Alkali-soluble Components Research Articles

Structure and Chemical Composition of Bast Fibers Isolated from Developing Hemp Stem

Microscopic and chemical changes of hemp bast fibers were studied during the maturation from vegetative to grain maturity stages at both apical and basal regions of the stems. The content of protein was the main factor related to fiber maturation, whereas increased proportions of mannose and glucose and decreasing levels of galactose were also highly significant. Enhanced glucose deposition in apical fibers could be related to the gradual thickening of the fibers, whereas in basal regions the thickness of the fibers nearly reached the maximum at vegetative stages. In contrast, the extent of lignification remained close to 3-4% during plant growth. Hemp fiber lignins were rich in guaiacyl units and would be rather condensed in nature. In addition, the proportion of p-hydroxyphenyl units displayed a constant decline during maturation. A progressive chemical fractionation of hemp fibers provided further insights to the occurrence and nature of noncellulosic polysaccharides. Notably, these data pointed out that maturation is accompanied by a significant increase in water- and alkali-soluble components containing glucose- and mannose-related polymers and a decrease in arabinose and galactose components disrupted by diluted hydrochloric acid. Taken together, chemical features of the noncellulosic components suggest that the architecture of hemp fibers differs slightly from that of the more widely studied flax fibers.

Charge aspects of hydrogen peroxide bleached de-inked pulps

The aim of this study was to evaluate the effect of hydrogen peroxide bleaching on fibre charge of a commercial de-inked recycled pulp. The pulp was bleached with hydrogen peroxide for brightness improvement. The results indicated that the brightness gain was a function of H 2O 2 dosage. The yield loss associated with the peroxide bleaching was significant due to the presence of alkali-soluble components in the de-inked recycled pulp. The loss of the total fibre charge was apparently linearly related to the yield loss, but the change of the fibre surface charge was insignificant.

Gene encoding two alkali-soluble components of the spore coat from Bacillus subtilis

We report the cloning and characterization of a gene called cotF from Bacillus subtilis that encodes alkali-soluble polypeptides of 5 and 8 kDa that are components of the spore coat. The 5- and 8-kDa polypeptides are generated by proteolytic cleavage of the primary product of the cotF gene, which is 160 codons in length and is capable of encoding a polypeptide of 19 kDa. Amino acid sequence analysis indicates that the 5-kDa species is derived from the NH2-terminal portion of the primary gene product and that the 8-kDa species is derived from the COOH-terminal portion. A mutant bearing an in vitro-constructed cotF null mutation produced normal-looking spores that contained an apparently complete set of coat proteins except for the absence of the 5- and 8-kDa polypeptides. The map position of cotF is 349 degrees. Transcription of cotF commenced coincidently (during h 6 of sporulation) with genes known to be under the control of sporulation transcription factor sigma kappa.

Behaviour of Aleurone Cells of Wild Oats (Avena fatua L.) — A Light Microscopic Study

The aleurone layer isolated from the mature caryopses of wild oats ( Avena fatua L.) was studied with the light microscope, with particular reference to changes resulting from desiccation and imbibition. The aleurone cells on drying produced characteristic spiny vesicles or rays, which extended within the cell from the protoplast to the thin cell wall. They showed on hydrating thickened cell walls and slightly swollen protoplasts. The spiny vesicles observed in dry cells were not seen on hydration. Cells treated with NaOH showed neither the development of spiny vesicles on drying nor the thickening of cell walls on hydrating. The changes in protoplast and cell wall dimensions showed that the maximum enlargement of protoplasts in alkali-untreated cells due to hydration was prevented by the thickening of cell walls. The aleurone cell wall has neither pits nor plasmodesmata. It contains two components, the inner alkali-soluble and the rigid outer alkali-insoluble. The alkali-soluble component (hemicellulose) was needed for wall thickening on imbibition and the lack of it in the cell wall prevented the development of spiny vesicles from the protoplast in aleurone cells upon desiccation. The ability of cell walls to swell on hydrating and of protoplasts to produce spiny vesicles on drying might be significant in the long retention of germinability of wild oat caryopses.

Interaction of yeast cell wall thermo-labile protein antigens (TLA a and TLA b) with a yeast cellular alkali-soluble component.

The major protein antigens of the yeast cell wall, TLA a and TLA b, were found to specifically bind with the alkali-soluble fraction (ASF) which was prepared from yeast cells (Saccharomyces cerevisiae) essentially by the method of Manners et al. Also, TLA a and TLA b were found to be present in the alkali-soluble fraction of yeast cells. This fraction was prepared from yeast cell homogenates after solubilizing by alkali (pH 9.0) followed by precipitating with acid (pH 6.0). The binding of TLA a and TLA b with ASF was completed rapidly. The optimum pH for the binding was 6.0. Concentrations of sodium chloride higher than 0.06 M and 0.1M inhibited the binding of TLA a and TLA b, respectively. TLA a or TLA b-ASF complexes were dissociated commpletely in 0.2M and 0.6M NaCl solution, respectively. ASF was reconstituted on the surface of protoplasts after 3 hr of incubation.

Two cell wall .BETA.-D-glucans from Neurospora crassa.

