Funcionalidade dos extratos fenólicos obtidos pelo cultivo semi-sólido de resíduos de abacaxi (Ananas comusus L.) e goiaba (Psidium guajava L.)

Solid substrate cultivation (SSC) has become an efficient alternative towards rational use of agro industrial wastes and production of value-added products, mainly in developing countries. This work presents the production and functional application results of phenolic extracts obtained by solid substrate cultivation of pineapple (Ananas comosus L.) and guava (Psidium guajava L.) residues associated to soy flour and bioprocessed by Rhizopus oligosporus fungus. Two experimental groups were tested: (1) 9g of fruit residue and 1g of soy flour (A9 or G9); (2) 5g of fruit residue and 5g of soy flour (A5 or G5). After SSC, 100ml of distilled water was added to each Erlenmeyer flask containing 10g of bioprocessed material in order to obtain the phenolic extracts. Samples were taken every two days for total phenolic concentration (TPC) and antioxidant capacity evaluation by DPPH test during 12-day cultivation. The 2-day and 10-d ay extracts were selected and concentrated by ebullition until 1/10 of original volume was reached. After that, both non-concentrated and concentrated extracts were evaluated for their antimicrobial activity against Staphylococcus aureus and Salmonella enterica and a-amylase inhibitory capacity. It was observed an inverse relationship between total phenolic concentration (TPC) and antioxidant capacity during the cultivation. Besides that, the concentrated pineapple samples after two days were able to inhibit both pathogens tested, especially S. aureus. Guava concentrated extracts after 2 days showed expressive inhibition against S. enterica, but negative results against S. aureus growth. When it comes to a-amylase inhibition, A9 extracts after 2 days, both concentrated or not, completely inhibited enzyme activity. Similar behavior was observed for G9 samples, but only for concentrated samples. It was shown that concentration by ebullition positively affected the enzymatic inhibition of G9 and A9 samples, but on the other side, decreased antiamylase activity of A5 and G5 samples

Strain variability in the DNA immigration control region (ICR) of Xylella fastidiosa

The genome of the bacterium Xylella fastidiosa contains four ORFs (XF2721, XF2725, XF2739 and XF0295) related to the restriction modification type I system, ordinarily named R-M. This system belongs to the DNA immigration control region (ICR). Each CIRF is related to different operon structures, which are homologues among themselves and with subunit Hsd R from the endonuclease coding genes. In addition, these ORFs are highly homologous to genes in Pseudomonas aeruginosa, Methylococcus capsulatus str. Bath, Legionella pneumophila, Helicobacter pylori, Xanthomonas oryzae pv. Oryzae and Silicibacter pomeroyi, as well as to genes from X. fastidiosa strains that infect grapevine, almond and oleander plants. This study was carried out on R-M ORFs from forty-three X. fastidiosa strains isolated from citrus, coffee, grapevine, periwinkle, almond and plum trees, in order to assess the genetic diversity of these loci through PCR-RFLP. PCR-RFLP analysis of the four ORFs related to the R-M system from these strains enabled the detection of haplotypes for these loci. When the haplotypes were defined, wide genetic diversity and a large range of similar strains originating from different hosts were observed. This analysis also provided information indicating differences in population genetic structures, which led to detection of different levels of gene transfer among the groups of strains. (c) 2005 Elsevier SAS. All rights reserved.

Road-killed wild animals: a preservation problem useful for eco-epidemiological studies of pathogens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fungos causadores de podridões pós-colheita em uvas apirênicas no pólo agrícola de Juazeiro - BA e Petrolina - PE

In Brazil, postharvest diseases caused by pathogenic microorganisms are a major problem that causes damage to around 80% of the total fruit production. In the lower middle Sao Francisco river valley numerous studies on identification and control of fungal diseases during postharvest of grapes are needed, in order to minimize losses in this step. In this context, bunches of seedless varieties 'Crimson', 'Sonaka'; 'Superior' and 'Thompson' were collected from July to November 2009, in order to identify and quantify the incidence of pathogenic fungi. The grapes were collected on five farms which specialize in the production of table grapes for export, all located in Juazeiro - BA and Petrolina - PE. During this period, 10 samples were taken. In the fruit farm five plants were used for sampling, and removal of two bunches of grapes per plant, totaling 10 bunches per variety. Subsequently, they were sent to the laboratory of Plant Pathology at UNEB/DTCS where they were placed separately in a moist chamber for 48 hours at an average temperature of 23 degrees C. After this period, isolations of berries and stems in Petri plates containing PDA - potato-dextrose-agar were carried out with 10 repetitions, which were placed on benches under laboratory conditions. From the 8th day on, the presence of Aspergillus niger, Alternaria alternata, Cladosporium herbarum, Lasiodiploidia theobromae was observed, which presented the highest incidence, as well as Rhizopus stolonifer, Penicillium expansum.

