Metabolism of Food Reserves in Germinating Velvetleaf

Weed Science ◽  
1970 ◽  
Vol 18 (5) ◽  
pp. 565-571
Author(s):  
J. A. Mulliken ◽  
C. A. Kust ◽  
L. E. Schrader
Keyword(s):  
Hydrogen Cyanide ◽  
Isocitrate Lyase ◽  
Dry Weight ◽  
Maximal Activity ◽  
Radicle Growth ◽  
Fat Mobilization ◽  
Lyase Activity ◽  
Radicle Emergence ◽  
Weight Protein ◽  
Food Reserves

Endosperm dry weight, protein, and fat losses accompanied rapid radicle growth of velvetleaf (Abutilon theophrasti Medic.) between 12 and 36 hr of germination at 31 C. Cotyledonary reserves were mobilized after 36 hr. Isocitrate lyase activity sedimented with a particulate fraction in varying degrees, but maximal activity developed at times coincident with fat mobilization. Respiration of excised endosperms reached maximal rates shortly after radicle emergence. The actions of hydrogen cyanide, carbon monoxide, and 2,4-dinitrolphenol indicated that respiration of endosperms excised from imbibed and germinated seed was due to cytochrome oxidase activity, and was coupled to phosphorylation.

scholarly journals Isocitrate Lyase Activity in Lactobacillus murinus CNRZ 313

1983 ◽  
Vol 66 (6) ◽  
pp. 1232-1236 ◽  
Author(s):  
M.C. Albizzatti de Rivadeneira ◽  
M.C. Manca de Nadra ◽  
A.A. Pesce de Ruiz Holgado ◽  
G. Oliver
Keyword(s):  
Isocitrate Lyase ◽  
Lyase Activity ◽  
Lactobacillus Murinus

scholarly journals THE FINE STRUCTURE OF ACANTHAMOEBA CASTELLANII (NEFF STRAIN)

1969 ◽  
Vol 41 (3) ◽  
pp. 786-805 ◽  
Author(s):  
Blair Bowers ◽  
Edward D. Korn
Keyword(s):  
Golgi Complex ◽  
Cyst Wall ◽  
Matrix Material ◽  
Acanthamoeba Castellanii ◽  
Dry Weight ◽  
Amorphous Layer ◽  
Wall Structure ◽  
Weight Protein ◽  
Granular Matrix ◽  
Mature Cyst

Encysting cells of Acanthamoeba castellanii, Neff strain, have been examined with the electron microscope. The wall structure and cytoplasmic changes during encystment are described. The cyst wall is composed of two major layers: a laminar, fibrous exocyst with a variable amount of matrix material, and an endocyst of fine fibrils in a granular matrix. The two layers are normally separated by a space except where they form opercula in the center of ostioles (exits for excysting amebae). An additional amorphous layer is probably present between the wall and the protoplast in the mature cyst. Early in encystment the Golgi complex is enlarged and contains a densely staining material that appears to contribute to wall formation. Vacuoles containing cytoplasmic debris (autolysosomes) are present in encysting cells and the contents of some of the vacuoles are deposited in the developing cyst wall. Lamellate bodies develop in the mitochondria and appear in the cytoplasm. Several changes are associated with the mitochondrial intracristate granule. The nucleus releases small buds into the cytoplasm, and the nucleolus decreases to less than half its original volume. The cytoplasm increases in electron density and its volume is reduced by about 80%. The water expulsion vesicle is the only cellular compartment without dense content in the mature cyst. The volume fractions of lipid droplets, Golgi complex, mitochondria, digestive vacuoles, and autolysosomes have been determined at different stages of encystment by stereological analysis of electron micrographs. By chemical analyses, dry weight, protein, phospholipid, and glycogen are lower and neutral lipid is higher in the mature cyst than in the trophozoite.

scholarly journals Large scale laboratory cultures of Ankistrodesmus gracilis (Reisch) Korsikov (Chlorophyta) and Diaphanosoma biergei Korinek, 1981 (Cladocera)

2008 ◽  
Vol 68 (4) ◽  
pp. 875-883 ◽  
Author(s):  
LH. Sipaúba-Tavares ◽  
AML. Pereira
Keyword(s):  
Exponential Growth ◽  
Large Scale ◽  
Light Availability ◽  
Sharp Decrease ◽  
Dry Weight ◽  
Good Alternative ◽  
Production Costs ◽  
Determining Factors ◽  
Weight Protein ◽  
Low Costs

