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https://www.readbyqxmd.com/read/28110230/identification-of-the-autotrophic-denitrifying-community-in-nitrate-removal-reactors-by-dna-stable-isotope-probing
#1
Wei Xing, Jinlong Li, Yuan Cong, Wei Gao, Zhongjun Jia, Desheng Li
Autotrophic denitrification has attracted increasing attention for wastewater with insufficient organic carbon sources. Nevertheless, in situ identification of autotrophic denitrifying communities in reactors remains challenging. Here, a process combining micro-electrolysis and autotrophic denitrification with high nitrate removal efficiency was presented. Two batch reactors were fed organic-free nitrate influent, with H(13)CO3(-) and H(12)CO3(-) as inorganic carbon sources. DNA-based stable-isotope probing (DNA-SIP) was used to obtain molecular evidence for autotrophic denitrifying communities...
January 12, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28110129/identifying-and-overcoming-the-effect-of-mass-transfer-limitation-on-decreased-yield-in-enzymatic-hydrolysis-of-lignocellulose-at-high-solid-concentrations
#2
Jian Du, Yuan Cao, Guodong Liu, Jian Zhao, Xuezhi Li, Yinbo Qu
Cellulose conversion decreases significantly with increasing solid concentrations during enzymatic hydrolysis of insoluble lignocellulosic materials. Here, mass transfer limitation was identified as a significant determining factor of this decrease by studying the hydrolysis of delignified corncob residue in shake flask, the most used reaction vessel in bench scale. Two mass transfer efficiency-related factors, mixing speed and flask filling, were shown to correlate closely with cellulose conversion at solid loadings higher than 15% DM...
January 12, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28109588/tea-saponin-reduced-methanogenesis-in-vitro-but-increased-methane-yield-in-lactating-dairy-cows
#3
J Guyader, M Eugène, M Doreau, D P Morgavi, C Gérard, C Martin
The effect of tea saponin supplementation in the ruminant diet on methane emissions, rumen fermentation, and digestive processes is still under debate. The objective of this study was to assess the effect of this plant extract on methanogenesis, total-tract digestibility, and lactating performances of dairy cows. The work included 2 independent and successive experiments. First, the effect of 7 tea saponin doses (from 0 to 0.50 g/L) on methane emissions and protozoa concentrations was tested in 2 repeated in vitro batch culture incubations using bovine rumen contents as inoculum and a cereal mixture as substrate...
January 18, 2017: Journal of Dairy Science
https://www.readbyqxmd.com/read/28101787/a-recombinant-highly-thermostable-%C3%AE-mannanase-retman26-from-thermophilic-bacillus-subtilis-tbs2-expressed-in-pichia-pastoris-and-its-ph-and-temperature-stability
#4
Zhangcai Luo, Jing Miao, Guoying Li, Yao Du, Xiaobin Yu
A gene encoding a highly thermostable β-mannanase from a thermophilic Bacillus subtilis (TBS2) was successfully expressed in Pichia pastoris. The maximum activity of the recombinant thermostable β-mannanase (ReTMan26) was 5435 U/mL, which was obtained by high-density, fed-batch cultivation after 168-h induction with methanol in a 50-L bioreactor. The protein yield reached 3.29 mg/mL, and the protein had a molecular weight of ~42 kDa. After fermentation, ReTMan26 was purified using a 10-kDa cut-off membrane and Sephadex G-75 column...
January 18, 2017: Applied Biochemistry and Biotechnology
https://www.readbyqxmd.com/read/28092734/combined-utilization-of-nutrients-and-sugar-derived-from-wheat-bran-for-d-lactate-fermentation-by-sporolactobacillus-inulinus-ybs1-5
#5
Jiahuang Li, Junfei Sun, Bin Wu, Bingfang He
To decrease d-Lactate production cost, wheat bran, a low-cost waste of milling industry, was selected as the sole feedstock. First, the nutrients were recovered from wheat bran by acid protease hydrolysis. Then, cellulosic hydrolysates were prepared from protease-treated samples after acid pretreatment and enzymatic saccharification. The combined use of nutrients and hydrolysates as nitrogen and carbon sources for fermentation by S. inulinus YB1-5 resulted in d-Lactate levels of 99.5g/L, with an average production efficiency of 1...
