Modern methods of plant analysis
01 Jan 1964-
About: The article was published on 1964-01-01 and is currently open access. It has received 1991 citations till now.
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TL;DR: The major isoform of peanut oleosin was purified by preparative electrophoresis with continuous elution, in sufficient amounts to raise specific antibodies, perform circular dichroism and N-sequence tryptic fragments, and form SDS-PAGE stable oligomers, which reflect the natural ability of oleOSins to strongly interact with each other via not only their central domains but also their N- and C-terminal domains.
29 citations
TL;DR: This method was used to study the proteolytic activity of leaf extracts from eleven plant species with no latex, and evidence is given suggesting that leaf proteases from these plants form a homogeneous group with low activity per g.
Abstract: The autolysis of proteins in leaf extracts and the proteolytic activity of crude preparations from such extracts against casein, as added substrate, was studied. If the proteins are not precipitated soon after preparation of extracts, they autolyse, and the loss from autolysis is directly related to the temperature and to the interval between preparing the extract and precipitating proteins. The advantages of the use of the NPN-increment over other methods as ail index of protein hydrolysis are discussed. This method was used to study the proteolytic activity of leaf extracts from eleven plant species with no latex. Leaf proteases from these plants form a homogeneous group with low activity per g. of protein-N, and evidence is given suggesting that they belong to the SH-group of enzymes with optimum pH between 5.2 and 5.7. Protease activity per g. of protein N increases in the leaves of wheat during the transformation of the shoot apex from vegetative into reproductive state.
29 citations
Journal Article•
TL;DR: In this paper, the influence of three levels of salinity (700, 2000 and 4000 ppm), cutting date (45, 90 and 135 days from transplanting) and their interaction on growth, yield and chemical composition of Achillea fragratissima plants was investigated.
Abstract: Two field experiments were carried out in the Experimental Farm of Desert Research Center, Ras Sudr Research Station at South Sinai Governorate, Egypt during two successive growing seasons (2006 and 2007) to study the influence of three levels of salinity (700, 2000 and 4000 ppm), cutting date (45, 90 and 135 days from transplanting) and their interaction on growth, yield and chemical composition of Achillea fragratissima plants. The results indicated that salinity concentration of 4000 ppm depressed significantly plant height, fresh and dry weight / plant, fresh and dry yield / fed., crude protein, total ash, essential oil and potassium percentage of Achillea fragratissima during both seasons, while, crude fiber, proline, phenol, tannin, alkaloid and sodium percentage increased significantly by increasing salinity from 700 to 4000 ppm in two seasons. On the other hand, cutting after 135 days from transplanting gave the highest values of plant height, fresh and dry weight / plant, fresh and dry yield / fed., crude fiber, total ash, proline, tannin, alkaloid, potassium and sodium compared with sampling date after 45 and 90 days from transplanting. On the contrary, essential oil increased in the plants cutting after 45 days from transplanting during 2006 and 2007seasons. The interaction between salinity and cutting date had a significant effect on plant height, fresh and dry weight / plant, fresh yield / fed., crude protein, total ash, potassium and sodium contents in both seasons, while crude fiber and proline were significant in the second season. However, essential oil, tannin and alkaloid were significant in the first season.
29 citations
Additional excerpts
...Crude protein was calculated by multiplying [16]...
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Journal Article•
TL;DR: Aegle marmelos, an antimicrobial plant was extracted with 100% methanol and the sensitivity of the extract was assessed against different fish diseases caused by pathogenic bacteria to find out whether 75 % was considered the best for survival and growth characteristics of the post larvae.
Abstract: Aegle marmelos, an antimicrobial plant was extracted with 100% methanol and the sensitivity of the extract was assessed against different fish diseases caused by pathogenic bacteria. For sensitivity test, the minimal bacterial population growth (10-20%) was observed in the 40 mg/100 ml concentration of the culture medium. Different concentrations (25,50,75 and 100%) of the extracts were enriched with Artemia franciscana nauplii/pre-adult. These were fed to the Penaeus indicus post-larvae (6.5 to 6.85 mg of average weight) for 25 days, which were reared with four different pathogens (Pseudomonas aeruginosa, Aeromonas hydrophila, Salmonella typhi and Vibrio sp.) inoculated seawater. Among the four pathogens, P.aeruginosa was very sensitive to A. marmelos extract. Penaeus indicus post larvae fed on the un-enriched Artemia exhibited the lowest survival, which averaged 21 %, and this increased to the maximum of 58 % (averaged) in the 75% extract enriched Anemia fed post larvae of P.indicus. Similarly, the weight gain and specific growth rate were also increased significantly (P< 0.01) in the enriched Artemia fed post-larvae of P.indicus. Among the four different pathogens inoculated, the post-larvae, which were reared in the P.aeruginosa inoculation, exhibited the maximum survival (37.35 mg) and better growth rate (12.03 %). Also the bacterial count (cfu/g) was significantly (P<0.01) differed from the un-enriched to enriched Artemia fed post-larvae. The extract helped to reduce the bacterial count of a maximum of 1.9, 2.45, 0.96 and 2.36 times in the P.aerugiosna, A.hydrophila, S.typhi and Vibrio sp. respectively in the 100 % extract enriched Anemia fed post-larvae of P.indicus. Among the different percentages of enrichment, 75 % was considered the best for survival and growth characteristics of the post larvae.
