Quantifying the dietary biotin requirement of the catfish,Clarias batrachus

Asian catfish, Clarias batrachus, were fed semi-purified basaldiets containing 0, 0.1, 0.5, 1, 3 and 5 mg biotin kg^–1diet for 60 days. Fish fed the control diet (no biotin) showed(P < 0.05) higher mortality, lower weight gain, specificgrowth rate (SGR), feed efficiency ratio (FER) and protein efficiencyratio (PER) than in fish fed diets supplemented with biotin. The highestweight gain, SGR, FER and PER were noticed in fish fed 1 mg biotinkg^–1, followed by 0.5, 5, 3 and 0.1 mg biotinkg^–1, except for PER (followed by 0.5, 5, 0.1 and 3 mgbiotin kg^–1). Quadratic analysis showed that the optimumdietary biotin requirements for maximal weight gain, PER and PER were2.49, 2.54 and 2.52 mg kg^–1, respectively. Liver biotinconcentrations were influenced by levels of biotin in the diet.Concentration of liver biotin increased as level of dietarysupplementation increased and no biotin was detected in the liver of thecontrol fish. Liver pyruvate carboxylase and acetyl CoA carboxylaseactivities were higher in fish fed biotin-supplemented diets than incontrols. Biotin concentrations, pyruvate carboxylase and acetyl CoAcarboxylase activities in liver associated with normal growth rangedfrom 10.59 to 10.66 g g^–1, 147.97 to 148.18 units mgprotein^–1 and 12.76 to 12.78 units mg protein^–1, respectively. Biotin deficiency symptoms such as anorexia, darkskin colour and convulsions were observed in fish fed the control diet.The optimum dietary biotin requirement for maximal growth of C.batrachus is about 2.49 mg kg^–1 diet.     

Micropropagation of red sanders (Pterocarpus santalinus L.) using mature nodal explants

In vitro clonal multiplication of Pterocarpus santalinus L. was achieved using mature nodal explants of a 10-year-old elite quality tree. Combinations of serial transfer technique and incorporation of antioxidants (250 mg/l L-ascorbic acid and 50 mg/l citric acid) into the culture medium helped to minimize medium browning and improve explant survival during shoot sprouting. About 70% of explants were sprouted on Murashige and Skoog (MS) liquid medium containing 4.4 μM 6-benzyladenine (BA). The explant harvest period also influenced the bud break and shoot sprouting in nodal explants. The combination of 4.4 μM BA and 2.2 μM thidiazuron (TDZ) was found to be the most suitable growth regulator for obtaining the highest percentage of nodal segment sprouting (74%–75%), the number of secondary shoots per primary shoot (two or three), the shoot length (5–6 cm), the number of new nodal segments generated per active explant (four or five), and the multiplication coefficient (3.5) within 6 weeks. Repeated subculturing of nodal explants obtained from shoot cultures enabled continuous production of healthy axillary shoots. At the end of the sixth passage, about 90% of nodal explants produced five or six healthy green shoots, each being about 6.6 cm long with six or seven nodes. Multiplication coefficient was also increased from the first subculture (5.4) to the sixth subculture (8.3). The best rooting response was achieved on solidified half-strength MS medium supplemented with 4.9 μM indole-3-butyric acid (IBA). About 70% of the micropropagated plantlets were established successfully in 20-cm pots containing a mixture of soil and farmyard manure (4 : 1 ratio) and formed new leaflets.     

Separation of pair housed roosters is associated with transient increased corticosteroid excretion

Immunoreactive corticosterone and corticosterone metabolites (ICCM) were quantified in excreta of permanently single housed (n = 10) and permanently pair housed (n = 20) roosters. The pair housed roosters were separated and single housed, and ICCM were quantified in the droppings before and during 15 days after separation. There was no statistically significant difference in ICCM excretion in the droppings between the permanently single or pair housed roosters. After separation, however, the previously pair housed roosters showed a significantly transient elevated excretion of ICCM in droppings the second day after separation indicating that the separation and relocation is associated with an activation of the hypothalamic-pituitary-adrenal axis.The excretion of ICCM in droppings was not correlated to the concentration of ICCM in droppings. It is thus important that excretion of ICCM be expressed as amount excreted per time unit since the total excretion is dependant on both concentration of ICCM and amount of droppings produced.     

