Removal of nitrate-nitrogen from drinking water using bamboo powder charcoal

The adsorption effectiveness of bamboo powder charcoal (BPC); made from the residual of Moso bamboo manufacturing; in removing nitrate-nitrogen from water has been investigated. Commercial activated carbon (CAC) was also used to compare the effectiveness of adsorption in removal of nitrate-nitrogen. The adsorption effectiveness of BPC was higher than that of CAC; regardless of the concentration of nitrate-nitrogen; in the range of 0-10 mg/l. The effect of temperature on adsorption by BPC and CAC in the range of 10-20 degrees C was also investigated. From the results, it was found that the temperature dependency of the adsorption effectiveness of BPC was weaker than that of CAC. This fact indicates that BPC can be an attractive option for the in situ treatment by adsorption of nitrate-nitrogen-contaminated underground and surface water.     

Feasibility of ethanol production from coffee husks

The objective of this work was to evaluate the feasibility of ethanol production by fermentation of coffee husks by Saccharomyces cerevisiae. Batch fermentation studies were performed employing whole and ground coffee husks, and aqueous extract from ground coffee husks. It was observed that fermentation yield decreased with an increase in yeast concentration. The best results were obtained for the following conditions: whole coffee husks, 3 g yeast/l substrate, temperature of 30°C. Under these conditions ethanol production was 8.49 ± 0.29 g/100 g dry basis (13.6 ± 0.5 g ethanol/l), a satisfactory value in comparison to literature data for other residues such as corn stalks, barley straw and hydrolyzed wheat stillage (5–11 g ethanol/l). Such results indicate that coffee husks present excellent potential for residue-based ethanol production.     

Extraction of water-soluble hemicelluloses from barley husks

Heat treatment of barley husks was performed to extract arabinoxylan with high yield and high weight-averaged molecular mass (M(W)). Microwave irradiation was employed for initial screening of suitable residence times (2-15 min), temperatures (120-210 degrees C) and initial pH (3-13) of the reaction slurry. Microwave irradiation was shown to be a good method for predicting the effects of heat treatment on a larger scale using steam pretreatment. A M(W) of about 40,000 Da was achieved without the addition of chemicals, by both microwave irradiation and steam pretreatment, with a yield of about 9%. The yield was significantly increased by slightly increasing the severity factor. However, the M(W) decreased below 20,000 Da at severity factors above 3.7. Arabinosyl side groups were enzymatically hydrolysed from the arabinoxylan by alpha-L-arabinofuranosidase to a degree of 47%, demonstrating the ability to specifically alter the side group substitution of arabinoxylans with the use of enzymes.     

A phylogenetic study of the gibbons (Hylobates) using DNA obtained noninvasively from hair.

Variation in a 252-nucleotide segment of the cytochrome b gene from 26 gibbons is described. DNA was extracted from hair, amplified, and directly sequenced. These sequences represent seven of the nine nominal species and three of the four hylobatid subgenera. Variation was observed at 55 sites, 42 of which are phylogenetically informative. Levels of transitional and transversional divergence between the taxa are similar to those reported for homologous mtDNA sequences in other mammals. Parsimony, maximum likelihood, and bootstrap analyses (1) support some traditional phylogenetic hypotheses (monophyly of the concolor gibbons), (2) suggest previously unrecognized affinities between the lar species group and Hylobates klossi and between H. lar and H. agilis unko, and (3) show that this segment does not contain information sufficient for completely resolving gibbon relationships at the subgeneric level. The study demonstrates the great potential of noninvasive DNA sampling for phylogenetic analyses of mammals.     

Ion binding constants for gramicidin a obtained from water permeability measurements

Gramicidin A pores are permeable to water and small monovalent cations. For K, Rb, and Cs there is good evidence from conductances and permeability ratios that a second ion can enter a pore already occupied by another, but for Na this evidence is inconclusive and comparison of tracer fluxes and single channel conductances suggests that second ion entries are prohibited. Partly as a result of the complications of second ion entry there have been widely differing estimates for the dissociation constants for the first ion in the channel. Dani and Levitt (1981, Biophys. J. 35: 485–499) introduced a method for calculating ion binding constants from simultaneous measurements of water fluxes and membrane conductance. They found no evidence for second ion binding and calculated dissociation constants of 115 mm for Li, 69 mm for K, and 2 mm for Tl. It is shown here that the two-ion, four-state model predicts a dependence of water permeability on ion concentration that is difficult to distinguish from the predictions of block by a single ion. Using a modified technique that allows measurement of higher conductances, the first ion dissociation constants have been determined as 80 mm for Na, 40 mm for Rb and 15 mm for Cs. These values and those of Dani and Levitt fall in a smooth sequence. The dissociation constant for Cs is consistent with single channel conductances and flux ratios. There is a discrepancy between this constant for Na and the value, 370 mm, calculated from the single channel conductances and the assumption that a second ion cannot enter or affect an occupied pore. The dissociation constant for Rb is intermediate between those for K and Cs whereas tracer flux measurements (Schagina, Grinfeldt & Lev, 1983. J. Membrane Biol. 73: 203–216) have suggested that Rb interacts much more strongly with the channel than Cs.We should like to thank the National Grid plc, for the grant which supported K.-W.W., the Wellcome Trust for a visiting Fellowship for S.T. in Cambridge, and the Cambridge Society of Bombay which supported S.B.H. in Bombay.     