29 citations
TL;DR: In this paper, it was suggested that loss of colour, which is mainly due to the presence of β-carotene, accompanies the development of off-flavour, and this has now been done in a series of storage tests in which both carotene analyses and taste panel assessment for natural and offflavour were performed.
Abstract: Dėhydrated carrot develops an unpleasant “off”-flavour when stored in the presence of oxygen. The off-flavour has been described as “having an odour similar to violets” and it was suggested to be due to the formation of β-ionone formed by oxidation of β-carotene. This suggestion is supported by the fact that loss of colour, which is mainly due to the presence of β-carotene, accompanies the development of off-flavour. If the above suggestion is true it should be possible to establish a direct relationship between loss of β-carotene and off-flavour, and this has now been done in a series of storage tests in which both carotene analyses and taste panel assessment for natural and off-flavour were carried out.
29 citations
References
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01 Jan 1963
TL;DR: In this article, a physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln.
Abstract: Kann ein physiologischer Vorgang auf eine enzymatische Wirkung zuruckgefuhrt werden (vgl. S. 301), so besteht die folgende Aufgabe darin, Naheres uber die Eigenschaften des beteiligten Enzyms zu ermitteln. Hierzu gehoren die Bestimmung der Reaktions- und Substratspezifitat sowie die Ermittlung der Bedingungen, unter denen eine optimale Wirkung des Enzyms gegeben ist. Wesentlich zur Charakterisierung ist ferner die Untersuchung der Stabilitat des Enzyms und dabei insbesondere die Feststellung, ob es sich um ein Ferment handelt, das zur vollen Aktivitat dialysable Cofaktoren benotigt. Falls diese Frage bejaht wird, ist auch die Bestimmung der unerlaslichen Cofaktoren anzuschliesen. Uberdies bietet auch der Nachweis der Lokalisation des Enzyms in der Zelle (oder im Zellverband) eine entscheidende Moglichkeit zur Charakterisierung des Fermentes. Hinzu kommt schlieslich noch die Untersuchung der Wirkung einzelner Inhibitoren1 auf das Enzym, die zu weitgehender Klarung des Reaktionsmechanismus beitragen kann und eine Abgrenzung der Eigenschaften des untersuchten Fermentes gegenuber ahnlichen Enzymen erlaubt.
2 citations
01 Jan 1962
TL;DR: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins and rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
Abstract: Optical rotation has been found to be one of the most convenient methods of following the denaturation of proteins. Generally speaking denaturation can be defined as a process or sequence of processes in which the spatial arrangement of the polypeptide chains within the molecule is changed from that typical of the native protein to a more disordered arrangement (Kauzmann 1959). The terms “configuration”, “conformation” and “state of folding” are widely used for spatial arrangement. It is probably best to follow the suggestion of Blout (1960) and restrict the use of “configuration” to its original sense, i.e. the spatial arrangement around an asymmetric carbon atom, and to use “conformation” for the shape of the molecule in its entirety. The properties discussed in the previous Chapter i.e., viscosity, diffusion, sedimentation, and light scattering — can all furnish information on the overall shape of proteins or other macromolecules and changes in this shape with environment. Thus Doty, Bradbury and Holtzer (1956) were able to show using these methods, together with streaming birefringence, that poly-γ-benzyl-L-glutamate could exist in two conformations, the α-helix and the solvated randomly coiled form, depending on the solvent. The change from α-helix to random coil was accompanied by marked changes in the optical rotatory properties of the polypeptides. It is to be expected that an α-helical structure should contribute to the rotatory power of a polypeptide since helices are asymmetric and not superimposable on their mirror images. The work on polypeptides has shown that rotatory dispersion is capable of providing information on the folding of the polypeptide chain in proteins and the changes accompanying denaturation.
1 citations