Standardization of polyphosphate treatment for tiny prawns (Parapenaeopsis stylifera) with special reference to its rehydration capacity and organoleptic quality

In the present study, an attempt was made to explore the benefits of polyphosphate for enhancement of dried prawn (Parapenaeopsis stylifera) quality commercially known as "sode" in Maharashtra coast. Dip treatment in polyphosphate solution at different concentrations (viz., 3, 5, 7 and 10%) was given to pealed and no deveined P. stylifera for different durations (viz., 1, 2, 3, 4 and 5 min). Treated prawns were dried and subjected to rehydration capacity test and organoleptic evaluation. Among the different treatments, rehydration capacity was found to increase with the increased duration and concentration of treatment. Tiny prawns treated with sodium tripolyphosphate solution at the rate of 5% concentration for 5 minutes showed an increase in pH from acidic to alkaline, and had better quality with respect to rehydration capacity and textural attributes as compared to other concentrations and durations of polyphosphate treatment.

VISUALIZATION OF THE CHROMOSOME SCAFFOLD IN A PRIMITIVE EUKARYOTE DINOFLAGELLATE CRYPTHECOAINIUM-COHNII

The chromosome scaffolds in higher eukaryotic nuclei have been described elsewhere. But it is unknown when they evolved. The dinoflagellates are the primitive organisms that may be the intermediate between prokaryotes and eukaryotes. Combining chromosome scaffold preparation methods with embedment-free section microscopy, we demonstrate that the dinoflagellate Crypthecodinium cohnii chromosome retains a protein scaffold after the depletion of DNA and soluble proteins. This scaffold preserves the morphology characteristic of the chromosome. Two-dimensional electrophoreses show that the chromosome scaffolds are mainly composed of acidic proteins. Our results suggest that a framework similar to the chromosome scaffold in the mammalian cell appeared in the primitive eukaryote. We propose that the chromosome scaffold possibly originated from the early stages of eukaryote evolution.

Hydrographical conditions and benthic assemblages in the Suez Gulf, Egypt

The coastal development and human activities along the Suez Gulf leading to sedimentation, degrade the quality of water, disturbing the natural structure and functions of aquatic communities. The Suez Gulf is a large semi-closed area with a 346 km long coastline on the western beach side. The prevailing physicochemical parameters in shallow intertidal waters were measured seasonally over the year. Benthic faunas in the sampling sites were studied indicating their regional distribution in relation to the impact of different environmental parameters in the intertidal region. The concentration of copper in seawater reached high level at St. IV (4.57 ug/1), which is exposed to sewage and petroleum hydrocarbons. The grain size of the sediment is a determining factor for the organic carbon concentration and the sandy substrate enhances organic matter degradation processes. A large number of oil fields are present along the western coast of the Suez Gulf, therefore, cadmium and organic matter appeared to be high. The values of pH did not vary greatly among the different sampling sites. It was high at EI-Ein, El-Sukhna and Ras-Shukeir due to the disposal of mainly acidic sewage and industrial effluents of the two stations Adabiya and Ras-Gharib respectively. The macrobenthos included 71 species embraced mainly from Mollusca (53.5% Gastropoda and 12.7% Bivalvia) and the other invertebrates included 7 groups namely, Rhizostoma, Polychaeta, Cirripedia, Amphipoda, Isopoda, Decapoda and Echinodermata. The distribution of benthos is affected by the temperature and salinity of seawater. The concentration of organic matter in seawater and in sediments in shallow waters shows high values in the central part of the Gulf of Suez.

Euglenophytes in aquaculture ponds - their ecology and role in fish production

The ecology of euglenophytes and their role in fish production were studied in 12 small earthen ponds beside the Faculty of Fisheries, BAU from July to November 2001. Four experiments each with three replications were conducted and those were as follows: pond treated with both poultry droppings and cowdung (T1); pond treated with only poultry droppings (T2), and pond treated with only poultry droppings (T3), while the control (T4) where no organic manure was applied. Fishes comprising of rohu (Labeo rohita), catla ( Catla catla), mrigal ( Cirrhinus cirrhosus), silver carp (Hypophthalmichthys molitrix) and silver barb (Barbonymus gonionotus) were stocked at the same stocking density of (10,621 fish/ha) and species ratio (1:1:1:2:2). The stocked fishes were fed with a common supplemental diet comprising of mustard oil cake and rice polish (1:1) at the rate of 4% of body weight per day. The highest cell density of euglenophytes was found in the ponds of T2, where poultry droppings were applied and was followed by T1, where both poultry droppings and cow dung were applied. Higher temperature, nitrate-nitrogen, phosphate-phosphorous and acidic pH were found to be conducive for the bloom of noxious euglenophytes. The bloom was found to use up most of the nutrients resulting in reduction in the growth of beneficial plankters and planktivorous fishes. The SGR (%/day) of catla, rohu and mrigal was lower during heavy bloom period while that of silver carp and silver barb were comparatively higher. The mortality of fishes in a pond of T2 during the bloom period was possibly due to formation of anoxic situation (dissolved oxygen level as low as 0.34 mg/1) in the early mornings through bacterial decomposition of the settled dead individuals or due to the combined effect of anoxic situation and toxic metabolite secretion by the euglenophytes.