Large-scale lab culture of Ankistrodesmus gracilis and Diaphanososma birgei were evaluated by studying the biology and biochemical composition of the species and production costs. Ankistrodesmus gracilis presented exponential growth until the 6th day, with approximately 144 x 10(4) cells.mL-1, followed by a sharp decrease to 90 x 10(4) cells.mL-1 (8th day). Algae cells tended to increase again from the 11th day and reached a maximum of 135 x 10(4) cells.mL-1 on the 17th day. D. birgei culture showed exponential growth until the 9th day with 140 x 10² individuals.L-1, and increased again as from the 12th day. Algae A. gracilis and zooplankton D. birgei contain 47 to 70% dry weight protein and over 5% dry weight carbohydrates. The most expensive items in the context of variable costs were labor and electricity. Data suggested that temperature, nutrients, light availability and culture management were determining factors on productivity. Results indicate that NPK (20-5-20) may be used directly as a good alternative for mass cultivation when low costs are taken into account, promoting adequate growth and nutritional value for cultured A. gracilis and D. birgei.

Effects of Herbicides on Growth and Extractable Phenylalanine Ammonia-Lyase Activity in Light- and Dark-Grown Soybean (Glycine max) Seedlings

Weed Science ◽  
1981 ◽  
Vol 29 (4) ◽  
pp. 433-439 ◽  
Author(s):  
Robert E. Hoagland ◽  
Stephen O. Duke
Keyword(s):  
Glycine Max ◽  
Phenylalanine Ammonia Lyase ◽  
Dry Weight ◽  
Root Tip ◽  
Continuous Darkness ◽  
Soybean Seedlings ◽  
Pal Activity ◽  
Lyase Activity ◽  
Phenylalanine Ammonia Lyase Activity

Effects of 16 herbicides representing 14 herbicide classes on growth and extractable phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) were examined in light- and dark-grown soybean [Glycine max(L.) Merr. ‘Hill’] seedlings. High purity (96 to 100%) herbicides were supplied via aqueous culture at various concentrations: 0.5 mM amitrole (3-amino-s-triazole), 0.1 mM atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], 0.07 mM diclofop-methyl {methyl ester of 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoicacid}, 0.5 mM DSMA (disodium methanearsonate), 0.2 mM fenuron (1,1-dimethyl-3-phenylurea), 0.05 mM fluridone {1-methyl-3-phenyl-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone}, 0.5 mM MH (1,2-dihydro-3,6-pyridazinedione), 0.5 mM metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one], 1.8 μM nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline], 0.5 mM norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone], 0.05 mM paraquat (1,1′-dimethyl-4,4′-bipyridinium ion), 0.15 mM perfluidone {1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl] methanesulfonamide}, 0.2 mM propanil (3′,4′-dichloropropionanilide), 0.1 mM propham (isopropyl carbanilate), 0.5 mM TCA (trichloroacetic acid), and 0.05 mM 2,4-D [(2,4-dichlorophenoxy)acetic acid]. Dark-grown soybean seedlings (3-day-old) were transferred to control solutions (2 mM CaSO4) or to herbicide solutions (in 2 mM CaSO4) and grown at 25 C in continuous white light (200 μE•m-2•s-1) or continuous darkness until harvested 24 or 48 h after transfer. After 48 h, growth (fresh weight, dry weight, elongation) was inhibited by most of the chemicals. Other signs of toxicity (necrosis, secondary root stunting, and root tip swelling) were noted for some treatments. Roots were most affected, although hypocotyls were generally not changed. Hypocotyl elongation was stimulated by atrazine, fluridone, and norflurazon after 48 h light. Extractable PAL activity from soybean axes was decreased by atrazine, fenuron, metribuzin, norflurazon, propanil, propham, and 2,4-D. Amitrole and paraquat were the only herbicides that increased extractable PAL activity. Other compounds tested had no effect on the enzyme. None of the herbicides significantly affected in vitro PAL activity.

