Varieties of lima bean shows different growth responses when inoculated with Bacillus sp. a plant growth-promoting bacteria / Variedades de feijão-fava exibem diferentes respostas de crescimento quando inoculadas com Bacillus sp. uma bactéria promotora de crescimento em plantas

Plant growth-promoting bacteria (PGPB) comprise of soil microorganisms that cause positive effects on plant growth. The hypothesis according to which the inoculation of lima bean with PGPB Bacillus stimulates vegetative growth, which may result in a higher plant productivity, was tested. Thus, this study aimed to evaluate the effects of inoculation of two varieties of lima bean (branca and boca de moça) with Bacillus sp., UFPEDA 472 strain, based on plant growth responses. The experiment was conducted in a greenhouse using a completely randomized design. Three treatments were applied separately to each lima bean variety: the first used inoculation with Bacillus, one was submitted to nitrogen supplementation, and one was the absolute control (non-inoculated plants). The following variables were evaluated: absolute and relative growth rate, root length, stem diameter, fresh and dry mass of shoots and roots, shoot:root ratio and total chlorophyll. The results showed that lima bean displayed better growth responses when inoculated with Bacillus sp. UFPEDA 472 in relation to the treatment with nitrogen and/or non-inoculated plants. When inoculated with PGPB Bacillus, the lima bean var. branca was superior to boca de moça in terms of root length and root dry mass. The lima bean var. boca de moça inoculated with Bacillus sp. UFPEDA 472 was superior to branca in terms of absolute growth rate, stem diameter, fresh and dry mass of shoot, shoot:root ratio and total chlorophyll. In general, the lima bean var. boca de moça inoculated with Bacillus shows a better growth performance. Our results suggest that growth responses of lima bean varieties branca and boca de moça are related with a positive interaction with the PGPB Bacillus.

Bactérias promotoras de crescimento em plantas (BPCP) compreendem microrganismos do solo que causam efeitos positivos no crescimento vegetal. A hipótese de que a inoculação de feijão-fava com BPCP Bacillus estimula o crescimento vegetativo, o qual pode resultar em uma maior produtividade vegetal, foi testado. Assim, este estudo objetivou avaliar o efeito da inoculação de duas variedades de feijão-fava (branca e boca de moça) com Bacillus sp., estirpe UFPEDA 472, baseado em respostas de crescimento vegetal. O experimento foi conduzido em casa de vegetação usando um delineamento completamente ao acaso. Três tratamentos foram aplicados separadamente à cada variedade de feijão-fava: o primeiro utilizou a inoculação com Bacillus sp. UFPEDA 472, um foi submetido à suplementação com nitrogênio e um foi o controle absoluto (plantas não inoculadas). As seguintes variáveis foram avaliadas: taxa de crescimento absoluto e relativo, comprimento das raízes, diâmetro do caule, massa fresca e seca da parte aérea e raízes, relação parte aérea:raiz e clorofila total. Os resultados mostram que o feijão-fava exibiu melhores respostas de crescimento quando inoculadas com Bacillus sp. UFPEDA 472 em relação ao tratamento com nitrogênio e/ou às plantas não inoculadas. Quando inoculado com Bacillus sp. UFPEDA 472, o feijão-fava var. branca foi superior à boca de moça em termos de comprimento e massa seca das raízes. O feijão-fava var. boca de moça inoculado com Bacillus sp. UFPEDA 472 foi superior à branca na taxa de crescimento absoluto, diâmetro do caule, massa fresca e seca da parte aérea, relação

Influence of glucose and stirring in the fermentation process in order to produce anti-Candida metabolites produced by Streptomyces sp

ABSTRACT This study evaluated the influence of glucose and stirring in the fermentation process in order to produce anti-Candida metabolites produced by Streptomyces sp. MPO4 isolated from Amazon soil. The anti-Candida metabolites production was registered after 24 h of fermentation in stirred ISP2 medium, having antifungal inhibition halos between 12.3 mm and 25.3 mm, yielding higher production of anti-Candida agents after 96 h. Stirring was a determining factor for the production of anti-Candida secondary metabolites, since the absence of glucose reflected in the late production of the antifungal starting from Streptomyces sp.

