Browsing by Author "Mtui, Godliving Y. S."
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Item Adaptation Technologies and Legal Instruments to Address Climate Change Impacts to Coastal and Marine Resources in Tanzania(2008-09) Sallema, R. E.; Mtui, Godliving Y. S.The increase in greenhouse gases in the atmosphere and the consequent pressures related to climate change are having significant impacts on the coastal and marine resources on which much of Tanzania’s coastal population depends for its livelihood. A decline in mangrove cover, coral bleaching and mortality and the destruction of seagrass beds are some of these impacts. Coastal erosion also poses threats to the country’s coastal tourism infrastructure. This study examines various approaches that integrate protection and conservation of coastal and marine resources. It briefly highlights the global and regional issues while emphasis is put on Tanzanian perspective. Guidelines and reports for management interventions and adaptive technologies are discussed. Environmental protection remains the most preferred approach with variety of options. An overview is given on soft and hard adaptation technologies. Furthermore, Tanzania’s relevant policies and legislation that address climate change impacts to coastal and marine resources are reviewed.Item Additive Effect of Soybean Curd Residue, Okara, for Enhancement of Methane Production from Pretreated Woody Waste(2005) Take, Harumi; Mtui, Godliving Y. S.; Kobayashi, Fumihisa; Nakamura, YoshitoshiIn order to convert woody waste into methane gas efficiently, the pretreatment effect of steam explosion and the additive effect of soybean curd residue, okara, were clarified. 180 mL of methane gas was obtained from 1 g of steam-exploded Japanese cedar chips at a steam pressure of 4.51 MPa and a steaming time of 5 min while no methane gas was produced from untreated chips. The addition of okara into the chips was attempted and the optimal condition, i.e. C/N of 18, increased the methane gas produced to 315 mL.Item Anaerobic Fermentation of Woody Biomass Treated by Various Methods(2003-06) Nakamura, Yoshitoshi; Mtui, Godliving Y. S.Anaerobic fermentation was attempted to produce methane from the wood chip (Eucalyptus globulus). By the pretreatment of the wood chip using hot water with high temperature, NaOH, and steam explosion, the production of methane gas was enhanced. The pretreatment using steam explosion resulted in more amount of methane gas produced than the treatment using either hot water or 1% (w/w) NaOH with high temperature, and the steam explosion at a steam pressure of 25 atm and a steaming time of 3 min was the most effective for the methane production. The amount of methane gas produced depended on the ratio of weight of Klason lignin, a high molecular weight lignin, in the treated wood chip.Item Bioconversion of Lignocellulosic Waste from Selected Dumping Sites in Dar es Salaam, Tanzania(2004-11) Mtui, Godliving Y. S.; Nakamura, YoshitoshiThe poor management of solid wastes in Tanzania urban centers is a chronic problem that has increasingly become a source of environmental pollution. Bioconversion offers a cheap and safe method of not only disposing these wastes, but also it has the potential to convert lignocellulosic wastes into usable forms such as reducing sugars that could be used as food. This paper reports a preliminary study on the physical characteristics, acid pretreatment, saccharification by cellulase from Trichoderma reesei and fermentation by Saccharomyces cerevisiae of the lignocellulosic component of the solid wastes collected from various dumping sites located in Kinondoni Municipality, Dar es Salaam city. The results showed that overall, the lignocellulosic component constitute about 50% of solid wastes dumped in the study areas. Maximum production of reducing sugars was obtained after 6 h of saccharification while highest concentrations of bioethanol were achieved after 48 h of fermentation. Microbial bioconversion of lignocellulose component yielded up to 21% bioethanol.Item Biodegradation of Endocrine-disrupting Phenolic Compounds Using Laccase Followed by Activated Sludge Treatment(2003-07) Nakamura, Yoshitoshi; Mtui, Godliving