Read by QxMD icon Read

Bioprocess and Biosystems Engineering

Xiao-Chen Ma, Si-Yu Zhu, Miao-Miao Luo, Xue-Chao Hu, Cheng Peng, He Huang, Lu-Jing Ren
Menaquinone-7 (MK-7) plays an important role in blood clotting, cardiovascular disease and anti-osteoporosis, and has been wildly used in the food additives and pharmaceutical industries. The aim of this study was to investigate the mechanism of menaquinone-7 biosynthesis in response to different oxygen supplies in Bacillus natto. The differences of fermentation performance, intracellular metabolites, oxidative stress reaction and enzyme activities of Bacillus natto R127 were analyzed under different KLa. Glycerol consumption rate and MK-7 yield at 24...
February 13, 2019: Bioprocess and Biosystems Engineering
Eleonora Sforza, Martina Pastore, Elena Barbera, Alberto Bertucco
Modeling microalgal mixotrophy is challenging, as the regulation of algal metabolism is affected by many environmental factors. A reliable tool to simulate microalgal behavior in complex systems, such as wastewaters, may help in setting the proper values of operative variables, provided that model parameters have been properly evaluated. In this work, a new respirometric protocol is proposed to quickly obtain the half-saturation constant values for several nutrients. The protocol was first verified for autotrophic exploitation of ammonium and phosphorus (Monod kinetics), as well as of light intensity (Haldane model), further elaborated on specific light supply basis...
February 12, 2019: Bioprocess and Biosystems Engineering
Jianrong Wu, Jingbo Zhang, Hongtao Zhang, Minjie Gao, Liming Liu, Xiaobei Zhan
Rhamnolipids (RLs) are anionic biosurfactants with great application potential. This study explored the possibility of producing RLs from cooking oil fume condensates (COFCs) collected from range hoods. A mutant of Pseudomonas aeruginosa AB93066 was obtained and used to produce RLs from COFCs as a substrate. RL yields in a 7-L fermenter reached 12.3 g/L, and MALDI-TOF MS showed that Rha2 -C10 -C10 and Rha-C10 -C10 are the most abundant (39.6% and 26.4%, respectively) RL components. The critical micellar concentration (CMC) of the RLs was 45...
February 11, 2019: Bioprocess and Biosystems Engineering
Caroline Torres de Oliveira, Eliana Albornoz Alves, Izelmar Todero, Raquel C Kuhn, Débora de Oliveira, Marcio A Mazutti
In the present study, it was presented a strategy to maximize the cutinase production by solid-state fermentation from different microorganisms and substrates. The best results were observed using Fusarium verticillioides, rice bran being the main substrate. Maximum yield of cutinase obtained by the strain was 16.22 U/g. For concentration, ethanol precipitation was used, and the purification factor was 2.4. The optimum temperature and pH for enzyme activity were 35 °C and 6.5, respectively. The enzyme was stable at a wide range of temperature and at all pH values tested...
February 9, 2019: Bioprocess and Biosystems Engineering
Bin Yang, Jiatao Zhou, Hui Zhao, Anling Wang, Yuanjun Lei, Qiuling Xie, Sheng Xiong
Stable transfection of mammalian cells using various expression cassettes for exogenous gene expression has been well established. The impact of critical factors in these cassettes, such as promoter and enhancer elements, on recombinant protein production in mammalian cells has been studied extensively to optimize the expression efficiency. However, few studies on the correlation between the strength of selection marker and the expression of gene of interest (GOI) have been reported. Here we investigated the correlation between the strength of a widely used selection marker, glutamine synthetase (GS) gene, and gene of interest in which the expression of GOI is driven by mouse cytomegalovirus (mCMV) major immediate early (MIE) promoter whereas the expression of GS is controlled by SV40E (Simian vacuolating virus 40E) promoter...
February 7, 2019: Bioprocess and Biosystems Engineering
Sarah Gretzinger, Stefanie Limbrunner, Jürgen Hubbuch
The continuous availability of cells with defined cell characteristics represents a crucial issue in the biopharmaceutical and cell therapy industry. Here, development of cell banks with a long-term stability is essential and ensured by a cryopreservation strategy. The strategy needs to be optimized for each cell application individually and usually comprises controlled freezing, storage at ultra-low temperature, and fast thawing of cells. This approach is implemented by the development of master and working cell banks...
February 4, 2019: Bioprocess and Biosystems Engineering
Bingxu Han, Guoxia Zheng, Junfeng Wei, Yusuo Yang, Ling Lu, Qian Zhang, Yunhua Wang
We present an automatic design process for microfluidic dilution network towards marine ecological toxicity assessment on microalgae. Based on the hydraulic-electric circuit analogy, we defined an abstract specification using computer-aided designing system. Several approaches, especially circuit partition, were applied to minimize design effort. Computational fluid dynamics (CFD) simulation was exploited to convert the electrics specification to fabrication model. We automatically designed the combinational-mixing-serial dilution microfluidics to generate parallel stepwise gradients for mixing chemicals (binary/ternary/quaternary mixture) using the present algorithm...