Acetate metabolism in Escherichia coli

1978 ◽  
Vol 24 (2) ◽  
pp. 149-153 ◽  
Author(s):  
T. M. Lakshmi ◽  
Robert B. Helling
Keyword(s):  
Isocitrate Dehydrogenase ◽  
Citrate Synthase ◽  
Isocitrate Lyase ◽  
Glyoxylate Cycle ◽  
Acetate Metabolism ◽  
Wild Type ◽  
Intermediary Metabolites ◽  
Lyase Activity ◽  
Acetate Medium ◽  
The Glyoxylate Cycle

Levels of several intermediary metabolites were measured in cells grown in acetate medium in order to test the hypothesis that the glyoxylate cycle is repressed by phosphoenolpyruvate (PEP). Wild-type cells had less PEP than either isocitrate dehydrogenase – deficient cells (which had greater isocitrate lyase activity than the wild type) or isocitrate dehydrogenase – deficient, citrate synthase – deficient cells (which are poorly inducible). Thus induction of the glyoxylate cycle is more complicated than a simple function of PEP concentration. No correlation between enzyme activity and the level of oxaloacetate, pyruvate, or citrate was found either. Citrate was synthesized in citrate synthase – deficient mutants, possibly via citrate lyase.

Production and Thermal Characterization of an Alkaline Pectin Lyase from Penicillium notatum

2015 ◽  
Vol 11 (4) ◽  
pp. 517-525 ◽  
Author(s):  
Umme Habibah Siddiqua ◽  
Haq Nawaz Bhatti ◽  
Shazia Nouren ◽  
Saima Noreen ◽  
Ismat Bibi
Keyword(s):  
Ammonium Sulphate ◽  
Thermal Inactivation ◽  
Thermal Characterization ◽  
Maximal Activity ◽  
Inhibitory Effect ◽  
Pectin Lyase ◽  
Partial Purification ◽  
Penicillium Notatum ◽  
Enhanced Production ◽  
Lyase Activity

Abstract The present study was aimed to investigate the potential of Penicillium notatum for the production of pectin lyase under solid state culture using wheat bran as substrate. Different process parameters were optimized using completely randomized design for enhanced production of the pectin lyase. P. notatum showed maximum production (1875 U/gds) of pectin lyase with substrate amount 15 g/250 ml, moisture level 60%, pH 6, incubation period 120 h at 30°C. Pectin lyase activity was further improved with the addition of maltose and ammonium sulphate as carbon and nitrogen additives (1%), respectively. Partial purification of enzyme was carried out by ammonium sulphate precipitation at 80% saturation level. The P. notatum pectin lyase showed maximal activity at 65°C and pH 8. Km and Vmax values were 0.29% and 0.487 µmol/min, respectively. Energy of activation was found to be 5.33 kJ/mol. A detailed kinetic study of thermal inactivation was carried out. The results showed that pectin lyase exhibited resistance against thermal unfolding. Effect of various metals on pectin lyase activity was also investigated. All the metals showed inhibitory effect on the enzyme activity. The present investigation revealed that pectin lyase isolated from P. notatum is thermally stable and alkaline in nature.

The Spawning of Echinus Esculentus and Some Changes in Gonad Composition

1931 ◽  
Vol 8 (2) ◽  
pp. 133-150
Author(s):  
F. C. STOTT
Keyword(s):  
Fatty Acid ◽  
Acid Content ◽  
Fatty Acid Content ◽  
Dry Weight ◽  
Sea Temperature ◽  
Male And Female ◽  
Simultaneous Decrease ◽  
Post Spawning ◽  
Food Reserves ◽  
Inshore Migration

1. The spring inshore migration of Echinus at Port Erin in 1930 started in early February and reached its maximum in the middle of March. Mature gonads were found at the end of February and throughout March and early April. At the end of June all gonads examined were spent. The sea temperature throughout this period was observed. It is probable that May was the chief month in which natural spawning took place. 2. A cycle of changes in the composition of the gonad are recorded from November 1929 to July 1930. The chief of these are: (a) In the males an increase in percentage dry weight as the gonads mature ; the opposite taking place in the females. (b) A large and simultaneous decrease in percentage glycogen in both male and female gonads prior to spawning followed by a great post-spawning increase. The fatty acid content does not alter with the maturation of the gonad, but an indication is given that an increase in the percentage of carbohydrates other than glycogen occurs. Hence it is suggested that glycogen is transformed in the maturing gonad into carbohydrate food reserves for the ripe eggs and sperm.

scholarly journals Synthesis of Polyhydroxyalkanoate in the Peroxisome of Saccharomyces cerevisiae by Using Intermediates of Fatty Acid β-Oxidation

