Quantification of trehalose in biological samples with a conidial trehalase from the thermophilic fungus Humicola grisea var. thermoidea

The partially-purified, thermally-stable trehalase from conidia of Humicola grisea was highly specific for trehalose and was free of potentially interfering activities. The enzyme was fully stable when stored in solution at -15°C for at least 6 months. This preparation could be used to quantify trehalose from 0.05 to 1.25 mol/ml either in carbohydrate mixtures or in complex biological materials.M.J. Neves, H.F. Terenzi and J.A. Jorge are with Departmento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirao Preto, Universidade de São Paulo, 14040-901-Ribeirão Preto, São Paulo, Brazil; F.A. Leone is with Departamento de Quimica, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901-Ribeirão Preto, São Paulo, Brazil.     

Disseminated dermatophytosis caused by Microsporum gypseum in two patients with the acquired immunodeficiency syndrome

Microsporum gypseum is not a common agent of human dermatophytosis. To the best of our knowledge, this fungus has not been described in human immunodeficiency virus (HIV)-infected patients. We report a tinea corporis infection with atypical presentation caused by M. gypseum in two patients with the acquired immunodeficiency syndrome (AIDS) studied at the São Paulo Hospital (São Paulo, Brazil).This revised version was published online in October 2005 with corrections to the Cover Date.     

Diversity of plant uses in two Caiçara communities from the Atlantic Forest coast, Brazil

Caiçaras are native inhabitants of the Atlantic coast on southeastern Brazil, whose subsistence is based especially on agriculture and artisanal fishing. Because of their knowledge about the environment acquired through generations, Caiçara people can play an important role in Atlantic Forest conservation. An ethnobotanical study was conducted within two Caiçara communities (Ponta do Almada and Camburí beach, São Paulo State, Brazil), focusing on plant uses. In 102 interviews, 227 plant ethnospecies were quoted, mainly for food, medicine, handicraft and construction of houses and canoes. People from studied communities depend on the native vegetation for more than a half of the species known and used. Using diversity indices, plant uses are compared between studied communities and between gender and age categories within each community. We found quantitative differences in the knowledge about plants between gender categories for each kind of use (medicinal, food and handicrafts). Older and younger informants also have different knowledge about plants for handicraft and medicine, but not for edible plants.     

Effect of carbon source on the β-glucosidase system of the thermophilic fungus Humicola grisea

H. grisea produced an extracellular -glucosidase (EC 3.2.1.21) at high activity in media supplemented with carboxymethyl cellulose (CMC) or cellobiose. Cellobiose-induced -glucosidase was insensitive to glucose repression whereas that of CMC-supplemented cultures was partially repressed. Molecular sieving revealed three main active components (M_r 50, 128 and 240 kDa). Glucose competitively inhibited -glucosidase activities with K_i values of 0.9mM and 3.3mM (extracellular) and 10.2mM and 22.6mM (cytosolic), induced in the presence of CMC or cellobiose respectively.The authors are with the Departamento de Biologia, Faculdade de Filosofia. Ciências e Letras de Ribeirão Preto, Universidade de São Paulo-14040-901 Ribeirão Preto, São Paulo, Brasil;     

Predation on and by pelagic Turbellaria in some lakes in Brazil

Planktonic Turbellaria are of common occurrence in both natural and man-made lakes in Brazil. Experiments were performed in 1987 and 1989 to determine which zooplankton species are consumed by predatory Mesostoma sp. from three natural lakes in the Rio Doce Valley. Experiments were also performed in 1989 with a yet unidentified flatworm from Barra Bonita reservoir. Both predators consumed Daphnia and Ceriodaphnia at a high rate: 4 individuals per day in the case of Mesostoma sp., a large species and 1.5 ind day^–1 in the case of the smaller species from Barra Bonita reservoir. Consumption of copepod nauplii, copepodids and adults was much lower, and Ostracoda were not consumed at all. Experiments on food selectivity showed a clear preference by the flatworms for cladocerans.In the lakes studied, flatworms are heavily preyed upon by larvae of Chaoborus and by Mesocyclops species.Turbellaria densities in the natural lakes were around 300 individuals per cubic meter, whereas in Barra Bonita reservoir, 1000 individuals per cubic meter was a mean value in a fifteen days study.Federal University of São Carlos - Laboratory of LimnologyUniversity of São Paulo - Canter of Water Resource and Applied EcologyPost-graduate student - University of São Paulo     

Song dialects on the Atlantic islands: goldcrests of the Azores ( Regulus regulus azoricus, R. r. sanctae-mariae, R. r. inermis)