RESUMO Este estudo avaliou a influência da glicose e agitação no processo de fermentação para a produção de metabólitos anti-Candida produzidos por Streptomyces sp. MPO4 isolado do solo da Amazônia. A produção dos metabólitos anti-Candida foi registrada a partir de 24 h de fermentação sob agitação em meio ISP2, apresentando halos de inibição entre 12,3 mm e 25,3 mm, obtendo-se maior produção do antifúngico em 96 h. A agitação foi um fator determinante para a produção de metabólitos secundários anti-Candida e a ausência de glicose refletiu na produção tardia do antifúngico a partir do Streptomyces sp.

Antibacterial activity of endophytic fungi from leaves of Indigofera suffruticosa Miller (Fabaceae).

Endophytic fungi were isolated from healthy leaves of Indigofera suffruticosa Miller, a medicinal plant found in Brazil which is used in folk medicine to treat various diseases. Among 65 endophytic fungi isolated, 18 fungi showed activity against at least one tested microorganism in preliminary screening, and the best results were obtained with Nigrospora sphaerica (URM-6060) and Pestalotiopsis maculans (URM-6061). After fermentation in liquid media and in semisolid media, only N. sphaerica demonstrated antibacterial activity (in Potato Dextrose Broth-PDB and in semisolid rice culture medium). In the next step, a methanolic extract from rice culture medium (NsME) and an ethyl acetate extract (NsEAE) from the supernatant of PDB were prepared and both exhibited antimicrobial activity against Gram-negative and Gram-positive bacteria. The best result was observed against Staphylococcus aureus, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 1.56 mg/mL and 6.25 mg/mL, respectively, for NsME and MIC and MBC values of 0.39 mg/mL and 3.12 mg/mL, respectively, for NsEAE. This study is the first report about the antimicrobial activity of endophytic fungi residing in I. suffruticosa leaves, in which the fungus N. sphaerica demonstrated the ability to produce bioactive agents with pharmaceutical potential, and may provide a new lead in the pursuit of new biological sources of drug candidates.

Organic extracts from Indigofera suffruticosa leaves have antimicrobial and synergic actions with erythromycin against Staphylococcus aureus.

A characteristic feature of Staphylococcus aureus is its ability to acquire resistance to antimicrobial agents. There is a need, therefore, for new approaches to combat this pathogen; for example, employing a combination of plant-derived products and antibiotics to overcome bacterial resistance. Indigofera suffruticosa is a plant popularly used to treat infections and has verified antimicrobial action. Here, we investigate the antimicrobial activity of different extracts from I. suffruticosa against S. aureus and their synergistic effects with erythromycin. Leaves of I. suffruticosa were extracted sequentially using diethyl ether, chloroform and acetone and the antimicrobial activity of each extract then tested against nine clinical isolates of S. aureus. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by microdilution tests, while the fractional inhibitory concentration (FIC) was assessed by checkerboard assay. All organic solvent extracts showed antimicrobial activity against S. aureus strains. The acetone extract was the most potent inhibitor of S. aureus (MIC and MBC of 0.78 and 3.12 mg/mL), followed by the chloroform extract (MIC and MBC of 3.12 and 6.25 mg/mL). Furthermore, acetone or chloroform extracts of I. suffruticosa enhanced the activity of erythromycin against S. aureus (FIC ≤ 0.5). We conclude that organic extracts from leaves of I. suffruticosa, alone or combined with erythromycin, are promising natural products for the development of new anti-S. aureus formulations.

Anti-Staphylococcus aureus action of three Caatinga fruits evaluated by electron microscopy.

This study evaluated the antibacterial activity of Anadenanthera colubrina, Libidibia ferrea and Pityrocarpa moniliformis fruit extracts against clinical strains of Staphylococcus aureus. The samples were active for all S. aureus strains (minimum inhibitory concentration: 0.38-3.13 mg mL⁻¹), including the multiresistant strain. The morphological changes suggested the cell wall as the main action target. The treated-cells also lose their ability to form aggregates. The analysis suggests cell wall impairment, which causes the loss of viability and death. This study showed for the first time the morphologic alterations involved in the anti-S. aureus action of fruits of A. colubrina, L. ferrea and P. moniliformis. These findings indicated that these fruit extracts are sources of bioactive compounds that can be used as antibacterial agents.