Y. S.Endocrine-disrupting phenolic compounds in the water were degraded by laccase fromTrametes sp. followed by activated sludge treatment. The effect of temperature on the degradation of phenolic compounds and the production of organic compounds were investigated using endocrine-disrupting chemicals such as bisphenol A, 2,4-dichlorophenol, and diethyl phthalate. Bisphenol A and 2,4-dichlorophenol disappeared completely after the laccase treatment, but no disappearance of diethyl phthalate was observed. The Michaelis-Menten type equation was proposed to represent the degradation rate of bisphenol A by the lacasse under various temperatures. After the laccase treatment of endocrine-disrupting chemicals, the activated sludge treatment was attempted and it could convert about 85 and 75% of organic compounds produced from bisphenol A and 2,4-dichlorophenol into H2O and CO2, respectively.Item Biosafety Systems in Eastern and Central Africa(2012-02) Mtui, Godliving Y. S.This review examines the biosafety systems of selected countries in the Eastern and Central Africa. The biosafety systems are meant to safeguard human health, animal health and the environment against any possible risks posed by development and application of modern biotechnology. Though the focus is in the Eastern and Central African region, the study gives an overview of worldwide biosafety frameworks as guided by the Cartagena protocol on biosafety. The Eastern and Central African countries covered in this study are Tanzania, Kenya, Uganda, Rwanda, Burundi, Ethiopia and the Democratic Republic of Congo (DRC). An attempt is made to assess the current status on the countries’ compliance to biosafety international conventions, institutional arrangements and regulatory regimes. A critical look is given to the existing biosafety frameworks, pinpointing their weaknesses and giving suggestions on what could be done to address the shortfalls. The study shows that Kenya is leading the group by having all the requirements in place, followed by Uganda. Tanzania has cleared the legal frameworks hurdles, but it is rather slow in processing applications of genetically modified organisms (GMOs) for containment and confined trials. Ethiopia, Rwanda, Burundi and DRC are still in the process of formulating their biosafety laws. The challenges facing the operationalization of the biosafety systems are financial constraints, insufficient trained human resources, poor facilities, low awareness and insufficient political will by some governments. It is argued that while biosafety frameworks stand to safeguard safe application of modern biotechnology, they should not have too stringent regulations, lest they impede the development of modern biotechnology in the Eastern and Central African region.Item Continuous Production of Lignin-degrading Enzymes by Bjerkandera Adusta Immobilized on Polyurethane Foam(2002-11) Mtui, Godliving Y. S.; Nakamura, YoshitoshiContinuous production of lignin-degrading enzymes by Bjerkandera adusta immobilized on polyurethane foam gave maximum activities of 220 U lignin peroxidase ml−1, 150 U manganese peroxidase ml−1, 50 U laccase ml−1 and 6.2 U protease ml−1 at the retention time of 24 h for 60 days. Protease secretion destabilized the produced lignin peroxidase, manganese peroxidase and laccase.Item Degradation of 2,4-Dichlorophenoxyacetic Acid (2,4-D) by Ozonation and TiO2/UV Treatment(2007-04) Daidai, Masakazu; Kobayashi, Fumihisa; Mtui, Godliving Y. S.; Nakamura, YoshitoshiThe degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was conducted by ozonation, TiO2/UV treatment only, and two-stage treatment of ozonation followed by TiO2/UV treatment. In the case of ozonation, 2,4-D could be degraded and vanished within about 10 min at pH 9 and 20°C, but the TOC value was reduced by only about 40% by 30 min ozonation. In the case of TiO2/UV treatment, about 5 d was needed for complete disappearance of 2,4-D at pH 5 and 20°C. On the other hand, when the two-stage treatment of ozonation plus TiO2/UV treatment was applied, 90% decline of TOC was achieved within about 20 h, i.e., 30 min ozonation and 20 h TiO2/UV treatment thereafter. Furthermore, 90% of chloride ions in 2,4-D were liberated by the two-stage treatment. From a bioassay test of the two-stage treated water by the use of an osteoclasts of goldfish scales or Daphnia magna, it was found that 2,4-D was degraded into harmless substances with little estrogen activity and toxicity.Item Development of optimal Culture Method of Sparassis crispa mycelia and new extraction method of Antineoplastic Constituent.