Integrated bioprocess for long-term continuous cultivation of Clostridium acetobutylicum coupled to pervaporation with PDMS composite membranes

2012 ◽  
Vol 111 ◽  
pp. 368-377 ◽  
Author(s):  
Wouter Van Hecke ◽  
Pieter Vandezande ◽  
Stan Claes ◽  
Silvia Vangeel ◽  
Herman Beckers ◽  
...  
Keyword(s):  
Clostridium Acetobutylicum ◽  
Continuous Cultivation ◽  
Composite Membranes ◽  
Integrated Bioprocess

Long-Term Stability against H2S Poisoning on Pd Composite Membranes by Thin Zeolite Coatings

2019 ◽  
Vol 58 (16) ◽  
pp. 6429-6437 ◽  
Author(s):  
Bingbing Chen ◽  
Jinxia Liu ◽  
Hui Li ◽  
Tianying Xu ◽  
Jixin Zhang ◽  
...  
Keyword(s):  
Composite Membranes ◽  
Term Stability ◽  
Long Term Stability ◽  
H2s Poisoning ◽  
Zeolite Coatings

scholarly journals Long term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. II. Total organic carbon and its rate of loss from the soil profile

Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 281 ◽  
Author(s):  
RC Dalal ◽  
RJ Mayer
Keyword(s):  
Activity Ratio ◽  
Clay Content ◽  
Continuous Cultivation ◽  
Stepwise Multiple Regression ◽  
Annual Rainfall ◽  
Aggregation Index ◽  
Organic C ◽  
Long Term Trends ◽  
Kinetics Of

The kinetics of organic C loss were studied in six southern Queensland soils subjected to different periods (0-70 years) of cultivation and cereal cropping. The equation: Ct = Ce + (C0 - Ce)exp(- kt), where C0, Ce and C, are organic C contents initially, at equilibrium and at time k respectively, and k is the rate of loss of organic C from soil, was employed in the study. The parameter k was calculated both for %C (kc) and for weight of organic C/volume of soil (k,), determined by correcting for differences in sampling depth due to changes in bulk density upon cultivation. Mean annual rainfall largely determined both C, and Ce, presumably by influencing the amount of dry matter produced. Values of kc and kw varied greatly among the soils studied. For the 0-0.1 m depth, kw was 0.065, 0.080, 0.180, 0.259, 0.069 and 1.224 year-1 respectively for Waco (black earth - initially grassland), Langland-Logie (grey brown and red clays - brigalow), Cecilvale (grey, brown and red clays - poplar box), Billa Billa (grey, brown and red clays - belah), Thallon (grey, brown and red clays - coolibah) and Riverview (red earths - silver-leaved ironbark). The k values were significantly correlated with organic Chrease activity ratio (r = 0.99***) and reciprocal of clay content (r = 0.97**) of the virgin soils. In stepwise multiple regression analysis, aggregation index (for kc values) or exchangeable sodium percentage (for kw) and organic C/urease activity ratio of soils were significantly associated with the overall rate of loss of organic C. It was inferred, therefore, that the relative inaccessibility and protection of organic matter against microbial and enzymic attack resulted in reduced organic C loss. Losses of organic C from the deeper layers (0-0.2 m, 0-0.3 m) were observed in Waco, Langlands-Logie, Cecilvale and Riverview soils, although generally rate of loss decreased with depth.

scholarly journals Electrospun poly (L-lactic acid)/gelatin membranes loaded with doxorubicin for effective suppression of glioblastoma cell growth in vitro and in vivo

2021 ◽  
Author(s):  
Boxun Liu ◽  
Zhizhong Jin ◽  
Haiyan Chen ◽  
Lun Liang ◽  
Yao Li ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Lactic Acid ◽  
Release Kinetics ◽  
Drug Loading ◽  
Composite Membranes ◽  
Spectroscopic Techniques ◽  
Loading Process

Abstract Electrospun membranes are attracting interest as a drug delivery system because of their material composition flexibility and versatile drug loading. In this study, the electrospun membrane was loaded with doxorubicin (DOX) via electrostatic adsorption for long-term drug delivery. DOX loading process was optimized by varying temperature, time, drug concentration, pH, and ionic strength of solutions. The loading process did not impair the structural properties of the membrane. Next, we investigated the drug release kinetics using spectroscopic techniques. The composite membranes released 22% of the adsorbed DOX over the first 48 h, followed by a slower and sustained release over 4 weeks. The DOX release was sensitive to acidic solutions that the release rate at pH 6.0 was 1.27 times as that at pH 7.4. The DOX-loaded membranes were found to be cytotoxic to U-87 MG cells in vitro that decreased the cell viability from 82.92% to 25.49% from 24 h to 72 h of co-incubation. These membranes showed strong efficacy in suppressing tumour growth in vivo in glioblastoma-bearing mice that decreased the tumour volume by 77.33% compared to blank membrane-treated group on Day 20. In conclusion, we have developed an effective approach to load DOX within a clinically-approved poly (L-lactic acid)/gelatin membrane for local and long-term delivery of DOX for the treatment of glioblastoma.