Antibiotics produced by Streptomyces

Streptomyces is a genus of Gram-positive bacteria that grows in various environments, and its shape resembles filamentous fungi. The morphological differentiation of Streptomyces involves the formation of a layer of hyphae that can differentiate into a chain of spores. The most interesting property of Streptomyces is the ability to produce bioactive secondary metabolites, such as antifungals, antivirals, antitumorals, anti-hypertensives, immunosuppressants, and especially antibiotics. The production of most antibiotics is species specific, and these secondary metabolites are important for Streptomyces species in order to compete with other microorganisms that come in contact, even within the same genre. Despite the success of the discovery of antibiotics, and advances in the techniques of their production, infectious diseases still remain the second leading cause of death worldwide, and bacterial infections cause approximately 17 million deaths annually, affecting mainly children and the elderly. Self-medication and overuse of antibiotics is another important factor that contributes to resistance, reducing the lifetime of the antibiotic, thus causing the constant need for research and development of new antibiotics.

Antibiotics produced by Streptomyces.

Streptomyces is a genus of Gram-positive bacteria that grows in various environments, and its shape resembles filamentous fungi. The morphological differentiation of Streptomyces involves the formation of a layer of hyphae that can differentiate into a chain of spores. The most interesting property of Streptomyces is the ability to produce bioactive secondary metabolites, such as antifungals, antivirals, antitumorals, anti-hypertensives, immunosuppressants, and especially antibiotics. The production of most antibiotics is species specific, and these secondary metabolites are important for Streptomyces species in order to compete with other microorganisms that come in contact, even within the same genre. Despite the success of the discovery of antibiotics, and advances in the techniques of their production, infectious diseases still remain the second leading cause of death worldwide, and bacterial infections cause approximately 17 million deaths annually, affecting mainly children and the elderly. Self-medication and overuse of antibiotics is another important factor that contributes to resistance, reducing the lifetime of the antibiotic, thus causing the constant need for research and development of new antibiotics.

Analysis of 16S rRNA and mxaF genes revealing insights into Methylobacterium niche-specific plant association.

The genus Methylobacterium comprises pink-pigmented facultative methylotrophic (PPFM) bacteria, known to be an important plant-associated bacterial group. Species of this group, described as plant-nodulating, have the dual capacity of producing cytokinin and enzymes, such as pectinase and cellulase, involved in systemic resistance induction and nitrogen fixation under specific plant environmental conditions. The aim hereby was to evaluate the phylogenetic distribution of Methylobacterium spp. isolates from different host plants. Thus, a comparative analysis between sequences from structural (16S rRNA) and functional mxaF (which codifies for a subunit of the enzyme methanol dehydrogenase) ubiquitous genes, was undertaken. Notably, some Methylobacterium spp. isolates are generalists through colonizing more than one host plant, whereas others are exclusively found in certain specific plant-species. Congruency between phylogeny and specific host inhabitance was higher in the mxaF gene than in the 16S rRNA, a possible indication of function-based selection in this niche. Therefore, in a first stage, plant colonization by Methylobacterium spp. could represent generalist behavior, possibly related to microbial competition and adaptation to a plant environment. Otherwise, niche-specific colonization is apparently impelled by the host plant.

Comparative study of the antimicrobial activity of native and exotic plants from the Caatinga and Atlantic Forest selected through an ethnobotanical survey.

CONTEXT: The idea that many commonly used medicinal plants may lead to the discovery of new drugs has encouraged the study of local knowledge of these resources. OBJECTIVE: An ethnobotanical survey of species traditionally used for the treatment of infectious diseases was undertaken in two areas of northeastern Brazil: one in the Caatinga (dry forest) and another in the Atlantic Forest (humid forest). MATERIALS: Initially, diffusion tests using paper disks and subsequently, for extracts presenting significant results (inhibition halos above 15 mm), minimum inhibitory concentrations were determined. The activity was evaluated as a percentage for each species, comparing the diameters of the inhibition halos and the number of positive results against the seven microorganisms studied. Extracts were classified into three categories: strong activity-species with halos exceeding 16 mm, moderate activity-species with halos between 13 mm and 15 mm and low activity-species with halos below 12 mm. We selected 34 species, 20 from the Caatinga and 14 from the Atlantic Forest. RESULTS: In the Caatinga, 50% of the 20 plant extracts studied had strong antimicrobial activity, 25% had moderate activity and 15% had low activity. In the Atlantic Forest, 28.5% of the 14 plant extracts studied showed strong activity, with 14.5% having moderate activity and 28.5% having low activity. The microorganism that was most susceptible to the extracts from the Caatinga, was Mycobacterium smegmatis; 85% of the species tested were able to inhibit its growth. The organism that was susceptible to the highest number of plant species (71%) from the Atlantic Forest was Staphylococcus aureus. DISCUSSION AND CONCLUSIONS: Extracts from the Caatinga showed a trend of superior antimicrobial activity compared to the species from the Atlantic Forest, in terms of both inhibiting a greater variety of microorganisms and demonstrating higher activity against susceptible strains.

