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Bioprocess and Biosystems Engineering

Sang Il Lee, Keon Jin Lee, Ho Hyun Chun, Sanghyun Ha, Hyun Jung Gwak, Ho Myeong Kim, Jong-Hee Lee, Hak-Jong Choi, Hyeong Hwan Kim, Teak Soo Shin, Hae Woong Park, Jin-Cheol Kim
Oxalic acid has potent nematicidal activity against the root-knot nematode Meloidogyne incognita. In this study, fermentation parameters for oxalic acid production in submerged culture of Aspergillus niger F22 at 23, 25, and 30 °C were optimized in 5-L jar fermenters. The viscosity of the culture broth increased with increasing temperature. There was a negative correlation between oxalic acid production and the apparent viscosity; high volumetric productivity of oxalic acid was obtained at low apparent viscosity (less than 1000 cP), with a productivity of more than 100 mg/L h...
November 17, 2017: Bioprocess and Biosystems Engineering
Paul Moretti, Jean-Marc Choubert, Jean-Pierre Canler, Pierre Buffière, Olivier Pétrimaux, Paul Lessard
The integrated fixed-film activated sludge (IFAS) process is being increasingly used to enhance nitrogen removal for former activated sludge systems. The aim of this work is to evaluate a numerical model of a new nitrifying/denitrifying IFAS configuration. It consists of two carrier-free reactors (anoxic and aerobic) and one IFAS reactor with a filling ratio of 43% of carriers, followed by a clarifier. Simulations were carried out with GPS-X involving the nitrification reaction combined with a 1D heterogeneous biofilm model, including attachment/detachment processes...
November 10, 2017: Bioprocess and Biosystems Engineering
Monika Mueller, Barbara Zartl, Agnes Schleritzko, Margit Stenzl, Helmut Viernstein, Frank M Unger
Bioavailability of flavonoids is low, especially when occurring as rhamnoglucosides. Thus, the hydrolysis of rutin, hesperidin, naringin and a mixture of narcissin and rutin (from Cyrtosperma johnstonii) by 14 selected probiotics was tested. All strains showed rhamnosidase activity as shown using 4-nitrophenyl α-L-rhamnopyranoside as a substrate. Hesperidin was hydrolysed by 8-27% after 4 and up to 80% after 10 days and narcissin to 14-56% after 4 and 25-97% after 10 days. Rutin was hardly hydrolysed with a conversion rate ranging from 0 to 5% after 10 days...
November 10, 2017: Bioprocess and Biosystems Engineering
Shashi Kant Bhatia, Jung-Ho Kim, Min-Sun Kim, Junyoung Kim, Ju Won Hong, Yoon Gi Hong, Hyun-Joong Kim, Jong-Min Jeon, Sang-Hyoun Kim, Jungoh Ahn, Hongweon Lee, Yung-Hun Yang
Polyhydroxyalkonate (PHA) is a type of polymer that has the potential to replace petro-based plastics. To make PHA production more economically feasible, there is a need to find a new carbon source and engineer microbes to produce a commercially valuable polymer. Coffee waste is an inexpensive raw material that contains fatty acids. It can act as a sustainable carbon source and seems quite promising with PHA production in Ralstonia eutropha, which is a well-known microbe for PHA accumulation, and has the potential to utilize fatty acids...
November 9, 2017: Bioprocess and Biosystems Engineering
Ehsan Mahdinia, Ali Demirci, Aydin Berenjian
Menaquinone-7 (MK-7) is the key form of vitamin K used as a dietary supplement and its production revolves around Bacillus subtilis natto. Current fermentation strategies, which suggest static fermentations without aeration and agitation, can be problematic for large scale MK-7 production due to biofilm formation. The use of biofilm reactors, therefore, is proposed in the present study, which could utilize both agitation and aeration without interrupting MK-7 secretion. In this study, biofilm reactors were constructed using the selected plastic composite support (PCS) and B...
November 8, 2017: Bioprocess and Biosystems Engineering
Anja Pia Koller, Lara Wolf, Thomas Brück, Dirk Weuster-Botz
Microalgae are flagged as next-generation biomass feedstock for sustainable chemicals and fuels, because they actively metabolize the climate gas CO2, do not impact food production, and are not associated with land-use change. Scaling microalgae cultivation processes from lab to pilot scale is key to assessing their economic and ecologic viability. In this work, process performances of two different Scenedesmus species were studied using a 300 L flat-plate gas-lift photobioreactor system (14 m(2) photosynthetically active area) equipped with a customized, broad-spectrum LED illumination system...
