Abstract:
:The feasibility of producing ethanol in a continuous system from cellulose using Clostridirrrn thermocellum was investigated. This anaerobic and therniophilic bacterium was able to degrade cellulose directly into ethanol with acetic acid, hydrogen. and carbon dioxide as by-products of this fermentation. The fermentation was first carried out in a batch mode to study the effects of buffers, temperature, and agitation on microbial growth and ethanol production. From the compounds used to control pH. sodium bicarbonate had the most preferred effects on generation time and ethanol production. As expected, there was a positive relationship between temperature and growth rate. On the other hand, agitation did not benefit from ethanol production or microbial growth. The possibility of noncompetitive inhibition within such a system was deduced from the calculation of the kinetic constants K(m) and V(max). Continuous fermentations were carried out at 60 degrees C and pH 7.0 using 1.5 and 3% pure cellulose as a limiting substrate. The maximum ethanol concentration reached during the 1.5% cellulose fermentation was 0.3%. and 0.9% during the 3% cellulose fermentation. The yield of ethanol was about 0.3 grams per gram of consumed cellulose. The overall yield in both schemes was around 0.45 and 0.75 grams per gram of cellulose degraded. It was concluded that cellulose could be degraded continuously in a system with C. thermocellum for production of ethanol. While the continuous system like the batch method is feasible, it may not be promising as yet because of the slow generation time of this microorganism.
journal_name
Biotechnol Bioengjournal_title
Biotechnology and bioengineeringauthors
Zertuche L,Zall RRdoi
10.1002/bit.260240106subject
Has Abstractpub_date
1982-01-01 00:00:00pages
57-68issue
1eissn
0006-3592issn
1097-0290journal_volume
24pub_type
杂志文章abstract::Water permeability (Lp), calculated from the volume variations of cells subjected to an osmotic shock, is classically used to characterize cell membrane properties. In this work, we have shown the importance of the kind of mixing reactor used to measure the Lp parameter. A mathematical model including the mixing time ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19971005)56:1<62::AID-BIT7
更新日期:1997-10-05 00:00:00
abstract::For all bacteria, nearly every antimicrobial fails since a subpopulation of the bacteria enter a dormant state known as persistence, in which the antimicrobials are rendered ineffective due to the lack of metabolism. This tolerance to antibiotics makes microbial infections the leading cause of death worldwide and make...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25963
更新日期:2016-09-01 00:00:00
abstract::In this article we present magnetic resonance microscopy (MRM) characterization of the advective transport in a biofilm capillary reactor. The biofilm generates non-axial flows that are up to 20% of the maximum axial velocity. The presence of secondary velocities of this magnitude alters the mass transport in the bior...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20400
更新日期:2005-03-30 00:00:00
abstract::A two-parameter deactivation model is proposed to describe the kinetics of activity stabilization for some enzymes. The single-step unimolecular mechanism exhibits non-first-order deactivation kinetics since the final enzyme state, E(1) is not completely inactivated. The usefulness of the model is demonstrated by appl...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260300604
更新日期:1987-10-20 00:00:00
abstract::The growth dynamics of a methanol utilizing bacterium, L3, in batch bioreactors were experimentally investigated. Formaldehyde, a key intermediate of methanol oxidation, is indicated to have a significant role in the complex batch growth behavior of L3. The intricate batch growth dynamics of many microorganisms can be...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260261113
更新日期:1984-11-01 00:00:00
abstract::Shake flask and stirred tank bioleaching experiments showed that the dissolution of chalcopyrite is inhibited by ferric ion concentrations as low as 200 mg L(-1) and redox potentials >420 mV (vs. Ag/AgCl). Chemical leaching of chalcopyrite (4% suspension, surface area 2.3 m2 g(-1)) was enhanced fourfold in the presenc...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10184
更新日期:2002-05-20 00:00:00
abstract::NS0, a nonsecreting mouse myeloma cell, is a major host line used for recombinant antibody production. These cells have a cholesterol-dependent phenotype and rely on an exogenous supply of cholesterol for their survival and growth. To better understand the physiology underlying cholesterol dependence, we compared NS0 ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.20429
更新日期:2005-06-05 00:00:00