Antimicrobial activity and phytochemical screening of Buchenavia tetraphylla (Aubl.) R. A. Howard (Combretaceae: Combretoideae).

This study evaluated the antimicrobial and hemolytic activities and phytochemical constituents of hydroalcoholic extract and its fractions from Buchenavia tetraphylla leaves. Cyclohexane (BTCF), ethyl acetate (BTEF), and n-butanol-soluble (BTSBF) and non-soluble (BTNBF) fractions were obtained from a liquid-liquid partition of hydroalcoholic extract (BTHE) from B. tetraphylla leaves. The hemolytic activity of active fractions was checked. The BTHE inhibited the growth of Micrococcus luteus (MIC: 0.10 mg/mL), Pseudomonas aeruginosa (MIC: 0.20 mg/mL), Mycobacterium smegmatis (MIC: 0.39 mg/mL), Proteus vulgaris, and Staphylococcus aureus (MIC: 0.78 mg/mL for both). The more active fractions were BTCF and BTBSF. BTCF showed better potential to inhibit M. luteus (0.10 mg/mL), P. aeruginosa (0.20 mg/mL), S. enteritidis (0.39 mg/mL), and S. aureus (1.56 mg/mL). BTBSF showed the best results for M. luteus (0.10 mg/mL), M. smegmatis, B. subtilis (0.39 mg/mL for both), and P. vulgaris (0.10 mg/mL). The HC50 were greater than observed MIC: 20.30, 4.70 and 2.53 mg/mL, respectively, to BTBF, BTHE and BTCF, which. The phytochemical analysis detected the presence of flavanoids, triterpene, carbohydrate, and tannin. Our work showed for the first time the broad-spread antimicrobial activity of B. tetraphylla, which has nonhemolytic action, creating a new perspective on the interesting association of traditional and scientific knowledge.

Analysis of 16S rRNA and mxaF genes reveling insights into Methylobacterium niche-specific plant association

The genus Methylobacterium comprises pink-pigmented facultative methylotrophic (PPFM) bacteria, known to be an important plant-associated bacterial group. Species of this group, described as plant-nodulating, have the dual capacity of producing cytokinin and enzymes, such as pectinase and cellulase, involved in systemic resistance induction and nitrogen fixation under specific plant environmental conditions. The aim hereby was to evaluate the phylogenetic distribution of Methylobacterium spp. isolates from different host plants. Thus, a comparative analysis between sequences from structural (16S rRNA) and functional mxaF (which codifies for a subunit of the enzyme methanol dehydrogenase) ubiquitous genes, was undertaken. Notably, some Methylobacterium spp. isolates are generalists through colonizing more than one host plant, whereas others are exclusively found in certain specific plant-species. Congruency between phylogeny and specific host inhabitance was higher in the mxaF gene than in the 16S rRNA, a possible indication of function-based selection in this niche. Therefore, in a first stage, plant colonization by Methylobacterium spp. could represent generalist behavior, possibly related to microbial competition and adaptation to a plant environment. Otherwise, niche-specific colonization is apparently impelled by the host plant.