A novel family of antimicrobial peptides from the skin of Amolops loloensis

While conducting experiments to investigate antimicrobial peptides of amphibians living in the Yunnan-Sichuan region of southwest China, a new family of antimicrobial peptides was identified from skin secretions of the rufous-spotted torrent frog, Amolops loloensis. Members of the new peptide family named amolopins are composed of 18 amino acids with a unique sequence, for example, NILSSIVNGINRALSFFG. By BLAST search, amolopins did no show similarity to any known peptides. Among the tested microorganisms, native and synthetic peptides only showed antimicrobial activities against Staphylococcus aureus ATCC2592 and Bacillus pumilus, no effects on other microorganisms. The CD spectroscopy showed that it adopted a structure of random combined with beta-sheet in water, Tris-HCl or Tris-HCl-SDS. Several cDNAs encoding amolopins were cloned from the skin cDNA library of A. loloensis. The precursors of amolopin are composed of 62 amino acid residues including predicted signal peptides, acidic propieces, and mature antimicrobial peptides. The preproregion of amolopin precursor comprises a hydrophobic signal peptide of 22 residues followed by an 18 residue acidic propiece which terminates by a typical prohormone processing signal Lys-Arg. The preproregions of precursors are very similar to other amphibian antimicrobial peptide precursors but the mature amolopins are different from other antimicrobial peptide families. The remarkable similarity of preproregions of precursors that give rise to very different antimicrobial peptides in distantly related frog species suggests that the corresponding genes form a multigene family originating from a common ancestor. (C) 2008 Elsevier Masson SAS. All rights reserved.

The first antimicrobial peptide from sea amphibian

The crab-eating frog, Rana cancrivora, is one of only a handful of amphibians worldwide that tolerates saline waters. It typically inhabits brackish water of mangrove forests of Southeast Asia. A large amount of antimicrobial peptides belonging to different families have been identified from skins of amphibians inhabiting freshwater. No antimicrobial peptide from sea amphibians has been reported. In this paper, we firstly reported the antimicrobial peptide and its cDNA cloning from skin secretions of the crab-eating frog R. cancrivora. The antimicrobial peptide was named cancrin with an amino acid sequence of GSAQPYKQLHKVVNWDPYG. By BLAST search, cancrin had no significant similarity to any known peptides. The cDNA encoding cancrin was cloned from the cDNA library of the skin of R. cancrivora. The cancrin precursor is composed of 68 amino acid residues including a signal peptide, acidic spacer peptide, which are similar to other antimicrobial peptide precursors from Ranid amphibians and mature cancrin. The overall structure is similar to other amphibian antimicrobial peptide precursors although mature cancrin is different from known peptides. The current results reported a new family of amphibian antimicrobial peptide and the first antimicrobial peptide from sea amphibian. (c) 2007 Elsevier Ltd. All rights reserved.

Cloning and characterization of the first amphibian bradykinin gene

More than ten bradykinin-related peptides and their cDNAs; have been identified from amphibians, but their genes are unknown. In present study, four cDNAs encoding one, two, four and six copies of bradykinin-related peptides were cloned from the frog (Odorrana grahami) skin cDNA library, respectively. Three bradykinin-related peptides (bradykinin, Thr6-bradykinin, Leu5Thr6-bradykinin) were deduced from these four cDNA sequences. Based on the cDNA sequence, the gene sequence encoding an amphibian bradykinin-related peptide from O. grahami was determined. It is composed of 7481 base pairs including two exons and two introns. The first exon codes signal peptide and the second exon codes acidic spacer peptide and Thr6-bradykinin. The promoter region of the bradykinin gene contains several putative recognition sites for nuclear factors, such as SRY, GATA-1, LYF-1, DeltaE, CDXA, NKX-2.5, MIF1 and S8. The current work may facilitate to understand the regulation and possible functions of amphibian skin bradykinin-related peptides. (C) 2009 Elsevier Masson SAS. All rights reserved.

