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Bioprocess and Biosystems Engineering

Theo S O Souza, Dagoberto Yukio Okada, Eugenio Foresti
In this study, two versions of a triple chamber biosystem, coupling anaerobic digestion, nitrification and mixotrophic endogenous denitrification (ADNMED), were evaluated and compared. They were designed to maximize the use of endogenous electron donors produced by anaerobic digestion (residual organic matter and sulfide) to abate a portion of the influent nitrogen contained in domestic sewage while removing the inconvenience of effluent sulfide. The first version was able to abate 40% of the influent nitrogen but presented operational and hydrodynamic problems, which resulted in sulfide emissions...
September 10, 2018: Bioprocess and Biosystems Engineering
Christian Canales, Claudia Altamirano, Julio Berrios
The methanol-glycerol co-feeding during the induction stage for heterologous protein production in Pichia pastoris has shown significant productive applications. Available model analysis applied to this dual-limited condition is scarce and normally does not consider the interaction effects between the substrates. In this work, a dual-limited growth model of P. pastoris considering an interactive kinetic effect was applied to an optimised fed-batch process production of heterologous Rhizopus oryzae lipase (ROL)...
September 8, 2018: Bioprocess and Biosystems Engineering
Noha S Elsayed, Khaled M Aboshanab, Mahmoud A Yassien, Nadia A Hassouna
To control the poly-β-hydroxybutyrate (PHB) biopolymer production by Acinetobacter baumannii isolate P39 kinetic modeling of the fermentation process, polymer downstream processing, enzymological analysis, and molecular characterization of PHA synthase, key biosynthetic enzyme, should be addressed. A. baumannii isolate P39 produced 0.15 g/L PHB after 24 h of incubation with a polymer content of 28% per dry weight. Logistic and Leudeking-Piret models were used for describing cell growth and PHB production, respectively...
September 7, 2018: Bioprocess and Biosystems Engineering
Duo-Tao Pan, Xu-Dong Wang, Hong-Yan Shi, De-Cheng Yuan, Zhi-Long Xiu
To investigate the relationship between the yield of 1,3-propanediol (1,3-PD) and the flux variation in metabolic pathways of Klebsiella pneumoniae, an optimized calculation method was constructed on basis of dynamic flux balance analysis by combining genome-scale flux balance analysis with a kinetic model of extracellular metabolites. Through optimizing calculations, a more completely expanded metabolic pathway was obtained, which includes the previously reported metabolic pathway and additional three pathways or site: a pentose phosphate pathway (PPP) elicited at the dihydroxyacetone (DHA) node to provide more reducing equivalents; a branch of synthetic amino acids at the 3-phosphoglycerate (3PG) node; and the α-ketoglutarate site in the tricarboxylic acid (TCA) cycle leading to anabolic pathways for glutamate and other amino acids...
September 1, 2018: Bioprocess and Biosystems Engineering
Aline Gomes de Oliveira Paranhos, Edson Luiz Silva
The production of 1,3-propanediol from crude glycerol and mixed anaerobic sludge was investigated in batch experiments and continuous reactors. Using a 23 complete factorial design, the effects of the concentration of glycerol (22-30 g L-1 ), KH2 PO4 (1.50-2.00 g L-1 ), and vitamin B12 (7-8 mg L-1 ) were examined in batch reactors. As an evaluated response, the highest 1,3-PD yields occurred for high concentrations of vitamin B12 and low levels of KH2 PO4 , reaching 0.57 g g-1 glycerol consumed. The variable glycerol concentration was not significant in the studied range...
August 30, 2018: Bioprocess and Biosystems Engineering
Luana Vieira da Silva, Maria Alice Z Coelho, Priscilla F Fonseca Amaral, Patrick Fickers
Polyethylene glycol (PEG) is polymer that was used to replace NaCl (reference media) as an osmotic stress agent for the synthesis of erythritol by the osmophilic yeast Yarrowia lipolytica. Two strains, the wild-type strain IMUFRJ 50682 and the lab strain W29, were grown in the presence of PEG of different molecular weights. For strain IMUFRJ 50682, the erythritol titer was increased by 40% in the presence of PEG2000 as compared to the reference media (with NaCl). A similar increase was also observed for strain W29, except that it occurred in the presence of PEG6000...
August 25, 2018: Bioprocess and Biosystems Engineering
Shaheen Amna Kashif, You Jin Hwang, Jae Kweon Park
Microalgae Tetraselmis species were used to evaluate the biological characteristics of water-soluble polysaccharides (WSPs) as one of the significant bioactive substances (BAS) from these photosynthetic microalgae species. Compositional analysis of these BAS shows that they are mainly composed of WSPs along with negligible amount of proteins and lipids. WSPs were partially purified and characterized for their compositional, structural and biological properties such as antioxidant, tyrosinase inhibitory activity and antifungal activies...
