Effect of pre-treatment palm oil mill effluent POME on biohydrogen production by local isolate clostridium butyricum

Palm oil mill effluent (POME) contains approximately 6% fiber. The effectiveness of pre-treatment on POME can serve a very good feedstock for hydrogen production in fermentation process. In this research, the effectiveness of pre-treatment methods on POME treated using acid and base were analysed based total carbohydrate and reducing sugar content. By using 1M NaOH with heat treatment, 26.12% carbon source converted to reducing sugar while by using 1M H2SO4 with heat treatment, over 32.09% carbon source converted to reducing sugar. The highest increment of total carbohydrate where from acid-heat treatment with 26.1% increment from initial concentration. At the initial pH (5.5) with fermentation temperature 37 oC, the highest hydrogen production rate given by acid-heat treatment was 0.5mL H2/mL POME. Different for initial pH 7.0 with the same temperature, the highest hydrogen produced rate was given by base-heat treatment with 0.59 mL H2/mL POME. The production of hydrogen in 2L bioreactor given much higher hydrogen production compare to production in serum bottle. This fermentation was run in batch mode with initial pH 7 and control at 5.5. The maximum hydrogen produce was 4304 mL H2/ L POME from acid-heat treatment

Hydrodynamic characteristics and model of fluidized bed reactor with immobilized cells on activated carbon for biohydrogen production

A mathematical model of minimum fluidization velocity (Umf) was developed based on thehydrodynamic characteristics of the fluidized bed reactors (FBR) with immobilised cellsattached to activated carbon at thermophilic biohydrogen fermentation. The maximumhydrogen productivity rate of 7.8 mmolH2/L.h and hydrogen yield of 2.2 molH2/mol of sugarconsumed was obtained when the HRT was shortened from 48 h to 6 h. The presence of theimmobilised cells enriched the biomass composition in the FBR from 4.9 to 7.1 g VSS/L andmaximum energy generated was 58.7 KJ H2/L.d. The FBR had to be operated at a high Umfof0.05e0.44 cm/s and a low terminal velocity of 2.11 cm/s to prevent the immobilised cellsfrom washed out from the FBR, hence achieved an adequate fluidization system. Ascreening of the microbial population by DGGE revealed that theT. thermosaccharolyticumsp. was dominant for all the HRTs, thereby indicating that this bacterium is resilient to-wards environmental disturbances

Effect of Various Cultivation Methods on Cellobiohydrolase Production from Aspergillus niger

Three different cultivation methods, i.e., shaking-flask culture (SFC), static surface liquid culture (SSLC) and membrane surface liquid culture (MSLC) were used to cultivate the filamentous fungi,  Aspergillus niger PY11 in order to differentiate its behaviours by different cultivation methods using the same media, by determination of growth profile during fermentation. The dry cell weight, protein concentration, cellobiohydrolase (CBH) activity and residual sugar concentration in SSLC and MSLC were 1.5 to 2-folds than that by SFC. Cultivation of A. niger using MSLC was higher than SSLC with maximum biomass concentration, protein concentration and enzyme activity were 0.93 g dry weight/ml medium, 3.49 mg/ml and 36.99 U/ml respectively. MSLC possess the best growth characteristics and was the best cultivation method in production of CBH from A. niger PY11

Influence of iron (II) oxide nanoparticle on biohydrogen production in thermophilic mixed fermentation

The effect of initial pH, metal oxide and concentration of nanoparticles (NP) on hydrogen production were investigated in batch assays using glucose-fed anaerobic mixed bacteria in thermophilic condition of 60 �C. Two type of metal oxide nanoparticles, iron (II) oxide and nickel oxide, were tested and both metal capable of increasing the hydrogen yield about 34.38% and 5.47% higher than the control test. The experiments on the effect of initial pH were done without adding the nanoparticles to determine the optimum pH for maximum hydrogen production, in which at pH 5.5, the maximum hydrogen yield has reached about 1.78 mol H2/mol glucose. However, at pH 5.5 and the optimal iron (II) oxide concentration of 50 mg/L, the maximum hydrogen yield has reached to 1.92 mol H2/mol glucose, and the hydrogen content was 51%. Furthermore, the analysis of metabolites has indicated that the hydrogen production follows the acetic acid pathway. In all experiments with metal oxide nanoparticles, the metal NP was not consumed by the microbes, and the amount of it at the end of the fermentation was similar to the starting amount, which can be concluded that it was acting as an enhancer to the system to improve the hydrogen production. These results suggest that the addition of iron (II) oxide nanoparticles in the system is the vital factor to enhance the hydrogen production