(2006-05) Kurosumi, Akihiro; Kobayasi, Fumihisa; Mtui, Godliving Y. S.; Nakamura, YoshitoshiThe optimal culture condition of basidiomycete Sparassis crispa mycelia was determined for producing a large amount of antineoplastic constituent, i.e. β-1,3-glucan. Furthermore, a new extraction method with steam explosion as a pretreatment was attempted to increase the amount of antineoplastic constituent extracted from S. crispa mycelia. The shake-flask liquid culture of fungal mycelia could shorten a culture time up to about 1/3 compared with the conventional stationary liquid culture. The productivity of S. crispa mycelia reached its maximum at an initial glucose concentration of 30 g/L, a culture temperature of 25–30 °C, and pH 5. Steam explosion at a steam temperature of 225 °C for 5 min not only enhanced the amount of antineoplastic constituent extracted from the mycelia but also shortened the extraction time significantly.Item Influence of Sampling Depth and Post-sampling Analysis Time on the Occurrence of Coliforms and Vibrio in Water and Shellfish(2005) Sallema, R.E; Mtui, Godliving Y. S.The bacteriological quality was examined at the water surface, 3 m depth and in the shellfish flesh, and the results were compared to other potential pathogenic indicator organisms. The study was conducted at Long Harbour (mussel farm), St. John's and Outer Cove sites of Newfoundland, Canada. Bacteriological analysis was carried out for samples taken at water depth and at 1, 6, 12 and 24 hours post-sampling. It was observed that the total and faecal coliform bacteria were significantly higher in the 3 m water depth samples than in the surface water samples (ANOVA, F = 59.41, 26.751, 9.82 (T.C); 46.41, 26.81, 10.72 (F.C); P <0.001). In addition, shellfish tissues had substantial amounts of coliform bacteria levels, which varied significantly with station and date of sampling (F = 128.21,37.42 (T.C); 1281, 37.42 (F.C); P <0.05). The higher levels reflect bioaccumulation. There were no correlations between estimates of total or faecal coliforms with potential pathogenic Vibrio groups. Furthermore, there were no significant differences in total and faecal coliforms among the post-sampling time intervals. The results suggest that sampling and bacteriological analysis of water and shellfish for quality control should consider both the water surface and depths proximal to the shellfish. Moreover, adoption of extended post-sampling time may lead to a more convenient and less costly approach to monitoring of bacteriological impact on the coastal marine environments.Item Involvement of Biotechnology in Climate Change Adaptation and Mitigation: Improving Agricultural Yield and Food Security(2011-12) Mtui, Godliving Y. S.In the context of climate change adaptation and mitigation, biotechnology can respond positively towards reducing vulnerability of natural and human systems to climate change effects. This paper reviews different approaches in which both conventional and modern biotechnology can be employed to address climate change adaptation and mitigation for improved crops adaptability, productivity and food security and contributing to the reduction of the greenhouse gases. The current challenges and future perspectives of biotechnology for climate change adaptation and mitigation are highlighted. The negative effects of climate change on agricultural productivity and food security as a result of extreme temperature, drought, salinity and infectious disease vectors include low yield, hunger and malnutrition. Conventional agricultural biotechnology methods such as energy-efficient farming, use of biofertilizers, tissue culture and breeding for adaptive varieties are among feasible options that could positively address the potential negative effects of climate change and thereby contributing to carbon sequestration initiatives. On the other