Porphyrin-sensitized solar cells with cobalt (II/III)-based redox electrolyte exceed 12 percent efficiency

The iodide/triiodide redox shuttle has limited the efficiencies accessible in dye-sensitized solar cells. Here, we report mesoscopic solar cells that incorporate a Co((II/III))tris(bipyridyl)-based redox electrolyte in conjunction with a custom synthesized donor-π-bridge-acceptor zinc porphyrin dye as sensitizer (designated YD2-o-C8). The specific molecular design of YD2-o-C8 greatly retards the rate of interfacial back electron transfer from the conduction band of the nanocrystalline titanium dioxide film to the oxidized cobalt mediator, which enables attainment of strikingly high photovoltages approaching 1 volt. Because the YD2-o-C8 porphyrin harvests sunlight across the visible spectrum, large photocurrents are generated. Cosensitization of YD2-o-C8 with another organic dye further enhances the performance of the device, leading to a measured power conversion efficiency of 12.3% under simulated air mass 1.5 global sunlight.     

Future Cereal Starch Bioengineering: Cereal Ancestors Encounter Gene Technology and Designer Enzymes

The importance of cereal starch production worldwide cannot be overrated. However, the qualities and resulting values of existing raw and processed starch do not fully meet future demands for environmentally friendly production of renewable, advanced biomaterials, functional foods, and biomedical additives. New approaches for starch bioengineering are needed. In this review, we discuss cereal starch from a combined universal bioresource point of view. The combination of new biotechniques and clean technology methods can be implemented to replace, for example, chemical modification. The recently released cereal genomes and the exploding advancement in whole genome sequencing now pave the road for identifying new genes to be exploited to generate a multitude of completely new starch functionalities directly in the cereal grain, converting cereal crops to production plants. Newly released genome data from cereal ancestors can potentially allow for the reintroduction of cereal traits including, for example, health‐promoting carbohydrates that may have been lost during domestication. Raw materials produced in this manner can be processed by clean enzyme‐assisted techniques or thermal treatment in combination to further functionalize or stabilize the starch polymers. Importantly, such products can be multifunctional in the sense of combined food/material or food/pharma purposes, for example, edible plastics, shape memory materials, and cycloamylose carriers and stabilizers for diverse bioactives.     

Characterization of a cinnamoyl derivative from broccoli (Brassica oleracea L. var. italica) florets

A new intact glucosinolate Cinnamoyl derivative [6'-O-trans-(4″- hydroxy cinnamoyl)-4-(methylsulphinyl) butyl glucosinolate] (A) has been isolated from Broccoli (Brassica oleracea L. var. italica) florets. The compound was isolated and characterized by LC, MS-ESI, FTIR, ¹H and ¹³C NMR as well as ¹H-¹H COSY, DEPT 135° spectrometric experiments.     

Adaptive changes in the patterns of carbohydrate metabolites in blood,liver, muscle and heart tissues of Sarotherodon mossambicus (Peters) exposed to the carbamate fungicide ziram

Adaptive changes in the levels of carbohydrate metabolites, glucose, glycogen and lactic acid, were studied in a freshwater edible fish, Sarotherodon mossambicus exposed to a carbamate fungicide, ziram. Based on the results obtained, it was concluded that the fish showed (i) adaptive utilization of stored glycogen, particularly in liver tissue; (ii) adaptive accumulation of glycogen in muscle and heart tissues, probably by glyconeogenesis and (iii) adaptive mechanism of operation of ‘diving syndrome’, to meet the stress of the pollutant under sub-lethal exposure. © 1998 SCI.     

