Optimized Production of Lignin Peroxidase, Manganese Peroxidase and Laccase in Submerged Cultures of Trametes Trogii Using Various Growth Media Compositions

A white-rot fungus, Trametes trogii, was isolated from coastal Tanzania and screened for crude lignolytic enzymes production using Rhemazol Brilliant blue R (RBBR) dye, 2,2-azino-bis (3-ethylbenzthiazoline)-6-sulfonate (ABTS) and guaiacol in a semi-solid medium. Lignin peroxidase (LiP), manganese peroxidase (MnP) and Laccase (Lac) were detected by pyrogallol and !- napthol solutions, respectively on the guaiacol supplemented solid media. The effect of temperature, pH, carbon, nitrogen, Cu2+, 2,5-xylidine, ferulic acid, varatryl alcohol and Mn2+ in submerged culture fermentations were investigated for maximum enzymes production. After 7 days of incubation, 72-100% oxidation of RBBR, ABTS and guaiacol was observed. With optimized culture conditions, the fungal filtrate had maximum LiP, MnP and Lac activities of 0.18, 4.44 and 593 U/ml, respectively compared to 0.0011, 0.0054 and 2.3 U/ml obtained with non-optimized ones, amounting to 16,264%, 82,122% and 25,683% increase in LiP, MnP and Lac activities, respectively. The enhanced crude enzymes activities, RBBR decolorization and ABTS guaiacol oxidation capabilities of T. trogii show its potential as a source of industrial enzymes for biotechnological applications.Keywords: Optimization, Trametes trogii, lignin peroxidase, manganese peroxidase, laccase, fermentation, submergedTanz. J. Sci. Vol 36, 2010, 1-1

Optimization of laccase and manganese peroxidase production in submerged culture of Pleurotus sajorcaju

A white-rot fungus, Pleurotus sajor-caju, was isolated from coastal Tanzania and screened for crude lignolytic enzymes production using rhemazol brilliant blue R (RBBR) dye, 2,2-azino-bis (3- ethylbenzthiazoline)-6-sulfonate (ABTS) and guaiacol in a semi-solid medium. Laccase (Lac) and manganese peroxidase (MnP) were detected by a-napthol and pyrogallol solutions, respectively, on the guaiacol supplemented semi-solid media. The effect of temperature, pH, carbon, nitrogen, Cu2+, 2,5- xylidine, ferulic acid, Mn2+ and immobilization using Luffa cylindrica sponges in submerged culture fermentations were investigated for maximum enzymes production. After 7 days of incubation, 83 to 100% oxidation of RBBR, ABTS and guaiacol was observed. With optimized culture conditions, the fungal filtrate had maximum Lac and MnP activities of 80 and 0.94 U/ml, respectively compared to 0.62 and 0.0003 U/ml obtained with non-optimized ones; amounting to 129 and 3133 times increase in Lac and MnP activities, respectively. The improved crude enzymes activities, RBBR decolourization, ABTS and guaiacol oxidation capabilities of P. sajor-caju show its potential as a source of industrial enzymes for biotechnological applications.Key words: White-rot fungi, optimization, Pleurotus sajor-caju, laccase, manganese peroxidase, submerged fermentation, immobilization

Performance of a sisal fibre fixed-bed anaerobic digester for biogas production from sisal pulp waste

A single stage anaerobic digester employing a sisal fibre waste fixed bed was studied for biogas production from sisal pulp waste. The fibre was colonized by microorganisms involved in biogas production. The sisal pulp waste to be digested was fed from the top and was sprinkled intermittently with recirculating leachate from the material. Organic loading rates of 0.1-10 kg volatile solids (VS) m-3d-1 could be applied and methane yields in the range of 0.13-0.48 m3 CH4 kg-1 VS added were obtained. The average methane content in the biogas produced from sisal pulp waste was 55%, and the biogas production rate was 0.15-0.54 m3m-3d-1. The methane yield obtained and the highest organic loading rate that could be sustained by this simple, fixed-bed digester are indications of an attractive system in terms of performance and reliability. It is concluded that the sisal fibre waste fixed bed is a promising carrier for microbes and can be employed for long-term operation without changing the bed. Tanzania Journal of Science Vol. 31 (2) 2005: pp. 41-5

ARPN Journal of Agricultural and Biological Science ANAEROBIC CO-DIGESTION OF BIOLOGICAL PRE-TREATED NILE PERCH FISH SOLID WASTE WITH VEGETABLE FRACTION OF MARKET SOLID WASTE

