Effects of pyruvate on primary metabolism and product quality for a high‐density perfusion process

Some key quality problems has been exposed in several years of quality supervision sampling inspection of industry products for HDPE silicore plastic duct, such as dimension, breaking elongation, performance of falling weight impact and ring stiffness. Quality consistency is an important indicator in evaluating product quality. Nondestructive testing can be used to evaluate the quality of the whole pan and batch of silicore plastic duct, and it will play important role in product quality controlling.

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Expression of Phenylalanine Ammonia Lyases in Synechocystis Sp. PCC 6803 and Subsequent Improvements of Sustainable Production of Phenylpropanoids

10.21203/rs.3.rs-1089824/v1 ◽

2021 ◽

Author(s):

Kateryna Kukil ◽

Pia Lindberg

Keyword(s):

Cinnamic Acid ◽

Protein Level ◽

Genetically Engineered ◽

Sustainable Production ◽

High Density ◽

Primary Metabolism ◽

Coumaric Acid ◽

Subsequent Increase ◽

Unicellular Cyanobacterium ◽

Pcc 6803

Abstract Background Phenylpropanoids represent a diverse class of industrially important secondary metabolites, synthesized in plants from phenylalanine and tyrosine. Cyanobacteria have a great potential for sustainable production of phenylpropanoids directly from CO2, due to their photosynthetic lifestyle with a fast growth compared to plants, and the ease of generating genetically engineered strains. This study focuses on photosynthetic production of the first compounds in the phenylpropanoid pathway, trans-cinnamic acid and p-coumaric acid, in the unicellular cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis). This was achieved firstly via heterologous overexpression of a selected set of phenylalanine ammonia lyase (PAL) enzymes from different organisms in Synechocystis. The resulting strains were evaluated for productivity to find the best performing candidate. Secondly, in order to further improve the titer of target compounds, we evaluated the use of stronger expression cassettes for increasing PAL protein levels, as well as knock-out of the laccase gene slr1573, as this was previously reported to prevent degradation of the target compounds in the cell. Finally, to investigate the effect of growth conditions on the production of trans-cinnamic acid and p-coumaric acid from Synechocystis, cultivation conditions promoting rapid, high density growth were tested. Results Results of comparative expression of PALs showed that the highest specific titer was achieved for the strain AtC, expressing a PAL from Arabidopsis thaliana, while a subsequent increase of protein level did not improve the productivity. In contrast to previous reports, the production of target compounds in strains where the slr1573 laccase had been knocked out was found to be lower compared to strains with wild type background. Additionally, the Δslr1573 strains exhibited a strong phenotype of slower growth rate and lower pigment content. The application of a high-density cultivation system for the growth of production strains allowed reaching the highest total titers of trans-cinnamic acid and p-coumaric acid reported so far, at around 0.8 and 0.4 g/L, respectively, after 4 days. Conclusions The production of trans-cinnamic acid, unlike that of p-coumaric acid, is not limited by the protein level of heterologously expressed PAL in Synechocystis. High density cultivation led to higher titres of both products, while knocking out slr1573 did not have a positive effect on production. This work contributes to capability of exploiting the primary metabolism of cyanobacteria for sustainable production of plant phenylpropanoids.

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Alternating flow filtration as an alternative to internal spin filter based perfusion process: Impact on productivity and product quality

Biotechnology Progress ◽

10.1002/btpr.2487 ◽

2017 ◽

Vol 33 (4) ◽

pp. 1010-1014 ◽

Cited By ~ 4

Author(s):

Belén Bosco ◽

Cristian Paillet ◽

Ignacio Amadeo ◽

Laura Mauro ◽

Eduardo Orti ◽

...

Keyword(s):

Product Quality ◽

Spin Filter ◽

Perfusion Process ◽

Flow Filtration

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Production of Human Growth Hormone in a Mammalian Cell High Density Perfusion Process

Cell Technology for Cell Products ◽

10.1007/978-1-4020-5476-1_145 ◽

2007 ◽

pp. 789-793 ◽

Cited By ~ 4

Author(s):

T. Nottorf ◽

W. Hoera ◽

H. Buentemeyer ◽

S. Siwiora-Brenke ◽

A. Loa ◽

...

