Pleurotus biomass production on vinasse and its potential use for aquaculture feed.

The vinasse is a by-product generated during the manufacture of alcohol from sugarcane fermentation. Rich in organic matter, it is known that the vinasse has the potential to be used as a source of nutrients for plants as well as microorganisms. In this study, the fungi Pleurotus sajor-caju, P. ostreatus, P. albidus and P. flabellatus were cultivated in vinasse and utilised as a complementary diet for Danio rerio fish. The fungi mycelia cultured in vinasse for 15 days were lyophilised and offered to the fishes at a rate of 2% (medium/body weight) for 28 days. P. albidus produced the highest biomass (16.27 g L-1). Bromatological analysis of mycelia showed similar values to commercial rations. Toxicity tests showed that fish survival was 100% and no significant biomass loss was observed, indicating that the tested fungi grown in vinasse showed no toxicity. Our results showed that vinasse is a promising by-product for fungal growth and the mycelia of Pleurotus sp. fungi can be included in the diets of fish as a nutritional supplement.

Endophytic and pathogenic isolates of the cacao fungal pathogen Moniliophthora perniciosa (Tricholomataceae) are indistinguishable based on genetic and physiological analysis.

We evaluated the genetic and physiological variability of Moniliophthora perniciosa obtained from healthy and diseased branches of cacao (Theobroma cacao) plants. The diversity of the isolates was evaluated by RAPD technique and by studies of virulence and exoenzyme production. The genetic variability of endophytic and pathogenic M. perniciosa was evaluated in association with pathogenicity assays. RAPD analysis showed eight genetic groups, which were not related to plant disease status (healthy versus diseased branches). Isolates from cacao were included in three groups, excluding isolates from other host plants. Pathogenicity and enzyme analysis showed that the virulence of the isolates is not related to exoenzyme production. This is the first evidence that M. perniciosa colonizes healthy parenchymatic tissues, showing that endophytic behavior may occur in this species.

Ecotoxicological assessment of water and sediment of the Corumbataí River, SP, Brazil.

The Corumbataí River drains an economically important area which is mainly represented by the municipalities of Piracicaba and Rio Claro. In view of the impacts caused by the discharge of industrial waste and domestic sewage into the Piracicaba River, the Corumbataí has become increasingly significant as a source of water for the municipality of Piracicaba. However, chemical, physical, and microbiological analyses carried out prior to the present study had already indicated a decline in the quality of the Corumbataí waters. This study aimed to assess, through water and sediment samples, both acute and chronic toxicity to Daphnia magna and Daphnia similis, and to analyze acid-volatile sulfide (AVS) and simultaneously extracted metal (SEM) in the sediment. Resulting data were intended to be a contribution to future projects for the management and recuperation of this system. To that aim, water and sediment were collected at seven Corumbataí sampling stations in November 2003 and March 2004. Acute toxicity to D. similis was detected in water and sediment samples from the Piracicaba station, located at the mouth of the Corumbataí River. Chronic toxicity was identified in the water or sediment samples of all stations, with the exception of Analândia Montante (upstream), at the head of the river. This was found to affect survival, growth, and fecundity of the test-organisms. The AVS and SEM analyses showed the bioavailability of the metals, thus explaining toxicity found in bioassaying samples of water and sediment. The use of two test-organism species made it possible to obtain a better assessment of the condition of both water and sediment samples of the Corumbataí River.

Ecotoxicological assessment of water and sediment of the Corumbataí River, SP, Brazil

The Corumbataí River drains an economically important area which is mainly represented by the municipalities of Piracicaba and Rio Claro. In view of the impacts caused by the discharge of industrial waste and domestic sewage into the Piracicaba River, the Corumbataí has become increasingly significant as a source of water for the municipality of Piracicaba. However, chemical, physical, and microbiological analyses carried out prior to the present study had already indicated a decline in the quality of the Corumbataí waters. This study aimed to assess, through water and sediment samples, both acute and chronic toxicity to Daphnia magna and Daphnia similis, and to analyze acid-volatile sulfide (AVS) and simultaneously extracted metal (SEM) in the sediment. Resulting data were intended to be a contribution to future projects for the management and recuperation of this system. To that aim, water and sediment were collected at seven Corumbataí sampling stations in November 2003 and March 2004. Acute toxicity to D. similis was detected in water and sediment samples from the Piracicaba station, located at the mouth of the Corumbataí River. Chronic toxicity was identified in the water or sediment samples of all stations, with the exception of Analândia Montante (upstream), at the head of the river. This was found to affect survival, growth, and fecundity of the test-organisms. The AVS and SEM analyses showed the bioavailability of the metals, thus explaining toxicity found in bioassaying samples of water and sediment. The use of two test-organism species made it possible to obtain a better assessment of the condition of both water and sediment samples of the Corumbataí River.

