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Bioprocess and Biosystems Engineering

Nils J H Averesch, Alex Prima, Jens O Krömer
Saccharomyces cerevisiae is a popular organism for metabolic engineering; however, studies aiming at over-production of bio-replacement precursors for the chemical industry often fail to overcome proof-of-concept stage. When intending to show real industrial attractiveness, the challenge is twofold: formation of the target compound must be increased, while minimizing the formation of side and by-products to maximize titer, rate and yield. To tackle these, the metabolism of the organism, as well as the parameters of the process, need to be optimized...
May 20, 2017: Bioprocess and Biosystems Engineering
Hend Omar Mohamed, M Obaid, Enas Taha Sayed, Yang Liu, Jinpyo Lee, Mira Park, Nasser A M Barakat, Hak Yong Kim
This study introduces activated carbon (AC) as an effective anode for microbial fuel cells (MFCs) using real industrial wastewater without treatment or addition of external microorganism mediators. Inexpensive activated carbon is introduced as a proper electrode alternative to carbon cloth and carbon paper materials, which are considered too expensive for the large-scale application of MFCs. AC has a porous interconnected structure with a high bio-available surface area. The large surface area, in addition to the high macro porosity, facilitates the high performance by reducing electron transfer resistance...
May 19, 2017: Bioprocess and Biosystems Engineering
Thiago Pajeú Nascimento, Amanda Emmanuelle Sales, Tatiana Souza Porto, Romero Marcos Pedrosa Brandão Costa, Leonid Breydo, Vladimir N Uversky, Ana Lúcia Figueiredo Porto, Attilio Converti
Fibrinolytic proteases are enzymes that degrade fibrin. They provide a promising alternative to existing drugs for thrombolytic therapy. A protease isolated from the filamentous fungus Mucor subtilissimus UCP 1262 was purified in three steps by ammonium sulfate fractionation, ion exchange, and molecular exclusion chromatographies, and characterized biochemically and structurally. The purified protease exhibited a molecular mass of 20 kDa, an apparent isoelectric point of 4.94 and a secondary structure composed mainly of α-helices...
May 12, 2017: Bioprocess and Biosystems Engineering
Monchai Dejsungkranont, Yusuf Chisti, Sarote Sirisansaneeyakul
The key factors influencing the production of C-phycocyanin (C-PC) and extracellular polymeric substances (EPS) by photoautotrophic culture of Arthrospira sp. were optimized using Taguchi method. Six factors were varied at either three or two levels as follows: light intensity at three levels; three initial culture pHs; two species of Arthrospira; three concentrations of Zarrouk's medium; three rates of aeration of the culture with air mixed with 2% v/v carbon dioxide; and two incubation temperatures. All cultures ran for 14 days...
May 11, 2017: Bioprocess and Biosystems Engineering
Felisbela Oliveira, José Manuel Salgado, Luís Abrunhosa, Noelia Pérez-Rodríguez, José M Domínguez, Armando Venâncio, Isabel Belo
Lipases are versatile catalysts with many applications and can be produced by solid-state fermentation (SSF) using agro-industrial wastes. The aim of this work was to maximize the production of Aspergillus ibericus lipase under SSF of olive pomace (OP) and wheat bran (WB), evaluating the effect on lipase production of C/N ratio, lipids, phenols, content of sugars of substrates and nitrogen source addition. Moreover, the implementation of the SSF process in a packed-bed bioreactor and the improvement of lipase extraction conditions were assessed...
May 9, 2017: Bioprocess and Biosystems Engineering
Hasan Yildiz, Elif Ozyilmaz, Asif Ali Bhatti, Mustafa Yilmaz
This work presents the synthesis of new mercapto calix[4]arenes derivatives (4 and 5). These derivatives were capped on Fe3O4 magnetic nanoparticles and subsequently encapsulated with Candida rugosa through sol-gel method to furnish enc-4 and enc-5, respectively, to enhance catalytic activity and enantioselectivity of lipase for hydrolysis reaction of racemic flurbiprofen methyl ester. Catalytic activity and enantioselectivity of enc-4 and enc-5 were assayed at different pH and temperature conditions and it was found that the resultant encapsulated enzyme exhibited higher thermal and operational stabilities compared to the free lipase in which enc-5 showed the excellent rate of enantioselectivity (E = 176) for S-flurbiprofen better than free lipase (E = 137) at pH 7 and 35 °C for 48 h...
