生物防治稻田与普通稻田水体中浮游植物的生态特征研究

通过对大沙镇生物防治稻田及普通稻田水体中浮游植物的调查研究,共检出藻类112种,其中生物防治稻田中82种,普通稻田中89种.稻田水体中的浮游植物以硅藻、裸藻和绿藻占优势.在普通稻田中,硅藻种类数超过生物防治稻田,其优势度最高的5种藻类中除双对栅藻外,其余4种均为硅藻;而在生物防治稻田中,裸藻种类数高于普通稻田,且其优势度最高的5种藻类中有两种为裸藻.通过比较发现,生物防治稻田水体中浮游生物的密度明显高于普通稻田.对水体浮游植物多样性及均匀度的分析表明,稻田水体中的浮游植物自秧苗插上至干田期间,多样性指数略有上升(主要是由于种类数的增加引起的),而均匀度呈下降趋势.     

Evaluation of manometric temperature measurement, a process analytical technology tool for freeze-drying: Part I, product temperature measurement

This study examines the factors that may cause systematic errors in the manometric temperature measurement (MTM) procedure used to evaluate product temperature during primary drying. MTM was conducted during primary drying using different vial loads, and the MTM product temperatures were compared with temperatures directly measured by thermocouples. To clarify the impact of freeze-drying load on MTM product temperatures, simulation of the MTM vapor pressure rise was performed, and the results were compared with the experimental results. The effect of product temperature heterogeneity in MTM product temperature determination was investigated by comparing the MTM product temperatures with directly measured thermocouple product temperatures in systems differing in temperature heterogeneity. Both the simulated and experimental results showed that at least 50 vials (5 mL) were needed to give sufficiently rapid pressure rise during the MTM data collection period (25 seconds) in the freeze dryer, to allow accurate determination of the product temperature. The product temperature is location dependent, with higher temperature for vials on the edge of the array and lower temperature for the vials in the center of the array. The product temperature heterogeneity is also dependent upon the freeze-drying conditions. In product temperature heterogeneous systems, MTM measures a temperature close to the coldest product temperature, even, if only a small fraction of the samples have the coldest product temperature. The MTM method is valid even at very low product temperature (−45°C). Published: February 10, 2006     

Energy coupling in Saccharomyces cerevisiae: selected opportunities for metabolic engineering

Free-energy (ATP) conservation during product formation is crucial for the maximum product yield that can be obtained, but often overlooked in metabolic engineering strategies. Product pathways that do not yield ATP or even demand input of free energy (ATP) require an additional pathway to supply the ATP needed for product formation, cellular maintenance, and/or growth. On the other hand, product pathways with a high ATP yield may result in excess biomass formation at the expense of the product yield. This mini-review discusses the importance of the ATP yield for product formation and presents several opportunities for engineering free-energy (ATP) conservation, with a focus on sugar-based product formation by Saccharomyces cerevisiae. These engineering opportunities are not limited to the metabolic flexibility within S.?cerevisiae itself, but also expression of heterologous reactions will be taken into account. As such, the diversity in microbial sugar uptake and phosphorylation mechanisms, carboxylation reactions, product export, and the flexibility of oxidative phosphorylation via the respiratory chain and H(+) -ATP synthase can be used to increase or decrease free-energy (ATP) conservation. For product pathways with a negative, zero or too high ATP yield, analysis and metabolic engineering of the ATP yield of product formation will provide a promising strategy to increase the product yield and simplify process conditions.     

Investigation of the performance of fermentation processes using a mathematical model including effects of metabolic bottleneck and toxic product on cells

A number of recent research studies have focused on theoretical and experimental investigation of a bottleneck in a metabolic reaction network. However, there is no study on how the bottleneck affects the performance of a fermentation process when a product is highly toxic and remarkably influences the growth and death of cells. The present work therefore studies the effect of bottleneck on product concentrations under different product toxicity conditions. A generalized bottleneck model in a fed-batch fermentation is constructed including both the bottleneck and the product influences on cell growth and death. The simulation result reveals that when the toxic product strongly influences the cell growth and death, the final product concentration is hardly changed even if the bottleneck is removed, whereas it is markedly changed by the degree of product toxicity. The performance of an ethanol fermentation process is also discussed as a case example to validate this result. In conclusion, when the product is highly toxic, one cannot expect a significant increase in the final product concentration even if removing the bottleneck; rather, it may be more effective to somehow protect the cells so that they can continuously produce the product.     