Peptidomics and genomics analysis of novel antimicrobial peptides from the frog, Rana nigrovittata

Much attention has been paid on amphibian peptides for their wide-ranging pharmacological properties, clinical potential, and gene-encoded origin. More than 300 antimicrobial peptides (AMPs) from amphibians have been studied. Peptidomics and genomics analysis combined with functional test including microorganism killing, histamine-releasing, and mast cell degranulation was used to investigate antimicrobial peptide diversity. Thirty-four novel AMPs from skin secretions of Rana nigrovittata were identified in current work, and they belong to 9 families, including 6 novel families. Other three families are classified into rugosin, gaegurin, and temporin family of amphibian AMP, respectively. These AMPs share highly conserved preproregions including signal peptides and spacer acidic peptides, while greatly diversified on mature peptides structures. In this work, peptidomics combined with genomics analysis was confirmed to be an effective way to identify amphibian AMPs, especially novel families. Some AMPs reported here will provide leading molecules for designing novel antimicrobial agents. (C) 2009 Elsevier Inc. All rights reserved

Five novel antimicrobial peptides from skin secretions of the frog, Amolops loloensis

While investigating antimicrobial peptide diversity of Amolops loloensis, five novel antimicrobial peptides belonging to two families were identified from skin secretions of this frog. The first family including two members is esculentin-2-AL (esculentin-2-ALa and -ALb): the second family including three members is temporin-AL (temporin-ALd to -ALf). The family of esculentin-2-AL is composed of 37 amino acid residues (aa); the family of temporin-AL is composed of 16, 13 and 10 aa, respectively. All of these antimicrobial peptides showed antimicrobial activities against tested microorganisms. cDNAs encoding precursors of esculentin-2-ALs and temporin-ALs were cloned from the skin cDNA library of A. loloensis. All the precursors share similar overall structures. There is a typical prohormone processing signal (Lys-Arg) located between the acidic propiece and the mature peptide. The antimicrobial peptide family of esculentin-2 is firstly reported in the genus of Amolops. Combined with previous reports, a total of four antimicrobial peptide families have been identified from the genus of Amolops; three of them are also found in the genus of Rana. These results suggest the possible evolutionary connection between the genera Amolops and Rana. (C) 2009 Elsevier Inc. All rights reserved.

Nutrient profile of pond water in north-eastern state of Tripura and impact of water acidity on aquaculture productivity

Physicochemical parameters of 31 fish pond water samples of Tripura were studied to ascertain the nutrient profile of acidic soil zone and the impact of water acidity towards aquaculture productivity. The pH was acidic (mean 6.63±0.44) with high Fe (mean1.04±0.40 mglˉ¹) and AI (mean 2.67±2.41 mglˉ¹) contents. These were mostly responsible for pond water acidity and poor productivity with low nitrogen, phosphate and total alkalinity. The study also showed strong negative relationship between water pH and redox potential (R²=0.5251). However, pH was positively significant with electrical conductivity. The roles of redox potential and electrical conductivity in water acidity were found highly important. Available calcium content was also found low (mean 2.91±2.96 mglˉ¹). Elevating level of pH of pond water could be the possible management practices in acidic water so that such unproductive water might be productive enough with higher phosphate and nitrogen levels for better biological production.

Improved handling and preservation of freshwater giant prawn, Macrobrachium rosenbergii for producing safe and wholesome products