Two β-d-glucan components have been obtained from mycelia of Neurospora crassa by fractionation with alkali. The component obtained by extraction with 4% NaOH had a unit structure of a linear β1,3-d-glucan consisting of about 86 glucosyl residues, two of which were substituted with single β-d-glucosyl residues at C6. The unit chain is linked in turn through two β-1,6-glucosidic linkages. The alkali insoluble component had a structure essentially similar to that of the alkali soluble component. But, the main chain of the unit structure of the latter was much shorter (ca. 20) and had both glucosyl and laminaribiosyl side chains.

Some components of particulate phosphorus in river water entering Lough Neagh

Particulate phosphorus obtained by continuous-flow centrifugation of 1001, volumes of each of the 6 major rivers entering Lough Neagh was subjected to fractionation by acid and alkali treatments. The major acid-soluble component was inorganic phosphorus (36%) while the major alkali-soluble component was organic phosphorus (24%). The insoluble residue accounted for 36% of the total particulate phosphorus. Acid and alkali extracts were subjected to gel filtration chromatography and the organic phosphorus divided into molecular weight ranges. The alkali-soluble organic phosphorus of mol. wt > 50,000 was isolated in sufficient quantity for elemental analysis and infra-red spectroscopy to be performed. Results indicated that the organic matter resembled humic acid. Iron may also have been associated with the phosphorus and organic matter. Phosphorus may have been an integral part of the humic acid structure or an organic phosphorus iron organic matter complex may have existed. No algal availability studies were performed but the fractionation data from the study would not conflict with the suggestion of other workers that algal available particulate phosphorus is about 20% of total particulate phosphorus.

Studies on the bacterial spore coat. (7) Properties of alkali-soluble components from spore coat of Bacillus megaterium.

Properties of alkali-soluble components from the spore coat of Bacillus megaterium were examined by physicochemical methods. They were composed of acidic polypeptides of various molecular weights with small amounts of phosphorus and sugar. They were allowed to dissociate to unit components by incubation with SDS. The major component was partially purified by gel filtration, and shown to have a mean molecular weight of about 11,000.

A high pressure liquid chromatographic method for the quantitation of sub-microgram amounts of zearalenone (F-2) in agricultural products.

A highly sensitive and reliable method for the quantitation of sub-microgram quantitaties of zearalenone (F-2) residues in corn, corn oil and mixed feed is described. The isolation of this mycotoxin from a mixed solvent extract involves partitioning of the alkali soluble components from a chloroform solution, followed by acidification and extraction of organic components into chloroform, a silica gel column clean-up and analysis by high pressure liquid chromatography using a ultraviolet (UV) detector at 280 nm. The limit of detection of the instrument is shown to be 2.5 ng and that of the method is 100 ppb. The percent recoveries of zearalenone in corn is found to be 72.1 +/- 6.0 at the levels between 0.1 and 1.0 ppm, in corn oil 72.6 +/- 8.8 at levels 0.25 and 1.0 ppm and in pig starter 67.3 +/- 4.5 at 1.0 ppm level. In the case of two field samples, the reproducibility of analysis is very good and the mycotoxin contents are shown to be 11.5 +/- 0.26 and 0.61 +/- 0.07 ppm.

Surface-active products from oxidation of catalytic naphtha and subsequent sulfonation of the oxidation product

1. The processes of oxidation of catalytic cracking naphtha and sulfonating the oxidation products have been studied with the objective of preparing flotation agents. 2. Optimum oxidation conditions have been found: temperature, 130–135°C; duration, 7–9 h; catalyst, manganese naphthenate in an amount of 1% by wt.; air input, 3.5–4 liters/kg per min. 3. Optimum conditions of sulfonating the oxidate have been found: temperature during additon of sulfonating agent, 10–15°C; additional treatment at 28–30°C; time, 3 h; ratio of oxidate to sulfonating agent in sulfonation with 97–100% sulfuric acid, 1∶3; in sulfonation with oleum (13% free SO3), 1∶1 or 1∶1.5. 4. It has been shown that the water- and alkali-soluble components of oxidized catalytic naphtha (OCN) and their sulfonation products possess well-displayed surface-active properties, especially the sulfonation product of OCN with 97% sulfuric acid in a 1∶3 ratio. 5. The surface-active reagents obtained can be used successfully as collectors and foam-formers in flotation of lead-baryte, lead-zinc, or other ores, and can completely replace flotation oil foaming agent or DS in flotation of polymetallic ores.

THE PROTEIN CRYSTALS OFBACILLUS THURINGIENSISBERLINER

On sporulation the cells of the insect pathogen Bacillus thuringiensis contain at one end a spore and at the other end a diamond shaped crystal. A method has been developed for the separation of the alkali dispersible crystal material from spores, vegetative cell debris, and their alkali soluble components. Two methods are given for the preparation of suspensions of intact crystals free from other material. One method depends on the mechanical disruption of the spores, the other on germination and autolysis of the spore contents. After either method clean suspensions of crystals were obtained by washing and differential centrifugation. The purest preparations have yielded a substance precipitable with trichloracetic acid, possessing the ultraviolet absorption characteristics of protein, containing over 17% nitrogen and at least 17 amino acids, but no phosphorus. Examination of the crystals with the electron microscope has shown that they have a tetragonal form and possess some fine structures; no virus particles were found in alkali dispersed crystal protein.