Optimising cutinase enzyme recovery in thermo-induced phase separation of LS54/DX ATPS by enhanced volume exclusion effect

Low recovery of cutinase enzyme in water-enriched phase after thermo-induced separation stage of LS54/Dx aqueous two-phase system was improved by enhanced volume exclusion effect in the polymer-water extraction system. It was done by increased the polymer concentration in the polymer-water system. After primary phase separation, more LS54 (polymer) which is the system’s component itself were added into polymer-enriched phase and mixed thoroughly before thermo-induced separation step proceeded. The compositions of LS54 added into the polymer-enriched phase were 0.25, 0.5 and 0.75 g LS54/g top phase. The thermo-induced phase separation was carried out at 37°C. It was found that cutinase recovery in water-enriched phase was increased up to 5-13% with the increment of polymer concentration in the system as compared to a system without polymer addition. The optimum concentration obtained for the polymer added was 0.5 g LS54/g top phase whereby it attained 82% recovery of cutinase enzyme in water-enriched phase after thermoseparation step. Although the increment of enzyme recovery was not exceptionally high as compared to another method such as adding ligand, an affinity tag or neutral salt, still this method is applicable because of its more straightforward work, polymer recycle capability, and enzyme recovery in water phase would definitely give benefit to further downstream processing

Dual Carbon Fermentation for the Production of Inducible Cellobiohydrolase by Recombinant Aspergillus Niger

Abstract-This study investigates the use of two carbon sources in fermentation for the production of cellobiohydrolase (CBH), an adaptive or inducible enzyme. Selection of carbon source was first done using single substrate cultivation between glucose, maltose and lactose using recombinant A. niger PY11. This recombinant microorganism will produce CBH in high quantity, with maltose acting as its main inducer. Glucose and maltose were selected in dual carbon fermentation, as glucose produce highest biomass 0.32g/ml at day 4 th and maltose produce 0.42g/ml biomass at day 9 th . Cultivation of A. niger was done for dual carbon containing sugar glucose and maltose with concentration ratio 1:1. Cultivation with medium containing maltose was done for comparison between single carbon and dual carbon. For dual carbon cultivation, highest biomass form at day 7 th at 0.44g/ml while specific enzyme activity reached 10.54 U/g at day 8 th . For single substrate, highest biomass production was recorded at day 9 th with 0.41g/ml.while specific enzyme activity at day 7 th at 4.02 U/g

Kinetic Model of Thermophilic Biohydrogen Production from POME

The study of fermentation kinetic parameters are crucial to understanding the environmental factors affect on biohydrogen production. Kinetic models for hydrogen production from anaerobic digestion of palm oil mill effluent (POME) by mixed culture were developed based on published work. The models accounted for substrate limitation, substrate inhibition, hydrogen production, and endogenous decay rate. Data from previous literature were used to compare four microbial growth kinetic models for hydrogen production in an ASBR system. The estimated values of the maximum specific growth rate (μm) were found to be 0.371 h-1. In this study, the parameters of Y, kd, and B0 calculated were 2.64 gVSS/gCOD, 0.053 h-1, and 0.133 L H2/gCOD, respectively. The model fitting was found to be in good agreement with the experimental and can be utilized for the optimization and design of the process

Enhancement in Monitoring for Integrated Project Implementation

AbstractIntegrated project for Year III has been introduced by the Department of Chemical and Process Engineering since 2007/2008 session. This project integrates three or four compulsory subject for each semester. The purpose of this project was to minimize student work load and help student to understand how each courses are related. Project monitoring is one of the procedures to evaluate the performance of integrated project. Since implementation of this project, the coordinator of integrated project will give feedbacks to the students on their performance after they have completed presenting their project. Even though this method is quite sufficient for student to learn their mistake unfortunately similar mistakes was repeated during their final year design project in final year. In order to overcome this problem, student self-assessment for integrated project was introduced during Semester II, Session 2011/2012. The results show that the students were able to detect their mistakes and errors, and some correction was done to their project