STARCH SYNTHESIS IN CHLORELLA VULGARIS

1954 ◽  
Vol 32 (1) ◽  
pp. 452-464 ◽  
Author(s):  
J. M. Bailey ◽  
A. C. Neish
Keyword(s):  
Cell Wall ◽  
Calcium Chloride ◽  
Chlorella Vulgaris ◽  
Higher Plants ◽  
Starch Synthesis ◽  
Dry Weight ◽  
Cell Wall Polysaccharide ◽  
Branching Enzyme

Chlorella vulgaris was found to deposit starch, in amounts up to 20% of the dry weight of the cells, when grown in a medium containing glucose. The cells did not contain cellulose or chitin. The starch was difficult to extract, being associated with an alkali-soluble, dextrorotatory, cell-wall polysaccharide. The starch, after extraction by a 26% solution of calcium chloride at 120 °C., had properties quite similar to starches from higher plants. It was composed of amylose (30–40%) and amylopectin. Glucose-1-C14 was incorporated into the starch, by growing cells, without much breakdown and resynthesis. Cell-free extracts, obtained from the alga, contained a phosphorylase and a branching enzyme similar to those of the potato. These brought about the synthesis of an amylopectin–glycogen type polysaccharide from glucose-1-phosphate. It is concluded that the mechanism of starch synthesis in Chlorella vulgaris is essentially the same as in higher plants.

STARCH SYNTHESIS IN CHLORELLA VULGARIS

1954 ◽  
Vol 32 (4) ◽  
pp. 452-464 ◽  
Author(s):  
J. M. Bailey ◽  
A. C. Neish
Keyword(s):  
Cell Wall ◽  
Calcium Chloride ◽  
Chlorella Vulgaris ◽  
Higher Plants ◽  
Starch Synthesis ◽  
Dry Weight ◽  
Cell Wall Polysaccharide ◽  
Branching Enzyme

Chlorella vulgaris was found to deposit starch, in amounts up to 20% of the dry weight of the cells, when grown in a medium containing glucose. The cells did not contain cellulose or chitin. The starch was difficult to extract, being associated with an alkali-soluble, dextrorotatory, cell-wall polysaccharide. The starch, after extraction by a 26% solution of calcium chloride at 120 °C., had properties quite similar to starches from higher plants. It was composed of amylose (30–40%) and amylopectin. Glucose-1-C14 was incorporated into the starch, by growing cells, without much breakdown and resynthesis. Cell-free extracts, obtained from the alga, contained a phosphorylase and a branching enzyme similar to those of the potato. These brought about the synthesis of an amylopectin–glycogen type polysaccharide from glucose-1-phosphate. It is concluded that the mechanism of starch synthesis in Chlorella vulgaris is essentially the same as in higher plants.

scholarly journals Iminosugar inhibitors of carbohydrate-active enzymes that underpin cereal grain germination and endosperm metabolism

2016 ◽  
Vol 44 (1) ◽  
pp. 159-165 ◽  
Author(s):  
Vasilios M. E. Andriotis ◽  
Martin Rejzek ◽  
Michael D. Rugen ◽  
Birte Svensson ◽  
Alison M. Smith ◽  
...  
Keyword(s):  
Cell Wall ◽  
Starch Synthesis ◽  
Degradation Pathway ◽  
Cereal Grains ◽  
Starch Degradation ◽  
Cell Wall Polysaccharide ◽  
Carbohydrate Active Enzymes ◽  
Cereal Grain ◽  
Energy Store ◽  
And Control

Starch is a major energy store in plants. It provides most of the calories in the human diet and, as a bulk commodity, it is used across broad industry sectors. Starch synthesis and degradation are not fully understood, owing to challenging biochemistry at the liquid/solid interface and relatively limited knowledge about the nature and control of starch degradation in plants. Increased societal and commercial demand for enhanced yield and quality in starch crops requires a better understanding of starch metabolism as a whole. Here we review recent advances in understanding the roles of carbohydrate-active enzymes in starch degradation in cereal grains through complementary chemical and molecular genetics. These approaches have allowed us to start dissecting aspects of starch degradation and the interplay with cell-wall polysaccharide hydrolysis during germination. With a view to improving and diversifying the properties and uses of cereal grains, it is possible that starch degradation may be amenable to manipulation through genetic or chemical intervention at the level of cell wall metabolism, rather than simply in the starch degradation pathway per se.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

scholarly journals Valorization of sugarcane bagasse by chemical pretreatment and enzyme mediated deconstruction