Territorial songs in island populations of songbirds are often highly divergent from those of neighbouring continental relatives. This is shown for the three goldcrest subspecies (Regulus regulus azoricus, R. r. sanctae-mariae and R. r. inermis) endemic on six islands of the Azorean archipelago. All investigated populations display a high intra- and inter-individual acoustic variation. On each island, up to six different song types have been found; and a single male sings up to three types. In contrast, all northwestern European populations of R. r. regulus and R. r. anglorum share only a single song type. In playback experiments, none of 18 tested dialect songs of Azorean goldcrests evoked notable territorial reaction in German and Czech goldcrest males (ssp. regulus). Two differing dialect groups of the goldcrest can be distinguished on the Azores. Populations of the eastern islands, São Miguel and Santa Maria, share common song types which are not found on the islands of the central and western groups. Dialect repertoires on the westernmost islands, Flores, Faial and Pico, are dominated by a different song type. In the geologically younger western crater of São Miguel, both western and eastern song types coexist. Acoustic similarities to a population from neighbouring Terceira suggest the western part of São Miguel as the origin for the westward expansion of R. regulus on the Azores.     

Improved culture media for growth of Bradyrhizobium japonicum

A freshly-prepared yeast extract at 30 or 50 g/l improved the growth of Bradyrhizobium japonicum SEMIA 587 in a 5-l stirred fermenter. Monosodium glutamate or a commercial yeast extract at 2.0 g/l almost doubled cell mass productivity and cell viability when added at the end of the first exponential growth phase.The authors are with the Divisão de Quimica, Agrupamento de Biotecnologia, Instituto de Pesquisas Tecnológicas do Estado de São Paulo, S/A.-IPT-Cidade Universitária s/n., Caixa Postal 7141, CEP 01064-970, São Paulo, SP, Brazil     

Effects of genotoxic agents on his + revertants and survival of spores of Streptomyces aureofaciens

The effects of u.v. light and of several chemical agents on spores of the tetracycline producer Streptomyces aureofaciens MT1 were studied using survival curves and induction of histidine prototrophic revertants (his ⁺). Spores were highly resistant to u.v.; NTG induced most his ⁺ revertants. 4-Nitroquinoline-1-oxide and methyl methanesulphonate also gave good yields of revertants. Whereas ethyl methanesulphonate had the least effect on inducing the revertants.M. Marins is with the Department of Biochemistry, Institute of Chemistry, University of São Paulo, SP, Brazil. S.O.P. Costa and G. Padilla are with the Department of Microbiology, Biomedical Science Institute, University of São Paulo, Avenida Prof. Lineu Prestes 1374, SP, Brazil, CEP 05508-900     

Structure and signaling in polyps of a colonial hydroid

Abstract. After feeding, polyps of colonial hydroids contract regularly, dispersing food throughout the colony via the gastrovascular fluid. Such contractions may trigger signaling pathways that allow colonies to grow in an adaptive manner, i.e., to initiate development of more polyps in food‐rich areas and to suppress polyp development in food‐poor areas. In this context, we investigated the structure and potential signaling of the junction between polyps and stolons in colonies of the hydroid Podocoryna carnea. Using transmission electron microscopy, we found that the density of mitochondrion‐rich epitheliomuscular cells was low in polyp and stolon tissues except at or near the polyp‐stolon junction, where many of these mitochondrion‐rich cells occur in ectodermal tissue. In vivo fluorescence microscopy suggests that these mitochondria are a principal source of the metabolic signals of the colony. Both native fluorescence of NAD(P)H and fluorescence from peroxides (visualized with H₂DCFDA) co‐localize to this region of the polyp. Rhodamine 123 fluorescence suggests that both these metabolic signals emanate from mitochondria. To test whether such metabolic signals may be involved in colony pattern formation, inbred lines of P. carnea were used. Colonies of a runner‐like inbred line grow with widely spaced polyps and long stolonal connections, much like wild‐type colonies in a food‐poor environment. Colonies of a sheet‐like inbred line grow with closely spaced polyps and short stolonal connections, similar to wild‐type colonies in a food‐rich environment. Polyp‐stolon junctions in runner‐like and sheet‐like colonies were imaged for the fluorescence of H₂DCFDA. Densitometric analysis of this signal indicates that the mitochondria in epitheliomuscular cells of runner‐like polyps emit greater amounts of peroxides. Because peroxides and other reactive oxygen species are frequently intermediaries in metabolic signaling pathways, we suspect that such signaling may indeed occur at polyp‐stolon junctions, affecting colony pattern formation in these inbred lines and possibly in hydroid colonies in general.     

