Optimized protocol for the pilot-scale preparation of fungal cellulase

Summary A 25-l scale protocol is devised for the optimal secretion and recovery of fungal cellulase. Using a selected higher yieldingTrichoderma viride SMC strain, a protocol consisted of: a) an optimized production medium rich in microcrystalline cellulose (MCC), fortified with 1% (w/v) ammonium sulphate, 0.5% (w/v) soybean flour, 0.1% (v/v) Tween-80 and other trace nutrients; b) optimized physical parameters of production, such as an inoculum containing a homogeneous suspension of 6×10⁷ conidia per 1,28±1°C, pH 4.0±0.5, 300±20 rpm, 11000±1000 l/h aeration, and 170–220 h duration; c) optimal recovery through a filter press (450 l/h rate of filtration) followed by precipitation with 2.5–3.0 volumes of acetone (15°C and basket centrifugation (27°C, 1700 rpm)); and d) vacuum drying (35°C, 4–6 h). This afforded 70% recovery of cellulase in the form of white fluffy powder containing 20000±2000 carboxy methyl cellulase and 1000±50 units filter paperase per g activities, with raw material cost of US$ 8–10 per million carboxy methyl cellulase units. During storage for 18 months at 4°C, ambient temperature and 37°C, the cellulase preparation was found to retain 100, 75 and 60% of its initial activity, respectively.     

Sciatin Is a Transferrin-Like Polypeptide

Abstract: Sciatin, an acidic glycoprotein from chicken sciatic nerve, has myotrophic effects on avian skeletal muscle cells in culture. As sciatin was found to have certain structural similarities to transferrin, we further investigated the physicochemical characteristics of sciatin in order to determine the relationship between these two proteins. Sciatin was found to be strikingly similar to ovotransferrin in amino acid composition. In addition, amino acid sequence analysis revealed that sciatin and ovotransferrin had identical amino-terminal sequences for at least the first 20 amino acid residues. Chicken ovotransferrin, but not human serum transferrin, cross-reacted with rabbit antisciatin antibodies upon rocket immunoelectrophoresis and double immunodiffusion in agar. In addition, in the presence of bicarbonate, sciatin bound approximately 2 mol ferrous iron/mol protein. Using the purification procedure developed for sciatin, we purified a protein from chicken serum that cross-reacted with antisciatin serum, migrated at a position identical to that of sciatin or ovotransferrin on two-dimensional gel electrophoresis, had an amino composition very similar to ovotransferrin and sciatin, and had myotrophic effects on cultured muscle cells. From these data, we conclude that sciatin is a growth-promoting polypeptide closely related in structure to transferrin.     

Shell-banding polymorphism of the land snail Xeropicta vestalis along the coastal plain of Israel

Along the coastal plain of Israel, shell darkness of the polymorphic land snail Xeropicta vestalis is positively related to the extent of perennial vegetation. It is not related to rain, temperature, geographic position or darkness of the ground.
White shells reflect more radiation than dark ones do, and therefore in Israel's coastal plain, where solar radiation is very strong, they are favoured. Perennial vegetation, where it occurs, shields the snails from the sun by absorbing radiation, so that snails amongst them can afford to be darker, and thus more cryptic. Hence, the more perennial vegetation in the habitat, the darker the shells.
Also during the Pleistocene, when temperatures were 5–10°C lower than today, the shells of the coastal plain were as pale as recent ones are. The distribution of a snail-predator, Gerbillus allenbyi , which is restricted to sandy biotopes where perennial bushes occur, and which was absent from Israel during the Pleistocene, could perhaps explain the distribution of X. vestalis morphs, both today and in the past.     

A phylogenetic analysis of the land plants

Phylogenetic systematics (cladistics) is a theory of phylogeny reconstruction and classification widely used in zoology. Taxa are grouped hierarchically by the sharing of derived (advanced) characters. The information is expressed in a cladogram, a best estimate of a phylogeny. Plant systematists generally use a phenetic system, grouping taxa on overall similarity which results in many groups being formed, at least in part, on the basis of shared primitive characters.
The methods of phylogenetic systematics are used to create a preliminary cladogram of land plants. The current classification of land plants is criticized for its inclusion of many groups which are not monophyletic.
Objections to the use of phylogenetic systematics in botany, apparent convergences within major groups and frequent hybridization, are shown to be invalid. It is concluded that cladistic analysis presents the best estimate of die natural hierarchy of organisms, and should be adopted by plant systematists in their assessment of plant interrelationships.     

