Food selection by Labeo Rohita (Ham.) and its feeding relationship with other major carps

Selectivity of food byLabeo rohita (Ham.) was studied in a stocking pond (Moat), by calculating an Electivity index (E) for each food organism as described byIvlev (1961). It was found thatL. rohita was definitely selective in its feeding. In case of fingerlings, there was a strong selection for zooplanktonic organisms (Arcella andDifflugia among protozoans,Keratella andBrachionus among rotifer andDaphnia andCyclops among crustaceans) and smaller algae (Cosmarium andClosterium among desmisd,Euglena andVolvox among phytoflagellates and algal spores and zygotes) while most of the phytoplanktonic organisms, belonging to green algae, diatoms and blue green algae, were avoided. In case of adults, a strong negative selection was observed for all zooplanktonic organisms and a strong positive selection for most of the green algae and diatoms (Ankistrodesmus, Zygnema, Spirogyra, Selenastrum, Pediastrum, Scenedesmus, Tetraspora, Stephanodiscus, Naviculla, Diatoma, Synedra andNitzchia). However, all blue green algae were avoided.The feeding relationship ofL. rohita with other major carps,Cirrhina mrigala (Ham.) andCatla catla (Ham.) was studied in two different habitats, pond and river. It was observed that in both habitats all three species were found to feed on almost similar types of food organisms, but the quantity of any food item eaten by adults differed markedly from one species to another and the food items which were dominant in one species, were of secondary importancce for the other two species. The adults ofL. rohita were found to feed mainly on phytoplankton and macrovegetation, the main food of adultC. mrigala was decayed organic matter, sand and mud supplimented by plankton, while the food of adultC. catla was chiefly composed of zooplankton, and some phytoplankton. Hence there was no true identity of feeding habits between the adults of any two species. However, there was an indication of competition for food between the fingerlings of all three species, because all of them feed mainly on zooplankton (Crustaceans, rotifers and protozoans). However, such feeding habits lasted a very short time only and as the fishes grew, their feeding habits diverged.     

Localization of a locus for Charcot-Marie-Tooth neuropathy type Ia (CMT1A) to chromosome 17

Phenotypic data for 71 genetic markers for members of five Caucasian kindreds were tested for linkage with the autosomal dominant mutations causing Charcot-Marie-Tooth (hereditary motor sensory) neuropathy type I, characterized by markedly reduced nerve conduction velocities. Lod score analysis gave no evidence of linkage to the closely linked chromosome 1 loci SPTA1-FY-F5-AT3 and APOA2. In contrast, these mutations were found to map closely (zeta = 10.828, theta = 0.0) to D17S58, an anonymous segment of DNA from 17p11.2-p11.1, and thus define the CMT1A locus. Segregation information data for an inferred recombinant offspring indicated that the CMT1A locus is probably proximal to MYH2, the locus encoding adult skeletal muscle myosin heavy polypeptide 2, which maps to 17p13. Analysis of the lod scores on a per kindred basis gave no evidence of genetic heterogeneity.     

Purification and characterization of a novel peroxidase from bitter gourd (Momordica charantia)

Peroxidase from bitter gourd was purified by three step purification scheme; ammonium sulphate fractionation, gel filtration and affinity chromatography. The enzyme was purified 42 fold with the retention of 67% of the initial activity. The enzyme exhibited its maximum activity at pH 5.6 and 40 degrees C. The enzyme retained half of its activity even after 1 h incubation at 60 degrees C. Molecular weight of the purified glycosylated bitter gourd peroxidase determined by Sephacryl S-100 and SDS-PAGE was 43 kDa. The stokes radius, diffusion coefficient and sedimentation coefficient of the purified peroxidase were 27.3 A, 8.17 x 10(-7) cm(2)/sec and 3.74 S, respectively. K(m) for o-dianisidine and ABTS were 1.3 and 4.9 mM, respectively. The activity of the enzyme was inhibited by sulfide, azide and L-cysteine. The carbohydrate content and sulfydryl groups of the enzyme were 25% (w/w) mass of the protein and 16 mmoles/mole of the protein, respectively.     