May 9, 2017: Bioprocess and Biosystems Engineering
Ugo Barry, Jean-Marc Choubert, Jean-Pierre Canler, Olivier Pétrimaux, Alain Héduit, Paul Lessard
This work presents a one-dimensional model of a moving bed bioreactor (MBBR) process designed for the removal of nitrogen from raw wastewaters. A comprehensive experimental strategy was deployed at a semi-industrial pilot-scale plant fed with a municipal wastewater operated at 10-12 °C, and surface loading rates of 1-2 g filtered COD/m(2) d and 0.4-0.55 g NH4-N/m(2) d. Data were collected on influent/effluent composition, and on measurement of key variables or parameters (biofilm mass and maximal thickness, thickness of the limit liquid layer, maximal nitrification rate, oxygen mass transfer coefficient)...
May 8, 2017: Bioprocess and Biosystems Engineering
Sivananth Murugesan, Regupathi Iyyaswami, Sahana Vijay Kumar, Arathi Surendran
L-Asparaginase synthesized by Azotobacter vinelandii via submerged fermentation in the presence of sucrose was successfully extracted using Reverse micellar extraction. Single step enzyme purification process was developed by varying the process variables which resulted in maximum specificity and extraction of L-asparaginase. The effect of different variables, including broth pH, addition of alcohol during the forward extraction and pH of the fresh stripping aqueous phase, addition of alcohol and electrolyte during backward extraction process were studied...
May 6, 2017: Bioprocess and Biosystems Engineering
T Sarat Chandra, S Aditi, M Maneesh Kumar, S Mukherji, J Modak, V S Chauhan, R Sarada, S N Mudliar
The freshwater green algae, Scenedesmus obtusus, was cultivated in a 3.4 L airlift photobioreactor. The hydrodynamic parameters were estimated at different inlet gas flow rates (1, 2, 3, and 4 LPM) and their subsequent impact on the growth and biochemical characteristics of microalgae was studied. The biomass concentration and productivity increased with an increase in flow rates from 1 to 4 LPM. A maximum of 0.07 g L(-1) day(-1) productivity of biomass was attained at 3 LPM. An increase of total carbohydrate content from 19...
May 4, 2017: Bioprocess and Biosystems Engineering
Xueshan Pan, Baobei Wang, Henri G Gerken, Yinghua Lu, Xueping Ling
The ratio of carbon to nitrogen (C/N) in media plays a crucial role in the production of microbial carotenoids. However, the effects of a high C/N ratio on carotenoid production are ambiguous, and the mechanism of how C/N ratio affects astaxanthin accumulation in X. dendrorhous is unclear. In this study, the influence of C/N ratio on astaxanthin biosynthesis in X. dendrorhous at a fixed nitrogen concentration was investigated, and comparative proteomics were applied to address how C/N ratio affects cell growth and astaxanthin accumulation in X...
April 28, 2017: Bioprocess and Biosystems Engineering
Cristina García, Manuel Rendueles, Mario Díaz
Pseudomonas taetrolens has recently been revealed as an effective microbial producer of lactobionic acid from carbohydrates contained in dairy byproducts. In terms of food industrial applications, the implementation of lactobionic acid biosynthesis coupled with the classic bacterial production of lactic acid appears an important goal. This research paper studies the simultaneous fermentation of residual cheese whey by P. taetrolens and Lactobacillus casei to co-produce lactic and lactobionic acids. Experimental data showed the importance of the interactions established between the two microorganisms...
April 27, 2017: Bioprocess and Biosystems Engineering
Chunli Ji, Junfeng Wang, Runzhi Li, Tianzhong Liu
The CO2 mass transfer model associated with growth kinetics of microalgal biofilm in attached cultivation photobioreactor was developed and verified by using the analysis of pH profiles which were in equilibrium with inorganic carbon components concentrations (CO2, H2CO3, HCO3(-) and CO3(2-)) in medium. Model simulation results showed that the model well presented the biofilm growth process. The overall volumetric mass transfer coefficient of CO2 was more influenced by CO2 concentration in aerated gas but less by gas aeration rate and medium circulation rate...
April 26, 2017: Bioprocess and Biosystems Engineering
L E Díaz-Nava, N Montes-Garcia, J M Domínguez, M G Aguilar-Uscanga
The importance of non-Saccharomyces yeast species in fermentation processes is widely acknowledged. Within this group, Pichia kudriavzevii ITV-S42 yeast strain shows particularly desirable characteristics for ethanol production. Despite this fact, a thorough study of the metabolic and kinetic characteristics of this strain is currently unavailable. The aim of this work is to study the nutritional requirements of Pichia kudriavzevii ITV-S42 strain and the effect of different carbon sources on the growth and ethanol production...