hand, the adoption of modern biotechnology through the use of genetically modified stress-tolerant, energy-efficient and high-yielding transgenic crops also stand to substantially counter the negative effects of climate change. Safe application of biotechnology will greatly complement other on-going measures being taken to improve agricultural productivity and food security. Both conventional and modern agricultural biotechnologies will significantly contribute to the current and future worldwide climate change adaptation and mitigation efforts.Item Lignin Peroxidase Production by Phanerochaete Chrysosporium Immobilized on Polyurethane Foam(2005-02) Nakamura, Yoshitoshi; Sawada, Tatsuro; Mtui, Godliving Y. S.; Kobayashi, Fumihisa; Kuwahara, Masaaki; Ito, HiromichiProduction of lignin peroxidase by a white-rot basidiomycete, Phanerochaete chrysosporium, was investigated experimentally using polyurethane foam as a carrier of immobilized fungal mycelia. The immobilized cell culture using polyurethane foam as a carrier of mycelia yielded significantly greater lignin peroxidase activity than the conventional stationary liquid culture. The effects of operational conditions, such as the kind and number of polyurethane foam cubes, glucose concentration and temperature, on the lignin peroxidase production were examined. Addition of 0.05% Tween 80, 1 mM veratryl alcohol and 1 mM FeSO4-·7H2O greatly improved the production of lignin peroxidase up to 2,700 units/ml culture medium. The lignin peroxidase activity in this culture was about three times larger than that obtained from the culture cultivated in the absence of these additives. Step change incubation lowering the temperature from 37°C to 30°C over an incubation time of three days was carried out for the large scale production of lignin peroxidase, and this incubation gave the highest lignin peroxidase activity 3,800 units/ml culture medium.Item Lignin-degrading Enzyme Production by Bjerkandera Adusta Immobilized on Polyurethane Foam(1999-10) Nakamura, Yoshitoshi; Mtui, Godliving Y. S.; Sawada, Tatsuro; Kuwahara, MasaakiProduction of the lignin-degrading enzymes lignin peroxidase (Lip), manganese peroxidase (MnP), and laccase (Lac) by the white-rot fungus Bjerkandera adusta was investigated experimentally using polyurethane foam (PUF) as a carrier of immobilized fungal mycelia. An immobilized cell culture with a low-nitrogen medium yielded significantly greater LiP, MnP, and Lac activities in comparison with those obtained in a liquid culture. The maximum activities of the three enzymes were 450, 370, and 100 U/ml, respectively, under the following incubation condition: glucose concentration, 20 g/l; temperature, 30°C; pH 4.5. The activities of MnP and Lac were significantly higher than those reported using other incubation methods. Lignin was degraded to the extent of 40% and its decolorization ratio was about 70% at an incubation time of 40 h using lignin-degrading enzymes from B. adusta. Six different isozymes of MnP were synthesized by B. adusta, two of which exhibited high MnP activity. Our preliminary finding that extracellular enzymes from B. adusta are capable of degrading and decoloring lignin makes these enzymes attractive for further research aimed at their large-scale application in lignin depolymerization, pulp biobleaching, and the degradation of toxic pollutants.Item Lignin-Degrading Enzymes from Mycelial Cultures of Basidiomycete Fungi Isolated in Tanzania(2004-06) Mtui, Godliving Y. S.; Nakamura, YoshitoshiThis research involved field surveys in different geographical locations in Tanzania for collection of fungi species, identification of the isolates, and screening for lignin-degrading enzyme production. Out of 18 saprophytic fungi (both wood and non-wood inhabiting) isolates, 17 were positive in the rhemazol brilliant blue-R (RBBR) decolorization test; 15 of the isolates oxidized guaiacol while 7 and 12 oxidized α-naphthol and pyrogallol, respectively. The cultures with 1% glucose concentration showed the fastest growth of mycelia and highest MnP, LiP, and Lac activities. MnP was found to be dominant among the tested isolates and Laetiporus sulphurae had the highest LiP activity of 65.2 U/ml. Most of