Purification and some properties of an extracellular acid protease from Aspergillus clavatus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hydrolysis of whey lactose by immobilized β-Galactosidase

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Screening of filamentous fungi for production of enzymes of biotechnological interest

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Germinação, qualidade sanitária e armazenamento de sementes de canafístula (Peltophorum dubium)

Neste trabalho, objetivou-se avaliar o efeito de métodos de superação de dormência e do ambiente de armazenamento sobre a qualidade fisiológica e fitopatológica das sementes de canafístula (Peltophorum dubium). As sementes foram submetidas aos seguintes tratamentos de superação de dormência: escarificação com lixa (200); imersão em água na temperatura ambiente, durante 24 e 72 h; imersão em ácido sulfúrico por 2, 6, 10, 15, 20 e 30 min; imersão em água quente (70, 80 e 90 C); e umedecimento do substrato com solução de KNO3 (0,2%). As sementes foram armazenadas na temperatura ambiente e a 10 C por 210 dias. Os efeitos dos tratamentos e do armazenamento foram avaliados por meio do teor de água, teste de germinação (cinco repetições de 30 sementes), de comprimento de plântulas e sanidade (400 sementes), com incubação por oito dias (22-25 C). Na análise estatística dos dados, utilizou-se o delineamento experimental inteiramente casualizado em esquema fatorial 2 x 14 (condições de armazenamento x tratamentos para a superação da dormência). As médias foram comparadas pelo teste de Tukey (P>0,5). Com relação às sementes não armazenadas, os melhores tratamentos para superar a dormência e promover a germinação foram escarificação com lixa ou ácido sulfúrico por 15 a 30 min; quanto às sementes armazenadas, houve a imersão em água quente (70 a 80 ºC). Os fungos detectados nas sementes foram Pestalotia sp., Alternaria sp., Rhizopus sp., Nigrospora sp., Curvularia sp., Fusarium sp., Rhizoctonia sp., Aspergillus sp., Cladosporium sp. e Fusarium semitectum.

TRATAMENTO DE SEMENTES DE ARROZ, TRIGO, FEIJÃO E SOJA COM UM PRODUTO FORMULADO À BASE DE CÉLULAS E DE METABÓLITOS DE Bacillus subtilis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fungus incidence on peanut grains as affected by drying method and Ca nutrition

An experiment was conducted to study the effects of liming and drying method on Ca nutrition, fungus infection and aflatoxin production potential on peanut (Arachis hypogea) grains. Peanut cv. Botutatu was grown in the absence or presence of liming to raise the base saturation of the soil from 20 to 56%. Calcium contents of the soil were increased from 5.5 to 14.6 mmol((c))kg-1 and pH from 4.2 to 4.9. After harvest, plants and pods were dried in (1) shade, (2) field down to 100 g water kg-1 (3) field down to 250 g water kg-1 and transferred to a forced-air oven at 30°C, (4) field down to 360 g water kg-1 and transferred to a forced-air oven at 30°C. Calcium contents were analyzed in the grains, pericarps and seed coats. The incidence of Aspergillus spp., Penicillium spp., Rhizopus spp. and potential aflatoxin production in vitro were evaluated, as well as the seed coat thickness. The seed coat was thicker when peanut was grown in the presence of lime, leading to a decrease in seed infection by Aspergillus spp. and Penicillium spp. When plants were dried in shade, the growth of aflatoxinogenic fungi was independent of liming. However, in plants dried in the field or field + oven, the development of these fungi was decreased and even suppressed when the Ca content of the seed coat was increased from 2.2 to 5.5 g kg-1.

Induction of physical paramorphogenesis in Aspergillus sp

A simple and easily reproducible method to obtain little fungical pellets from mycelial fractionization, completely under control with respect to development, size and homogeneity without genetic compromise, is described. The method has been successully employed with Aspergillus niger and also showed similar results with Aspergillus oryzae.