December 30, 2016: Bioresource Technology
https://www.readbyqxmd.com/read/28089580/medium-optimization-based-on-yeast-s-elemental-composition-for-glutathione-production-in-saccharomyces-cerevisiae
#6
Maximilian Schmacht, Eric Lorenz, Ulf Stahl, Martin Senz
The production of glutathione (GSH) or GSH enriched yeast is still in the focus of research driven by a high industrial interest. In this study, an optimal growth rate for GSH production via Saccharomyces cerevisiae Sa-07346 was investigated. To further improve the fermentation process in a way that it is independent of lots, the influence of different WMIX medium compositions on biomass and GSH production was studied. Thereby, the fermentation medium was adjusted based on yeast's elemental composition. The resulting chemically defined fermentation medium led to high cell densities in fed-batches...
January 12, 2017: Journal of Bioscience and Bioengineering
https://www.readbyqxmd.com/read/28089378/butyrate-production-under-aerobic-growth-conditions-by-engineered-escherichia-coli
#7
Naoya Kataoka, Alisa S Vangnai, Thunyarat Pongtharangkul, Toshiharu Yakushi, Kazunobu Matsushita
Butyrate is an important industrial platform chemical. Although several groups have reported butyrate production under oxygen-limited conditions by a native producer, Clostridium tyrobutylicum, and by a metabolically engineered Escherichia coli, efforts to produce butyrate under aerobic growth conditions have met limited success. Here, we constructed a novel butyrate synthetic pathway that functions under aerobic growth conditions in E. coli, by modifying the 1-butanol synthetic pathway reported previously...
January 11, 2017: Journal of Bioscience and Bioengineering
https://www.readbyqxmd.com/read/28089045/biotransformation-of-limonene-by-an-endophytic-fungus-using-synthetic-and-orange-residue-based-media
#8
Mário Cesar Jucoski Bier, Adriane Bianchi Pedroni Medeiros, Carlos Ricardo Soccol
Aroma and fragrances have high commercial value for use in food, cosmetics and perfumes. The biotransformation of terpenes by microorganisms represents an attractive alternative method for production of flavourings. Endophytic fungi offer a great potential for the production of several groups of compounds; however, few studies have evaluated the biotransformation of limonene. Following preliminary studies on the biotransformation of limonene, submerged fermentation was carried out using an endophytic fungus isolated from Pinus taeda and identified as Phomopsis sp...
February 2017: Fungal Biology
https://www.readbyqxmd.com/read/28088541/secretory-pathway-optimization-of-cho-producer-cells-by-co-engineering-of-the-mitosrna-1978-target-genes-cers2-and-tbc1d20
#9
Lisa A Pieper, Michaela Strotbek, Till Wenger, Martin Gamer, Monilola A Olayioye, Angelika Hausser
Chinese Hamster Ovary (CHO) cells are the most commonly used host for the production of biopharmaceuticals. Although transcription and translation engineering strategies have been employed to generate high-producer cell clones, the secretory pathway still remains a bottleneck in cellular productivity. In this study we show that ectopic expression of a human mitochondrial genome-encoded small RNA (mitosRNA-1978) in an IgG expressing CHO cell line strongly improved specific productivity by functioning in a microRNA-like fashion...
January 11, 2017: Metabolic Engineering
https://www.readbyqxmd.com/read/28088197/production-of-human-pro-relaxin-h2-in-the-yeast-pichia-pastoris
#10
D Cimini, K Della Corte, R Finamore, L Andreozzi, A Stellavato, A V A Pirozzi, F Ferrara, R Formisano, M De Rosa, M Chino, L Lista, A Lombardi, V Pavone, C Schiraldi
BACKGROUND: Initially known as the reproductive hormone, relaxin was shown to possess other therapeutically useful properties that include extracellular matrix remodeling, anti-inflammatory, anti-ischemic and angiogenic effects. All these findings make relaxin a potential drug for diverse medical applications. Its precursor, pro-relaxin, is an 18 kDa protein, that shows activity in in vitro assays. Since extraction of relaxin from animal tissues raises several issues, prokaryotes and eukaryotes were both used as expression systems for recombinant relaxin production...
January 14, 2017: BMC Biotechnology
https://www.readbyqxmd.com/read/28078826/the-impact-of-ph-inhomogeneities-on-cho-cell-physiology-and-fed-batch-process-performance-two-compartment-scale-down-modelling-and-intracellular-ph-excursion
#11
Matthias Brunner, Philipp Braun, Philipp Doppler, Christoph Posch, Dirk Behrens, Christoph Herwig, Jens Fricke
Due to high mixing times and base addition from top of the vessel, pH inhomogeneities are most likely to occur during large-scale mammalian processes. The goal of this study was to set-up a scale-down model of a 10-12 m(3) stirred tank bioreactor and to investigate the effect of pH perturbations on CHO cell physiology and process performance. Short-term changes in extracellular pH were hypothesized to affect intracellular pH and thus cell physiology. Therefore, batch fermentations, including pH shifts to 9...