Dietary biotin requirement determined for Indian catfish, Heteropneustes fossilis (Bloch), fingerlings

Triplicate groups of Indian catfish, Heteropneustes fossilis (Bloch), fingerlings (average wet weight 3.55 ± 0.03 g) were fed semi-purified diets containing six levels of biotin (0, 0.086, 0.26, 0.86, 2.5 and 4.3 mg kg⁻¹ diet) for 15 weeks. After 42 days of feeding, fish fed the control (no biotin) diet had developed severe deficiency signs characterized by convulsions, heavy mortality, listlessness, poor feed conversion and feed intake, dark skin colour, tetanus and weight loss. None of these signs was seen in fish fed biotin-supplemented diets. Among all the biotin-supplemented diets, percentage weight gain was significantly highest for fish fed the diet supplemented with 0.26 mg of biotin kg⁻¹ and significantly lowest for fish fed the diet supplemented with 0.086 mg of biotin kg⁻¹. Feed conversion ratio (FCR) and protein efficiency ratio (PER) patterns were similar to that of percentage weight gain. The carcass protein and lipid contents were influenced by the dietary biotin up to fish fed 0.26 mg of biotin kg⁻¹. Significantly higher body biotin content, liver pyruvate carboxylase and acetyl CoA carboxylase activities were observed in fish fed biotin-supplemented diets than in fish fed the control diet. Broken-line analyses showed that the optimum dietary requirement for biotin for maximal weight gain, body biotin content, liver pyruvate carboxylase and acetyl CoA carboxylase activities was about 0.25 mg kg⁻¹. Associated liver pyruvate carboxylase and acetyl CoA carboxylase activities for normal growth ranged from 105 to 120 units mg⁻¹ protein and from 9 to 11 units mg⁻¹ protein respectively.     

Effect of wastewater irrigation on mineral com‐position of corn and sorghum plants in a pot experiment

Effect of wastewater irrigation was investigated on mineral composition of corn and sorghum plants in a pot experiment. The ranges for the concentration of different minerals in corn plants were 0.67–0.89% calcium (Ca), 0.38–0.58% magnesium (Mg), 0.09–1.29% sodium (Na), 0.81–1.87% nitrogen (N), 1.81–2.27% potassium (K), 0.12–0.16% phosphorus (P), 190–257 mg/kg iron (Fe), 3.5–5.6 mg/kg copper (Cu), 37.1–44.5 mg/kg manganese (Mn), 21.6–33.6 mg/kg zinc (Zn), 1.40–1.84 mg/kg molydbenum (Mo), 11.0–45.7 mg/kg lead (Pb), and 2.5–10.8 mg/kg nickel (Ni). Whereas for sorghum plants, the ranges were: 0.56–0.68% Ca, 0.19–0.32% Mg, 0.02–0.27% Na, 0.69–1.53% N, 1.40–1.89% K, 0.10–0.14% P, 190–320 mg/kg Fe, 3.8–6.0 mg/kg Cu, 29.2–37.6 mg/kg Mn, 21.1–29.9 mg/kg Zn, 2.2–3.7 mg/kg Mo, 12.3–59.0 mg/kg Pb, and 2.5–15.2 mg/kg Ni. Heavy metals such as cobalt (Co) and cadmium (Cd) were below detection limits at mg/kg levels. The concentrations of Ca, N, K, P, Cu, and Mn in corn plants were in the deficient range except for Mg, Fe, Zn, and Al. The concentrations of Ca, N, P, K, Cu, Mn, Mg, and Zn in sorghum plants were in the deficient range except for Fe and aluminum (Al). The analysis of regression indicated a strong interaction between Pb, Ni, Ca, and Fe in corn and sorghum plants. In conclusion, waste water irrigation did not increase mineral concentrations of either macro‐ and micro‐elements or heavy trace metals in corn and sorghum plants to hazardous limits according to the established standards and could be used safely for crop irrigation.