Reactions of hydrated electrons with triazine derivatives in aqueous medium

A study is made of the kinetics and mechanism of the reaction of radiolytically produced hydrated electron (e-(aq)) with some triazine derivatives [1,3,5-triazine (T), 2,4,6-trimethoxy-1,3,5-triazine (TMT), 2,4-dioxohexahydro-1,3,5-triazine (DHT), 6-chloro N-ethyl N-(1-methylethyl)-1,3,5-triazine 2,4-diamine (atrazine, AT), and cyanuric acid (CA)] in aqueous medium using pulse and steady-state radiolysis techniques. The second-order rate constants were determined from the pseudo first-order decay of e(-)(aq) in the presence of triazines at 720 nm, and the values obtained with T, TMT, AT, and CA are in the order of 10(9) dm(3) mol(-1) s(-1) and that of DHT was 10(8) dm(3) mol(-1) s(-1) at pH 6. The transient absorption spectra from the reaction of e(-)(aq) with T and TMT are characterized by their lambda(max) at 310 nm, and those of DHT and CA are around 280 and 290 nm, respectively. However, a very weak and featureless absorption spectrum is obtained from AT. On the basis of the spectral evidence and on the quantitative electron transfer from the transient intermediates to the oxidant, methyl viologen (MV(2+)), the intermediate radicals are assigned to N-protonated electron adducts (with the unpaired spin density at carbon) of triazines. The degradation profiles, monitored as the disappearance of parent triazine concentrations as a function of dose, obtained with AT, TMT, CA, and DHT, highlight the potential use of e-(aq) in the degradation of triazines.     

Micropropagation of Cymbidium Sleeping Nymph through protocorm-like bodies production by thin cell layer culture

Transverse thin cell layers (tTCLs) of protocorm-like bodies of two stages of PLBs (30 d and 60 d old) of Cymbidium Sleeping Nymph were used as explants to induce PLBs by using coconut water (CW) as a natural additive. 5% (v/v) CW supplemented to KC medium induced an average of 5 PLBs per responding tTCL of 30 d old PLBs with 83% of responding tTCLs. A low percentage of responding tTCLs were observed in 60 d old PLBs’ tTCLs. Anatomical and confocal microscopic studies traced the origin of PLBs to subepidermal layers of the tTCL. A significantly high percentage of shoot regeneration was obtained from PLBs formed on 1–10% (v/v) CW from tTCLs of 30 d old PLBs in comparison to PLBs induced on control after first subculture on KC medium (without CW). The induced PLBs regenerated into plantlets with velamenous roots and these plantlets were transferred to greenhouse conditions on cocopeat:perlite (9:1) with nearly 100% survival. Post-transfer performance of the plantlets was monitored. The results suggest tTCLs as potential explants (with respect to economy of precious hybrid materials) which can overcome the slow growth of hybrid PLBs and coconut water as a single natural additive for the mass multiplication of commercially important orchids.     

Development of biofilm of <Emphasis Type="Italic">Vibrio alginolyticus</Emphasis> for oral immunostimulation of shrimp

Biofilm (BF) of Vibrio alginolyticus was developed on chitin flakes. BF formation was studied at various nutrient concentrations and incubation time. Highest colony-forming units of BF cells were obtained with 0.15% trypticase soya broth and at 3 days of incubation. The BF cells could be completely inactivated at 80°C in 10 min and with 10% formalin in 24 h. SDS–PAGE profile of BF cells revealed repression of four proteins and expression of three new proteins compared to free cells (FC). The preliminary immune response studies showed that BF cells were superior to FC in stimulating the non-specific immune response of Penaeus monodon.     

Enzymatic treatment and use of starters for the nutrient enhancement in fermented flour of red and white varieties of finger millet (Eleusine coracana).

Two varieties of finger millet (Eleusine coracana)-a tannin-containing red variety, CO13, and nontannin white variety, CO9-processed by treatment with enzymes (cellulase and hemicellulase) and fermentation with starters (from previously fermented finger millet batter), achieved the desirable goals of reduced fermentation time (12 h), increased acidity (2.2 to 2.4%), enhanced in vitro protein digestibility (IVPD) (14 to 26%), and mineral availability compared to 48 h uncontrolled natural fermentation (Usha Antony and Chandra, 1998). Fermentation with starters alone increased titratable acidity (1.02 to 1.88%), IVPD (5. 5 to 22%) and mineral availability, and decreased phytate (23 to 26%) and tannin (10.8 to 40.5%) in the millets. Enzymatic treatment (3 h, 50 degrees C) did not significantly alter the pH, phytate, tannins, IVPD, or HCl-mineral extractability but enhanced fermentative changes. Overall, the changes were marked when the 48 h starter was used and the improvements in nutrient availability was greater in the CO13 variety.     

An efficient method for extraction of astaxanthin from green alga Haematococcus pluvialis

Haematococcus pluvialis is one of the potent organisms for production of astaxanthin, a high value ketocarotenoid. Astaxanthin is accumulated in thick-walled cyst cells of Haematococcus. The thick cell wall is made up of sporopollenin-like material, algaenan, which hinders solvent extraction of astaxanthin. In the present study, an improved method for extraction of astaxanthin without homogenization of cells is reported. Extractability of astaxanthin from cyst cells was evaluated by treating cells with various solvents and pretreating the cells with organic and mineral acids at 70 degrees C followed by acetone extraction. Hydrochloric acid treatment facilitated 86-94% extractability of astaxanthin. Treatment time, temperature, and concentration of the acid were found to be critical factors for maximum extractability. The treatment did not affect the astaxanthin ester profile and the treated cells can be preserved until further use.     

A note on the relationship between the production rates of volatile fatty acids and their concentration,digestible organic matter and total digestible nutrient intake in buffalo calves

Volatile fatty acid (VFA) production rates were measured by isotope dilution technique in the rumen of buffalo calves fed on wheat straw plus concentrate, green maize, cow pea and berseem. Correlations derived between the VFA production rates and their concentration and DOM were significant except in animals fed on cow pea. The VFA production rates were also significantly correlated with the TDN intake in all the four feeds tested.The regression equations obtained for the four feeds were different, which suggested that VFA production may vary with the quantity and quality of feed digested. These experiments suggest the use of different regression equations for different feeds.     

Morphometric and developmental consequences in Spodoptera litura due to feeding on three varieties of sweet potato plants (Ipomoea batata)

The tobacco caterpillar, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), is a polyphagous pest defoliating sweet potato, Ipomoea batata (Lam) (Convolvulaceae), throughout Asia. The study of morphometric parameters of S. litura as a result of feeding on three varieties (RNSP1, KIRAN and RNSP3) of host plant revealed that a greater number of egg masses were laid on the KIRAN variety than on the others. I. batata varieties showed statistically significant effects on length, breadth and weight of different larval instars. KIRAN-fed larvae molted to bigger-sized pupae. S. litura larvae reared on KIRAN variety had the highest feeding index as well as growth index. The low concentrations of phenols and carbohydrates coupled with elevated levels of proteins and amino acids were found in KIRAN as compared with RNSP1 and RNSP3. Collectively, the results of this study revealed that KIRAN cultivar was the most suitable food plant for the development of S. litura. Concurrently, it is suggested that this cultivar is therefore least suitable for sweet potato cultivation.