An ecological study of the rare rotifer species Trochosphaera solstitialis (Thorpe 1893) and the first report of the male

An ecological study of the rotifer species Trochosphaera solstitialis (Thorpe, 1893) was conducted for a period of eight months in a temporary pond in eastern Texas, U.S.A. The pond was found to be environmentally stressed and contained large amounts of decomposing vegetation. Physico-chemical factors contributing to the stressed conditions were low dissolved oxygen concentrations, low pH values, high ammonia concentrations, and high color values caused by large concentrations of iron, tannin and lignin. Large concentrations of iron, tannin, and lignin seem to be highly correlated with T. solstitialis populations. Physicochemical conditions probably eliminated predators of the rotifer, such as fish. Males of T. solstitialis were observed which never left the body cavity of the female. Males probably do not feed with an apparent rudimentary digestive system.     

The influence of thick floating vegetation (Water hyacinth: Eichhornia crassipes) on the physico — chemical environment of a fresh water wetland

Measurements made in fresh water wetland have shown that temperature, pH, dissolved oxygen and bicarbonate alkalinity in the hyacinth infested area were lower, but dissolved free carbon dioxide concentration was excitingly greater than in the open water area. This extreme hypoxic and hypercarbic condition of hyacinth covered areas was caused by the thick coverage of Eichhornia crassipes which was crucial for the composition of the characteristic flora and fauna.     

Biological properties of human melanoma cells in culture

Summary Three human melanoma cell lines derived from one primary and two metastatic tumors from three different patients were characterized for growth properties usually associated with malignant transformation; these include cell morphology, growth rate, saturation density, growth in semisolid media, colony-forming ability on contact-inhibited monolayers of normal fibroblasts and epithelial cells, and tumorigenicity in immunosuppressed mice. Variations in expression of aberrant properties were evident among the lines. One of the metastatic lines satisfied all the parameters of malignancy tested and the other showed a number of these properties, whereas the primary essentially fulfilled only one. These results suggest that cultured melanoma cells reflect the clinical variability often observed among melanoma patients and the metastatic melanoma seems to display a higher degree of malignant transformation than the primary. THis work was supported in part by USPHS Grant No. 5 T01 AI00332-06 from the National Institutes of Health, Contract E73-2001-N01-CP-3-3237 from the Virus Cancer Program of the National Cancer Institute, and USPHS Grant No. 0H00714-02 from the National Institute for Occupational Safety and Health.     

Blood parameters of two hill stream cobitids in relation to their habitat

The blood of two fresh water cobitids — Botia lohachata, an exclusive water breathing form and Lepidocephalus guntea a dual breather, — showed a comparatively higher range of Hb (16.0–19.0 g%), Hct (50.0–61.1%) and number of RBC (2.71–6.7 millions/mm³) than many other water and air breathing fishes. Significant sexual difference exists in these characteristics (P > 0.05).The impact of life in oxygen depleted water, also inhabited by L. guntea as a result of its air breathing habit, is well reflected in its greater RBC size (11.86 × 8.66 µm) and their larger surface area (83.96 µm²) compared to that of Botia (53.16 µm²). The smaller size (9.92 × 6.45 µm) and consequently greater number of erythrocytes (4.67 millions/mm³) in Botia, are related to its active mode of life in the swiftly flowing water of hilly rivers. Though the higher nucleo-cytoplasmic ratio of 1 : 5.2 in Botia and 1 : 6.9 in Lepidocephalus suggest a slower red cell metabolism, the greater number of erythrocytes seems to have compensated for their active mode of life.     

SPATIAL FLOWER PARAMETERS AND INSECT SPATIAL VISION

The present article reviews recent and older literature on the spatial parameters that flowers display, as well as on the capacities of anthophilous insects to perceive and use these parameters for optimizing their foraging success. Although co-evolution of plants and pollinators has frequently been discussed with respect to floral colours and insect colour vision, it has rarely been assessed with respect to insect spatial vision and spatial floral cues, such as shape, pattern, size, contrast, symmetry, spatial frequency, contour density and orientation of contours. This review is an attempt to fill this gap. From experimental findings and observations on both flowers and insects, we arrive at the conclusion that all of the spatial and spatio-temporal parameters that flowers offer are relevant to the foraging task and are tuned to the insect's visual capacities and visually guided behaviour. We try, in addition, to indicate that temporal cues are closely related to spatial cues, and must therefore be included when flower–pollinator interactions are examined. We include results that show that colour vision and spatial vision have diverged over the course of evolution, particularly regarding the processing of spatio-temporal information, but that colour vision plays a role in the processing of spatial cues that are independent of temporal parameters. By presenting this review we hope to contribute to closer collaboration among scientists working in the vast fields of botany, ecology, evolution, ethology and sensory physiology.