to the environment. Conventional methods used for dye treatment are generally not always effective and environmentally friendly. This drove attention of scores of researchers to investigate alternative methods for the biodegradation of dyes using fungal strains. In this work, white-rot fungus (Panus tigrinus) was used as a biosorbent for the decolorization of Reactive Blue 19. The process parameters that were varied were initial concentration (50­150 mg/L), contact time (30­90 min), and pH (2­6). In addition, to gain important data for the evaluation of a sorption process, the equilibrium and kinetics of the process were determined. Results: White-rot fungus showed great potential in decolorizing Azo dyes. The strain showed the maximum decolorization of 83.18% at pH 2, a contact time of 90 min, and an initial concentration of 50 mg/L. The Langmuir isotherm described the uptake of the Reactive Blue 19 dye better than the Freundlich isotherm. Analysis of the kinetic data showed that the dye uptake process followed the pseudo second-order rate expression. Conclusion: The biosorption process provided vital information on the process parameters required to obtain the optimum level of dye removal. The isotherm study indicated the homogeneous distribution of active sites on the biomass surface, and the kinetic study suggested that chemisorption is the rate-limiting step that controlled the biosorption process. According to the obtained results, P. tigrinus biomass can be used effectively to decolorize textile dyes and tackle the pollution problems in the environment.

Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus

Lenzites betulinus, known as gilled polypore belongs to Basidiomycota was isolated from fruiting body on broadleaf dead trees. It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07, and 0.26 g of ethanol per gram of sugar consumed, respectively. This fungus relatively exhibited a good ethanol production from xylose at 0.26 g of ethanol per gram of sugar consumed. However, the ethanol conversion rate of arabinose was relatively low (at 0.07 g of ethanol per gram sugar). L. betulinus was capable of producing ethanol directly from rice straw and corn stalks at 0.22 g and 0.16 g of ethanol per gram of substrates, respectively, when this fungus was cultured in a basal medium containing 20 g/L rice straw or corn stalks. These results indicate that L. betulinus can produce ethanol efficiently from glucose, mannose, and cellobiose and produce ethanol very poorly from galactose and arabinose. Therefore, it is suggested that this fungus can ferment ethanol from various sugars and hydrolyze cellulosic materials to sugars and convert them to ethanol simultaneously.

Novel application of fungal Phanerochaete sp. and xylanase for reduction in pollution load of paper mill effluent.

Four different strategies of pulping and bleaching were carried out to develop alternative mechanistic ecoenvironmental friendly approaches and generated effluent was characterised. Strategy-I included Phanerochaete sp. fungal pretreatment followed by conventional bleaching, whereas in strategy-II, fungal pretreatment was followed by enzyme xylanase aided bleaching. Strategy-III also included xylanase supplement but without prior fungal pretreatment. Chemically driven pulping and bleaching was the IV strategy. Conventional CDEOPD1D2 sequence of bleaching was used for strategy–I and IV whereas XCDEOPD1D2 sequence was applied to strategy–II and III. Strategy–II was responsible for 27.5% reduction in Kappa no. whereas the maximum (27.5%) reduction in refining energy was observed with strategy–II. Biobleaching strategies– II and III were helpful in saving 37.3 and 20.3% of elemental chlorine (Cl2) and 30.8 and 23.1% of chlorine dioxide (ClO2), respectively. In comparison to control (strategy-IV), strategy II resulted in maximum pollution load reduction of chemical oxygen demand (COD), biological oxygen demand (BOD), color and adsorbable organic halides (AOX) upto 57, 60, 30 and 43.6%, respectively.

STUDIES ON BLEACHING OF PULP BY WHITE-ROT FUNGUS / 微生物学通报

This article summarizes the bleaching of pulp by white-rot fungus, including the type of white-rot fungus, the type of pulp, the equipment used to bleach by white-rot fungus, and some problems and prospect in practical application by white-rot fungus.

PRELIMINARY STUDIES ON LACCASE PRODUCTION BY A WHITE-ROT FUNGUS AH28-2 / 微生物学通报

A novel white-rot fungus AH28-2,which was isolated from 224 fungi samples,ability to produce effectively laccase by induction.Several factors influencing laccase production were investigated.The optimum conditions were as follows:the 300mL Erlenmeyer flask containing 150mL of liquid medium was inoculated with 7.5mL of mycelial fragments and the medium was supplied with lignin at a concentration of 0.1%(initial pH8.5).The cultures was incubated at 28℃ on rotary shaker(150r/min) for 4～5 days.The maximum enzyme activity was 20184IU/L.

STUDY ON LIQUID CONDITIONS IN SHAKING FLASKS FOR LACCASE PRODUCTION BY A WHITE ROT FUNGUS / 微生物学通报

A white-rot fungi Rigidoporus sp.W-1 which could produce laccase was isolated. The fermentation conditions in shaking flasks were investigated. The optimal carbon source was wheat bran and (NH 4) 2SO 4 was the optimal nitrogen source. The components of the medium were optimized by orthogonal experiment. When W-1 was cultured under the optimum conditions, the activity of laccase could get to 7.1U/mL in 7 days.A great amount of crude laccase could be obtained by adding fresh medium to the 7 days old mycelium.