The biodiversity and conservation of the birds of São Tomé and Príncipe

At present the majority of the endemic bird species occurring on São Tomé and Príncipe remain common, the rarer species being those largely confined to primary rainforest. In 1990 the dwarf olive ibis (Bostrychia bocagei), São Tomé fiscal shrike (Lanius newtoni), São Tomé short-tail (Amaurocichla bocagii) were rediscovered and in 1991 the São Tomé grosbeak (Neospiza concolor) was seen for the first time since 1888. Lowland primary forest is the only habitat on São Tomé in which all the endemic species are found. Primary forest on Príncipe remains largely unsurveyed since the beginning of the century. Due to the decline in the cocoa industry and poor infra-structure post-independence the extent of secondary forest is probably at its greatest since the late 1800s. This habitat is an important buffer zone against development for the remaining primary forest and also contains important populations of many of the endemic species, in particular the São Tomé scops owl (Otus hartlaubi), São Tomé oriole (Oriolus crassirostris) and giant weaver (Ploceus grandis). On both islands the remaining areas of primary forest need immediate protection and suitable boundaries have been designated under the Zona Ecológica plan. Fortunately, except for an important area around Lagôa Amélia, primary forest is not under immediate threat, although a variety of pressures are likely to increase. In conjunction with the protection of primary forest, a plant for managing the remaining timber resource on the islands will be a vital requirement, particularly if areas of shade forest, an important habitat for endemic bird species and a potentially valuable economic resource, are to be conserved and sustainably managed.     

Thin section and freeze fracture studies of the hypophyseal proximal pars distalis in a teleost (Rhamdia hilarii Val.) during different stages of the reproductive cycle

Summary Chromophilic cells in the proximal pars distalis of the adenohypophysis of Rhamdia hilarii were studied in thin section and freeze fracture preparations. The gonadotropic cells (GTH-cells) exhibit a diversity of form, the frequency of which can be related to stages (maturation, mature and spent) in the sexual cycle. GTH-cells showing a cytoplasm filled with electron dense polymorphic secretory granules and small rough endoplasmic reticulum (RER) vesicles, have been termed non-vacuolated. During the mature gonadal stage, such cells become increasingly vacuolated. The small RER vesicles become dilated and/or fuse, forming a single enormous cisternum (4–11 m diameter), the contents of which show direct contact with the inner nuclear membrane. These morphological aspects support the idea that Rhamdia hilarii possesses only one GTH-cell type. Evidence from freeze fracture replicas suggests that membrane-associated events precursory to exocytosis take place in regions where the cell and secretory granule membranes are in close apposition. Thin section analysis of secretory granule formation revealed their derivation from the dilated extremities of the inner Golgi saccule which appears to resemble the rigid lamella described in other cells. After detachment of the inner saccule, the immature secretory granules appear to enlarge by microvesicular transport. Freeze fracture and ultrastructural data on the morphology of the cells that presumably synthetise growth hormone are also presented.This work was aided by the Fundação de Amparo à Pesquisa do Estado de São Paulo (75/1282)     

Spatial patterns in pupal mortality in urban palm caterpillars

Mortality factors were determined in over 20000 pupal skins of Brassolis sophorae and Opsiphanes invirae, collected from 55 sites in the urban area of Campinas, São Paulo, southeast Brazil. Almost 50% of B. sophorae pupae and 30% of O. invirae pupae were killed by various identifiable factors, which may have an appreciable influence in determining adult population size. Mortality was related to type of attachment site, distance from the center of the city, area occupied by buildings and houses, vegetation cover, and other urban variables. Exposed pupation sites such as outside walls had a lower frequency of successful eclosions than darker or more sheltered sites, such as offset skirting boards, garages, or mailboxes, which act as partial refuges against parasitoids. Mortality levels were higher in regions of the city with high vegetation cover. Vegetation cover and distance from the city center were the best predictors of parasitism level of B. sophorae by the chalcidid wasp Spilochalcis morleyi. The viability of S. morleyi (data from parasitized B. sophorae) did not differ significantly among different regions of the city. These data do not support an exclusive model of escape from parasites (or other natural enemies) for explaining the abundance of urban butterflies.This paper was presented at the VI INTECOL, Manchester, UK, in September 1994     

Mycoflora of the toxic feeds associated with equine leukoencephalomalacia (ELEM) outbreaks in Brazil