January 12, 2017: Biotechnology Journal
https://www.readbyqxmd.com/read/28078651/fed-batch-enzymatic-saccharification-of-high-solids-pretreated-lignocellulose-for-obtaining-high-titers-and-high-yields-of-glucose
#12
Young Hoon Jung, Hyun Min Park, Dong Hyun Kim, Jungwoo Yang, Kyoung Heon Kim
To reduce the distillation costs of cellulosic ethanol, it is necessary to produce high sugar titers in the enzymatic saccharification step. To obtain high sugar titers, high biomass loadings of lignocellulose are necessary. In this study, to overcome the low saccharification yields and the low operability of high biomass loadings, a fed-batch saccharification process was developed using an enzyme reactor that was designed and built in-house. After optimizing the cellulase and biomass feeding profiles and the agitation speed, 132...
January 11, 2017: Applied Biochemistry and Biotechnology
https://www.readbyqxmd.com/read/28078395/high-production-of-2-3-butanediol-from-glycerol-without-1-3-propanediol-formation-by-raoultella-ornithinolytica-b6
#13
Taeyeon Kim, Sukhyeong Cho, Han Min Woo, Sun-Mi Lee, Jinwon Lee, Youngsoon Um, Jin-Ho Seo
Conversion of crude glycerol derived from biodiesel processes to value-added chemicals has attracted much attention. Herein, Raoultella ornithinolytica B6 was investigated for the high production of 2,3-butanediol (2,3-BD) from glycerol without 1,3-propanediol (1,3-PD) formation, a by-product hindering 2,3-BD purification. By evaluating the effects of temperature, agitation speed, and pH control strategy, the fermentation conditions favoring 2,3-BD production were found to be 25 °C, 400 rpm, and pH control with a lower limit of 5...
January 11, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28074318/boosted-large-scale-production-and-purification-of-a-thermostable-archaeal-phosphotriesterase-like-lactonase-for-organophosphate-decontamination
#14
Odile Francesca Restaino, Maria Giovanna Borzacchiello, Ilaria Scognamiglio, Elena Porzio, Giuseppe Manco, Luigi Fedele, Cinzia Donatiello, Mario De Rosa, Chiara Schiraldi
Thermostable phosphotriesterase-like lactonases (PLLs) from extremophile archaea, like SsoPox from Sulfolobus solfataricus, are attractive biotechnological tools with industrial applications as organophosphate decontaminants, but their manufacturing still remains an unresolved issue because of the high costs and the low production yields. In this paper, for the first time, an efficient biotechnological process for the production and purification of a recombinant, engineered PLL, SsoPox W263F, expressed in E...
January 11, 2017: Journal of Industrial Microbiology & Biotechnology
https://www.readbyqxmd.com/read/28073929/improving-heterologous-production-of-phenylpropanoids-in-saccharomyces-cerevisiae-by-tackling-an-unwanted-side-reaction-of-tsc13-an-endogenous-double-bond-reductase
#15
Beata Joanna Lehka, Michael Eichenberger, Walden Emil Bjørn-Yoshimoto, Katherina Garcia Vanegas, Nicolaas Buijs, Niels Bjerg Jensen, Jane Dannow Dyekjær, Håvard Jenssen, Ernesto Simon, Michael Naesby
Phenylpropanoids, such as flavonoids and stilbenoids, are of great commercial interest, and their production in S. cerevisiae is a very promising strategy. However, to achieve commercially viable production, each step of the process must be optimized. We looked at carbon loss, known to occur in the heterologous flavonoid pathway in yeast, and identified an endogenous enzyme, the enoyl reductase Tsc13, which turned out to be responsible for the accumulation of phloretic acid via reduction of p-coumaroyl-CoA...