August 22, 2018: Bioprocess and Biosystems Engineering
Xiaoyun Liu, Xiaojuan Sun, Tong Wang, Xin Zhang, Xiwei Tian, Yingping Zhuang, Ju Chu
Candicidin is one of the most effective antimonilial agents. In order to enhance candicidin productivity, medium optimization and pH stepwise control strategy in process optimization were conducted by Streptomyces ZYJ-6. With the aid of Design Expert software and N/C/P-sources regulation, chemically defined medium fit for cell growth and candicidin biosynthesis was developed. Moreover, pH effects on cell growth and metabolism were investigated. The results indicated that the optimal pH for cell growth and candicidin biosynthesis were 6...
August 21, 2018: Bioprocess and Biosystems Engineering
Cong Li, Lu-Kwang Ju
A substantial amount of organic matter is wasted in current wastewater treatment processes. To reclaim the value of organic matter, a two-stage continuous-flow open process has been developed by utilizing the capability of phagotrophic algae in ingesting bacterial cells. In this process, wastewater is first pumped into a bacteria tank to grow bacterial cells, and then the effluent containing grown bacteria cells is fed to an algae tank to grow phagotrophic algae. The operation conditions such as dilution rate, pH, and dissolved oxygen level were comprehensively investigated and optimized with long-term tests...
August 11, 2018: Bioprocess and Biosystems Engineering
Jung Hun Kim, Jong Min Lee
When a dynamic model is used for the description of (fed-)batch bioreactors, it is typical that the model parameters are highly correlated to each other. In this case, it is important to keep the parameter correlation as small as possible to obtain a reliable set of parameter estimates. In this study, we propose an anticorrelation parameter estimation scheme that can be best utilized when a number of different batch experiments are sequentially processed. The scheme iteratively performs parameter estimation and model-based design of experiment (MBDOE) at the beginning and between the batches...
August 11, 2018: Bioprocess and Biosystems Engineering
Rubin Jiang, Hao Chen, Sen Xu
pH excursions exist due to frequent base addition and environmental heterogeneity in large-scale bioreactors. Such excursions could lead to suboptimal culture performance. Here we investigated the impact of pH excursions on cell culture performance and N-linked glycosylation for three MAb-producing Chinese hamster ovary cell lines. Frequent pH excursions were introduced by bolus base addition (in total 2-6% of initial volume, fixed bolus addition distributed from day 2 to 8) into small-scale bioreactors. Base addition led to increase in osmolality, pCO2 , and lactate production...
August 7, 2018: Bioprocess and Biosystems Engineering
Kathy Elst, Neha Babbar, Sandra Van Roy, Stefania Baldassarre, Winnie Dejonghe, Miranda Maesen, Stefano Sforza
Sugar beet pulp pectin is an attractive source for the production of pectic oligosaccharides, an emerging class of potential prebiotics. The main aim of the present work was to investigate a new process allowing to produce pectic oligosaccharides in a continuous way by means of a cross flow enzyme membrane reactor while using a low-cost crude enzyme mixture (viscozyme). Preliminary experiments in batch and semi-continuous setups allowed to identify suitable enzyme concentrations and assessing filtration suitability...
August 3, 2018: Bioprocess and Biosystems Engineering
Guangyuan Wang, Tingting Bai, Zhengang Miao, Weiguang Ning, Wenxing Liang
Microbial oils can be used for biodiesel production and fumaric acid (FA) is widely used in the food and chemical industries. In this study, the production of lipids and FA by Aureobasidium pullulans var. aubasidani DH177 was investigated. A high initial carbon/nitrogen ratio in the medium promoted the accumulation of lipids and FA. When the medium contained 12.0% glucose and 0.2% NH4 NO3 , the yeast strain DH177 accumulated 64.7% (w/w) oil in its cells, 22.4 g/l cell biomass and 32.3 g/l FA in a 5-L batch fermentation...
August 1, 2018: Bioprocess and Biosystems Engineering
Nishat R Khan, Sarita D Gawas, Virendra K Rathod
This work exhibits the implementation of ultrasound technology in solvent-free synthesis study of n-butyl palmitate using Fermase CALB™10000. Sequential experimental design study was instrumental in determining the most significant process variables. The effect of acid-alcohol molar ratio, enzyme dose, temperature, power and duty cycle on the reaction kinetics was studied. Highest conversion of ~ 96.6% was observed in 50 min at 1:1 molar ratio of palmitic acid to n-butanol, 70 °C temperature, 4% w/w enzyme loading, 40 W power, 70% duty cycle, 25 kHz frequency and 100 rpm speed of impeller...