The mycoflora of 39 feed samples associated with 29 Equine Leukoencephalomalacia (ELEM) outbreaks was studied from 1988 to 1990, in Brazil. Microbiological examination indicatedFusarium spp. as the most frequent mold which occurred in 97.4% of samples followed byPenicillium spp. in 61.5% andAspergillus spp. in 35.9%. The moisture content of feed implicated in death of horses was above 15% which can favor the development ofFusarium spp. From the genus,F. moniliforme was the predominant species with an occurrence of 82.0%. Two additional species, not commonly associated with animal toxicosis, were isolated in low frequency,F. proliferatum (12.8%) andF. subglutinans (2.6%). It is important to emphasize that the isolation ofF. proliferatum andF. subglutinans from feed obtained from the epizootic areas has not been documented previously in Brazil.Part of the thesis of M.C.A. Meireles to get the degree of Doctor Leucoencefalomalácia Eqüina (LEME) no Brasil: Aspectos epizootiológicos, microbiológicos e micotoxicológicos, Preliminary communication in 1989, Congresso Brasileiro de Microbiologia, Rev Microbiol (São Paulo) 20 (Sup. 1): 359 (F 181).     

Phylogenetic analysis of Theobroma (Sterculiaceae) based on Kunitz-like trypsin inhibitor sequences

Trypsin inhibitor gene sequences were used to investigate the phylogenetic relationships among Theobroma and Herrania species, considered as sister-groups, with particular interest on the monophyly and infra-generic relationships of Theobroma. The presumed amino acid sequences of 23 analyzed samples, from 11 Theobroma and three Herrania species, comprising all sections from both genera, demonstrated a high similarity with a previously characterized T. cacao Kunitz trypsin inhibitor. The trypsin inhibitor gene accumulated mutations at faster rate than prior analyzed nuclear or chloroplastic genes. None of the sequences presented introns. The phylogeny of the trypsin inhibitor sequences was congruent with the phylogenetic hypotheses of the Theobroma and Herrania species based on morphology. The monophyly of Theobroma was not strongly supported, corroborating previously described absence of obvious synapomorphies for Theobroma. The species grouped consistently according to genus and section. The monophyly of all Theobroma sections was supported, except for section Glossopetalum, which was paraphyletic to section Andropetalum. Evidences sustain that T. mammosum may be included into section Glossopetalum. The potential use of trypsin inhibitor gene sequences in phylogenetic studies of Theobroma was demonstrated.We acknowledge the financial support by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); International Foundation of Science (IFS), and the permission from Empresa Brasileira de Pesquisas Agropecuária (EMBRAPA); Comissão Executiva do Plano da Lavoura Cacaueira (CEPLAC) to use the plant material. We thank the useful comments from the reviewers.     

Ecology and dynamics of two intertidal algal communities on the littoral of the island of São Miguel (Azores)

The intertidal benthic algal communities of two sites located on opposite coasts of São Miguel Island (Azores), were studied over a 2-year period (September 1993–September 1995). At both sites (São Roque on the south coast and São Vicente on the north), the littoral region was surveyed from the upper intertidal down to the sublittoral fringe. The survey revealed five distinct zones, with a variable degree of overlapping. The two upper zones were characterized by animals (littorinids and barnacles, respectively). Lower down, algal communities formed three distinct zones: an upper Fucus spiralis/Gelidium microdon association, a more extensive turf zone, and a belt featuring erect or frondose algae. Upper in the eulittoral, the turf was mainly monospecific, and dominated by Caulacanthus ustulatus. The lower eulittoral turf was dominated by articulated coralline algae, the associated species differing between the two sites studied. Mainly erect algae (Pterocladiella, Asparagopsis, etc.) occurred furthest down the shore and extended into the nearby shallow sublittoral. Two intertidal communities were studied at each locality: the upper eulittoral (Caulacanthus turf in São Roque and the Fucus spiralis/Gelidium microdon association at São Vicente), and the lower eulittoral (the coralline turf). The lower littoral communities had a higher algal diversity. A general pattern was observed in the seasonal variation of biomass: the lower levels exhibited the higher values in late summer/early autumn, the period in which the upper levels had the lowest standing crops. Physical factors are proposed to account for this. No significant inter-annual variations could be detected, indicating relatively stable communities, at least on a short-term basis.     

Pectinase production by Penicillium frequentans

High activities of extracellular pectinase with viscosity-diminishing and reducing groups-releasing activities were produced by Penicillium frequentans after 48 h at 35°C, in agitated cultures supplemented with 0.5% citrus pectin and initial pH of 2.5. Under these conditions the fungus also produced high activity of pectinesterase. At an initial pH of 7.0 or 8.0, pectin lyase activity was also detected. Enzyme activity releasing reducing sugars was more stable at 50°C than viscosity-diminishing activity. Both activities were maximal at pH 2.5 to 5.2 and at 55°C.The authors are from the Faculdade de Ciências Farmacêuticas de Ribeirão Preto da Universidade de São Paulo, Avenida do Café, s/n^o, Bairro Monte Alegre, 14.049 Ribeirão Preto, S.P., Brazil.     