Keyword(s):

Growth Hormone ◽

Mammalian Cell ◽

Human Growth Hormone ◽

Human Growth ◽

High Density ◽

Perfusion Process

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Proteome changes in pepper (Capsicum annuum L.) leaves induced by the green peach aphid (Myzus persicae Sulzer)

BMC Plant Biology ◽

10.1186/s12870-020-02749-x ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Victoria Florencio-Ortiz ◽

Susana Sellés-Marchart ◽

José L. Casas

Keyword(s):

Capsicum Annuum ◽

Myzus Persicae ◽

Green Peach Aphid ◽

Defense Responses ◽

High Density ◽

Differentially Expressed ◽

Primary Metabolism ◽

Single Leaf ◽

Aphid Density ◽

Altered Proteins

Abstract Background Aphid attack induces defense responses in plants activating several signaling cascades that led to the production of toxic, repellent or antinutritive compounds and the consequent reorganization of the plant primary metabolism. Pepper (Capsicum annuum L.) leaf proteomic response against Myzus persicae (Sulzer) has been investigated and analyzed by LC-MS/MS coupled with bioinformatics tools. Results Infestation with an initially low density (20 aphids/plant) of aphids restricted to a single leaf taking advantage of clip cages resulted in 6 differentially expressed proteins relative to control leaves (3 proteins at 2 days post-infestation and 3 proteins at 4 days post-infestation). Conversely, when plants were infested with a high density of infestation (200 aphids/plant) 140 proteins resulted differentially expressed relative to control leaves (97 proteins at 2 days post-infestation, 112 proteins at 4 days post-infestation and 105 proteins at 7 days post-infestation). The majority of proteins altered by aphid attack were involved in photosynthesis and photorespiration, oxidative stress, translation, protein folding and degradation and amino acid metabolism. Other proteins identified were involved in lipid, carbohydrate and hormone metabolism, transcription, transport, energy production and cell organization. However proteins directly involved in defense were scarce and were mostly downregulated in response to aphids. Conclusions The unexpectedly very low number of regulated proteins found in the experiment with a low aphid density suggests an active mitigation of plant defensive response by aphids or alternatively an aphid strategy to remain undetected by the plant. Under a high density of aphids, pepper leaf proteome however changed significantly revealing nearly all routes of plant primary metabolism being altered. Photosynthesis was so far the process with the highest number of proteins being regulated by the presence of aphids. In general, at short times of infestation (2 days) most of the altered proteins were upregulated. However, at longer times of infestation (7 days) the protein downregulation prevailed. Proteins involved in plant defense and in hormone signaling were scarce and mostly downregulated.

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Expression of phenylalanine ammonia lyases in Synechocystis sp. PCC 6803 and subsequent improvements of sustainable production of phenylpropanoids

Microbial Cell Factories ◽

10.1186/s12934-021-01735-8 ◽

2022 ◽

Vol 21 (1) ◽

Author(s):

Kateryna Kukil ◽

Pia Lindberg

Keyword(s):

Cinnamic Acid ◽

Protein Level ◽

Genetically Engineered ◽

Sustainable Production ◽

High Density ◽

Primary Metabolism ◽

Coumaric Acid ◽

Subsequent Increase ◽

Unicellular Cyanobacterium ◽

Pcc 6803

Abstract Background Phenylpropanoids represent a diverse class of industrially important secondary metabolites, synthesized in plants from phenylalanine and tyrosine. Cyanobacteria have a great potential for sustainable production of phenylpropanoids directly from CO2, due to their photosynthetic lifestyle with a fast growth compared to plants and the ease of generating genetically engineered strains. This study focuses on photosynthetic production of the starting compounds of the phenylpropanoid pathway, trans-cinnamic acid and p-coumaric acid, in the unicellular cyanobacterium Synechocystis sp. PCC 6803 (Synechocystis). Results A selected set of phenylalanine ammonia lyase (PAL) enzymes from different organisms was overexpressed in Synechocystis, and the productivities of the resulting strains compared. To further improve the titer of target compounds, we evaluated the use of stronger expression cassettes for increasing PAL protein levels, as well as knock-out of the laccase gene slr1573, as this was previously reported to prevent degradation of the target compounds in the cell. Finally, to investigate the effect of growth conditions on the production of trans-cinnamic and p-coumaric acids from Synechocystis, cultivation conditions promoting rapid, high density growth were tested. Comparing the different PALs, the highest specific titer was achieved for the strain AtC, expressing PAL from Arabidopsis thaliana. A subsequent increase of protein level did not improve the productivity. Production of target compounds in strains where the slr1573 laccase had been knocked out was found to be lower compared to strains with wild type background, and the Δslr1573 strains exhibited a strong phenotype of slower growth rate and lower pigment content. Application of a high-density cultivation system for the growth of production strains allowed reaching the highest total titers of trans-cinnamic and p-coumaric acids reported so far, at around 0.8 and 0.4 g L−1, respectively, after 4 days. Conclusions Production of trans-cinnamic acid, unlike that of p-coumaric acid, is not limited by the protein level of heterologously expressed PAL in Synechocystis. High density cultivation led to higher titres of both products, while knocking out slr1573 did not have a positive effect on production. This work contributes to capability of exploiting the primary metabolism of cyanobacteria for sustainable production of plant phenylpropanoids.

