scholarly journals Strength of Flocs Formed by the Complexation of Lysozyme with Leonardite Humic Acid

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1770
Author(s):  
Wan Khairunnisa Wan Abdul Khodir ◽  
Azizul Hakim ◽  
Motoyoshi Kobayashi
Keyword(s):  
Humic Acid ◽  
Humic Substances ◽  
Isoelectric Point ◽  
Salt Concentration ◽  
Positive Charge ◽  
Mass Ratio ◽  
Low Salt ◽  
Floc Strength ◽  
Soil And Water ◽  
Leonardite Humic Acid

Aggregation and aggregates properties of natural organic and nanosized macromolecules such as humic substances and proteins are crucial to explore so-called colloid-mediated transport and the fate of substances in soil and water environments. Therefore, the aggregation and dispersion, charging, and floc strength of lysozyme (LSZ)–leonardite humic acid (LHA) flocs were experimentally investigated. The experiments were performed in different salt concentrations and LSZ to LHA mass ratios as a function of pH. We obtained the stronger flocs at pH 4.4, where the isoelectric point (IEP) of the complex with the mass ratio 2.5 was confirmed. Thus, the aggregation of LSZ–LHA flocs is mainly caused by charge neutralization. We obtained the floc strength of 4.7 nN around IEP at low salt concentration of 3 mM, which was stronger than 2.8 nN in high salt concentration of 50 mM. The effect of salt concentration can be rationalized by charge-patch attraction at low salt concentration. With increasing mass ratio, the IEP shifted to higher pH. This is due to the increase in positive charge from LSZ in the mixture. The effect of the LSZ to LHA mass ratio on the maximum strength was weak in the range studied.

Synthesis and conformation of sequential basic polypeptides with branched and linear side chains

1985 ◽  
Vol 50 (12) ◽  
pp. 2925-2936 ◽  
Author(s):  
Štěpánka Štokrová ◽  
Jan Pospíšek ◽  
Jaroslav Šponar ◽  
Karel Bláha
Keyword(s):  
Amino Acid ◽  
Salt Concentration ◽  
Salt Solution ◽  
Theoretical Work ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Cd Spectra ◽  
Low Salt ◽  
Conformational Freedom ◽  
Basic Polypeptides

Polypeptides (Lys-X-Ala)n and (Lys-X-Gly)n in which X represents residues of isoleucine and norleucine, respectively, and polypeptide (Tle-Lys-Ala)n, were synthesized via polymerization of 1-hydroxysuccinimidyl esters of the appropriate tripeptides to complete previously studied series. Circular dichroism (CD) spectra of the respective polymers were measured as a function of pH and salt concentration of the medium. The results were correlated with those obtained previously with the same series containing different amino acid residues at the X-position. The helix forming ability of the polypeptides (Lys-X-Ala)n with linear X side chain was found to be independent of the length. In the series (Lys-X-Gly)n the unordered conformation was the most probable one except (Lys-Ile-Gly)n. This polymer assumed the β conformation even in low salt solution at neutral pH. An agreement with some theoretical work concerned with the restriction of conformational freedom of amino acid residue branching at Cβ atom with our experimental results is evident.

scholarly journals Determination of Organic Compounds, Fulvic Acid, Humic Acid, and Humin in Peat and Sapropel Alkaline Extracts

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2995
Author(s):  
Laurynas Jarukas ◽  
Liudas Ivanauskas ◽  
Giedre Kasparaviciene ◽  
Juste Baranauskaite ◽  
Mindaugas Marksa ◽  
...  
Keyword(s):  
Humic Acid ◽  
Fulvic Acid ◽  
Humic Substances ◽  
Organic Compounds ◽  
Chemical Constituents ◽  
Acid Amide ◽  
Extraction Methods ◽  
Ultrasound Extraction ◽  
Different Origins

Black, brown, and light peat and sapropel were analyzed as natural sources of organic and humic substances. These specific substances are applicable in industry, agriculture, the environment, and biomedicine with well-known and novel approaches. Analysis of the organic compounds fulvic acid, humic acid, and humin in different peat and sapropel extracts from Lithuania was performed in this study. The dominant organic compound was bis(tert-butyldimethylsilyl) carbonate, which varied from 6.90% to 25.68% in peat extracts. The highest mass fraction of malonic acid amide was in the sapropel extract; it varied from 12.44% to 26.84%. Significant amounts of acetohydroxamic, lactic, and glycolic acid derivatives were identified in peat and sapropel extracts. Comparing the two extraction methods, it was concluded that active maceration was more efficient than ultrasound extraction in yielding higher amounts of organic compounds. The highest amounts of fulvic acid (1%) and humic acid and humin (15.3%) were determined in pure brown peat samples. This research on humic substances is useful to characterize the peat of different origins, to develop possible aspects of standardization, and to describe potential of the chemical constituents.