November 8, 2017: Bioprocess and Biosystems Engineering
Peng Yan, Haoben Sun, Pengqi Lu, Haili Liu, Lei Tang
Our previous work indicated that the vigor of Streptomyces decreased at the later stage of ε-poly-L-lysine (ε-PL) fermentation. In this study, we observed that the level of reactive oxygen species (ROS) in vivo increased sharply after 24 h, and the addition of an antioxidant glutathione (GSH) before this increase in ROS stimulated ε-PL synthesis in shake-flask fermentation. The enhancement of ε-PL production by GSH was further verified in batch and fed-batch fermentations. On a 5-l fermenter scale, the highest increasement was 68...
October 28, 2017: Bioprocess and Biosystems Engineering
Yitong Zhang, Zijun Qian, Peng Liu, Lei Liu, Zhaojuan Zheng, Jia Ouyang
To get rid of the dependence on lactic acid neutralizer, a simple and economical approach for efficient in situ separation and production of L-lactic acid was established by Bacillus coagulans using weak basic anion-exchange resin. During ten tested resins, the 335 weak basic anion-exchange resins demonstrated the highest adsorption capacity and selectivity for lactic acid recovery. The adsorption study of the 335 resins for lactic acid confirmed that it is an efficient adsorbent under fermentation condition...
October 26, 2017: Bioprocess and Biosystems Engineering
Hongfei Wei, Genhai Zhao, Hui Liu, Han Wang, Wenfeng Ni, Peng Wang, Zhiming Zheng
Menaquinone homologs (MK-n), that is, MK-4, MK-5, and MK-6, can be produced by the fermentation of Flavobacterium. In this study, we proposed a simple and efficient method for the extraction of menaquinones from wet cells without the process of drying the biomass. Meanwhile, a rapid and effective solution for the separation of menaquinone homologs was developed using a single organic solvent, which was conducive to the recovery of the solvent. The results showed that the highest yield was obtained with pretreatment using absolute ethanol at a ratio of 6:1 (v/m) for 30 min and then two extractions of 30 min each using methanol at a ratio of 6:1 (v/m)...
October 26, 2017: Bioprocess and Biosystems Engineering
Paula Nicolás, Verónica Lassalle, María Luján Ferreira
Magnetic biocatalysts offer enormous advantages over traditional ones. Their ability to be isolated by means of a magnet, in combination with their extensive reuse possibilities, makes them highly attractive and competitive from the commercial point of view. In this work, magnetic biocatalysts were prepared by immobilization of Candida antarctica Lipase B (E.C., CALB) on magnetite-lysine nanoparticles. Two methodologies were explored tending to find the optimal biocatalyst in terms of its practical implementation: I-physical adsorption of CALB followed by cross-linking, and II-covalent coupling of the lipase on the nanoparticles surface...
October 24, 2017: Bioprocess and Biosystems Engineering
Analia Borges Folle, Victoria Maria Baschera, Luiza Tessaro Vivan, Sabrina Carra, Tomás Augusto Polidoro, Eloane Malvessi, Mauricio Moura da Silveira
Equimolar amounts of lactobionic acid and sorbitol may be obtained in a reaction catalyzed by the enzymes glucose-fructose oxidoreductase and glucono-δ-lactonase, which are found in the periplasm of Zymomonas mobilis. These reactions are generally conducted using immobilized bacterial cells, and the cell treatment and immobilization steps are costly and time-consuming. This study evaluated alternatives to simplify the preparation of calcium alginate-immobilized biocatalyst and its application in different operation modes and types of reactors...
October 20, 2017: Bioprocess and Biosystems Engineering
Francisca Lameiras, Cor Ras, Angela Ten Pierick, Joseph J Heijnen, Walter M van Gulik
In its natural environment, the filamentous fungus Aspergillus niger grows on decaying fruits and plant material, thereby enzymatically degrading the lignocellulosic constituents (lignin, cellulose, hemicellulose, and pectin) into a mixture of mono- and oligosaccharides. To investigate the kinetics and stoichiometry of growth of this fungus on lignocellulosic sugars, we carried out batch cultivations on six representative monosaccharides (glucose, xylose, mannose, rhamnose, arabinose, and galacturonic acid) and a mixture of these...
October 19, 2017: Bioprocess and Biosystems Engineering
Abhishek Kumar Singh, Mausumi Mukhopadhyay
In this study, the silica nanoparticles surface was modified by carboxylic acid with different number of alkyl chain and two different lipases were immobilized on it to increase the glycerolysis activity of the immobilized lipases in organic solvent system. Silica nanoparticles of about 15 nm diameter were grafted with various carboxylic acid modifiers from valeric, caprylic, capric, lauric, stearic and oleic acids. Lipases from Candida antarctica and Candida rugosa were immobilized onto the carboxylic acid, modified silica nanoparticles and used in the mono and diglycerides production through glycerolysis with or without organic solvents...