the fungi isolates produced more than two extracellular enzymes, suggesting that these isolates possess the ability to degrade lignin or related polyphenolic compounds, and thus they can be used in upgrading low quality animal feed. The selected fungi isolates reduced cellulose and hemicellulose contents in rice straw by an average of 10% and 35%, respectively, delignification ratio of 23% and increased its relative crude protein content by more than 50%.Item Lignocellulosic Enzymes from Flavodon Flavus, a Fungus Isolated from Western Indian Ocean off the Coast of Dar es Salaam, Tanzania(2008-07) Mtui, Godliving Y. S.; Nakamura, Y.Marine basidiomycetes fungus Flavodon flavus (Klotzsch) Ryvarden was isolated from sea grass at Mjimwema in the Western Indian Ocean off the Coast of Dar es Salaam, Tanzania, and cultured in the laboratory. Protein content and lignocellulosic enzyme activities were measured by photometric methods. Desalted and size-separated enzyme filtrates were resolved by sodium docecyl sulphatepolyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF). The fungal filtrate had maximum lignin peroxidase (LiP), manganese peroxidase (MnP) and Laccase (Lac) activities of 42, 25 and 15 U/mL, respectively. At low carbon medium, F. flavus showed effective (92 - 100%) decolorization of raw textile wastewater and synthetic dyes such as rhemazol brilliant blue-R (RBB-R), Brilliant green, Congo red, Reactive black and Reactive yellow. SDS-PAGE analysis showed major bands of sizeseparated enzymes from F. flavus at relative molecular weights between 45 and 70 kDa. The LiP of F. flavus, purified by ion exchange chromatography, revealed that it has a molecular weight of 46 kDa and isoelectric point (pI) of 3.8. The study confirmed extracellular enzymes from F. flavus to be potential degraders of organic pollutants and showed that facultative marine fungi that live under harsh seawater conditions are suitable for bioremediation of recalcitrant environmental pollutants.Item Manufacturing Method of Okara-Containing Soybean Curd Using Steam Explosion(2008) Nakamura, Yoshitoshi; Kurosumi, Akihiro; Mtui, Godliving Y. S.Development of novel manufacturing method of soybean curd including Okara using steam explosion was attempted. Furthermore, the main contents (i.e. moisture, crude fiber, protein lipid and ash) and rupture stress of the soybean curd produced by novel manufacturing method were investigated. It was able to produce the soybean curd which included a lot of crude fiber by the miniaturization of crude fiber in Okara using steam explosion. By addition of the steam exploded Okara to soybean curd not only the utilization of Okara but also the possibility of the high-nutrition soybean curd production was suggested.Item Microbial Treatment of Kraft Pulp Wastewater Pretreated with Ozone(1997-02) Nakamura, Y.; Sawada, T.; Kobayashi, F.; Mtui, Godliving Y. S.Kraft pulp wastewater was treated with a combination of ozone and activated sludge. The effects of pH on the degradation of lignin and the production of organic acids were examined experimentally in the ozonolysis of wastewater. The strong alkaline condition enhanced not only the degradation of lignin but also the production of organic acids. The dynamic behaviours of microbial growth and substrate consumption were investigated in the biodegradation of organic acids using activated sludge. Maleic acid and oxalic acid in the ozonized wastewater were degraded completely by the activated sludge. The immobilized activated sludge culture using polyurethane foam was effective in degrading organic acids.Item Monitoring of Heavy Metal Loading into the Wetlands South of Lake Victoria Basin, Nothern Tanzania(2009) Mutakyahwa, M.K.D; Ikingura, J.R.; Mtui, Godliving Y. S.The paper discusses sources, concentrations and physicochemical parameters of heavy metals of environmental concern in the wetlands of Lake Victoria basin in Tanzania. The metals investigated include copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr), nickel (Ni), arsenic (As), manganese (Mn), cobalt (Co) and mercury (Hg). These metals are released into the wetlands via weathering and erosion of rock formations, mining operations and industrial activities, discharge