Browsing by Author "Nges, Ivo A."
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Item Mixed Palm Oil Waste Utilization through Integrated Mushroom and Biogas Production(2016) Temu, Stella; Moshi, Anselm P.; Nges, Ivo A.; Mshandete, Anthony M.; Kivaisi, Amelia K.; Mattiasson, BoAim of the Study: The study was to integrate mushroom and biogas production using mixed palm oil to provide both food and energy source to palm oil producing communities as well as reducing environmental pollution. Design of the Study: Mixed palm oil waste was divided into two portions. One portion was used for mushroom cultivation and afterwards the spent mushroom substrate and the untreated portion were used for biogas production. Methodology: Structural sugars analysis was performed using double acid hydrolysis technique. Total crude protein was determined through kjeldal acid digestion method. Lipids were extracted using a mixture of chloroform and methanol and quantified gravimetrically. The mushroom strain (Coprinus scinereus) was cultivated on the mixed palm oil waste. Afterwards, the spent mushroom substrate and the untreated palm oil waste were subjected to anaerobic digestion in automatic methane potential test system. Place and Duration of Study: The study was completed in 2 years from 2014-2015. Mushroom cultivation was carried out at the University of Dar-e salaam, Tanzania, whereas feedstock characterization and anaerobic digestion were performed at Lund University, Sweden. Results: Compositional analysis disclosed that the feedstock contains (% w/w) 0.1 proteins, 3.3 carbohydrates, 22.5 lipids, and 73 lignin. Mushroom yield was 0.64 g /g of substrate at a biological efficiency of 71.4 g/100 g of substrate and productivity of 21.5±0.5%. Consequently total carbohydrates and lipids were decreased by 70% and 76% while the relative content of lignin and protein increased by 23% and 50%, respectively. Particle size reduction (<4 mm) resulted to increased methane yield by 66%. The untreated and biologically treated mixed palm oil wastes yielded 517 and 287 of CH4 L/Kg VS added which corresponded to 80% and 64.5% of theoretical methane yield, respectively. Conclusion: Combined mushroom and biogas production offer superior benefits in the utilization of the palm oil waste.Item Production of Bioethanol from Wild Cassava Manihot glaziovii through Various Combinations of Hydrolysis and Fermentation in Stirred Tank Bioreactors(2015) Moshi, Anselm P.; Hosea, Ken M.; Elisante, Emrode; Mshandete, Anthony M.; Nges, Ivo A.Aim of the Study: The aim of this study was to evaluate three ethanol fermentation approaches namely (I) separate hydrolysis and common fermentation (II) separate hydrolysis and fermentation and (III) simultaneous saccharification and fermentation in stirred tank reactors using inedible wild cassava as feedstock. Study Design: Tubers of wild cassava (Manihot glaziovii) were obtained from two districts i Tanzania. Fermentation of hydrolysate and partially liquefied cassava flour was performed in stirred tank reactors. Methodology: Feedstock composition analysis for structural carbohydrate was performed using acid hydrolysis and high pressure liquid chromatography technique. Analysis of total nitrogen was done by Kjeldahl acid digestion technique, total cyanide was determined using linamarase loaded picrate paper whereas macro-and micronutrients were analysed by inductively coupled plasma atomic emission spectrometry. Thermostable α-amylase and glucoamylase were used to partially hydrolyze the cassava flour to fermentable sugars prior to yeast fermentation. The hydrolysis (liquefaction) was performed at 90°C, 1h followed by saccharification using glucoamylase at 60°C, 2h for approaches I and II. For approach III, liquefaction was performed at 90°C, 1h followed by direct saccharification and fermentation. Fermentation of hydrolysate and partially liquefied starch from wild cassava was done in stirred tank reactors at 30±2°C using baker’s yeast. Place and Duration of Study: Department of Biotechnology, Lund University from January to June 2014. Results: The wild cassava (M. glaziovii) tubers possessed comparable physical dimensions to the domesticated cassava, however they displayed higher average flesh proportion (76 to 79%) compared to the domesticated cassava (74%). Compositional analysis disclosed that the wild cassava possessed interesting properties for bioethanol production such as dry matter of up to 89% w/w, degradable carbohydrate up to 90% (dry weight basis), total kjeldahal nitrogen 0.8-1.6% w/w and satisfactory concentration of macro-and micronutrients. Amongst the three fermentation approaches, high ethanol titre of 10-11% (v/v) at high conversion efficiency of 97.6% was achieved for separate hydrolysis and fermentation and simultaneous saccharification and fermentation, whereas low ethanol titre (4.2% v/v) at efficiency of 39% was achieved for separate hydrolysis and common fermentation. Volumetric productivities for the three approaches; ‘separate hydrolysis and common fermentation’, ‘separate hydrolysis and fermentation’, and ‘simultaneous saccharification and fermentation’ were 2.0, 5.5 and 6.5 respectively. Conclusion: The results obtained in the present study demonstrated that wild cassava has a high starch content, contain balanced nutrients required for efficient bioethanol production and that simultaneous saccharification and fermentation is the best approach for bioconversion of the wild cassava to bioethanol using stirred tank reactors.Item Production of Raw Starch-Degrading Enzyme by Aspergillus Sp. And Its Use in Conversion of Inedible Wild Cassava Flour to Bioethanol(Elsevier, 2016) Moshi, Anselm P.; Hosea, Ken M.; Elisante, Emrode; Mamo, Gashaw; Önnby, Linda; Nges, Ivo A.The major bottlenecks in achieving competitive bioethanol fuel are the high cost of feedstock, energy and enzymes employed in pretreatment prior to fermentation. Lignocellulosic biomass has been proposed as an alternative feedstock, but because of its complexity, economic viability is yet to be realized. Therefore, research around non-conventional feedstocks and deployment of bioconversion approaches that downsize the cost of energy and enzymes is justified. In this study, a non-conventional feedstock, inedible wild cassava was used for bioethanol production. Bioconversion of raw starch from the wild cassava to bioethanol at low temperature was investigated using both a co-culture of Aspergillus sp. and Saccharomyces cerevisiae, and a monoculture of the later with enzyme preparation from the former. A newly isolated strain of Aspergillus sp. MZA-3 produced raw starch-degrading enzyme which displayed highest activity of 3.3 U/mL towards raw starch from wild cassava at 50°C, pH 5.5. A co-culture of MZA-3 and S. cerevisiae; and a monoculture of S. cerevisiae and MZA-3 enzyme (both supplemented with glucoamylase) resulted into bioethanol yield (percentage of the theoretical yield) of 91 and 95 at efficiency (percentage) of 84 and 96, respectively. Direct bioconversion of raw starch to bioethanol was achieved at 30°C through the co-culture approach. This could be attractive since it may significantly downsize energy expenses.