Feruloyl esterase from aspergillus sp.: purification, properties, and action on natural substrates

An enzyme active toward the methyl ester of ferulic acid was isolated from the fungus Aspergillus sp. and purified to homogeneity using ion-exchange and hydrophobic chromatography. The molecular weight of the enzyme is 42 kD, and its pI is 3.7. The enzyme has a pH optimum in the range 4-6 and a temperature optimum in the range 40 to 60 degrees C. Using a number of synthetic and natural substrates, the enzyme was identified as a feruloyl esterase. The feruloyl esterase did not hydrolyze wheat straw. Ferulic acid was detected as a product of hydrolysis of wheat bran and sugar-beet pulp. Other products were also detected after sugar-beet pulp hydrolysis.     

Mitochondrial DNA sequence evolution in sharks: rates, patterns, and phylogenetic inferences

Abundant representation of sharks in the fossil record makes this group a superb system in which to investigate rates and patterns of molecular evolution and to explore the strengths and weaknesses of phylogenetic inferences from molecular data. In this report, the molecular evolution of the cytochrome b gene in sharks is described and the information related to results from phylogenetic analysis of the data evaluated in the light of a phylogeny derived independently of the molecular data. Across divergent lineages of sharks there is evidence for significant substitution rate variation, departure from compositional equilibrium, and substantial homoplasy; nevertheless, the signal of evolutionary history is evident in patterns of shared transversions and amino acid replacements.      

From the Bay of Naples to the River Don: the Campanian Ignimbrite eruption and the Middle to Upper Paleolithic transition in Eastern Europe

The Campanian Ignimbrite (CI) eruption, dated by ⁴⁰Ar/³⁹Ar and various stratigraphic methods to ca. 39,000 cal BP, generated a massive ash plume from its source in southern Italy across Southeastern and Eastern Europe. At the Kostenki-Borshchevo open-air sites on the Middle Don River in Russia, Upper Paleolithic artifact assemblages are buried below, within, and above the CI tephra (which is redeposited by slope action at most sites) on the second terrace. Luminescence and radiocarbon dating, paleomagnetism, and soil and pollen stratigraphy provide further basis for correlation with the Greenland and North Atlantic climate stratigraphy. The oldest Upper Paleolithic occupation layers at Kostenki-Borshchevo may be broadly correlated with warm intervals that preceded the CI event and Heinrich Event 4 (HE4; Greenland Interstadial: GI 12-GI 9) dating to ca. 45,000-41,000 cal BP. These layers contain an industry not currently recognized in other parts of Europe. Early Upper Paleolithic layers above the CI tephra are correlated with HE4 and warm intervals that occurred during 38,000-30,000 cal BP (GI 8-GI 5), and include an assemblage that is assigned to the Aurigancian industry, associated with skeletal remains of modern humans.     

Cloning, purification, and characterization of galactomannan-degrading enzymes from Myceliophthora thermophila

Genes of β-mannosidase 97 kDa, GH family 2 (bMann9), β-mannanase 48 kDa, GH family 5 (bMan2), and α-galactosidase 60 kDa, GH family 27 (aGal1) encoding galactomannan-degrading glycoside hydrolases of Myceliophthora thermophila C1 were successfully cloned, and the recombinant enzymes were purified to homogeneity and characterized. bMann9 displays only exo-mannosidase activity, the K _m and k _cat values are 0.4 mM and 15 sec^?1 for p-nitrophenyl-β-D-mannopyranoside, and the optimal pH and temperature are 5.3 and 40°C, respectively. bMann2 is active towards galac-tomannans (GM) of various structures. The K _m and k _cat values are 1.3 mg/ml and 67 sec^?1 for GM carob, and the optimal pH and temperature are 5.2 and 69°C, respectively. aGal1 is active towards p-nitrophenyl-α-D-galactopyranoside (PNPG) as well as GM of various structures. The K _m and k _cat values are 0.08 mM and 35 sec^?1 for PNPG, and the optimal pH and temperature are 5.0 and 60°C, respectively.     