July 31, 2018: Bioprocess and Biosystems Engineering
Sarma Mutturi
There exist several optimization strategies such as sequential quadratic programming (SQP), iterative dynamic programing (IDP), stochastic-based methods such as differential evolution (DE), genetic algorithm (GA), particle swarm optimization (PSA), and ant colony optimization (ACO) for finding optimal feeding profile(s) during fed-batch fermentations. Here in the present study, flower pollination algorithm (FPA) which is inspired by the pollination process in terrestrial flowering plants has been used for the first time to find the optimal feeding profile(s) during fed-batch fermentations...
July 30, 2018: Bioprocess and Biosystems Engineering
Xiwei Tian, Yuting Shen, Yingping Zhuang, Wei Zhao, Haifeng Hang, Ju Chu
To further understand fermentation kinetics of sodium gluconate (SG) production by Aspergillus niger with different inlet oxygen concentrations, logistic model for cell growth and two-step models for SG production and glucose consumption were established. The results demonstrated that the maximum specific growth rate (µm ) presented exponential relationship with inlet oxygen concentration and the maximum biomass (Xm ) exhibited linear increase. In terms of SG production, two-step model with Luedeking-Piret equation during growth phase and oxygen-dependent equation during stationary phase could well fit the experimental data...
July 30, 2018: Bioprocess and Biosystems Engineering
Ill-Min Chung, Kaliyaperumal Rekha, Govindasamy Rajakumar, Muthu Thiruvengadam
Glucosinolates (GSLs) and phenolic compounds (PCs) are biologically active and involved in the defense reaction of plants; these compounds have a beneficial effect on human health. In this study, we described the influence of biologically synthesized silver nanoparticles (Ag NPs) to enhance the phytochemicals (GSLs and PCs), their transcription levels, and their biological activities in genetically transformed root cultures (hairy root cultures) of Brassica rapa. The concentrations of silver and reactive oxygen species (malondialdehyde and hydrogen peroxide) were highly elevated in the Ag NP-elicited hairy roots (HRs)...
July 28, 2018: Bioprocess and Biosystems Engineering
Daniel de Castro Assumpção, Elmer Alberto Ccopa Rivera, Laura Plazas Tovar, Thaddeus Chukwuemeka Ezeji, Rubens Maciel Filho, Adriano Pinto Mariano
In flexible ethanol-butanol plants, low tolerance to butanol by solventogenic clostridia (and resulting dilute fermentation) results in considerable number of empty fermentors whenever production focuses on ethanol. This research identified scenarios in which vacuum fermentation (in-situ vacuum recovery) may be applied to solve this problem. We conducted ethanol (Saccharomyces cerevisiae) and ABE (Clostridium beijerinckii NCIMB 8052) batch vacuum fermentations of eucalyptus hydrolysates according to the distribution of sugars in a flexible plant...
July 26, 2018: Bioprocess and Biosystems Engineering
Guadalupe Montserrat Valdes Labrada, Mehdi Nemati
Waters contaminated with naphthenic acids (NAs) and associated tailings are one of the major environmental challenges associated with the processing of oil sands and production of heavy oil. In the current work biodegradation of linear and cyclic naphthenic acids, namely octanoic acid and 4-methyl-1-cyclohexane carboxylic acid (trans-4MCHCA), individually and in mixture were evaluated in microbial fuel cells (MFCs). In batch MFCs with single rod electrodes and freely suspended bacteria, biodegradation rate increased as NA initial concentration increased from 100 to 250 mg L-1 with no further improvement when a concentration of 500 mg L-1 was evaluated...
July 25, 2018: Bioprocess and Biosystems Engineering
Hudson B Carminati, Paula S Lima, Argimiro R Secchi, João P Bassin
Biofilm-based wastewater treatment systems have become attractive due to their numerous advantages when compared to other suspended growth processes. However, the mathematical modeling of these reactors is relatively complex, since it has to consider a wide range of phenomena to accurately describe the process behavior. This work deals with the modeling of a two-stage MBBR system run in pre-denitrification mode for the removal of organic matter and nitrogen from wastewater. The model development took into account diffusive phenomena and kinetics in a homogeneous biofilm composed of different bacterial functional groups (namely heterotrophs and nitrifiers)...
July 24, 2018: Bioprocess and Biosystems Engineering
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