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Vihang S. Thite ◽  
Anuradha S. Nerurkar
Keyword(s):  
Cell Wall ◽  
Sugarcane Bagasse ◽  
Structural Changes ◽  
Enzymatic Saccharification ◽  
Dry Weight ◽  
Gravimetric Analysis ◽  
Chemical Pretreatment ◽  
Cell Wall Degrading Enzymes ◽  
First Time ◽  
Soluble Components

Abstract After chemical pretreatment, improved amenability of agrowaste biomass for enzymatic saccharification needs an understanding of the effect exerted by pretreatments on biomass for enzymatic deconstruction. In present studies, NaOH, NH4OH and H2SO4 pretreatments effectively changed visible morphology imparting distinct fibrous appearance to sugarcane bagasse (SCB). Filtrate analysis after NaOH, NH4OH and H2SO4 pretreatments yielded release of soluble reducing sugars (SRS) in range of ~0.17–0.44%, ~0.38–0.75% and ~2.9–8.4% respectively. Gravimetric analysis of pretreated SCB (PSCB) biomass also revealed dry weight loss in range of ~25.8–44.8%, ~11.1–16.0% and ~28.3–38.0% by the three pretreatments in the same order. Release of soluble components other than SRS, majorly reported to be soluble lignins, were observed highest for NaOH followed by H2SO4 and NH4OH pretreatments. Decrease or absence of peaks attributed to lignin and loosened fibrous appearance of biomass during FTIR and SEM studies respectively further corroborated with our observations of lignin removal. Application of commercial cellulase increased raw SCB saccharification from 1.93% to 38.84%, 25.56% and 9.61% after NaOH, H2SO4 and NH4OH pretreatments. Structural changes brought by cell wall degrading enzymes were first time shown visually confirming the cell wall disintegration under brightfield, darkfield and fluorescence microscopy. The microscopic evidence and saccharification results proved that the chemical treatment valorized the SCB by making it amenable for enzymatic saccharification.

scholarly journals Crystal structure to 2.45 Å resolution of a monoclonal Fab specific for theBrucellaA cell wall polysaccharide antigen

1993 ◽  
Vol 2 (7) ◽  
pp. 1106-1113 ◽  
Author(s):  
D. R. Rose ◽  
M. Przybylska ◽  
R. J. To ◽  
C. S. Kayden ◽  
E. Vorberg ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Cell Wall ◽  
Cell Wall Polysaccharide ◽  
Polysaccharide Antigen

scholarly journals PUL-Mediated Plant Cell Wall Polysaccharide Utilization in the Gut Bacteroidetes

2021 ◽  
Vol 22 (6) ◽  
pp. 3077
Author(s):  
Zhenzhen Hao ◽  
Xiaolu Wang ◽  
Haomeng Yang ◽  
Tao Tu ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Microbial Community ◽  
Gut Microbiota ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Cell Wall Polysaccharide ◽  
Prominent Feature ◽  
Cell Wall Polysaccharides ◽  
Gut Microbial Community

Plant cell wall polysaccharides (PCWP) are abundantly present in the food of humans and feed of livestock. Mammalians by themselves cannot degrade PCWP but rather depend on microbes resident in the gut intestine for deconstruction. The dominant Bacteroidetes in the gut microbial community are such bacteria with PCWP-degrading ability. The polysaccharide utilization systems (PUL) responsible for PCWP degradation and utilization are a prominent feature of Bacteroidetes. In recent years, there have been tremendous efforts in elucidating how PULs assist Bacteroidetes to assimilate carbon and acquire energy from PCWP. Here, we will review the PUL-mediated plant cell wall polysaccharides utilization in the gut Bacteroidetes focusing on cellulose, xylan, mannan, and pectin utilization and discuss how the mechanisms can be exploited to modulate the gut microbiota.

scholarly journals Effect of Exogenously Applied 24-Epibrassinolide and Brassinazole on Xylogenesis and Microdistribution of Cell Wall Polymers in Leucaena leucocephala (Lam) De Wit