Studies were undertaken to evaluate the quality changes in freshwater giant prawn, Macrobrachium rosenbergii during various storage conditions of handling and preservation and producing safe and quality products. The samples kept in ice immediately after catch with head-on and head-less condition were found to be acceptable for 6 days and 7 days, respectively. Delaying of icing considerably shortened the shelf-life. The pH value increased from 6.36 to 8.0 after 10 days in ice. The initial average TVB-N value of sample increased from below 10 mg/100 g to 25 mg/100 g with the lapse of storage period. The Ca++ ATPase activity in presence of 0.1M KCl slightly decreased at the end of 10 days of ice storage. Immediately after harvest, initial aerobic plate count (APC) was 2.88x10^6 CFU/g which gradually increased to 1.12x10^8 CFU/g after 6 days in ice storage and showed early signs of spoilage. Initial bacterial genera in the prawn iced at 0 hours were comprised of Coryneform (22.21 %), Bacillus (7.40%), Micrococcus (11.11 %), Achromobacter (48.14%), Flavobacterium/Cytophaga (7.40%), Pseudomonas (3.70%) and Aeromonas (3.70%). During ice storage Coryneforms and Bacillus were always dominating along with less prominent ones - Micrococcus, Achromobacter and Flavobacterium. Studies were conducted on the stability of myofibrillar protein of M. rosenbergii under different storage and pH conditions. The influence of a wide range of pH on the remaining Ca++ ATPase activity of M. rosenbergii muscle myofibrils after storage at -20°C for 2 days, at 0°C for 2 days and at 35°C for 30 minutes demonstrated that ATPase activities were lower in acidic and alkaline pH regions and the activity remained relatively high. Mg++ ATPase activities both in presence and absence of Ca++ remained high at neutral pH compared to those of acidic and alkaline region. The solubility of myofibrillar protein decreased gradually both in acidic and alkaline pH regions. The study also examined the bacteriological quality of freshly harvested M. rosenbergii, pond sediment and pond water from four commercial freshwater prawn farms at Fulpur and Tarakanda upazilas in the district of Mymensingh. The study included aerobic plate count (APC), total coliform count, detection, isolation and identification of suspected public health hazard bacteria and their seasonal variation, salt tolerance test, antibiotic sensitivity test of the isolates and washing effect of chlorinated water on the bacterial load in the prawn samples. APC in sediment soil and water of the farm and gill and hepatopancreas of freshly harvested prawns varied considerably among the farms and between summer and winter season. The range of coliform count in water, gill and hepatopancreas ranged between 6 - 2.8x10^2 CFU/ml, 1.2x10^2 - 3.32x10^2 CFU/g and 1.43x10^2 - 3.89 x10^3 CFU/g, respectively. No coliform was detected in pond sediment sample. Suspected health hazard bacteria isolated and identified from pond sediment, water, gill and hepatopancreas included Streptococcus, Bacillus, Escherichia coli, Klebsialla, Salmonella, Staphylococcus, Pseudomonas and Aeromonas. Bacillus, Salmonella and Staphyloccus [sic], and were found to be highly salt tolerant and capable of growing at 10% NaCl. The antibiotic discs with different concentration of antibiotics were used for the sensitivity test. The organisms were found to be most sensitive against Tetracyclin and Gentamycin.

Noxious euglenophytes bloom in fertilized fish ponds

A study was carried out in nine fertilized fish ponds under three treatments at Bangladesh Agricultural University, Mymensingh, Bangladesh, to record the influence of different fertilizers on noxious euglenophytes bloom. Some water quality parameters (viz., temperature, pH, phosphate-phosphorus, nitrate-nitrogen and chlorophyll-a) and phytoplankton populations were monitored at certain intervals. During the study period, three genera of euglenophytes such as Euglena, Phacus and Trachelomonas were recorded of which Euglena was most dominant. Significantly (p<0.05) higher cell density of euglenophytes was observed in the ponds treated with chicken manure followed by the ponds treated with both cow dung and chicken manures and the ponds treated with only cow dung. The higher cell density of euglenophytes was explained by acidic pH (around 6.5) and higher phosphate-phosphorus (1.37 mg/1) and nitrate-nitrogen (1.47 mg/I) concentrations. The population size of euglenophytes showed positive correlation with phosphate-phosphorus and nitrate-nitrogen concentration while negative with pH. Nutrient enrichment and acidic pH enhanced the growth of euglenophytes but reduced the growth of chlorophytes and bacillariophytes.

Feasibility study of biofuel production from freshwater fern, Azolla sp in Anzali Wetland