2001 ◽  
Vol 67 (11) ◽  
pp. 5254-5260 ◽  
Author(s):  
Yves Poirier ◽  
Nadine Erard ◽  
Jean MacDonald-Comber Petétot
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Isocitrate Lyase ◽  
Dry Weight ◽  
Pha Synthase ◽  
Recombinant Yeast ◽  
Medium Chain Length ◽  
The Media

ABSTRACT Medium-chain-length polyhydroxyalkanoates (PHAs) are polyesters having properties of biodegradable thermoplastics and elastomers that are naturally produced by a variety of pseudomonads.Saccharomyces cerevisiae was transformed with thePseudomonas aeruginosa PHAC1 synthase modified for peroxisome targeting by the addition of the carboxyl 34 amino acids from the Brassica napus isocitrate lyase. The PHAC1 gene was put under the control of the promoter of the catalase A gene. PHA synthase expression and PHA accumulation were found in recombinantS. cerevisiae growing in media containing fatty acids. PHA containing even-chain monomers from 6 to 14 carbons was found in recombinant yeast grown on oleic acid, while odd-chain monomers from 5 to 15 carbons were found in PHA from yeast grown on heptadecenoic acid. The maximum amount of PHA accumulated was 0.45% of the dry weight. Transmission electron microscopy of recombinant yeast grown on oleic acid revealed the presence of numerous PHA inclusions found within membrane-bound organelles. Together, these data show that S. cerevisiae expressing a peroxisomal PHA synthase produces PHA in the peroxisome using the 3-hydroxyacyl coenzyme A intermediates of the β-oxidation of fatty acids present in the media. S. cerevisiaecan thus be used as a powerful model system to learn how fatty acid metabolism can be modified in order to synthesize high amounts of PHA in eukaryotes, including plants.

scholarly journals The Saccharomyces cerevisiae ICL2 Gene Encodes a Mitochondrial 2-Methylisocitrate Lyase Involved in Propionyl-Coenzyme A Metabolism

2000 ◽  
Vol 182 (24) ◽  
pp. 7007-7013 ◽  
Author(s):  
Marijke A. H. Luttik ◽  
Peter Kötter ◽  
Florian A. Salomons ◽  
Ida J. van der Klei ◽  
Johannes P. van Dijken ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nitrogen Source ◽  
Coenzyme A ◽  
Isocitrate Lyase ◽  
Significant Activity ◽  
Mrna Levels ◽  
Wild Type ◽  
Cell Extracts ◽  
Lyase Activity ◽  
Null Mutants

ABSTRACT The Saccharomyces cerevisiae ICL1 gene encodes isocitrate lyase, an essential enzyme for growth on ethanol and acetate. Previous studies have demonstrated that the highly homologousICL2 gene (YPR006c) is transcribed during the growth of wild-type cells on ethanol. However, even when multiple copies are introduced, ICL2 cannot complement the growth defect oficl1 null mutants. It has therefore been suggested thatICL2 encodes a nonsense mRNA or nonfunctional protein. In the methylcitrate cycle of propionyl-coenzyme A metabolism, 2-methylisocitrate is converted to succinate and pyruvate, a reaction similar to that catalyzed by isocitrate lyase. To investigate whetherICL2 encodes a specific 2-methylisocitrate lyase, isocitrate lyase and 2-methylisocitrate lyase activities were assayed in cell extracts of wild-type S. cerevisiae and of isogenicicl1, icl2, and icl1 icl2 null mutants. Isocitrate lyase activity was absent in icl1 andicl1 icl2 null mutants, whereas in contrast, 2-methylisocitrate lyase activity was detected in the wild type and single icl mutants but not in the icl1 icl2mutant. This demonstrated that ICL2 encodes a specific 2-methylisocitrate lyase and that the ICL1-encoded isocitrate lyase exhibits a low but significant activity with 2-methylisocitrate. Subcellular fractionation studies and experiments with an ICL2-green fluorescent protein fusion demonstrated that theICL2-encoded 2-methylisocitrate lyase is located in the mitochondrial matrix. Similar to that of ICL1, transcription of ICL2 is subject to glucose catabolite repression. In glucose-limited cultures, growth with threonine as a nitrogen source resulted in a ca. threefold induction ofICL2 mRNA levels and of 2-methylisocitrate lyase activity in cell extracts relative to cultures grown with ammonia as the nitrogen source. This is consistent with an involvement of the 2-methylcitrate cycle in threonine catabolism.

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