2021 ◽  
Author(s):  
S. Pramod ◽  
M. Anju ◽  
H. Rajesh ◽  
A. Thulaseedharan ◽  
Karumanchi S. Rao
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Leucaena Leucocephala ◽  
Higher Plants ◽  
Lignin Content ◽  
Wood Quality ◽  
Wall Structure ◽  
Vessel Element ◽  
Xylem Differentiation ◽  
Cell Wall Polymers

AbstractPlant growth regulators play a key role in cell wall structure and chemistry of woody plants. Understanding of these regulatory signals is important in advanced research on wood quality improvement in trees. The present study is aimed to investigate the influence of exogenous application of 24-epibrassinolide (EBR) and brassinosteroid inhibitor, brassinazole (BRZ) on wood formation and spatial distribution of cell wall polymers in the xylem tissue of Leucaena leucocephala using light and immuno electron microscopy methods. Brassinazole caused a decrease in cambial activity, xylem differentiation, length and width of fibres, vessel element width and radial extent of xylem suggesting brassinosteroid inhibition has a concomitant impact on cell elongation, expansion and secondary wall deposition. Histochemical studies of 24-epibrassinolide treated plants showed an increase in syringyl lignin content in the xylem cell walls. Fluorescence microscopy and transmission electron microscopy studies revealed the inhomogenous pattern of lignin distribution in the cell corners and middle lamellae region of BRZ treated plants. Immunolocalization studies using LM10 and LM 11 antibodies have shown a drastic change in the micro-distribution pattern of less substituted and highly substituted xylans in the xylem fibres of plants treated with EBR and BRZ. In conclusion, present study demonstrates an important role of brassinosteroid in plant development through regulating xylogenesis and cell wall chemistry in higher plants.

scholarly journals UDP-glucose dehydrogenases of maize: a role in cell wall pentose biosynthesis

2005 ◽  
Vol 391 (2) ◽  
pp. 409-415 ◽  
Author(s):  
Anna Kärkönen ◽  
Alain Murigneux ◽  
Jean-Pierre Martinant ◽  
Elodie Pepey ◽  
Christophe Tatout ◽  
...  
Keyword(s):  
Cell Wall ◽  
Sequence Similarity ◽  
Glucose Dehydrogenase ◽  
Soya Bean ◽  
Amino Acid Sequences ◽  
Cell Wall Polysaccharide ◽  
Polysaccharide Biosynthesis ◽  
Polysaccharide Synthesis ◽  
Ethanol Dehydrogenase ◽  
Adh Activity

UDPGDH (UDP-D-glucose dehydrogenase) oxidizes UDP-Glc (UDP-D-glucose) to UDP-GlcA (UDP-D-glucuronate), the precursor of UDP-D-xylose and UDP-L-arabinose, major cell wall polysaccharide precursors. Maize (Zea mays L.) has at least two putative UDPGDH genes (A and B), according to sequence similarity to a soya bean UDPGDH gene. The predicted maize amino acid sequences have 95% similarity to that of soya bean. Maize mutants with a Mu-element insertion in UDPGDH-A or UDPGDH-B were isolated (udpgdh-A1 and udpgdh-B1 respectively) and studied for changes in wall polysaccharide biosynthesis. The udpgdh-A1 and udpgdh-B1 homozygotes showed no visible phenotype but exhibited 90 and 60–70% less UDPGDH activity respectively than wild-types in a radiochemical assay with 30 μM UDP-glucose. Ethanol dehydrogenase (ADH) activity varied independently of UDPGDH activity, supporting the hypothesis that ADH and UDPGDH activities are due to different enzymes in maize. When extracts from wild-types and udpgdh-A1 homozygotes were assayed with increasing concentrations of UDP-Glc, at least two isoforms of UDPGDH were detected, having Km values of approx. 380 and 950 μM for UDP-Glc. Leaf and stem non-cellulosic polysaccharides had lower Ara/Gal and Xyl/Gal ratios in udpgdh-A1 homozygotes than in wild-types, whereas udpgdh-B1 homozygotes exhibited more variability among individual plants, suggesting that UDPGDH-A activity has a more important role than UDPGDH-B in UDP-GlcA synthesis. The fact that mutation of a UDPGDH gene interferes with polysaccharide synthesis suggests a greater importance for the sugar nucleotide oxidation pathway than for the myo-inositol pathway in UDP-GlcA biosynthesis during post-germinative growth of maize.

Sign in / Sign up

Export Citation Format

Share Document