April 26, 2017: Bioprocess and Biosystems Engineering
Xuelian Yu, Jiaqi Sun, Weiyu Wang, Li Jiang, Ruyue Wang, Wenjun Xiao, Beijiu Cheng, Jun Fan
In this study, four fusion proteins were designed, in which the N-terminal cellulose-binding module as the affinity tag was immobilized on the regenerated amorphous cellulose (RAC), and the release of the C-terminal colored proteins was detected easily and rapidly after on-resin cleavage using the free tobacco etch virus protease (TEVp) variant, or the immobilized cognate protease with a binding capacity of up to 220 mg protein per gram of RAC. The enhanced stability and repetitive use of the immobilized TEVp compensated slight loss of the catalytic efficiency toward the soluble protein substrate...
April 24, 2017: Bioprocess and Biosystems Engineering
Joseph Camire, Dongjoo Kim, Soonjo Kwon
The improvement in the production of recombinant proteins has been linked in a number of small molecules such as carboxylic acids to the inhibition of histone deacetylase, leading to increased transcription of genes. However, carboxylic acids such as pentanoic acid and butanoic acid have been shown to promote an apoptotic response in Chinese hamster ovary (CHO) cell culture. Supplementation of cultures with antioxidants has shown the ability to reduce the apoptotic response of carboxylic acid supplementation, leading to increased therapeutic protein production...
April 21, 2017: Bioprocess and Biosystems Engineering
Omar Anaya-Reza, Teresa Lopez-Arenas
L-Lysine is an essential amino acid that can be produced by chemical processes from fossil raw materials, as well as by microbial fermentation, the latter being a more efficient and environmentally friendly procedure. In this work, the production process of L-lysine-HCl is studied using a systematic approach based on modeling and simulation, which supports decision making in the early stage of process design. The study considers two analysis stages: first, the dynamic analysis of the fermentation reactor, where the conversion of sugars from sugarcane molasses to L-lysine with a strain of Corynebacterium glutamicum is carried out...
April 13, 2017: Bioprocess and Biosystems Engineering
M M Câmara, R M Soares, T Feital, P Naomi, S Oki, J M Thevelein, M Amaral, J C Pinto
A strategy for monitoring fermentation processes, specifically, simultaneous saccharification and fermentation (SSF) of corn mash, was developed. The strategy covered the development and use of first principles, semimechanistic and unstructured process model based on major kinetic phenomena, along with mass and energy balances. The model was then used as a reference model within an identification procedure capable of running on-line. The on-line identification procedure consists on updating the reference model through the estimation of corrective parameters for certain reaction rates using the most recent process measurements...
April 8, 2017: Bioprocess and Biosystems Engineering
Nor Syafirah Zambry, Adilah Ayoib, Nur Asshifa Md Noh, Ahmad Ramli Mohd Yahya
The present study focused on developing a wild-type actinomycete isolate as a model for a non-pathogenic filamentous producer of biosurfactants. A total of 33 actinomycetes isolates were screened and their extracellular biosurfactants production was evaluated using olive oil as the main substrate. Out of 33 isolates, 32 showed positive results in the oil spreading technique (OST). All isolates showed good emulsification activity (E24) ranging from 84.1 to 95.8%. Based on OST and E24 values, isolate R1 was selected for further investigation in biosurfactant production in an agitated submerged fermentation...
April 7, 2017: Bioprocess and Biosystems Engineering
Baoshi Wang, Hua Li, Linghuan Zhu, Fengling Tan, Youran Li, Liang Zhang, Zhongyang Ding, Guiyang Shi
Citric acid (CA), an important platform-compound, has attracted much attention because of its broad applications and huge market demand. To solve high residual sugar at the fermentation end, we put forwarded strategy of pre-saccharification and then fermentation. Results showed that the residual total sugar decreased by 10.4% and the productivity increased by 4.0% and initially high glucose inhibited cell growth. Furthermore, commercial glucoamylase with high low-pH stability was proposed to staged-add in the fermentation process, which timely compensated enzyme loss, ensuring the glucose supply rate...
April 7, 2017: Bioprocess and Biosystems Engineering
Dominic Deo Androga, Basar Uyar, Harun Koku, Inci Eroglu
In this study, a one-dimensional transient model was developed to analyze the temperature variation of tubular photobioreactors operated outdoors and the validity of the model was tested by comparing the predictions of the model with the experimental data. The model included the effects of convection and radiative heat exchange on the reactor temperature throughout the day. The temperatures in the reactors increased with increasing solar radiation and air temperatures, and the predicted reactor temperatures corresponded well to the measured experimental values...
April 6, 2017: Bioprocess and Biosystems Engineering
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