Goals of stability evaluation throughout the vaccine life cycle

Stability studies play a critical role in assuring product quality at all points in the vaccine life cycle. At and after licensure, stability studies on quality attributes (including potency) provide a critical link between marketed and clinically evaluated vaccine product, addressing important regulatory concerns by assuring that product quality is maintained throughout the dating period. During development, stability studies are done to assure product quality and to obtain the data needed to support licensure. Stability studies may also be performed after licensure to assure that product continues to perform as it did pre-licensure, as well as to evaluate the effect on product quality of deliberately introduced manufacturing changes. At each phase in the product life cycle, it is important to consider the goals of stability evaluation and to perform appropriate statistical analyses in order to assure and reach appropriate conclusions about product quality.     

Real‐time product attribute control to manufacture antibodies with defined N‐linked glycan levels

Pressures for cost‐effective new therapies and an increased emphasis on emerging markets require technological advancements and a flexible future manufacturing network for the production of biologic medicines. The safety and efficacy of a product is crucial, and consistent product quality is an essential feature of any therapeutic manufacturing process. The active control of product quality in a typical biologic process is challenging because of measurement lags and nonlinearities present in the system. The current study uses nonlinear model predictive control to maintain a critical product quality attribute at a predetermined value during pilot scale manufacturing operations. This approach to product quality control ensures a more consistent product for patients, enables greater manufacturing efficiency, and eliminates the need for extensive process characterization by providing direct measures of critical product quality attributes for real time release of drug product. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1433–1441, 2015     

Affinity-based in situ product removal coupled with co-immobilization of oily substrate and filamentous fungus

In situ product removal (ISPR) involves actions taken for the fast removal of a product from the producing cell. ISPR is implemented to improve yield and productivity via minimization of product inhibition, minimization of product losses due to degradation or evaporation, and reduction of the number of subsequent downstream processing steps. Here we describe the implementation of affinity-based, specific ISPR as a crucial component of an integrative approach to problems associated with the biocatalytic production of a product exhibiting poor water solubility from an oily, water-insoluble precursor. Our integrative ISPR-based approach consists of co-immobilization of the oily substrate emulsion and the biocatalyst within bilayered alginate beads. A particulate-specific adsorbent, exhibiting high binding capacity of the product, is suspended in the reaction medium with periodical replacements. According to this approach, ISPR implementation is expected to shift the equilibration of product distribution between the co-immobilized oily substrate and the outer medium via specific product immobilization onto the added adsorbent. The product may subsequently be readily recovered via single-step final purification. This integrative approach was successfully demonstrated by the affinity-based ISPR of gamma-decalactone (4-decanolide). gamma-Decalactone was produced from castor oil via its beta-oxidation by the filamentous fungus Tyromyces sambuceus, co-immobilized with emulsified substrate within bilayered alginate beads. Product immobilization onto medium-suspended epichlorohydrin-crosslinked beta-cyclodextrin resulted in higher yield and easy pure product recovery.     

Model-based monitoring of industrial reversed phase chromatography to predict insulin variants

Downstream processing in the manufacturing biopharmaceutical industry is a multistep process separating the desired product from process- and product-related impurities. However, removing product-related impurities, such as product variants, without compromising the product yield or prolonging the process time due to extensive quality control analytics, remains a major challenge. Here, we show how mechanistic model-based monitoring, based on analytical quality control data, can predict product variants by modeling their chromatographic separation during product polishing with reversed phase chromatography. The system was described by a kinetic dispersive model with a modified Langmuir isotherm. Solely quality control analytical data on product and product variant concentrations were used to calibrate the model. This model-based monitoring approach was developed for an insulin purification process. Industrial materials were used in the separation of insulin and two insulin variants, one eluting at the product peak front and one eluting at the product peak tail. The model, fitted to analytical data, used one component to simulate each protein, or two components when a peak displayed a shoulder. This monitoring approach allowed the prediction of the elution patterns of insulin and both insulin variants. The results indicate the potential of using model-based monitoring in downstream polishing at industrial scale to take pooling decisions.     