Production of ethanol from mesquite (Prosopis juliflora (SW) D. C) pods mash by Zymomonas mobilis and Saccharomyces cerevisiae

This study aimed to assess the use of mesquite pods hydrated mash as biomass for the growth of Saccharomyces cerevisiae UFEPEDA-1012 and Zymomonas mobilis UFEPEDA-205 and for ethanol production using a submerged fermentation. A 2³ factorial design was used to analyze the effects of the type of microorganism, time of fermentation and condition of cultivation on the ethanol production in mesquite pods mash (30 g 100 mL-1). From the obtained results the hydrated mesquite pods mash presented as a good substrate for the growth of S. cerevisiae and Z. mobilis in comparison to the standard media. The effect that most affected the ethanol production was the type of microorganism. The highest ethanol concentration (141.1 gL-1) was found when Z. mobilis was cultivated in mesquite pods mash under static condition for 36 hrs. Ethanol production by S. cerevisiae was higher (44.32 gL-1) after 18 hrs of fermentation under static condition. According to these results, the mesquite pods could be known as an alternative substrate to be used for biotechnological purposes, mainly for ethanol production.

In vivo assessment of possible probiotic properties of Zymomonas mobilis in a Wistar rat model

In recent years the incorporation of probiotic bacteria into foods has received increasing scientific interest for health promotion and disease prevention. The safety and probiotic properties of Zymomonas mobilis CP4 (UFPEDA-202) was studied in a Wistar rat model fed the 10(9) colony forming units (cfu)/mL-1 of the assayed strain for 30 days. No abnormal clinical signs were noted in the group receiving viable cells of Z. mobilis and water (control) during the period of the experiment. There were no significant difference (p > 0.05) in feed intake and weight gain among mice fed the Z. mobilis in comparison to the control group. No bacteria were found in blood, liver and spleen of any animals. Mice receiving Z. mobilis showed significantly differences (p < 0.05) in total and differential leucocytes count, excepting for neutrophils, after the experimental period. Otherwise, it was not found in control group. Histological examination showed that feeding mice with Z. mobilis caused no signs of adverse effects on gut, liver and spleen. From these results, Z. mobilis CP4 (UFEPEDA-202) is likely to be nonpathogenic and safe for consumption, and could have a slight modulating effect on immunological performance in mice.

Atividade antimicrobiana de três espécies de Phyllanthus (quebra-pedra) e de seu produto comercial / Antimicrobial activity of three species of Phyllanthus (quebra-pedra) and its commercial product / Actividad antimicrobiana de las tres especies de Phyllanthus (quebre-pedra) y sus productos comerciales

Objetivo: determinar a atividade antimicrobiana de três espécies de plantas do gênero Phyllanthus (P. amarus Schum e Thom., P. tenellus Roxb. e Phyllanthus niruri L.) e de sua tintura comercial (fitoterápico), frente a bactérias e leveduras. Método: foi avaliada a atividade antimicrobiana frente a microrganismos através do método de disco difusão, em seguida foram avaliadas as concentrações mínimas inibitórias dos melhores resultados a partir do método da microdiluição. Resultados: as espécies medicinais apresentam atividade antimicrobiana para bactérias Gram-positivas. A tintura comercial apresentou sensível atividade antimicrobiana. Os extratos apresentaram melhor atividade para S. aureus (P. amarus com MIC 0,16 mg/mL e P. tenellus com MIC 0,10 mg/mL), frente a B. subtilis os resultados também foram satisfatórios (P. amarus 0,25mg/mL e P. tenellus 0,30mg/mL). A tintura comercial apresentou MIC maior que 1mg/mL apenas para S. aureus com MIC de 0,70mg/mL, já para B. subtilis apresentou MIC 1,10mg/mL. Com relação as leveduras, todas as substâncias resultaram ser menos expressivos que para as bactérias gram-positivas, variando de 0,70 a 1mg/mL para os extratos brutos e 1,10 a 1,20 mg/mL para a tintura comercial. Conclusão: este estudo mostrou o potencial antibacteriano e antifúngicos destas espécies cujo valor terapêutico pode ser melhor avaliado.(AU)