Composition and bioactivity of polysaccharides from tea seeds obtained by water extraction

In this paper, the composition and biological activities of polysaccharides from tea seed (TSPS) obtained by water extraction were investigated. The properties and chemical compositions of TSPS were analyzed with HPGPC, IC, and IR methods. The results showed that TSPS consisted of three kinds of polysaccharides with the molecular weight of 500 kDa, 130 kDa, and 5 kDa. TSPS consisted of rhamnose, xylose, arabinose, glucose and galactose, GalA, GulA, with a molar ratio of 4.9:1.7:11.1:27.2:14.0:3.4:1, sugar backbone of TSPS might consist of glucose, but branched chain may consist of rhamnose, xylose, arabinose, and galactose. The IR spectrum of TSPS revealed the typical characteristics of polysaccharides and protein. TSPS significantly inhibited the growth of K562 cells, especially, at the concentration of 50 μg/ml; the inhibition activity of TSPS was the highest with an inhibition ratio beyond 38.44 ± 2.22% (P < 0.01). TSPS with high concentrations (100, 200 and 400 μg/ml) had higher proliferation effect on lymphocyte. Results of these studies demonstrated that the polysaccharide had a potential application as natural antitumor drugs.     

Removal of water turbidity by natural coagulants obtained from chestnut and acorn

The ability of seed extracts of several species of chestnut and acorn to act as natural coagulants was tested using a synthetic turbid water. Active components were extracted from ground seeds of Horse chestnut and acorns of some species of family Fagaceae: Common oak, Turkey oak, Northern red oak and European chestnut. All investigated extracts had coagulation capabilities and their amounts depended on pH values and initial turbidities. The seed extracts from European chestnut and Common oak acorn were the most efficient expressing the highest coagulation activities, about 80% and 70%, respectively, in both low and medium investigated water turbidities at the lowest coagulant dose 0.5 ml/L.     

Comparative study of alkali-soluble hemicelluloses isolated from bamboo (Bambusa rigida)

The physicochemical properties and structural characteristics of seven alkali-soluble hemicellulosic preparations were determined. These were extracted from bamboo (Bambusa rigida) with 1 M NaOH, KOH, LiOH, NH₃·H₂O, (CH₃CH₂)₃N, Ca(OH)₂, Ba(OH)₂, respectively, at 50 °C for 3 h, were comparatively studied. Sugar analysis showed that these hemicelluloses contained d-xylose as the major constituent, along with d-glucose and l-arabinose in noticeable amounts. Uronic acids, principally 4-O-methyl-d-glucuronic acid, occurred in a small amount. Furthermore, based on the sugar analysis and FTIR and NMR spectroscopy, it can be concluded that the hemicelluloses consist of a backbone of β-(1→4)-linked d-xylopyranosyl units having branches of arabinose and 4-O-methyl-d-glucuronic acid. Nitrobenzene oxidation revealed that the hemicelluloses obtained are mostly free of bound lignins. Moreover, it is noteworthy that hemicelluloses isolated with the different alkaline solutions presented different chemical compositions and slightly dissimilar structural features, indicating that alkalinity played an important role in cleaving the chemical linkages between the hemicelluloses and the lignins.     

A new Gloeoporus species growing on bamboo from southern Brazil

Gloeoporus guerreroanus sp. nov. is described and illustrated from specimens collected on bamboo in Rio Grande do Sul State, southern Brazil. The new taxon presents hymenium continuum along the tubular internal surface and dissepiments and represents an addition into the relatively small, poroid-merulioid genus Gloeoporus.     

A preliminary study of fresh water fungi from Abaco Island,the Bahamas

Fresh water on a small marine island is rather limited and could be the habitat of aquatic fungi. Members of the Saprolegniales and Peronosporales can survive on organic matter found floating or submerged in shallow water. Recently a preliminary study was conducted on the keratinophilic fungi of Abaco Island, The Bahamas (5). The same island was surveyed for fresh water fungi in this investigation.