Soil Augmentation by Humus: Replenishing lost soils and supplementing new ones

2021 ◽  
Author(s):  
Hemlata Bagla ◽  
Asma Khan
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Plant Growth ◽  
Humic Substances ◽  
Soil Degradation ◽  
Lunar Regolith ◽  
Radioactive Waste Disposal ◽  
Saline Stress ◽  
Plant Metabolites ◽  
Growth Phenomenon

<p>Earth’s regolith consists of a vital component that is lacking on other planets ­­– the pedosphere or soil body – that is rich in organic matter, soil fauna, minerals, water, gases, that together support life and is thus essential for plant growth. In stark contrast to our blue planet, Martian regolith is devoid of organic matter and contains crushed volcanic rocks, with high mineral content and toxic chemicals like perchlorates. Nevertheless, Martian and Lunar regolith simulants formulated by NASA, have been experimented for crop growth by addition of organic matter suitable to bind xenobiotics and provide ample nutrients, as an essential step towards expanding our horizon in the extensive field of soil sciences.</p><p>Soil is an ecosystem as a whole and acts as a modifier of planet Earth’s atmosphere. The organic matter present in it originates mainly from plant metabolites with the onset of senescence and humification. Humic substances thus formed in the pedosphere exhibit exceptional characteristics for soil conditioning. Besides providing nutrients and aeration to the soil, they interact and bind with toxic heavy metals, radionuclides, pesticides, industrial dyes, and other xenobiotics that may be present as pollutants in the ecosystem, thus acting as natural sieves. As top soils have maximum organic matter, essential for plant growth, phenomenon like soil erosion leave the soils devoid of humic substances. Another major reason for soil degradation is excessive salinity, leading to osmotic and ionic stress in plants, eventually reducing their growth. Addition of humic acid in soils provides protection against high saline stress and minimizes yield losses. In India, one of the leading agrarian countries, it is a common practice to enrich soils with manure, which is an inexpensive form of humus-boost for the crops. Such practices aid the cyclic flow of organic matter in the environment, against the background of widespread soil degradation.</p><p>Another global form of soil degradation is radioactive contamination of soils which occurs mainly due to nuclear accidents and improper practices of radioactive waste disposal. In order to explore such interactions with humic acid following Green technique, batch biosorption studies were performed over a range of parameters, with radionuclides Cs and Sr that are found in low level radioactive wastes. Biosorption percentages of 91±2% and 84±1% were obtained for Cs and Sr respectively. The technique is chemical-free and emphasizes the ‘nature for nature’ outlook of solving environmental problems. Humic acid and its various forms thus act as traps for radionuclides and work as excellent restorative soil stimulants that supplement depleted soils, boost plant growth, and play a vital role in sustaining life on Earth.</p>

Effect of Salt Concentration and Incubation Temperature on Formation of Histamine, Phenethylamine, Tryptamine and Tyramine During Miso Fermentation

1986 ◽  
Vol 49 (6) ◽  
pp. 423-427 ◽  
Author(s):  
K.-D. HENRY CHIN ◽  
P. E. KOEHLER
Keyword(s):  
Salt Concentration ◽  
Incubation Temperature ◽  
High Salt ◽  
Soybean Paste ◽  
Salt Level ◽  
Low Salt ◽  
Two Factors

Two factors, salt concentration and incubation temperature, were examined for their effect on the formation of histamine, phenethylamine, tryptamine and tyramine during miso (soybean paste) fermentation. Misos containing 5 and 10% NaCl were prepared and incubated at 25 and 35°C. The effect of each factor was determined from the chemical and microbiological changes in the misos during fermentation. Salt level was a significant factor in the formation of amines. Higher amine levels were found in low-salt (5% NaCl) formulations than in high-salt (10% NaCl) misos. Incubation temperature within the range of 25 to 35°C during fermentation had little effect on amine formation in misos.

scholarly journals Studies on Chitin

1955 ◽  
Vol 8 (4) ◽  
pp. 530 ◽  
Author(s):  
RH Hackman
Keyword(s):  
Isoelectric Point ◽  
Salt Concentration ◽  
Water Soluble ◽  
Protein Fractions ◽  
Cuticular Protein ◽  
Adsorbed Protein ◽  
Effects Of Ph