Occurrence and diversity of entomopathogenic fungi in cultivated and uncultivated soils in Pakistan

The distribution of entomopathogenic fungi in various geographical areas of Punjab, Pakistan, is poorly understood. The present study was planned to explore the occurrence and diversity of entomopathogenic fungi from soils collected from cultivated and non‐cultivated habitats. The detailed survey of different habitats (crop fields, fruits, vegetables, forests) was conducted to collect soil samples and the associated fungi were isolated using Galleria bait method. Among 210 soil samples, 168 fungal isolates were recovered and identified, with 98 from forests, 32 from vegetables, 30 from field crops and 8 from fruits. The major entomopathogenic fungi recovered from these samples were Beauveria bassiana, Metarhizium anisopliae, Paecilomyces lilacinus, B. brongniartii, P. chlamydosporia and Lecanicillium attenuatum. The diversity of entomopathogenic fungi was greater in soil samples from forests compared to crop fields, vegetables and fruits, respectively. The geographical attributes (altitude, longitude, latitude) greatly influenced the occurrence of entomopathogenic fungi with the highest number of isolates found from >600 m altitude, 33°–34′N latitude, and 73°74′E longitude from soil samples. The results of the surveys clearly indicated that the entomopathogenic fungi are distributed in the soils which may be used in successful IPM programs in future.     

Calcium alginate entrapped preparations of Aspergillus oryzae beta galactosidase: its stability and applications in the hydrolysis of lactose

Insoluble concanavalin A-beta galactosidase complex was obtained by using jack bean extract and this complex was crosslinked with glutaraldehyde, in order to maintain the integrity of complex in the presence of its substrate or products. Concanavalin A-beta galactosidase complex retained 92% of the initial enzyme activity whereas crosslinked complex showed 88% activity. Entrapment of concanavalin A-beta galactosidase complex into calcium alginate beads provided suitability to use this preparation in reactors. Temperature- and pH-optima of the various immobilized beta galactosidase preparations were the same as its soluble counterpart. Entrapped crosslinked concanavalin A-beta galactosidase complex retained more than 50% activity after 1h exposure with 4.0 M urea at room temperature. Moreover, entrapped crosslinked concanavalin A-beta galactosidase complex retained 81 and 62% of the original enzymatic activity in the presence of 5% calcium chloride and 5% galactose, respectively. Entrapped crosslinked concanavalin A-beta galactosidase complex preparation was more superior in the continuous hydrolysis of lactose in a batch process as compared to the other entrapped preparations. This entrapped crosslinked concanavalin A-beta galactosidase complex retained 95% activity after seventh repeated use and 93% of its original activity even after 2 months storage at 4 degrees C.     

Impact of heat stress responsive factors on growth and physiology of cotton (Gossypium hirsutum L.)

Molecular Biology Reports - Pakistan ranked highest with reference to average temperatures in cotton growing areas of the world. The heat waves are becoming more intense and unpredictable due to...     

Peroxidase mediated decolorization and remediation of wastewater containing industrial dyes: a review

In this article an effort has been made to review literature based on the role of peroxidases in the treatment and decolorization of a wide spectrum aromatic dyes from polluted water. Peroxidases can catalyze degradation/transformation of aromatic dyes either by precipitation or by opening the aromatic ring structure. Peroxidases from plant sources; horseradish, turnip, tomato, soybean, bitter gourd, white radish and Saccharum uvarum and microbial sources; lignin peroxidases, manganese peroxidases, vanadium haloperoxidases, versatile peroxidases, dye decolorizing peroxidases have been employed for the remediation of commercial dyes. Soluble and immobilized peroxidases have been successfully exploited in batch as well as in continuous processes for the treatment of synthetic dyes with complex aromatic molecular structures present in industrial effluents at large scale. However, recalcitrant dyes were also decolorized by the action of peroxidases in the presence of redox mediators.