Enzyme reactions at the surface of living cells. I. Electric repulsion of charged ligands and recognition of signals from the external milieu

The dynamic behaviour of a polyelectrolyte-bound enzyme is studied when diffusion of substrate or diffusion of product is coupled to electric repulsion and to Michaelis-Menten enzyme reaction. The definition of the classical concepts of electric partition coefficients and Donnan potential of a polyelectrolyte membrane has been extended under global non-equilibrium conditions. This extension is permissible when a strong repulsion exists of substrate and product by the fixed negative charges of the membrane. Coupling between product diffusion, electric repulsion and enzyme reaction at constant advancement may result in a hysteresis loop of the partition coefficient as the product concentration is increased in the reservoir. This hysteresis loop vanishes as the rate of product diffusion increases. No hysteresis loop may occur when electric repulsion effects are coupled to substrate diffusion and reaction. The existence of multiple values of the partition coefficient for a fixed concentration of product implies that the membrane may store short-term memory of the former product concentration present in the external milieu. The occurrence of hysteresis generated by coupling enzyme reaction, product diffusion, electric partition effects at constant advancement of the reaction may be viewed as a sensing device of product concentration in the external milieu. Surprisingly, non-linearities required to generate this sensing device come from electrostatic effects and not from enzyme kinetics.     

Ecological studies on the occurrence of bacteria utilizing lactic acid at pH values below 4.5

Sites within two cheese factories, a silage tower and silage pit and two pet food factories were investigated for lactic acid utilizing bacteria. The bacteria isolated, together with known lactic acid utilizing and aciduric bacteria, were tested for their ability to 'alkalinize' a fermented meat product containing more than 20 g/1 lactic acid at pH > 4.3 a ten-fold dilution of this product and synthetic media, both at pH 4.5. Strains able to alkalinize the diluted product were 13 aerobic isolates (all Acetobacter spp.), nine anaerobic cultures, one strain of Megasphaera elsdenii and two strains of Clostridium tyrobutyricum. Eight of the aerobes could alkalinize undiluted product containing < 1 g/1 residual potassium sorbate, but had no effect on product containing > 3 g/1 sorbate; none of the anaerobic cultures was able to alkalinize undiluted product. Acetobacter spp., therefore, threatened the microbial stability of a fermented product containing < 3 g/1 potassium sorbate. The cultures able to alkalinize diluted product were all from sites contaminated with whey, silage or fermented product for at least 2 d, suggesting substantial accumulation of lactic acid utilizing bacteria at these sites.     

Introducing Templates for Sustainable Product Development

We have previously developed a method for sustainable product development (MSPD) based on backcasting from basic sustainability principles. The MSPD informs investigations of product‐related social and ecological sustainability aspects throughout a concurrent engineering product development process. We here introduce “templates” for sustainable product development (TSPDs) as a complement. The idea is to help product development teams to arrive faster and more easily at an overview of the major sustainability challenges and opportunities of a product category in the early development phases. The idea is also to inform creative communication between top management, stakeholders, and product developers. We present this approach through an evaluation case study, in which the TSPDs were used for a sustainability assessment of televisions (TVs) at the Matsushita Electric Group. We study whether the TSPD approach has the ability to (1) help shift focus from gradual improvements of a selection of aspects in relation to past environmental performance of a product category to a focus on the remaining gap to a sustainable situation, (2) facilitate consensus among organizational levels about major sustainability challenges and potential solutions for a product category, and (3) facilitate continued dialogue with external sustainability experts, identifying improvements that are relevant for strategic sustainable development. Our findings indicate that the TSPD approach captures overall sustainability aspects of the life cycle of product categories and that it has the above abilities.     

The developmental effect of overexpressing a Ubx product in Drosophila embryos is dependent on its interactions with other homeotic products

We report the developmental effects of expressing an Ultrabithorax (Ubx) product under the hsp70 promoter. Heat induction gives rise to a high, ubiquitous expression of Ubx product that lasts for several hours. We find that whether or not the overexpression of Ubx has a developmental effect on a particular body region of the larva depends on the interactions with the resident homeotic genes. In head and thorax the Ubx product overrides Sex combs reduced, Antennapedia, and probably other homeotic genes and dictates its own developmental program. In abdominal segments A1-A8 the overexpressed Ubx product establishes a normal pattern, alone (A1) or in combination with abdominal-A (A2-A4) and Abdominal-B (A5-A8), indicating that the excess of product is irrelevant. In segment A9 the highly expressed Ubx product is phenotypically suppressed by the r product of Abdominal-B. The presence of high levels of Ubx protein is also irrelevant in the telson.     