Plankton studies in a lacustrine environment

Summary Weekly zooplankton samples were taken during the period February, 1972 to January, 1973 at station III in a shallow and turbulent tropical reservoir (Broa Reservoir, São Carlos, São Paulo, State-Brazil). The samples were taken by plankton standard net with 68 mesh size, and collected through the horizontal hawls during 3 min. Rotifera was the most abundant group with 77.6%; Cladocera 13.6%, and Copepoda 8.7% (adult and naupliae stages). Other forms like Chaoborus larvae and some worms occurred sporadically. The seasonal fluctuation of the total zooplankton was very irregular in warm and rainy season and more stable in the dry and cold season. The composition of the zooplankton and its patterns of seasonal variation for eutrophic and oligotrophic aquatic ecosystems, in tropical regions, may differ significantly from temperate waters.     

Predation on Ceriodaphnia cornuta and Brachionus calyciflorus by two Mesocyclops species coexisting in Barra Bonita reservoir (SP,Brazil)

Feeding experiments with two species of carnivorous copepod, Mesocyclops longisetus (Thiebaud) and Mesocyclops kieferi Van de Velde from Barra Bonita, a eutrophic reservoir in São Paulo, Brasil, were performed using two common types of prey: Ceriodaphnia cornuta, a cladoceran, with a mean body length of 464 µm (including spines) or 393 µm (without spines), and Brachionus calyciflorus, a rotifer with a mean body length of 350 µm (including spines) or 279 µm (without spines).Both species showed higher consumption rates on Brachionus than on Ceriodaphnia. For Mesocyclops longisetus, the average rates were: 2.19 prey ind^–1 h^–1 (Brachionus), and 1.30 prey ind^–1 h^–1 (Ceriodaphnia). For Mesocyclops kieferi, the rates were 1.85 prey ind^–1 h^–1 (Brachionus) and 0.60 prey ind^–1 h^–1 (Ceriodaphnia). These experimental data are discussed with reference to the dynamics of the predator and prey populations in the reservoir.Laboratorio de Limnologia, Departamento de Ciencias Biologicas, Universidade Federal de São CarlosCentro de Recursos Hidricos e Ecologia Aplicada Lab. de Limnologia, Departamento de Hidraulica e Saneamento, Escola de Engenharia de São Carlos, Universidade de São Paulo     

Diversity and status of sea turtle species in the Gulf of Guinea islands

In West Africa, the Gulf of Guinea islands are important nesting places for four sea turtle species. The Green turtle (Chelonia mydas), the Hawksbill (Eretmochelys imbricata), the Olive Ridley (Lepidochelys olivacea) and the Leatherback (Dermochelys coriacea) turtles nest on Bioko's southern beaches. The Green, Hawksbill and Leatherback turtles breed on Príncipe and São Tomé. The Leatherback turtle nests, at least, on Annobón. The Leatherback turtle is reported on the four islands for the first time, and the Olive Ridley turtle for Bioko. Bioko is probably the most important island in terms of number of species and nesting individuals; the Green turtle being the most abundant species. However, the nesting places are at present restricted to barely 20 km along the coastline. On Príncipe and São Tomé, the most common species is the Hawksbill turtle. Sea turtle nesting populations are being severely depleted on the four islands. The main causes of cverexploitation are the meat and egg trade on Bioko and the Hawksbill shell-craft trade on São Tomé and Príncipe.     

Determination of the enzymatic activity of pectinases from different microorganisms

The decrease in viscosity is widely used to estimate the activity of pectinolytic enzymes. This method is shown to be influenced by the production strain and this prevents an accurate comparison between the activities of different microorganisms, especially under different conditions.A.E. Maiorano and Y. Ogaki are with the Divisão de Quimica, with the Agrupamento de Biotecnologia, Instituto de Pesquisas Tecnológicas do Estado de São Paulo S/A.-IPT, Cidade Universitária, Caixa Postal 7141, CEP 01064-970, São Paulo, SP, Brazil; W. Schmidell is with the Departamento de Engenharia Quimica, Escola Politécnia, Universidade de São Paulo, Caixa Postal 61548, CEP 05424-970, São Paulo, SP, Brazil.