Evaluation of the potential of fungal and plant laccases for active-packaging applications

Laccases from Trametes versicolor (TvL), Myceliophthora thermophila (MtL), and Rhus vernicifera (RvL) were investigated with regard to their potential utilization as oxygen scavengers in active packages containing food susceptible to oxidation reactions. The substrate selectivity of the laccases was investigated with a set of 17 reducing substrates, mainly phenolic compounds. The temperature dependence of reactions performed at low temperatures (4-31 °C) was studied. Furthermore, the laccases were subjected to immobilization in a latex/clay matrix and drying procedures performed at temperatures up to 105 °C. The results show that it is possible to immobilize the laccases with retained activity after dispersion coating, drying at 75-105 °C, and subsequent storage of the enzyme-containing films at 4 °C. TvL and, to some extent, MtL were promiscuous with regard to their reducing substrate, in the sense that the difference in activity with the 17 substrates tested was relatively small. RvL, on the other hand, showed high selectivity, primarily toward substrates resembling its natural substrate urushiol. When tested at 7 °C, all three laccases retained >20% of the activity they had at 25 °C, which suggests that it would be possible to utilize the laccases also in refrigerated food packages. Coating and drying resulted in a remaining enzymatic activity ranging from 18 to 53%, depending on the drying conditions used. The results indicate that laccases are useful for active-packaging applications and that the selectivity for reducing substrates is an important characteristic of laccases from different sources.     

Genetic analysis of juvenile growth and carcass traits in a full diallel mating in selected colored broiler lines

The juvenile growth and carcass traits were evaluated in a 4 × 4 full diallel crossing involving four colored broiler chicken lines viz., Naked neck (NN), Dwarf, Punjab Broiler-1 (PB-1), and Punjab Broiler-2 to study the performance and crossbreeding parameters. The data on 2,280 chicks were analyzed using least squares techniques to assess the effect of genetic group, and the significant traits were further analyzed for crossbreeding parameters. Genetic group had significant influence on the body weights and carcass traits. The cross of PB-1 × NN recorded significantly (p ≤ 0.05) higher body weight at 6 weeks of age. The data revealed that general combining ability (GCA), specific combining ability (SCA), maternal ability (MA), sex-linked effect (SE), and purebred effects significantly influenced the growth and carcass traits in the broiler crosses. The crossbred PB-1 × NN showed positive heterosis for growth as well as carcass traits. The results suggest that GCA, SCA, SE, and MA are important in the inheritance of the body weights and carcass traits indicating the presence of both additive and nonadditive genetic variation along with reciprocal effects. Therefore, pure line selection along with development of specialized sire and dam lines followed by crossing will improve the growth performance and benefit the poultry farmers. It is concluded that PB-1 as a male line and NN as a female line performed significantly higher, therefore, may be used for improving the performance of colored broilers.     

Cell cycle-dependent coupling of the calcitonin receptor to different G proteins.

Calcitonin is a calcium regulating peptide hormone with binding sites in kidney and bone as well as in the central nervous system. The mechanisms of signal transduction by calcitonin receptors were studied in a pig kidney cell line where the hormone was found to regulate sodium pumps. Calcitonin receptors activated the cyclic adenosine monophosphate (cAMP) or the protein kinase C (PKC) pathways. The two transduction pathways required guanosine triphosphate (GTP)-binding proteins (G proteins) (the choleratoxin sensitive Gs and the pertussis toxin sensitive Gi, respectively) and led to opposite biological responses. Moreover, selective activation of one or the other pathway was cell cycle-dependent. Therefore, calcitonin may induce different biological responses in target cells depending on their positions in the cell cycle. Such a modulation of ligand-induced responses could be of importance in rapidly growing cell populations such as during embryogenesis, growth, and tumor formation.     

Radiological physics characteristics of the extracted heavy ion beams of the bevatron

Studies of the depth-ionization properties and the biological effects of heavy ion beams produced at the bevatron have extended work previously done with less energetic beams from other sources. Results indicate that heavy ion beams are suitable for tumor therapy, studies relating to space biology, and fundamental radiobiology.     

Ultrastructural Alterations in the Gills of Labeo rohita Fingerlings Exposed to Thermal Extremes

This study aimed to determine the cellular alterations in the gill of Labeo rohita exposed to lethal temperature maxima (LT_Max) and lethal temperature minima (LT_Min) by means of transmission electron microscopy (TEM). Acclimation of advanced fingerlings of L. rohita was carried out at 26°C for 30 days. Acclimated fish were subjected to a constant rate of increase or decrease in temperature (0.3°C/min) until the LT_Max and LT_Min values were reached. Dissected gills were processed for TEM, both at the end of acclimation period at ambient temperature (26°C) and at lethal temperatures. Results indicated that at ambient temperature, the gill tissues appeared normal. However, significant changes were observed at lethal temperatures. The gill tissues at lethal temperature maxima showed severely damaged lamellae, with more vacuolated space. At lethal temperature minima, gill tissues showed increased density of mitochondria. Our prima‐facie report indicated that L. rohita exposed to lethal temperatures exhibited marked ultrastructural changes in the gills.     

Disturbances in Growth,Yield, Sucrose Concentration and Antioxidative Defense System by Excess Cobalt in Sugarcane

The aim of the study was to implicate induction of oxidative stress and antioxidative responses with the effects of cobalt excess on sugarcane plants. Sugarcane (Saccharum officinarium L.) cv. ‘CoS 99225’ grown in refined sand at excess cobalt i.e. 100, 200, 300, 400, and 500 μM. The effect of excess cobalt (>300 μM) was observed on sugarcane as interveinal chlorosis and necrotic spots in middle leaves. Later, affected leaves turned necrotic, dry, and withered. The toxicity of cobalt was also discernible on root weight, cane yield, reduced concentration of sucrose in cane juice, carotenoides, Hill reaction activity, chlorophylls, iron (Fe), relative water content, decreased activity of catalase in leaves, and increase in concentration of lipid peroxidation, phenols, sugars, starch, proline and higher activity of peroxidase, ascorbate peroxidase and superoxide didmutase and accumulation of cobalt in sugarcane leaves.     

The Influence of 1-Butanol and Trisodium Citrate Ion on Morphology and Chemical Properties of Chitosan-Based Microcapsules during Rigidification by Alkali Treatment

Linseed oil which has various biomedical applications was encapsulated by chitosan (Chi)-based microcapsules in the development of a suitable carrier. Oil droplets formed in oil-in-water emulsion using sodium dodecyl sulfate (SDS) as emulsifier was stabilized by Chi, and microcapsules with multilayers were formed by alternate additions of SDS and Chi solutions in an emulsion through electrostatic interaction. No chemical cross-linker was used in the study and the multilayer shell membrane was formed by ionic gelation using Chi and SDS. The rigidification of the shell membrane of microcapsules was achieved by alkali treatment in the presence of a small amount of 1-butanol to reduce aggregation. A trisodium citrate solution was used to stabilize the charge of microcapsules by ionic cross-linking. Effects of butanol during alkali treatment and citrate in post alkali treatment were monitored in terms of morphology and the chemical properties of microcapsules. Various characterization techniques revealed that the aggregation was decreased and surface roughness was increased with layer formation.     

Triterpenes from Adiantum lunulactum

The petrol extract of the whole plant of Adiantum lunuactum yielded a new hopane triterpenoid characterized as 6 alpha-acetoxy-16 beta,22-dihydroxy-3-ketoisohopane, along with the known 3beta,6 alpha,16 beta,22-tetrahydroxyisohopane (mollugogenol A). The structures were elucidated by spectral as well as chemical studies.