Addressing a whole bioprocess in real-time using an optical biosensor-formation,recovery and purification of antibody fragments from a recombinant<Emphasis Type="Italic"> E. coli</Emphasis> host

The use of biosensor technology is described to address in real-time the production and subsequent purification of a bioactive recombinant protein product. The product, D1.3 Fv antibody fragment, was expressed in Escherichia coli and purified via two process routes, one for extracellular and one for intracellular product material. The cells were harvested by centrifugation in a solid bowl CARR Powerfuge and stored at –70°C. Clarification of the supernatant was performed by depth filtration, followed by affinity chromatography for final purification of the extracellular product. To purify the intracellular product the harvested cells were resuspended and homogenised. Removal of debris in the CARR Powerfuge was followed by depth filtration and affinity chromatography. In this work we have shown the rapid determination of bioactive product levels, and the impact this has on improved accountability and confidence is demonstrated in process mass balances on the product using the data acquired during process operation.     

Anti-inflammatory, antiarthritic and analgesic activity of a herbal formulation (DRF/AY/4012)

Anti-inflammatory, antiarthritic and analgesic effect of a herbal product (DRF/AY/4012) was evaluated in animal models. Herbal product treatment induced a dose dependent anti-inflammatory activity in acute inflammatory models (carrageenin and egg-albumin induced rat hind paw edema). It also elicited promising anti-inflammatory activity in chronic inflammatory models (cotton pellet granuloma and Freund's adjuvant induced polyarthritis in rats). Further, the product inhibited the increased level of serum lysosomal enzyme activity viz. serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase, alkaline phosphatase and the lipid peroxidation in liver. In Freund's adjuvant induced polyarthritis, herbal product reduced the increased level of hydroxy proline, hexosamine and total protein content in edematous tissue. The product also exhibited mild to moderate analgesic activity in acetic acid induced writhing in mice. The LD50 value of the herbal product was more than 16 gm/kg by oral route in mice. The product has distinct advantages over the existing agents and deserves further developmental studies.     

Use of rRNA gene restriction patterns to evaluate lactic acid bacterium contamination of vacuum-packaged sliced cooked whole-meat product in a meat processing plant.

Molecular typing was applied to an in-plant lactic acid bacterium (LAB) contamination analysis of a vacuum-packaged sliced cooked whole-meat product. A total of 982 LAB isolates from the raw mass, product, and the environment at different production stages were screened by restriction endonuclease (EcoRI and HindIII) analysis. rRNA gene restriction patterns were further determined for different strains obtained from each source. These patterns were used for recognizing the spoilage-causing LAB strains from the product on the sell-by day and tracing the sources and sites of spoilage LAB contamination during the manufacture. LAB typing resulted in 71 different ribotypes, of which 27 were associated with contamination routes. Raw material was distinguished as the source of the major spoilage strains. Contamination of the product surfaces after cooking was shown to be airborne. The removal of the product from the cooking forms was localized as a major site of airborne LAB contamination. Food handlers and some surfaces in contact with the product during the manufacture were also contaminated with the spoilage strains. Some LAB strains were also able to resist cooking in the core of the product bar. These strains may have an effect on the product shelf life by contaminating the slicing machine. The air in the slicing department and adjacent cold room contained very few LAB. Surface-mediated contamination was detected during the slicing and packaging stages. Food handlers also carried strains later found in the packaged product. Molecular typing provided useful information revealing the LAB contamination sources and sites of this product. The production line will be reorganized in accordance with these results to reduce spoilage LAB contamination.     