January 10, 2017: FEMS Yeast Research
https://www.readbyqxmd.com/read/28067645/assessment-of-the-endogenous-respiration-rate-and-the-observed-biomass-yield-for-methanol-fed-denitrifying-bacteria-under-anoxic-and-aerobic-conditions
#16
Jamal Alikhani, Ahmed Al-Omari, Haydee De Clippeleir, Sudhir Murthy, Imre Takacs, Arash Massoudieh
In this study, the endogenous respiration rate and the observed biomass yield of denitrifying methylotrophic biomass were estimated through measuring changes in denitrification rates (DNR) as a result of maintaining the biomass under methanol deprived conditions. For this purpose, activated sludge biomass from a full-scale wastewater treatment plant was kept in 10-L batch reactors for 8 days under fully aerobic and anoxic conditions at 20 °C without methanol addition. To investigate temperature effects, another biomass sample was placed under starvation conditions over a period of 10 days under aerobic conditions at 25 °C...
January 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/28061932/biodegradation-of-2-4-dichlorophenol-in-packed-bed-biofilm-reactor-effect-of-hydraulic-retention-time-biogenic-substrate-and-loading-rate
#17
Bhishma P Patel, Arvind Kumar
  The removal of 2,4-dichlorophenol (2,4-DCP) by a pure culture of Bacillus endophyticus strain immobilized on ceramic balls was studied in a packed bed biofilm reactor (PBBR). The biodegradation of 2,4-DCP was studied in fed-batch and continuous mode and the effect of different parameters such as hydraulic retention time (HRT), biogenetic substrate concentration, and loading rate on the removal of 2,4-DCP were evaluated. Field emission scanning electron microscope (FESEM) results established the biofilm formation on the ceramic beads...
December 1, 2016: Water Environment Research: a Research Publication of the Water Environment Federation
https://www.readbyqxmd.com/read/28050847/production-of-r-3-hydroxybutyric-acid-by-arxula-adeninivorans
#18
Mateusz Biernacki, Jan Riechen, Urs Hähnel, Thomas Roick, Kim Baronian, Rüdiger Bode, Gotthard Kunze
(R)-3-hydroxybutyric acid can be used in industrial and health applications. The synthesis pathway comprises two enzymes, β-ketothiolase and acetoacetyl-CoA reductase which convert cytoplasmic acetyl-CoA to (R)-3-hydroxybutyric acid [(R)-3-HB] which is released into the culture medium. In the present study we used the non-conventional yeast, Arxula adeninivorans, for the synthesis enantiopure (R)-3-HB. To establish optimal production, we investigated three different endogenous yeast thiolases (Akat1p, Akat2p, Akat4p) and three bacterial thiolases (atoBp, thlp, phaAp) in combination with an enantiospecific reductase (phaBp) from Cupriavidus necator H16 and endogenous yeast reductases (Atpk2p, Afox2p)...
December 2017: AMB Express
https://www.readbyqxmd.com/read/28040869/metabolic-engineering-of-klebsiella-pneumoniae-based-on-in-silico-analysis-and-its-pilot-scale-application-for-1-3-propanediol-and-2-3-butanediol-co-production
#19
Jong Myoung Park, Chelladurai Rathnasingh, Hyohak Song
Klebsiella pneumoniae naturally produces relatively large amounts of 1,3-propanediol (1,3-PD) and 2,3-butanediol (2,3-BD) along with various byproducts using glycerol as a carbon source. The ldhA and mdh genes in K. pneumoniae were deleted based on its in silico gene knockout simulation with the criteria of maximizing 1,3-PD and 2,3-BD production and minimizing byproducts formation and cell growth retardation. In addition, the agitation speed, which is known to strongly affect 1,3-PD and 2,3-BD production in Klebsiella strains, was optimized...
December 31, 2016: Journal of Industrial Microbiology & Biotechnology
https://www.readbyqxmd.com/read/28034770/combining-gal4p-mediated-expression-enhancement-and-directed-evolution-of-isoprene-synthase-to-improve-isoprene-production-in-saccharomyces-cerevisiae
#20
Fan Wang, Xiaomei Lv, Wenping Xie, Pingping Zhou, Yongqiang Zhu, Zhen Yao, Chengcheng Yang, Xiaohong Yang, Lidan Ye, Hongwei Yu
Current studies on microbial isoprene biosynthesis have mostly focused on regulation of the upstream mevalonic acid (MVA) or methyl-erythritol-4-phosphate (MEP) pathway. However, the downstream bottleneck restricting isoprene biosynthesis capacity caused by the weak expression and low activity of plant isoprene synthase (ISPS) under microbial fermentation conditions remains to be alleviated. Here, based on a previously constructed Saccharomyces cerevisiae strain with enhanced precursor supply, we strengthened the downstream pathway through increasing both the expression and activity of ISPS to further improve isoprene production...
January 2017: Metabolic Engineering
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