of municipal and domestic waste, and use of agrochemicals. The levels of these heavy metals in soil, sediment, water, and biota differ. Wetlands impacted by gold mining activities in the South Lake Victoria basin show elevated heavy metal contents in soil and sediment, particularly Cu (13-415 mg/kg), Pb (24-94 mg/kg), Zn (9-80 mg/kg), Cr (19-77 mg/kg), Ni (12-37 mg/kg) and Hg (0.19-1.76 mg/kg), contrary to non-impacted wetlands, which contain relatively low concentration of these metals (Cu 1-18 mg/kg, Pb 0-27 mg/kg, Zn 5-22 mg/kg; Cr 5-25 mg/kg, Ni 2-8 mg/kg, Hg <0.075 mg/kg). Elevated metal concentrations in soil and sediment are correlated with high metal contents in some plants within the affected wetlands. Oxidation and leaching of sulfide-bearing gold mine tailings resulted in acid mine drainage (AMD) with pH 3.25 - 4.10) and enhancement of heavy metal load and dissolved solids in streams draining into Nungwe Bay wetland on the southwestern shore of the Lake Victoria. Water samples from Bulyankhulu wetland drainage system were found to contain abnormally high Cu concentrations in the order of 270 mg/l. Samples from Mwakitolyo-Isanga and Nungwe Bay had higher values of Cr concentrations than those from Bulyankhulu and Luchili wetlands. Manganese was recorded to be 2.04 mg/L in a sample from Nungwe Bay, the reason being its mobilization from deeply weathered terrain associated with iron oxidesItem Novel Extraction Method of Antioxidant Compounds from Sasa Palmata (Bean) Nakai using Steam Explosion(2007-10) Kurosumi, Akihiro; Sasaki, Chizuru; Kumada, Kentaro; Kobayashi, Fumihisa; Mtui, Godliving Y. S.; Nakamura, YoshitoshiAntioxidant compounds were extracted from various parts of Sasa palmata (Bean) Nakai, a bamboo plant whose leaves are commonly used to wrap foodstuffs such as Sushi in Japan. Highest concentrations of antioxidant compounds existed in the leaf part of S. palmata. Steam explosion treatment followed by hot water and methanol extractions was used for separating the antioxidant compounds from S. palmata leaf. The steam explosion treatment is the physical–chemical treatment which crushes a sample by sudden reduction of the pressure in reactor to atmospheric pressure after steaming the sample at high temperature and pressures. Sasa palmata leaf was hydrolyzed by steaming and crushed by the rapid decompression. The optimal condition of steam explosion for the effective extraction of antioxidant compounds from S. palmata was determined as a steam of temperature of 250 °C and a steaming time of 1 min. In these conditions 217.41 mg/(g-Sasa leaf) of phenolic compounds and 142.81 mg/(g-Sasa leaf) of radical scavenging activity, that was expressed as butylated hydroxyanisole (BHA), were obtained.Item Oxalic Acid Pretreatment, Fungal Enzymatic Saccharification and Fermentation of Maize Residues to Ethanol(2011-12) Mtui, Godliving Y. S.Dilute oxalic acid pretreatment was investigated as a feasible method for conversion of maize residues into sugars and subsequent production of bioethanol. Oxalic acid concentration of 200 mM for samples treated at 160°C for 10 min was found to be the best pretreatment conditions. Cellulases, mainly cellobiohydrolases from Trichoderma reesei, recorded activities of up to 116 U/ml during saccharification of the cellulosic substrates. The optimum saccharification conditions using 0.2% (v/v) enzyme concentrate were the incubation temperature of 45°C for 48 h. Up to 46% (w/w) glucose and 28% (w/w) xylose were obtained from the pretreated maize residues (stalk, leaf, husk and cobs). Furthermore, a native Saccharomyces cerevisiae (strain KB) was able to convert 78% (w/w) of glucose (and other fermentable sugars) to ethanol after 60 h of incubation at 32°C, under stationary culture conditions. The challenges encountered in chemical and biological conversions included incomplete hydrolysis and fermentation due to substrate recalcitrance and the inability of the yeast cells to utilize 5-carbon sugars such as xylose. This study therefore provided baseline research data and information that could be used for more elaborate and scaled-up studies for possible industrial-scale conversion of the readily available crop residues into bioenergy.