Mathematical modeling of an aqueous film coating process in a Bohle Lab-Coater: Part 2: Application of the model

For the prediction of the air and product temperatures, the product moisture, and the air humidity during a coating process in a Bohle Lab-Coater, a model was developed. The purpose of this work was to determine the limit moisture, the critical moisture, and the constant for the exchange rate between both zones and to use these values for other sets of experiments to test the model. The adaptation of the 3 parameters (limit moisture, critical moisture, and exchange rate constant), was done by calculation of the product temperature in both zones for several sets of parameters in order to minimize the sum of square deviation between the calculated and the measured product temperatures. This set of parameters was used to test the validity of the model. By applying the model, the product temperature could be predicted based on the product, process, and equipment-related parameters. Hence, the model can be used to theoretically investigate the influence of different process paramaters. The mean difference between the predicted, and measured product temperatures in the steady state is ≈2 up to 3 K using the determined parameter set for the limit moisture, the critical moisture, and the exchange rate constant. The model is useful for the prediction of the air and product temperatures, the product moisture, and air humidity during a coating process in the Bohle Lab-Coater using round, biconvex tablets.     

A fast and simple approach to optimize the unit operation high pressure homogenization - a case study for a soluble therapeutic protein in E. coli

Escherichia coli is one of the most commonly used host organisms for the production of recombinant biopharmaceuticals. E. coli is usually characterized by fast growth on cheap media and high productivity, but one drawback is its intracellular product formation. Product recovery from E. coli bioprocesses requires tedious downstream processing (DSP). A typical E. coli DSP for an intracellular product starts with a cell disruption step to access the product. Different methods exist, but a scalable process is usually achieved by high pressure homogenization (HPH). The protocols for HPH are often applied universally without adapting them to the recombinant product, even though HPH can affect product quantity and quality. Based on our previous study on cell disruption efficiency, we aimed at screening operational conditions to maximize not only product quantity, but also product quality of a soluble therapeutic protein expressed in E. coli. We screened for critical process parameters (CPPs) using a multivariate approach (design of experiments; DoE) during HPH to maximize product titer and achieve sufficient product quality, based on predefined critical quality attributes (CQAs). In this case study, we were able to gain valuable knowledge on the efficiency of HPH on E. coli cell disruption, product release and its impact on CQAs. Our results show that HPH is a key unit operation that has to be optimized for each product.     

Immunoglobulin degradation and D-penicillamine action

Treatment of human IgG with pancreatic elastase gave a product of higher molecular weight than IgG. Its formation was inhibited by blocking IgG sulfhydryl groups with iodoacetamide. Incubation of the high molecular weight product with either glutathione or D-penicillamine yielded Fab- and Fc-like fragments. Addition of oxidized glutathione to mixtures containing either reduced thiol gave a new product of molecular weight intermediate between the high molecular weight product and Fab- and Fc-like fragments. Oxidized D-penicillamine did not substitute for oxidized glutathione. This new product was formed under conditions that favor protein sulfhydryl-disulfide exchange. The effect of D-penicillamine on its formation was discussed in terms of D-penicillamine's mode of action in rheumatoid arthritis.     

Minimal self-replicating systems

Minimal self-replicating systems typically consist of three components: a product molecule, and two substrate molecules that become joined to form another product molecule. An important characteristic of self-replicating systems is the ability of the product to catalyze the formation of additional product, resulting in autocatalytic behavior. Recent advances in the area of self-replication have led to improved efficiency of autocatalysis, both by increasing the fraction of product molecules that can participate in further rounds of replication, and by improving the efficiency of the catalysts themselves. This review analyzes chemical self-replicating systems that have been developed to date and discusses ongoing challenges in this area of research.     

USING HIGH-LEVEL CONSUMER-RESEARCH METHODS TO CREATE A TOOL-DRIVEN GUIDEBOOK AND DATABASE FOR PRODUCT DEVELOPMENT AND MARKETING

We present aspects and data for a tool‐driven database for marketing and product development, which are publicly accessible. The objective is to create a method whereby knowledge of concepts and products can be archived using overviews of a specific product category. The first phase of the database comprises systematic analysis of product concepts, which contain elements dealing both with features and emotions. The concept phase provides an idea about responses to statements about product features, along with responses to emotional elements and brands. The second phase comprises an analysis of the competitive frame of products, even before systematic product development is initiated. This second phase identifies expected and thus reasonable ranges of product‐sensory features, levels of acceptance of typical products, relations between liking and sensory attributes and segmentation of sensory preferences. Together, the two phases provide a guide to product developers new in a category, archive current knowledge and provide a sourcebook for marketers and developers alike, which is accessible using research tools. The two phases allow product development to become more scientific, more based on common experience rather than individual expertise and thus more efficient, without compromising corporate knowledge of specific ingredients, processes or business opportunities.