February 4, 2019: Bioprocess and Biosystems Engineering
Md Shamim Howlader, Janice DuBien, El Barbary Hassan, Neeraj Rai, William Todd French
Microbial cell disruption using pressurized gases (e.g., CO2 ) is a promising approach to improve the lipid recovery from wet oleaginous microorganisms by eliminating the energy-intensive drying required for conventional methods. In this study, we perform cell disruption of Rhodotorula glutinis using pressurized CH4 , N2 , and Ar where we find the efficacy of these gases on cell viability is minimal. Since CO2 is found to be the only viable gas for microbial cell disruption among these four gases, we use a combination of Box-Behnken design and response surface methodology (RSM) to find the optimal cell disruption by tuning different parameters such as pressure (P), temperature (T), exposure time (t), and agitation (a)...
February 1, 2019: Bioprocess and Biosystems Engineering
Rituparna Das, Arundhati Pal, A K Paul
Co-polymerization of microbial polyesters, polyhydroxyalkanoates (PHAs), with synthetic polymers has become an established and promising tool in the recent past for improving the material and biological properties of the biopolyesters. Bacillus cereus RCL 02, a leaf endophytic bacterium of the oleaginous plant Ricinus communis L., has been reported to produce a significant amount of poly(3-hydroxybutyrate) [P(3HB)] and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] under batch cultivation. The present study demonstrates the synthesis and accumulation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-polyethylene glycol [P(3HB-co-3HV)-PEG] co-polymer by the isolate RCL 02 in glucose, valeric acid, and PEG-200 supplemented mineral salts medium following dual-step cultivation...
February 1, 2019: Bioprocess and Biosystems Engineering
Caterina Armato, Daniyal Ahmed, Valeria Agostino, Deborah Traversi, Raffaella Degan, Tonia Tommasi, Valentina Margaria, Adriano Sacco, Giorgio Gilli, Marzia Quaglio, Guido Saracco, Tiziana Schilirò
The characterization of anodic microbial communities is of great importance in the study of microbial fuel cells (MFCs). These kinds of devices mainly require a high abundance of anode respiring bacteria (ARB) in the anode chamber for optimal performance. This study evaluated the effect of different enrichments of environmental freshwater sediment samples used as inocula on microbial community structures in MFCs. Two enrichment media were compared: ferric citrate (FeC) enrichment, with the purpose of increasing the ARB percentage, and general enrichment (Gen)...
January 29, 2019: Bioprocess and Biosystems Engineering
Gang Zhou, Xiwei Tian, Yumeng Lin, Siliang Zhang, Ju Chu
A rational high-throughput screening can significantly improve the efficiency of strain screening with high performance. In this study, based on the addition reaction of unsaturated fatty acids in the sophorolipids (SLs) and I2 molecules, a simple and rapid high-throughput detection method for SLs was established which demonstrated a correlation coefficient (R2 ) of 0.9106 with high-performance liquid chromatography (HPLC) method. Moreover, chlorpromazine, as a rational selecting pressure for enrichment of mutants with high cytochrome P450 enzyme activity, which was a key enzyme in the synthesis of SLs, was introduced into the high-throughput screening model...
January 24, 2019: Bioprocess and Biosystems Engineering
Kahina Mellahi, Denis Brochu, Michel Gilbert, Michel Perrier, Sven Ansorge, Yves Durocher, Olivier Henry
Mammalian-inducible expression systems are increasingly available and offer an attractive platform for the production of recombinant proteins. In this work, we have conducted process development for a cumate-inducible GS-CHO cell-line-expressing rituximab. To cope with the limitations encountered in batch when inducing at high cell densities, we have explored the use of fed-batch, sequential medium replacements, and continuous perfusion strategies applied during the pre-induction (growth) phase to enhance process performance in terms of product yield and quality...
January 23, 2019: Bioprocess and Biosystems Engineering
Shun Jiang, Hongying Jiang, Yuling Zhou, Sijing Jiang, Guimin Zhang
β-N-Acetylglucosaminidases (NAGase) can remove N-acetylglucosamine (GlcNAc) from the non-reducing end of chitin or chitosan. GlcNAc has many important physiological functions in organism, which can be used for the treatment of rheumatoid arthritis clinically and be used as food antioxidant, infant food additive and diabetic sweetener. Thus, it is very important to develop genetic-engineering strains with high-yield NAGase to hydrolyze chitin into GlcNAc. Here, the NAGase gene of Bacillus subtilis 168 (BsnagZ) was synthesized according to the codon bias of Pichia pastoris and expressed in P...
