Rheological,Physico-chemical,and Surface-Active Properties of Gelatin Extracted from Bigeye Tuna (Thunnus obesus) Skin Waste

ABSTRACT

In the present investigation, bigeye tuna (Thunnus obesus) skin waste was utilized for the extraction of gelatin. Physico-chemical, rheological, and surface-active properties of the obtained gelatin were assessed. Proximate compositional analysis of tuna skin gelatin recorded high protein content of 88.6% and low levels of fat and ash contents. The isoelectric point (IEP) of tuna skin gelatin was around 6.24. Amino acid profiling recorded a glycine [31.7%] higher proportion, followed by imino acids (hydroxyproline + proline) [18.4%], and alanine [12.2%]. The electrophoretic pattern of purified gelatin exhibited three major bands (β, α1, and α2) with wider molecular weight distribution in the range of 200–120 kDa. The Fourier Transform Infrared (FT-IR) spectra of gelatin also confirmed the bands corresponding to α helix, β sheet, and random coil structures. The rheological studies of tuna skin gelatin revealed Newtonian and shear thickening properties. The method of extraction and assessment of its characteristic properties could be useful in the field of formulation of functional foods, nutraceutical, and biomedical applications.     

Responses of phosphate solubilizing bacteria to qualitatively different fertilization in simulated and natural fish ponds

The growth of phosphate solubilizing bacteria (PSB) was examined inresponse to pond fertilization with poultry dropping (PD) (12,500 kgha^–1 y^–1), cattle manure (CM) (25,000 kg ha^–1 y^–1), inorganic fertilizer (IF) consisting of urea (10.83 kg ha^–1 y^–1) and single super phosphate (43.52 kg ha^–1 y^–1) and inorganic-organic mixed fertilizers (PD:CM:IF – 1:1:1) in simulated fish ponds under alluvial and laterite soil conditions as well as in natural pondslocated in alluvial soil zone. The high correlation between dissolved oxygenand density of PSB implied the contribution of the latter in the aerobicorganic decomposition. The PSB were maximal in the PD, and minimal in theIF treatments. The distribution pattern of PSB was related to theautochthonous C/N ratio and the N/P ratios of water. Relatively low C/N ratios caused greater abundance of PSB. Increased fish production in PD treatments was clearly due to increased primary productivity and higher zooplankton abundance resulting from nutrient-grazing-detritus-microbial-food chain complex pathways.     

Impact of Pollutant Elements on Vegetables Growing in Sewage-Sludge-Treated Soils

Samples from potato (Solanum tubersosum), cauliflower (Bropica Oleracu var. Botryhs), and cabbage (Brassica Olerace var. Capitela) and soil samples were collected from fields receiving sewage sludge loads for a long periods and were analyzed for their total concentration of chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), and cobalt (Co) in different plant parts and in soil samples. Estimation of these pollutant elements was also made in the extract of the rooting zone (soil) of these plants. The accumulation of pollutant elements was higher in roots than in leaves and shoots, whereas the soil nearer to the discharge point had the maximum DTPA-CaCl₂ extractable pollutant elements and their concentrations diminished with distance. In soil samples, accumulation of the pollutant elements occurred in the order Pb > Cr > Ni > Cd > Co. In vegetables, the rate of accumulation was in the order potato > cauliflower > cabbage. The growth of the vegetable plants on contaminated soil was depressed, young leaves showed marked chlorosis, and brown necrotic spots later developed on almost the entire foliage of plants. With increase in age, the affected leaves had a wilted look. The vegetables growing near the discharge point contained the maximum amounts of heavy metals, which were above toxic limits. Of these elements, the accumulation of Cr by potato was highest.     

Do Cover Crop And Soil-Mediated Legacy Influence Succeeding Wheat Production?