scholarly journals Long-Term Storage and Use of Artificially Immobilized Anaerobic Sludge as a Powerful Biocatalyst for Conversion of Various Wastes Including Those Containing Xenobiotics to Biogas

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 326 ◽  
Author(s):  
Olga Senko ◽  
Marina Gladchenko ◽  
Olga Maslova ◽  
Elena Efremenko
Keyword(s):  
Clostridium Acetobutylicum ◽  
Immobilized Cells ◽  
Poly Vinyl Alcohol ◽  
Anaerobic Sludge ◽  
Lignocellulosic Waste ◽  
Long Term Storage ◽  
Anaerobic Consortium ◽  
High Level ◽  
Term Storage

The aim of this paper is to demonstrate the possibilities of anaerobic sludge cells immobilized into poly(vinyl alcohol) cryogel for the methanogenic conversion of various lignocellulosic waste and other media containing antibiotics (ampicillin, kanamycin, benzylpenicillin) or pesticides (chlorpyrifos or methiocarb and its derivatives). It was established that the immobilized cells of the anaerobic consortium can be stored frozen for at least three years while preserving a high level of metabolic activity. The cells after the long-term storage in an immobilized and frozen state were applied for the methanogenesis of a wide number of wastes, and an increase in both methane yield and methane portion in the produced biogas as compared to the conventionally used suspended anaerobic sludge cells, was ensured. It was shown that the “additional” introduction of bacterial Clostridium acetobutylicum, Pseudomonas sp., Enterococcus faecalis cells (also immobilized using same support) improves characteristics of methanogenesis catalyzed by immobilized anaerobic sludge.

scholarly journals Study on the Durability of Recast Nafion/Montmorillonite Composite Membranes in Low Humidification Conditions

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
A. Pozio ◽  
A. Cemmi ◽  
F. Mura ◽  
A. Masci ◽  
R. F. Silva
Keyword(s):  
Fuel Cell ◽  
Relative Humidity ◽  
Polymer Membranes ◽  
Composite Membranes ◽  
Polymeric Membrane ◽  
Membrane Degradation

Nafion composite membranes were formed from a recasting procedure previously reported by the authors. Montmorillonite (MMT) was used as a filler in the recasting procedure, and dimethylformamide (DMF) was used as the casting solvent. Fuel cell tests performed with the recast membrane showed that at low relative humidity (R.H.) the conductivity of the MMT-containing membranes is 10% higher than that of the MMT-free samples. In order to investigate the durability of such composite perfluorosulfonate membranes, long-term fuel cell experiments have been carried out. Results evidenced a strong effect of low RH on the lifetime of commercial polymer membranes, but the addition of a small silicate amount to the polymeric membrane reduced strongly the membrane degradation.

scholarly journals Lysozyme and Penicillin Inhibit the Growth of Anaerobic Ammonium-Oxidizing Planctomycetes

2013 ◽  
Vol 79 (24) ◽  
pp. 7763-7769 ◽  
Author(s):  
Ziye Hu ◽  
Theo van Alen ◽  
Mike S. M. Jetten ◽  
Boran Kartal
Keyword(s):  
Cell Wall ◽  
Continuous Cultivation ◽  
Penicillin G ◽  
Anammox Bacteria ◽  
Short Term ◽  
Content Type ◽  
Genome Data ◽  
Wall Structures ◽  
Anammox Activity

ABSTRACTAnaerobic ammonium-oxidizing (anammox) planctomycetes oxidize ammonium in the absence of molecular oxygen with nitrite as the electron acceptor. Although planctomycetes are generally assumed to lack peptidoglycan in their cell walls, recent genome data imply that the anammox bacteria have the genes necessary to synthesize peptidoglycan-like cell wall structures. In this study, we investigated the effects of two antibacterial agents that target the integrity and synthesis of peptidoglycan (lysozyme and penicillin G) on the anammox bacteriumKuenenia stuttgartiensis. The effects of these compounds were determined in both short-term batch incubations and long-term (continuous-cultivation) growth experiments in membrane bioreactors. Lysozyme at 1 g/liter (20 mM EDTA) lysed anammox cells in less than 60 min, whereas penicillin G did not have any observable short-term effects on anammox activity. Penicillin G (0.5, 1, and 5 g/liter) reversibly inhibited the growth of anammox bacteria in continuous-culture experiments. Furthermore, transcriptome analyses of the penicillin G-treated reactor and the control reactor revealed that penicillin G treatment resulted in a 10-fold decrease in the ribosome levels of the cells. One of the cell division proteins (Kustd1438) was downregulated 25-fold. Our results suggested that anammox bacteria contain peptidoglycan-like components in their cell wall that can be targeted by lysozyme and penicillin G-sensitive proteins were involved in their synthesis. Finally, we showed that a continuous membrane reactor system with free-living planktonic cells was a very powerful tool to study the physiology of slow-growing microorganisms under physiological conditions.