Objective: to determine the antimicrobial activity of three plant species of the genus Phyllanthus (P. amarus Schum. and Thom., P. tenellus Roxb. and Phyllanthus niruri L.) and its commercial dye (phytotherapic), opposite the bacteria and yeasts. Method: we evaluated the antimicrobial activity against microorganisms by disk diffusion method, and then evaluated minimum inhibitory concentration of the best results from the microdilution method. Results: the medicinal species have antimicrobial activity to Gram-positive bacteria. The commercial dye showed significant antimicrobial activity. The extracts showed the best activity for S. aureus (P. amarus with MIC 0.16 mg / mL and P. tenellus with MIC 0.10 mg / mL), opposite to B. subtilis results were also satisfactory (P. amarus 0.25 mg / mL and P. tenellus 0.30 mg / mL). The commercial dye showed MIC greater than 1mg/ml only for S. aureus with MIC of 0.70 mg / mL, and for B. subtilis showed MIC 1.10 mg / mL. With respect to the yeast, all substances were less significant than for gram-positive bacteria, ranging from 0.70 to 1mg/ml for crude extracts and 1.10 to 1.20 mg / mL for the dyeing trade. Conclusion: this study showed the potential antibacterial and antifungal therapeutic value of these species can be better evaluated. (AU)

Objetivo: determinar la actividad antimicrobiana de tres especies de plantas del género Phyllanthus (P. amarus Schum y Thom., P. tenellus Roxb. y Phyllanthus niruri L.) y su tinte comercial (phytotherapic), frente a las bacterias y levaduras. Método: se evaluó la actividad antimicrobiana contra microorganismos por el método de difusión en disco y, a continuación, detectado concentración mínima inhibitoria de los mejores resultados de la microdilución método. Resultados: los medicamentos especies actividad antimicrobiana de las bacterias Gram-positivas. El tinte comercial mostraron un importante actividad antimicrobiana. Los extractos mostraron la mejor actividad para S. aureus (P. amarus MIC con 0,16 mg / ml y P. tenellus MIC con 0,10 mg / ml), frente a B. subtilis resultados también fueron satisfactorios (P. amarus 0,25 mg / ml y P. tenellus 0,30 mg / ml). El tinte comercial mostró superior a 1mg/ml MIC sólo para S. aureus con CMI de 0,70 mg / ml, y para B. subtilis mostró MIC 1,10 mg / mL. Con respecto a la levadura, todas las sustancias eran menos importantes que para las bacterias gram-positivas, que van desde 0,70 a 1mg/ml de extractos crudos y de 1,10 a 1,20 mg / ml de tintura para el comercio. Conclusión: este estudio demostró el potencial antibacteriano y antimicótico valor terapéutico de estas especies pueden ser mejor evaluadas.(AU)

Optimization of the production of rhamnolipids by Pseudomonas aeruginosa UFPEDA 614 in solid-state culture.

In recent years, biosurfactants have attracted attention because of their low toxicity, high biodegradability, and good ecological acceptability. However, their production in submerged liquid culture is hampered by the severe foaming that occurs. Solid-state cultivation can avoid this problem. In the current work, we optimized the production of a rhamnolipid biosurfactant by Pseudomonas aeruginosa UFPEDA 614, grown on a solid medium impregnated with a solution containing glycerol. During the study, we increased the production of the biosurfactant over tenfold, with levels reaching 172 g of rhamnolipid per kilogram of dry initial substrate after 12 days. On the basis of the volume of impregnating solution added to the solid support, this yield is of the order of 46 g/L, which is comparable with the best results that have been obtained to date in submerged liquid cultivation. Our results suggest that there is a great potential for using solid-state cultivation for the production of rhamnolipids.

Interspecies variation of Kitasatospora recifensis endophytic from yam bean producing thermostable amylases in alternative media.

An endophytic actinomycete isolated from tubers of yam beam (Pachyrhizus erosus L. Urban) was classified as a novel species nominated Kitasatospora recifensis based in phenotypic and genotypic analysis (16S rDNA gene sequence). Monosporic culture using specific ISP2 media revealed three interspecies, which were identified by DNA southern hybridization (Wild strain 13817 W, Aerial Mycelium strain 13817 AM and Vegetative Mycelium strain 13817 VM). The strains were tested for the production of amylolitic enzymes in alternative media. Maximum yields for both enzymes were observed in starch-casein. Higher α-amylase was obtained with strain 13817 W in starch-urea, and amyloglucosidase with strain 13817 AM in starch-ammonium that are economic sources and may be important for industrial purposes. Type strain (DAUFPE 13817(T) = KCTC 9972(T )= DSM 44943(T)).