Production of bioethanol through acidic and enzymatic hydrolysis of aquatic Azolla sp., as a new source of bio-mass, has been performed, as a means to control increasing growth and reducing undesirable effects of this plant in Anzali lagoon. After sampling, drying and crushing, Azolla was hydrolyzed, using diluted acid and enzyme. Diluted acid hydrolysis was done using both autoclave and a high-pressure system (Batch Synth® Microwave synthesizer). The effects of temperature and time (in autoclave) and concentration of acid (in both) were compared. Cellubrix®, a ommercial cellulase source, was used for enzymatic hydrolysis process. The amounts of reducing sugars, glucose and furfural, released from hydrolyzate, were measured. To produce alcohol, Sacchromyces cerevisiae (to ferment sixcarbon sugars), Zygowilliopsis californica and Pichia stipitis (to ferment five-carbon and sixcarbon sugars) were used. Maximum amounts of glucose (4.83% w/w) and reducing sugars (14.15% w/w) were obtained using acid hydrolysis in autoclave. In the microwave oven, maximum glucose (5.04% w/w) and reducing sugars (13.27 w/w) were obtained at 180 and 200 °C, respectively. Under these conditions, maximum produced furfural was 1.54 g/L. The difference between amounts of furfural obtained from acid hydrolysis of Azolla in microwave oven compared to autoclave was statistically significant. Amounts of alcohol produced and its yields were 3.99 g/L and 33.13% for S. cerevisiae in 48 hours, 3.73 g/L and 30.45% for Pichia stipites in 48 hours, and 3.73 g/L and 30.45% for Z. californica in 24 hours after inoculation, respectively, with significant differences. Statistical comparison of results showed significant differences (P<0.05) in glucose production, at different conditions. Amounts of reducing sugars and glucose increased after optimization of levels of acid, time, and temperature. The overall optimum released sugar and glucose were obtained with 1.67% (w/v) acid using autoclave. Higher temperatures in microwave oven caused a significant increase (P<0.05) in furfural. Furfural severely inhibits fermentation. Hence, regarding the issues of energy consumption and time, amounts of inhibiting substances and sugar production, autoclave is found to be superior to the high temperature and pressure, generated in microwave oven, for hydrolyzing Azolla. Furthermore, given the amounts of Azolla in Anzali lagoon, it may be recommendable to use this plant as a biomass resource.

Properties of the proton-evoked currents and their modulation by Ca2+ and Zn2+ in the acutely dissociated hippocampus CA1 neurons

The characterization of acid-sensing ion channel (ASIC)-like currents has been reported in hippocampal neurons in primary culture. However, it is suggested that the profile of expression of ASICs changes in culture. In this study, we investigated the properties of proton-activated current and its modulation by extracellular Ca2+ and Zn2+ in neurons acutely dissociated from the rat hippocampal CA1 using conventional whole-cell patch-clamp recording. A rapidly decaying inward current and membrane depolarization was induced by exogenous application of acidic solution. The current was sensitive to the extracellular proton with a response threshold of pH 7.0-6.8 and the pH(50) Of 6.1, the reversal potential close to the Na+ equilibrium potential. It had a characteristic of acid-sensing ion channels (ASICs) as demonstrated by its sensitivity to amiloride (IC50 = 19.6 +/- 2.1 muM). Either low [Ca2+](0) or high [Zn2+](0) increased the amplitude of the current. All these characteristics are consistent with a current mediated through a mixture of homomeric ASIC1a and heteromeric ASIC1a + 2a channels and closely replicate many of the characteristics that have been previously reported for hippocampal neurons cultured for a week or more, indicating that culture artifacts do not necessarily flaw the properties of ASICs. Interestingly, we found that high [Zn2+] (>10(-4) M) slowed the decay time constant of the ASIC-like current significantly in both acutely dissociated and cultured hippocampal neurons. In addition, the facilitating effects of low [Ca2+](0) and high [Zn2+](0) on the ASIC-like current were not additive. Since tissue acidosis, extracellular Zn elevation and/or Ca2+ reduction occur concurrently under some physiological and/or pathological conditions, the present observations suggest that hippocampal ASICs may offer a novel pharmacological target for therapeutic invention. (C) 2004 Elsevier B.V. All rights reserved.

Cytochemical changes in the developmental process of Nostoc sphaeroides (cyanobacterium)

There are several apparent developmental stages in the life cycle of Nostoc sphaeroides Kutzing, an edible cyanobacterium found mainly in paddy fields in central China. The cytochemical changes in developmental stages such as hormogonia, aseriate stage, filamentous stage and colony in N. sphaeroides were examined using fluorescent staining and colorimetric methods. The staining of acidic and sulfated polysaccharides increased with development when hormogonia were used as the starting point. Acidic polysaccharides (AP) were most abundant at the aseriate stage and then decreased, while the sulfated polysaccharides (SP) were highest at the colony stage. Quantitatively, along the developmental process from hormogonia to colony, total carbohydrates first increased, then became stable, and then reached their highest level at the colony stage, while reducing sugars were highest at the hormogonia stage and then decreased sharply once development began. SP were not detectable in the hot water soluble polysaccharides (HWSP), and hormogonia had the lowest content of AP, while old colonies had the highest. The AP content of the aseriate stage, filamentous stage and young colony stage were very similar. The evolutionary relationships reflected in the developmental stages of N. sphaeroides are discussed.