October 17, 2017: Bioprocess and Biosystems Engineering
Ana S Fernandes, Susana M Paixão, Tiago P Silva, José C Roseiro, Luís Alves
With the increasing awareness on the toxicity of several synthetic dyes, demand for pigments from natural sources, such as microbial carotenoids, has gained interest as a promising safe alternative colour additive. In this study, a surface response methodology based on the Doehlert distribution for two factors [% of glucose in a mixture of glucose + fructose (10 g/L total sugars), and sulfate concentration] was used towards the optimal carotenoids production by Gordonia alkanivorans strain 1B in the presence of light (400 lx)...
October 17, 2017: Bioprocess and Biosystems Engineering
Yanli Huo, Yangyang Zhan, Qin Wang, Shunyi Li, Shihui Yang, Christopher T Nomura, Changjun Wang, Shouwen Chen
Acetolactate synthase catalyzes two molecules of pyruvates to form α-acetolactate, which is further converted to acetoin and 2,3-butanediol. In this study, by heterologous expression in Escherichia coli, the enzymatic properties of acetolactate synthase (AlsS) from Bacillus licheniformis WX-02 were characterized. Its K m and k cat for pyruvate were 3.96 mM and 514/s, respectively. It has the optimal activity at pH 6.5, 37 °C and was feedback inhibited by L-valine, L-leucine and L-isoleucine. Furthermore, the alsS-deficient strain could not produce acetoin, 2,3-butanediol, and L-valine, while the complementary strain was able to restore these capacities...
October 11, 2017: Bioprocess and Biosystems Engineering
Han-Yu Chen, Yong-De Liu, Bin Dong
An anaerobic/aerobic moving-bed biofilm (A/O-MBBR) reactor system was constructed, and the treatment efficiency of aqueous antibiotics in wastewater was investigated. The effects of antibiotics on the microbial communities in the A/O-MBBR were also investigated. Under the optimized reaction conditions, removal of tetracycline antibiotics (TCs) was studied in a series of experiments. When a low concentration of tetracycline (TC) was added to the reactor system, high removal efficiency of conventional pollutants (TC concentration decreased from 10 turn to 2...
October 10, 2017: Bioprocess and Biosystems Engineering
Xiaoyan Tan, Junshe Sun, Zhangyang Xu, Hengchang Li, Jing Hu, Huijuan Ning, Zifang Qin, Haisheng Pei, Tian Sun, Xiuqing Zhang
Ganoderma lucidum is a traditional Chinese medicine, and its polysaccharides possess diverse and significant pharmacological activities. This study aimed to investigate the polysaccharide production, molecular characteristics and in-vitro antioxidant activity of G. lucidum fruiting body after the mushroom was harvested and treated with heat stress (HS). HS enhanced the production of polysaccharides after harvest and treatment of 42 °C HS for 2 h, and that resulted in the highest polysaccharide yield of 10...
October 10, 2017: Bioprocess and Biosystems Engineering
Zonglian She, Lan Wu, Qun Wang, Mengchun Gao, Chunji Jin, Yangguo Zhao, Linting Zhao, Liang Guo
The effect of increasing salinity on nitrogen removal via simultaneous nitrification and denitrification, microbial activities and extracellular polymeric substances (EPS) were investigated in a hybrid sequencing batch biofilm reactor filled with soft combination carriers. In the influent salinity range from 1.0 to 2.0%, average COD, NH4(+)-N and TN removal efficiencies were higher than 97.1, 97.8 and 86.4% at the steady state. When salinity was increased to 2.5 and 3.0%, ammonium oxidation was obviously inhibited in the reactor...
October 9, 2017: Bioprocess and Biosystems Engineering
Tássia Silva Tavares, Juliana Arriel Torres, Maria Cristina Silva, Francisco Guilherme Esteves Nogueira, Adilson C da Silva, Teodorico C Ramalho
A significant enhancement in the catalytic performance due to enzymes immobilization is a great way to enhance the economics of biocatalytic processes. The soybean peroxidase (SP) immobilization under ferroxyte and the ferulic acid removal by the enzyme free and immobilized were investigated. The immobilization via silica-coated ferroxyte nanoparticles was effective, and immobilization yield of 39%. The scanning electron microscopy (SEM) images showed significant changes in the materials morphology. Substantial differences were observed in the particles' Fourier Transform Infrared (FTIR) spectra...
October 6, 2017: Bioprocess and Biosystems Engineering
Yuting Shen, Xiwei Tian, Wei Zhao, Haifeng Hang, Ju Chu
Different concentrations of oxygen-enriched air were utilized for sodium gluconate (SG) fermentation by Aspergillus niger. The fermentation time shortened from 20 to 15.5 h due to the increase of volumetric oxygen transfer coefficient (KLa) and the formation of more dispersed mycelia when inlet oxygen concentration ascended from 21 to 32%. According to metabolic flux analysis, during the growth phase, extracellular glucose for SG synthesis accounted for 79.0 and 85.3% with air and oxygen-enriched air (25%), respectively, whereas the proportions were 89...
October 4, 2017: Bioprocess and Biosystems Engineering
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