abstract::The effects of ZnCl2 additions on a mercuric reductase, merA, ammonia monooxygenase, amoA, and hydroxylamine (NH2OH) oxidoreductase, hao, gene expression were examined in continuously cultured Nitrosomonas europaea cells. The reactor was operated for 85 days with a 6.9 d hydraulic retention time and with four successi...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22069
更新日期:2009-02-01 00:00:00
abstract::On-line NAD(P)H fluorescence and culture redox potential (CRP) measurements were utilized to investigate the role of Vitreoscilla hemoglobin (VHb) in perturbing oxygen metabolism of microaerobic Escherichia coli Batch cultures of a VHb-synthesizing E. coli strain and the iso-genic control under fully aerated condition...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260470309
更新日期:1995-08-05 00:00:00
abstract::The rate of celluose degradation, limited due to the inhibition by cellobiose, can be increased by the hydrolysis of cellobiose to glucose using immobilized beta-glucosidase. Production of beta-glucosidase in four yeasts was studied and a maximum activity of 1.22 IU/mg cells was obtained in cells of Pichia etchellsii ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260260408
更新日期:1984-04-01 00:00:00
abstract::Wastewater-fed microbial fuel cells (MFCs) are a promising technology to treat low-organic carbon wastewater and recover part of the chemical energy in wastewater as electrical power. However, the interactions between electrochemically active and fermentative microorganisms cannot be easily studied in wastewater-fed M...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.25137
更新日期:2014-04-01 00:00:00
abstract::A model is proposed that accounts for the decreases in yield which occur in chemostat cultures of mesophilic yeasts at superoptimal growth temperatures. Two yield depressing effects were identified, one due to increased maintenance requirements by the viable fraction of the population, the other due to energy substrat...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260180603
更新日期:1976-06-01 00:00:00
abstract::Cell morphology is an important macroscopic indicator of cellular physiology and is increasingly used as a mean of probing culture state in vitro. Phase contrast microscopy (PCM) is a valuable tool for observing live cells morphology over long periods of time with minimal culture artifact. Two general approaches are c...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.26064
更新日期:2017-01-01 00:00:00
abstract::A process is described in which the baboon endogenous virus (BaEV) is produced under optimum conditions in cell culture, and concentrated by hollow-fiber ultrafiltration technology under conditions of large-scale production. This system has advantages over conventional systems in that the flow rate is increased 2.5-fo...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260220103
更新日期:1980-01-01 00:00:00
abstract::An approach is presented for the stable covalent immobilization of proteins with a high retention of biological activity. First, chemical modification studies were used to establish enzyme structural and functional properties relevant to the covalent immobilization of an enzyme to agarose based supports. Heparinase wa...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260370305
更新日期:1991-02-05 00:00:00
abstract::A simple methodology has been successfully employed to explain the solvent dependence of the substrate specificity of enzymes in organic media. This methodology, which does not require the knowledge of the enzyme structure and is thus applicable to lyophilized and other noncrystalline enzyme preparations, predicts tha...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(SICI)1097-0290(19971105)56:3<340::AID-BIT
更新日期:1997-11-05 00:00:00
abstract::Compared to the conventional microbial and mammalian systems, transgenic plants produce proteins in a different matrix. This provides opportunities and challenges for downstream processing. In the context of the plant host Brassica napus (canola), this work addresses the bioprocessing challenges of solid fractionation...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10524
更新日期:2003-03-30 00:00:00
abstract::Effectively releasing the locked polysaccharides from recalcitrant lignocellulose to fermentable sugars is among the greatest technical and economic barriers to the realization of lignocellulose biorefineries because leading lignocellulose pre-treatment technologies suffer from low sugar yields, and/or severe reaction...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21386
更新日期:2007-06-01 00:00:00
abstract::Biofilm growth in porous media is difficult to study non-invasively due to the opaqueness and heterogeneity of the systems. Magnetic resonance is utilized to non-invasively study water dynamics within porous media. Displacement-relaxation correlation experiments were performed on fluid flow during biofilm growth in a ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24803