ABSTRACT Anaerobic co-digestion of various organic wastes has been shown to improve biogas yield of fish wastes. This paper presents the effect of pre-treating Nile perch fish solid waste (FSW) using CBR-11 bacterial culture (CBR-11-FSW) and commercial lipase enzyme (Lipo-FSW), followed by batch anaerobic co-digestion with vegetable fractions of market solid waste (VFMSW) in various proportions, using potato waste (PW) and cabbage waste (CW) as co-substrates either singly or combined. Results indicated that CBR-11 pre-treated FSW co-digested with PW or CW in 1:1 ratio (substrate: inoculum) had positive effect on methane yield, while Lipo pre-treated FSW had negative effect on methane yield. Using CBR-11-FSW:PW the highest yield was 1.58 times more than the untreated FSW. Whereas, using Lipo-FSW:CW the highest yield was 1.65 times lower than un-treated FSW. Furthermore, the optimal mixture of CBR-11 pre-treated FSW and PW and CW co-substrates resulted into higher methane yield of 1, 322 CH 4 ml/gVS using CBR-11-FSW (10):PW (45):CW (45) ratio. The ratio enhanced methane yield to 135% compared to control. In conclusion, results demonstrates that optimal mixture of CBR-11 pre-treated FSW with both PW and CW as co-substrates enhanced methane yield and provide base line data for potential application in continuous anaerobic bioreactors investigation

Anaerobic batch co-digestion of sisal pulp and fish wastes

Co-digestion of various wastes has been shown to improve the digestibility of the materials and biogas yield. Batchwise digestion of sisal pulp and fish waste was studied both with the wastes separately and with mixtures in various proportions. While the highest methane yields from sisal pulp and fish waste alone were 0.32 and 0.39 m(3) CH4/kg volatile solids (VS), respectively, at total solid (TS) of 5%. co-digestion with 33% of fish waste and 67% of sisal pulp representing 16.6% of TS gave a methane yield of 0.62 m(3) CH4/kg VS added. This is an increase of 59-94% in the methane yield as compared to that obtained from the digestion of pure fractions at 5% TS. (C) 2004 Elsevier Ltd. All rights reserved

Effect of particle size on biogas yield from sisal fibre waste

The degradation and biogas production potential of sisal fibre waste could be significantly increased by pre-treatment for reduction of particle size. Batch-wise anaerobic digestion of sisal fibre waste was carried out in 1-l digesters with fibre sizes ranging from 2 to 100 mm, at an ambient temperature of 33 °C. Sediment from a stabilisation pond at a sisal production plant was used as starter seed. Total fibre degradation increased from 31% to 70% for the 2 mm fibres, compared to untreated sisal fibres. Furthermore, the results confirmed that methane yield was inversely proportional to particle size. Methane yield increased by 23% when the fibres were cut to 2 mm size and was 0.22 m3 CH4/kg volatile solids, compared to 0.18 m3 CH4/kg volatile solids for untreated fibres. By anaerobic digestion and biogas production, the 148,000 tonne of waste sisal fibres generated annually in Tanzania could yield 22 million m3 of methane, and an additional 5 million m3 of methane if pre-treatment by size reduction to 2 mm was applied

Influence of recirculation flow rate on the performance of anaerobic packed-bed bioreactors treating potato-waste leachate

The performance of anaerobic, packed-bed bioreactors treating leachate from potato waste was evaluated in terms of organic loading rate (OLR) as well as the recirculation flow rate. Two 1 litre bioreactors, filled with porous glass beads as biofilm carriers and with continuous recirculation flow rates of 10 ml min(-1) and 20 ml min(-1) respectively, were used in the experiment. The OLR applied to each bioreactor was increased stepwise from 4 to 12 kg chemical oxygen demand (COD) m(-3)d(-1) by increasing feed flow rate. The methane yields decreased with increasing OLR in both bioreactors. The methane yield for the bioreactor with the lower recirculation flow rate ranged between 0.10 and 0.14 m(3) CH4 kg COD-1 removed, while for the other bioreactor it was 0.14-0.20 m(3) CH4 kg COD-1 removed. Both bioreactors demonstrated stable COD removal which was around 95% for the bioreactor with lower flow of recirculation while for the other it was 92%, over a range of OLRs of 4-8 kg COD m(-3)d(-1). The bioreactor with the lower recirculation flow rate showed operational stability when a high OLR, namely 12 kg COD m(-3)d(-1), was applied, while the other one became overloaded. There was an accumulation of volatile fatty acids which gave a corresponding drop in pH because the system had a low buffering capacity and this thus ultimately led to process failure. This study demonstrated the suitability of a packed bed bioreactor operated at lower recirculation flow rate for treating leachate from potato waste

Waste management from pulp and paper production in the European Union

Eleven million tonnes of waste are produced yearly by the European pulp and paper industry, of which 70% originates from the production of deinked recycled paper. Wastes are very diverse in composition and consist of rejects, different types of sludges and ashes in mills having on-site incineration treatment. The production of pulp and paper from virgin pulp generates less waste but the waste has similar properties to waste from the production of deinked pulp, although with less inorganics. Due to legislation and increased taxes, landfills are quickly being eliminated as a final destination for wastes in Europe, and incineration with energy recovery is becoming the main waste recovery method. Other options such as pyrolysis, gasification, land spreading, composting and reuse as building material are being applied, although research is still needed for optimization of the processes. Due to the large volumes of waste generated, the high moisture content of the waste and the changing waste composition as a result of process conditions, recovery methods are usually expensive and their environmental impact is still uncertain. For this reason, it is necessary to continue research on different applications of wastes, while taking into account the environmental and economic factors of these waste treatments