January 23, 2019: Bioprocess and Biosystems Engineering
Guilan Zhu, Na Guo, Yanan Yong, Yawen Xiong, Qunyi Tong
2-Deoxy-D-glucose (2-DG) is a non-metabolizable glucose analogue and competitive inhibitor of glycolysis. Effect of 2-DG on gellan gum biosynthesis by Sphingomonas paucimobilis ATCC31461 were studied in this research. The concentration and the addition time of 2-DG significantly affected the biomass and gellan gum accumulation. The maximum gellan gum yield of 20.78 g/L was obtained with the addition of 50 µg/L of 2-DG at 24 h. The mechanism of 2-DG addition favoring to gellan production was revealed by determining the activities of key enzymes...
January 22, 2019: Bioprocess and Biosystems Engineering
Raquel Guidetti Vendruscolo, Mariane Bittencourt Fagundes, Mariana Manzoni Maroneze, Tatiele Casagrande do Nascimento, Cristiano Ragagnin de Menezes, Juliano Smanioto Barin, Leila Queiroz Zepka, Eduardo Jacob-Lopes, Roger Wagner
Environmental factors directly affect the growth and composition of microalgal biomass. Therefore, the present work analyzed the metabolomics (amino acids, organic acids, and fatty acids) of the microalga Scenedesmus obliquus cultivated in 24:0 and 12:12 (light:dark) photoperiods and different phases of cell growth. Furthermore, the metabolites were related to protein, lipid, and chlorophyll contents at the end of cultivation. The highest biomass concentration (4020 mg L- 1 ) and protein (47.3%) were obtained in culture under constant illumination...
January 22, 2019: Bioprocess and Biosystems Engineering
Viviane Astolfi, Angela Luiza Astolfi, Marcio A Mazutti, Elisandra Rigo, Marco Di Luccio, Aline Frumi Camargo, Caroline Dalastra, Simone Kubeneck, Gislaine Fongaro, Helen Treichel
This study evaluated the production of cellulolytic enzymes from different agricultural residues. The crude enzyme extract produced was characterized and applied for saccharification of some agricultural residues. Maximum cellulolytic activities were obtained using soybean hulls. All enzymatic activities were highly stable at 40 °C at a pH range of 4.5-5.5. For stability at low temperatures, the enzyme extract was stored at freezing temperature and cooling for about 290 days without major loss of activity...
January 19, 2019: Bioprocess and Biosystems Engineering
Ezhaveni Sathiyamoorthi, Prasun Kumar, Beom Soo Kim
The efficiency of Cryptococcusalbidus was evaluated for its abilities to assimilate onion and apple hydrolysates as a medium for lipid production. Onion waste (OW) and apple waste (AW) were hydrolysed at an organic load of 2% total solids by indigenous microbes under mesophilic conditions. The indigenous microbes effectively hydrolysed both wastes giving the highest reducing sugar content of 4.8 g/L and 10.8 g/L with OW and AW hydrolysates, respectively. The microbiome analysis revealed that most of the indigenous microbes belonged to genus Bacillus and a significant population of α-proteobacteria and γ-proteobacteria were also present...
January 19, 2019: Bioprocess and Biosystems Engineering
Guanhua Li, Ying Fu, Wenxian Dang, Ruiping Hu, Huiting Xue
Chemical composition and physical structure of solid substrate have significantly impacts on fermentation performance. The aqueous ammonia was used to pretreat rice straw. Furthermore, the feasibility of pretreatment to improve laccase production was also evaluated in terms of the enzymatic digestibility, chemical structure, physical structure, and laccase production. The results showed that aqueous ammonia pretreatment could modify chemical compositions, destroy rigid structure of the lignocellulosic substrate, increase enzymatic digestibility and change water state, which were beneficial to facilitate the fungus growth and nutrition utilization...
January 17, 2019: Bioprocess and Biosystems Engineering
Lanmei Zhao, Congcong Zhang, Haoshuai Li, Mutai Bao, Peiyan Sun
The types and concentrations of electron acceptor are the significant factors influencing the oxidation and biotransformation of organic matter in the process of pollutant biodegradation. Regulation of O2 , SO4 2- and NO3 - as electron acceptors on petroleum hydrocarbon biotransformation to final products was studied using the multiple methods including mesoscale biodegradation experiments, thermodynamic theoretical calculations and stoichiometric analyses. Petroleum hydrocarbon biodegradation ratio (PHBR) rose from 64...
January 14, 2019: Bioprocess and Biosystems Engineering
Xin Zeng, Wenyun Miao, Beibei Wen, Zhonggui Mao, Mingzhi Zhu, Xusheng Chen
A glucose-glycerol mixed carbon source (MCS) can substantially reduce batch fermentation time and improve ε-poly-L-lysine (ε-PL) productivity, which was of great significance in industrial microbial fermentation. This study aims to disclose the physiological mechanism by transcriptome analyses. In the MCS, the enhancements of gene transcription mainly emerged in central carbon metabolism, L-lysine synthesis as well as cell respiration, and these results were subsequently proved by quantitative real-time PCR assay...
January 12, 2019: Bioprocess and Biosystems Engineering
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"