Estudo do comportamento de RSU em uma célula experimental e suas correlações com aspectos microbiológicos, físicos e químicos / Behavior study of MSW in an experimental cell and its correlations with microbiological, physical and chemical aspects

Células experimentais (lisímetros) possibilitam entender o comportamento de aterros de RSU e representam uma técnica bastante interessante para obter parâmetros de projetos, dimensionamento e construção de aterros, além do mais pode fornecer contribuições na área de saneamento através de monitoramento de processos. O objetivo deste trabalho é avaliar o processo biodegradativo dos resíduos depositados em uma célula experimental correlacionando parâmetros como recalque, temperatura e contagem de microrganismos. O monitoramento mostrou que há uma relação entre estes parâmetros. Verificou-se que a temperatura no lisímetro variou no decorrer do processo possivelmente devido às mudanças de fases de decomposição dos resíduos. Os estudos vislumbram uma nova abordagem para recalques em RSU mostrando a ocorrência de três fazes distintas de deformações verticais e a íntima ligação de processos biodegradativos e aspectos mecânicos.

Experimental cells (lysimeters) make possible to understand the landfill behavior of MSW and represent a very interesting technique for the obtainment of projects parameters, design and constructions of landfills. Besides that, they provide contributions to the sanitation area through processes monitoring. The purpose of this paper is to evaluate the solid waste biodegradation process deposited in an experimental cell correlating parameters like settlement, temperature and microorganisms counting. The monitoring showed that there is a relation between these parameters. It was observed that the temperature in the lysimeter varied in the course of the process, possibly because of the changes in the stages of the solid waste decomposition. The studies descry a new approach to settlements in MSW showing that there are three different stages of vertical deformations and the close connection of biodegradation processes and mechanical aspects.

Synthesis, antitumour and antimicrobial activities of new peptidyl derivatives containing the 1,3-benzodioxole system.

Two series of 5 and 6-substituted 1,3-benzodioxole peptidyl derivatives were synthesized and evaluated as antitumour and antimicrobial agents. The compounds that could be conveniently prepared in a few steps processes from natural safrole have been characterised by IR and 1H-NMR spectroscopy. In vivo antitumor activity tests showed that some of the compounds were able to inhibit carcinoma S-180 tumour growth in mice. The in vitro antimicrobial activity of all compounds revealed that they are able to promote the growth of some organisms, including Bacillus subtilis.

Genetic variability in regenerated Metarhizium flavoviride protoplasts

A formação e regeneração de protoplastos foram avaliadas em duas linhagens selvagens e duas linhagens mutantes para coloração de conídios em Metarhizium flavoviride. O cultivo em meio líquido seguido do tratamento do micélio com Novozym 234 na presença de KCl 0,7 M como estabilizador osmótico, resultou na produção de 5,05´106 a 1,15´107 protoplastos´mL-1. A porcentagem de regeneração das diferentes linhagens variou de 6,65 a 27,92%. Após a regeneração, uma das linhagens selvagens produziu espontaneamente variantes estáveis, com morfologia alterada. Embora variantes morfológicos já tenham sido observados após regeneração de protoplastos em bactérias, esta parece ser a primeira vez que tal ocorrência é descrita em fungos filamentosos. Um desses variantes, além da linhagem selvagem da qual ele foi originado, foi testado para sensibilidade aos fungicidas benomil e captano.

Seleçäo de Bacillus spp. para produçäo de esterases e melhoramento de Bacillus cereus(C124) / Selection of Bacillus spp. for esterase production and genetic improvement of Bacillus cereus(C124)

Forty-four Bacillus spp. strains obtained from sugar cane derivates and residues, six of them isolated in this work, were tested using Tween 80 as substrate (agar-Tewwn 80 medium), in order to determine their esterase activity through the enzymatic index averages. After statistic analysis, B. cereus(C124) strain, which presented better results, was submitted to genetic improvement by treatment with ultraviolet light (UV). The survival curve pointed out 28" as the time necessary to obtain 30 per cent of survivors. Fifty survivors and the wild strain C124 were compared in relation to their esterase activity as mentioned previously. The wild strain and the mutant C124UV35, which showed enzymatic index average higher than C124, were characterized in polyacrilamide gel electrophoresis (PAGE). Electrophoretic patterns for total proteins of wild and mutant strain showed different profiles according to number, position and intensity of bands. For esterase, the bands varied only in intensity