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Planar defects in ordered (Ga,In)P

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100106570 ◽

1988 ◽

Vol 46 ◽

pp. 902-903

Author(s):

S. McKernan ◽

C. B. Carter ◽

D. Bour ◽

J. R. Shealy

Keyword(s):

Electron Diffraction ◽

Vapor Phase ◽

Growth Direction ◽

High Density ◽

Ordered Structure ◽

Planar Defects ◽

Diffraction Patterns ◽

Ternary Semiconductors ◽

Anion Species ◽

Metallic Vapor

The growth of ternary III-V semiconductors by organo-metallic vapor phase epitaxy (OMVPE) is widely practiced. It has been generally assumed that the resulting structure is the same as that of the corresponding binary semiconductors, but with the two different cation or anion species randomly distributed on their appropriate sublattice sites. Recently several different ternary semiconductors including AlxGa1-xAs, Gaxln-1-xAs and Gaxln1-xP1-6 have been observed in ordered states. A common feature of these ordered compounds is that they contain a relatively high density of defects. This is evident in electron diffraction patterns from these materials where streaks, which are typically parallel to the growth direction, are associated with the extra reflections arising from the ordering. However, where the (Ga,ln)P epilayer is reasonably well ordered the streaking is extremely faint, and the intensity of the ordered spot at 1/2(111) is much greater than that at 1/2(111). In these cases it is possible to image relatively clearly many of the defects found in the ordered structure.

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Quantitative defect studies in semiconductor TEM samples prepared by low angle ion milling

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138932 ◽

1995 ◽

Vol 53 ◽

pp. 512-513

Author(s):

L. Mulestagno ◽

J.C. Holzer ◽

P. Fraundorf

Keyword(s):

Sample Preparation ◽

Milling Time ◽

High Density ◽

Low Density ◽

Ion Milling ◽

High Quality ◽

Variable Angle ◽

Major Disadvantage ◽

Induced Defects

Due to the wealth of information, both analytical and structural that can be obtained from it TEM always has been a favorite tool for the analysis of process-induced defects in semiconductor wafers. The only major disadvantage has always been, that the volume under study in the TEM is relatively small, making it difficult to locate low density defects, and sample preparation is a somewhat lengthy procedure. This problem has been somewhat alleviated by the availability of efficient low angle milling.Using a PIPS® variable angle ion -mill, manufactured by Gatan, we have been consistently obtaining planar specimens with a high quality thin area in excess of 5 × 104 μm2 in about half an hour (milling time), which has made it possible to locate defects at lower densities, or, for defects of relatively high density, obtain information which is statistically more significant (table 1).

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Using the scanning electron microscope for failure analysis of high density magnetic media

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126755 ◽

1987 ◽

Vol 45 ◽

pp. 392-393

Author(s):

Evelyn R. Ackerman ◽

Gary D. Burnett

Keyword(s):

Electron Microscope ◽

Scanning Electron Microscope ◽

Failure Analysis ◽

High Density ◽

Magnetic Media ◽

Specific Data ◽

Retrieval Systems ◽

Operating Environments ◽

The Media ◽

Scanning Electron

Advancements in state of the art high density Head/Disk retrieval systems has increased the demand for sophisticated failure analysis methods. From 1968 to 1974 the emphasis was on the number of tracks per inch. (TPI) ranging from 100 to 400 as summarized in Table 1. This emphasis shifted with the increase in densities to include the number of bits per inch (BPI). A bit is formed by magnetizing the Fe203 particles of the media in one direction and allowing magnetic heads to recognize specific data patterns. From 1977 to 1986 the tracks per inch increased from 470 to 1400 corresponding to an increase from 6300 to 10,800 bits per inch respectively. Due to the reduction in the bit and track sizes, build and operating environments of systems have become critical factors in media reliability.Using the Ferrofluid pattern developing technique, the scanning electron microscope can be a valuable diagnostic tool in the examination of failure sites on disks.

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