ABSTRACT

Biotic interaction of cover crops (CCs) can have a legacy effect on succeeding crops mediated by changes in nutrient dynamics. Depending on species, CCs influence nitrogen (N) dynamics by sequestering N and subsequent N release. Interactions of three CC species, Austrian Pea (Pisum sativum L.), winter rye (Secale cereal L.), and winter camelina (Camelina sativa L.), and three different soils were studied under greenhouse conditions on wheat (Triticum aestivum L.) grain yield and soil N availability. CCs were grown for two months and then incorporated, followed by the planting of wheat. CC biomass production ranged from 0.10 to 2.05 Mg ha^?1 in this order by species: Pea> Rye> Camelina. Biomass production by soil was in the order of Casselton>Ada>Minot. Succeeding wheat grain yield and grain N uptake was highest under pea in the order of pea>camelina>control>rye. Rye reduced grain yield and N uptake. Wheat yield ranged from 2.19 to 3.24 Mg ha^?1 depending on CC species-soil interaction. The N balance showed a 3–79% higher N surplus with the CCs. The N balance ranged from 78 kg N ha^?1 for the control to 140 kg N ha^?1 for pea. N surplus was greater for a pea in all soils, indicating pea can be regarded as an effective cover that can efficiently recycle N and provide additional agronomic benefits. Greater N balance with CCs shows that CCs can increase the amount of N accounted for in the system, which can significantly affect the N dynamics throughout the growing season.     

On-farm comparisons of soil organic carbon under no-tillage and chisel-plow systems

Purpose: Role of no-tillage (NT) in soil conservation has been already established but its influence on soil organic carbon (SOC) is still under debate.

Materials and methods: Three paired sites, with NT and chisel-plow (CT) fields adjacent to each other were selected for this study. Fields were under the same tillage practices for more than 20 years. Fields were sampled up to 90?cm depth to determine SOC and different C pools based on soil CO₂ flux during 86?d of incubation.

Results and conclusion: Significant differences in SOC and its pools were limited within the surface 0–15?cm depth only. Profile SOC did not vary between NT and CT. Tillage had a significant influence on soil C pools but the effect was not consistent across sites.     

Effects of forcing,etiolation and indole butyric acid on rooting of cuttings of Artocarpus heterophyllus Lam.

Rooting of cuttings of jackfruit (Artocarpus heterophyllus Lam.) has been successfully induced through forcing of shoots, etiolation and application of indole butyric acid (IBA) under mist spray. Maximum rooting (84%) and maximum survival (50–75%) were obtained with the forced and etiolated shoots treated with 5000 mg/l IBA. The next best treatment was the forced and etiolated shoots treated with 10 000 mg/l IBA, which was somewhat similar to forced, non-etiolated shoots treated with 5000 mg/l IBA. In the control without IBA no success was obtained even under forcing and etiolation.     

Use of RAPD-PCR for genetic analysis of Nicobari fowl of Andamans

1. The present study was conducted to estimate genetic relatedness among Nicobari fowls (Brown, Black and White) and an exotic bird (White Leghorn) using random amplified polymorphic DNA (RAPD) polymorphism. 2. A total of 25 decamer primers were screened among all the breeds of which 24 primers amplified the genomic DNA, generating 2000 to 200 bp bands. Ten primers generated reproducible and distinct RAPD profiles and were used for further analysis. 3. A total of 94 bands were amplified and 30 polymorphic bands (32%) were produced. The number of polymorphic loci ranged from 1 to 5 with an average of 3.0. 4. Among the native breeds Brown Nicobari showed higher genetic similarity (0.85) than Black Nicobari (0.80) and White Nicobari fowl (0.82). 5. Brown Nicobari showed high genetic similarity with Black Nicobari (0.87 +/- 0.029); least similarity was between White Nicobari and White Leghorn (0.77 +/- 0.028). 6. The RAPD profile of all Nicobari fowls on amplification with the primers PBG5 and PBA12 showed specific bands of molecular size 1050 and 785 bp, respectively. 7. The native breeds showed the least genetic distance with each other while White Leghorn appeared to be most distant from the native breeds.     

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.