The role of fish-poultry integration on fish growth performance,yields and economic benefits among smallholder farmers in sub-Saharan Africa,Tanzania

Aquaculture practices from sub-Saharan Africa are characterised by low production, owing to improper technology. Production can be increased through integrating fish farming with other existing on-farm activities, particularly livestock husbandry. We assessed the role of fish-poultry integration on all male Nile tilapia, Oreochromis niloticus growth performance, yields and economic benefits among smallholder farmers in sub-Saharan Africa, Tanzania. The study also compared phytoplankton species composition, abundance and biomass between the fish-poultry integration and non-integrated system. After 180 days of the experiment, all male O. niloticus cultured under fish-poultry integration exhibited significantly higher growth rates than those in the non-integrated system (p < 0.05). Gross fish yield (GFY), net fish yield (NFY) and net annual yields (NAY) obtained from fish-poultry integration were significantly higher than those from non-integrated system (p < 0.05). Partial enterprise budget analysis revealed that fish-poultry integration was more profitable than the non-integrated system. Moreover, fish-poultry integrated system produced significantly higher phytoplankton abundance and biomass than those from the non-integrated system. Results demonstrate that rural smallholder farmers can achieve higher growth rate, farm net yields and income by integrating all male O. niloticus with other on-farm activities than practising a stand-alone fish culture system.     

Creation of a heterologous gene expression system on the basis of Aspergillus awamori recombinant strain

A heterologous gene expression system was created in a domestic Aspergillus awamori Co-6804 strain, which is a producer of the glucoamylase gene. Vector pGa was prepared using promoter and terminator areas of the glucoamylase gene, and A. niger phytase, Trichoderma reesei endoglucanase, and Penicillium canescens xylanase genes were then cloned into pGa vector. Separation of enzyme samples using FPLC showed the amount of the recombinant proteins to be within the 0.6-14% range of total protein.     

Sex characteristics of neuroendocrine effects of prenatal exposure to exogenous glucocorticoids

The effects of hydrocortisone acetate treatment of rats during the last gestational week on neurochemical and morphological characteristics of the brain in early postnatal and mature offspring were studied. Disappearance of sexual differences both in aromatase and 5alpha-reductase activities and noradrenaline concentration in the preoptic area in 10-day old rats was found. Meanwhile a sexual dimorphism in serotonin metabolism emerged. In adult offspring, the prenatal exposure to glucocorticoids resulted in disappearance of sexual differences in neurocytes' nuclei volume in medial preoptic and suprachiasmatic nuclei. The adrenocortical reaction to noradrenaline infusion to the 3rd brain ventricle was absent in the experimental males and intensified in females. In males, adrenocortical reaction to restraint decreased while post-stress changes in hypothalamic noradrenaline concentration and hippocampal glutamate decarboxylase activity were not observed. In the similar experiments in females both the augmentation of adrenocortical reaction and inhibition of GABA-ergic system were revealed. The results obtained indicate the modifying effect of prenatal exposure to glucocorticoids on sexual dimorphism of neuroendocrine system.     

Studies of hydrolytic activity of enzyme preparations of <Emphasis Type="Italic">Penicillium</Emphasis> and <Emphasis Type="Italic">Trychoderma</Emphasis> fungi

Enzyme preparations were isolated from the culture liquid of five mutant strains of the cellulase producer Penicillium verruculosum. The hydrolytic activities of these preparations against unbleached eucalypt cellulose was compared to that of commercial preparations of Trichoderma reesei (T. longibrachiatum). In the majority of cases, P. verruculosum enzymes provided higher yields of reducing sugars (RSs) and glucose. A correlation was found between the yield of RSs and the avicelase activity of the preparations in the reaction mixture.Translated from Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 2, 2005, pp. 210–212.Original Russian Text Copyright © 2005 by Skomarovsky, Gusakov, Okunev, Soloveva, Bubnova, Kondrateva, Sinitsyn.     

Use of a preparation from fungal pectin lyase in the food industry

A new enzyme preparation of fungal pectin lyase (EC 4.2.2.10) was shown to be useful for the production of cranberry juice and clarification of apple juice in the food industry. A comparative study showed that the preparation of pectin lyase is competitive with commercial pectinase products. The molecular weight of homogeneous pectin lyase was 38 kDa. Properties of the homogeneous enzyme were studied. This enzyme was most efficient in removing highly esterified pectin.