更新日期:2013-05-01 00:00:00
abstract::Foam separation may have potential for protein recovery. However, for foam separation to be a viable protein recovery technique it is important to demonstrate, not only that high enrichments and recoveries can be achieved for single proteins, but also that high enrichments and recoveries, together with selectivity of ...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(19990205)62:3<291::aid-bit
更新日期:1999-02-05 00:00:00
abstract::The scope in improving enzyme productivities from the cellulose fermentation process is examined in laboratory-scale fermentors. The maximum productivity (30 IU/liter hr) is attained in a continuous-culture process with cell recycle using modified medium containing 0.5% cellulose. Optimum dilution rate and recycle rat...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260210213
更新日期:1979-02-01 00:00:00
abstract::Pre-filtration using ion exchange membrane adsorbers can improve parvovirus filter throughput of monoclonal antibodies (mAbs). The membranes work by binding trace foulants, and although some antibody product also binds, yields > or =99% are easily achieved by overloading. Results show that foulant adsorption is depend...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.22729
更新日期:2010-07-01 00:00:00
abstract::The functional analysis of plant cells at the cellular and subcellular levels requires novel technologies for the directed manipulation of individual cells. In this report, we demonstrate the use of an infrared (1,064 nm) picosecond laser for the perforation of tobacco cell protoplasts. A single pulse was sufficient t...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21549
更新日期:2008-01-01 00:00:00
abstract::This research focused on how the extent and type of primary solid-liquid separation can affect the performance of guard filtration and chromatography, in this instance hydrophobic interaction chromatography. The system used in the study was yeast (Saccharomyces cerevisiae) with the target molecule being an intracellul...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.21823
更新日期:2008-08-01 00:00:00
abstract::To study the influence of ammonium on an antibiotic cultivation, mass transfer measurements of ammonium through microporous hydrophobic membranes using different stripping methods were carried out and compared. The higher overall mass transfer coefficients for ammonium were obtained with an acid stripping solution com...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260351012
更新日期:1990-04-25 00:00:00
abstract::Non-invasive methods for online monitoring of biotechnological processes without compromising the integrity of the reactor system are very important to generate continuous data. Even though calorimetry has been used in conventional biochemical analysis for decades, it has not yet been specifically applied for online d...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.24815
更新日期:2013-05-01 00:00:00
abstract::This study demonstrated that hydrogen-producing acidogenic sludge could agglutinate into granules in a well-mixed reactor treating a synthetic sucrose-containing wastewater at 26 degrees C, pH 5.5, with 6 h of hydraulic retention. A typical matured granule is 1.6 mm in diameter, 1.038 g/mL in density, 11% in ash conte...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.10174
更新日期:2002-04-05 00:00:00
abstract::Flow cytometry is a fast and sensitive method that allows monitoring of different cellular parameters on large samples of a population. Protein distributions give relevant information on growth dynamics, since they are related to the age distribution and depend on the law of growth of the population and the law of pro...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260250510
更新日期:1983-05-01 00:00:00
abstract::Saccharomyces cerevisiae (yeast) cells were employed as a source of alcohol dehydrogenase in the NAD(+)-to-NADH reaction. The cells were immobilized in calcium alginate monofilament fibers and used in a biological reactor. The alginate could not be heat sterilized since temperatures above 80 degrees C caused the polym...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/bit.260360706
更新日期:1990-10-05 00:00:00
abstract::The treatment of meta- and para-nitrobenzoic acid in an industrial wastestream by Comamonas sp. JS46 and Comamonas sp. JS47 is investigated. The most important feature of the wastestream is the constantly changing concentration ratio of the two isomers. The most extreme occurrence is considered here: the complete chan...
journal_title:Biotechnology and bioengineering
pub_type: 杂志文章
doi:10.1002/(sici)1097-0290(19980705)59:1<21::aid-bit4
更新日期:1998-07-05 00:00:00