The effects of pH, salt concentration, and temperature on the adsorption of a water-soluble insect cuticular protein to chitin have been investigated. The adsorption is dependent upon pH, decreasing rapidly as the pH increases from the region of the isoelectric point of the protein. Increase in salt concentration decreases adsorption but the adsorption appears to be little influenced by changes in temperature. Tyrosine-rich protein fractions are preferentially adsorbed. The adsorption is partly irreversible and an increase to pH 9 is necessary before all the adsorbed protein can be removed. It is concluded that there is only a weak bonding between the chitin and the water-soluble cuticular protein.

Bioavailability of a nonylphenol isomer in dependence on the association to dissolved humic substances

2004 ◽  
Vol 50 (5) ◽  
pp. 277-283 ◽  
Author(s):  
R. Vinken ◽  
A. Höllrigl-Rosta ◽  
B. Schmidt ◽  
A. Schäffer ◽  
P.F.-X. Corvini
Keyword(s):  
Humic Acid ◽  
Carbon Source ◽  
Humic Substances ◽  
Organic Compounds ◽  
Sole Carbon Source ◽  
Equilibrium Dialysis ◽  
Fulvic Acids ◽  
Degrading Bacterium ◽  
Bacterium Strain ◽  
Dissolved Humic Substances

Humic substances are important environmental components since they represent a very large part of organic compounds on earth. According to many reports, dissolved humic substances are a determinant parameter for the bioavailability of xenobiotic compounds. For the present bioavailability studies, two kinds of dissolved humic substances, a commercially available humic acid and fulvic acids isolated from peat were used. As the relevant xenobiotic, a defined branched nonylphenol isomer, 4(3′,5′-dimethyl-3′-heptyl)-phenol (p353NP) was synthesised according to Friedel-Crafts alkylation. Equilibrium dialysis studies were implemented in order to investigate the association between 14C-labelled p353NP and dissolved humic substances. The biodegradability in the presence of dissolved humic substances was examined in experiments with the nonylphenol degrading bacterium strain Sphingomonas TTNP3 and with p353NP as sole carbon source. The results showed that p353NP-humic acid associates were formed in high amounts, whereas no adducts with fulvic acids occurred. In the degradation studies with Sphingomonas TTNP3, no effects of dissolved humic substances on the bioavailability of p353NP could be observed. It was assumed that the association between nonylphenol and humic acids occurs rapidly and is reversible. Thus, the formation of "labile" complexes did not influence biodegradation rates, which were quite low.

EFFECT OF HUMIC AND FULVIC ACIDS ON MICROBIAL GROWTH

2021 ◽  
Author(s):  
Milanka Radulovic ◽  
◽  
Svetlana Mitrovski
Keyword(s):  
Humic Acid ◽  
Humic Substances ◽  
Minimal Medium ◽  
Microbial Growth ◽  
Growth Curves ◽  
Fulvic Acids ◽  
Humic And Fulvic Acids ◽  
Staphyloccocus Aureus ◽  
Low Ionic Strength ◽  
Strength Medium

Peat is a natural substrate for growth of microorganisms because it is rich in compounds that microorganisms can use as sources of carbon, nitrogen and growth factors. Peat originating from Vlasina lake in Eastern Serbia is especially rich in organic matter. The content of humic substances (humic acid, fulvic acid and humine) is almost twice that found in other peat-rich regions of similar origin and geochemical age. Humic and fluvic acids are known to promote microbial growth. In this work, humic and fulvic acids were first extracted from Vlasina lake peat and then added to minimal medium (synthetic, low ionic strength medium). The humic substances were added separately and combined in a 1:1 ratio by mass to study their individual and combined effect on microbial growth of Escherichia coli ATCC 25922 (Gr–), Staphyloccocus aureus (Gr+) i Aureobasidium pullulans, strain CH-1. The microbial growth was measured microspectrophotometrically over a 24-hour period and growth curves were obtained for a range of acid concentrations between 25 µg cm-3 and 100 µg cm-3. It was found that both humic and fulvic acids promote the growth of all three microorganisms by up to a maximum of 40%-80% the extent of which varied with the concentration of the acid and the identity of the microorganism. In general, humic acid was found to result in higher microbial growth (at highest concentrations, up to ~80% for all three microbial species).

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