Antimicrobial activity of essential oils from plants used in Brazilian popular medicine

Essential oils from, Salvia officinalis L. (SO), Mentha sylvestris L. (MS), Casearia sylvestris Sw. (CS), Mentha piperita L. (MP), Ocimum micrantum Willd. (OM) and Mentha arvensis L. (MA), plants used in Brazilian popular medicine were extracted using method I, as described in the Brazilian Pharmacopoeia, in order to obtain the phytochemical profile and to evaluate their antimicrobial activity against the following microorganisms: Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Serratia marcescens, Candida albicans and Aspergilus oryzae. Test was made by means of the disk-plaque diffusion test in liquid medium using 1% essential oil. In the disk-plaque diffusion test, all the essential oils exhibited activity against B. subtilis, but OM showed the greatest inhibition zone and was the only one to show activity against S. aureus. Samples of SO, MS, MP, OM and MA were active against M. luteus, E. coli and S. marcescens, while A. oryzae was sensitive to MS, MP, OM and MA. No sample, however, was active against C. albicans. In the liquid medium test, significant results were observed for OM and MA, which inhibited the growth of all microorganisms for 24 hours, and OM continued active against E. coli and A. oryzae until the last reading.

Antibiótico antifungico produzido por um estreptomiceto da região de Araraquara

With the significant increase in the incidence of invasive fungal infections during the last decade, mainly in patients with cancer, AIDS and other hospitalized patients who stay for long periods in intensive care units, there is an urgent need to screen for new antifungal agents possessing some advantages over known ones. This article reports a search in the field for a microorganism producing antibacterial and antifungal substances. Strains from soil samples collected in the region of Araraquara, Brazil, were isolated and analyzed for their antimicrobial potential against standard microorganisms (fungi Candida albicans and Aspergillus oryzae and bacteria Staphylococcus aureus and Escherichia coli). Out of the 64 strains isolated, 34 produced detectable antimicrobial activity. The streptomycete strain Ar4014 was chosen for further study, owing to its good antimicrobial activity against Candida albicans. Two of the fermentation media tested, 608-K and 602-B, were found to be best for the production and extraction of the antibiotic from Ar4014. After chromatographic separation of the crude extract on a silica column, the active fractions obtained showed UV-VIS absorption peaks characteristic of normal pentaenic antibiotics. The antibiotic was provisionally designated Ara 4014-75.

Qualidade fisiológica e sanitária de sementes de feijoeiro (Phaseolus vulgaris L.) provenientes do estado de Goiás

The common beans (Phaseolus vulgaris L.) is a fabacea sufficiently spread out in all domestic territory. However, the quality of its seeds represents one of the main causes of low productivity in the beans farmings in Brazil. The objective of this work was to evaluate physiological and sanitary seed qualities of eleven bean cultivars. The physiological seed quality was evaluated trough standard germination and vigor tests. The sanitary seed quality was evaluated through two tests: blotter test was employed to evaluate fungi incidence and Koch & Menten method was employed to observe Sclerotinia sclerotiorum (Lib) de Bary occurrence. Xamego, BRS Valente, Bambu and Pérola had the best results of physiological tests. Jalo Precoce, Roxo 90, Corrente and Aporé had no good results of vigor and germination, besides presenting the lowest indices of died seeds. Fusarium sp., Aspergillus spp., Penicillium sp., Phoma sp., Rhizopus sp. and Botrytis sp. were the fungi detected in the sanity tests.

Qualidade fisiológica e sanitária de sementes de mamona submetidas a diferentes tratamentos químicos

The use of fungicides for treating seeds has become an essential measure in the control of pathogens. However, the effectiveness of many products is not well-known to some crops. The objective of this research was to evaluate the effect of different doses of carbendazin and carboxin + thiram fungicides for controlling pathogens and their interference on the physiologic quality of castor bean seeds. The test consisted of the following treatments (g i.a./100 kg of seeds): carbendazin (15, 30, and 60), carboxin + thiram (25 + 25, 50 + 50, and 100 + 100), formol 0.15% (v/v), and control (distilled water). The physiologic quality of the seeds was determined by germination, first counting, field emergence, speed emergence index, length, fresh and dry weight of the aerial part, and electrical conductivity. There were no statistical differences for germination and fresh and dry matter index. The treatment with formol provided lower values for first counting and field emergence. Seeds treated with fungicides presented higher values for electrical conductivity, but did not differ, statistically, among themselves. The fungi Cladosporium spp.; Bipolaris spp.; Curvularia spp.; Aspergillus flavus; Aspergillus niger; Rhizopus sp.; Penicillium sp.; Rhizoctonia sp.; Verticillium sp.; Fusarium sp.;Arthrobotrys sp.; and Epicocum sp. were identified. All tested products, independently of the dose, provided efficient control for pathogens.