SUSTAINABLE MAIZE PRODUCTION USING GLIRICIDIA/MAIZE INTERCROPPING IN SOUTHERN MALAWI

2006 ◽  
Vol 42 (4) ◽  
pp. 441-457 ◽  
Author(s):  
F. K. AKINNIFESI ◽  
W. MAKUMBA ◽  
F. R. KWESIGA
Keyword(s):  
Soil Fertility ◽  
Cropping Systems ◽  
Continuous Cultivation ◽  
Maize Yield ◽  
Fertilizer Application ◽  
Maize Production ◽  
Soil Fertility Replenishment ◽  
P Fertilizer ◽  
Maize Yields

Maize production in Malawi is limited by high costs and sub-optimal use of chemical fertilizers under continuous cultivation. A long-term gliricidia/maize trial was undertaken on a Ferric Lixisol from 1991/92 to 2001/02. The purpose of the study was to assess the performance of a gliricidia/maize intercropping system as a low-input soil fertility replenishment option in southern Malawi. The experiment was a 2 × 3 × 3 factorial design with three replications. Treatments included two maize cropping systems (with and without gliricidia trees), and three rates of inorganic N fertilizer (0, 24 and 48 N kg ha−1 representing 0, 25 and 50% of the national recommended N rate), and three rates of P fertilizer application (0, 20 and 40 P ha−1 representing 0, 50 and 100% of the recommended rate). No effect of P was detected on yield early in the trial, and this treatment was discontinued. The gliricidia pruning biomass did not decline after 10 years of intensive pruning, with strong correlation between tree biomass production and years after establishment (r = 0.91, p < 0.001). Application of gliricidia prunings increased maize yields by three times compared to the yield of unfertilized sole maize. Maize yield from the unfertilized gliricidia pruning treatment was superior to the yield from sole maize supplemented with a quarter or half the recommended N rate. The study confirmed that a gliricidia/maize intercropping system is a promising soil fertility replenishment option in southern Malawi and elsewhere in southern Africa.

scholarly journals Scaling-Up and Semi-Continuous Cultivation of Locally Isolated Marine Microalgae Tetraselmis striata in the Subtropical Island of Gran Canaria (Canary Islands, Spain)

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1326
Author(s):  
Zivan Gojkovic ◽  
Flavio Guidi ◽  
Begoña Bustamante ◽  
Marianna Venuleo ◽  
Patrícia Alexandra Clemente Janeiro de Assunçao ◽  
...  
Keyword(s):  
Large Scale ◽  
Photosynthetic Activity ◽  
Continuous Cultivation ◽  
Scaling Up ◽  
Good Source ◽  
Gran Canaria ◽  
Tetraselmis Striata ◽  
Large Scale Cultivation ◽  
Photosynthetic Efficiencies

The goal of this study was to determine the feasibility of the large-scale cultivation of locally isolated Tetraselmis striata in different open ponds in Gran Canaria. The biomass productivities were 24.66 ± 0.53 kgDW in 32 days (28.9t/ha/year) for 8000 L indoors, 42.32 ± 0.81 kgDW in 43 days (38.8 t/ha/year) for an 8000 L pond outdoors, and 54.9 ± 0.58 kgDW in 28 days (19.6 t/ha/year) for a 45,000 L pond outdoors. The photosynthetic efficiencies were 1.45 ± 0.03% for an 8000 L pond indoors, 1.95 ± 0.04% for 8000 L outdoors. and 1.10 ± 0.01% for a 45,000 L pond outdoors. The selected strain was fast-growing (µ = 0.21 day−1) and could be rapidly scaled up to 45,000 L; it formed healthy cultures that maintained high photosynthetic activity during long-term cultivation and provided stable biomass productivities, able to grow on urea, which acted as a cheap and effective grazer control. The obtained biomass is a good source of proteins and has an FA profile with a high content of some nutritionally important fatty acids: oleic, α-linolenic (ALA) and EPA. The high ash content in the biomass (>35%) can be reduced by the implementation of additional washing steps after the centrifugation of the culture.

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