O rio Corumbataí drena uma área de importância econômica representada principalmente pelos municípios de Piracicaba e Rio Claro. Face aos impactos causados pelos lançamentos de efluentes industriais e domésticos no rio Piracicaba, o rio Corumbataí assumiu importância para o abastecimento do município de Piracicaba. Entretanto, análises químicas, físicas e microbiológicas realizadas no rio Corumbataí anteriormente a este estudo, indicaram a queda da qualidade de suas águas. Os objetivos deste estudo foram a avaliação da toxicidade aguda e da toxicidade crônica das amostras de água e sedimento, para Daphnia magna e Daphnia similis, e a análise do sulfeto volatilizável por acidificação (SVA) e dos metais simultaneamente extraídos do sedimento (MSE), no sentido de fornecer dados que possam contribuir com projetos futuros de manejo e recuperação desse sistema. Para tanto, água e sedimento provenientes de sete estações de coleta do rio Corumbataí foram coletados em novembro de 2003 e março de 2004. Foi detectada toxicidade aguda para D. similis das amostras de água e sedimento da estação Piracicaba, na foz do rio Corumbataí. A toxicidade crônica foi identificada na água ou no sedimento de todas as estações de coleta, exceto Analândia Montante (nascente do rio), influenciando a sobrevivência, crescimento e fecundidade dos organismos-teste. As análises do SVA e MSE revelaram a biodisponibilidade dos metais, explicando a toxicidade das amostras de água e de sedimento encontrada nos bioensaios. A adoção de duas espécies de organismos-teste possibilitou uma melhor avaliação dos compartimentos amostrados.

Effect of composted textile sludge on growth, nodulation and nitrogen fixation of soybean and cowpea.

The effect of composted textile sludge on growth, nodulation and nitrogen fixation of soybean and cowpea was evaluated in a greenhouse experiment. The compost was incorporated into soil at 0, 9.5, 19 and 38 t ha(-1) (bases upon the N requirement of the crops, i.e., 0, 50, 100 and 200 kg available N ha(-1)). Growth, nodulation and shoot accumulation of nitrogen were evaluated 36 and 63 days after plant emergence. Nodule glutamine synthetase (GS) activity and leghemoglobin content were evaluated 63 days after emergence. Composted textile sludge did not show negative effects on nodule number and weight, nodule GS activity and leghemoglobin content. Nitrogen accumulation in shoot dry matter in soybean and cowpea was higher than other treatments with application of 19 t ha(-1) of compost. Composting can be an alternate technology for the management of solid textile mill sludge. This study verifies that the composted textile sludge was not harmful to growth, nodulation and nitrogen fixation of soybean and cowpea.

Toxicity assessment of reference and natural freshwater sediments with the LuminoTox assay.

We examined the possibility of adapting the LuminoTox, a recently-commercialized bioanalytical testing procedure initially developed for aqueous samples, to assess the toxic potential of sediments. This portable fluorescent biosensor uses photosynthetic enzyme complexes (PECs) to rapidly measure photosynthetic efficiency. LuminoTox testing of 14 CRM (Certified Reference Material) sediments was first undertaken with (1) a "solid phase assay" (Lum-SPA) in which PECs are in intimate contact with sediment slurries for a 15 min exposure period and (2) an elutriate assay (Lum-ELU) in which PECs are exposed for 15 min to sediment water elutriates. CRM sediment toxicity data were then compared with those generated with the Microtox Solid Phase Assay (Mic-SPA). A significant correlation (P < 0.05) was shown to exist between Lum-SPA and Mic-SPA, indicating that both tests display a similar toxicity response pattern for CRM sediments having differing contaminant profiles. The sediment elutriate Lum-ELU assay displayed toxicity responses (i.e. measurable IC20s) for eight of the 14 CRM sediments, suggesting that it is capable of determining the presence of sediment contaminants that are readily soluble in an aqueous elutriate. Lum-SPA and Mic-SPA bioassays were further conducted on 12 natural freshwater sediments and their toxicity responses were more weakly, yet significantly, correlated. Finally, Lum-SPA testing undertaken with increasing mixtures of kaolin clay confirmed that its toxicity responses, in a manner similar to those reported for the Mic-SPA assay, are also subject to the influence of grain size. While further studies will be required to more fully understand the relationship between Lum-SPA assay responses and the physicochemical makeup of sediments (e.g., grain size, combined presence of natural and anthropogenic contaminants), these preliminary results suggest that LuminoTox testing could be a useful screen to assess the toxic potential of solid media.

Microbial biomass and activity in a Brazilian soil amended with untreated and composted textile sludge.

This laboratory study examines the effect of application of untreated and composted textile sludge on microbial biomass and activity in a Brazilian soil. The soil was amended with untreated and composted sludge at rates equivalent of 6.4t ha(-1) (0.64 g per 100g of soil) and 19t ha(-1) (1.90 g per 100g of soil), respectively, and were incubated at 28 degrees C for 60 days and daily sampled for microbial activity. An additional experiment, in the same condition, was conduced for evaluation of microbial biomass and enumeration of microorganisms at 15, 30 and 60 days after incubation. The application of composted sludge increased significantly the microbial biomass and activity, and bacteria number of soil. There were not differences in the microbial activity and bacteria number among the control and untreated sludge amended soils. In conclusion, after 2 months of incubation, the effects of the two amendments on soil microorganisms were: microbial biomass, soil respiration and bacteria number were increased only in composted sludge treated soil. qCO2 and fungi number were not affected by untreated and composted sludge.

Effect of glyphosate on the microbial activity of two Brazilian soils.

Glyphosate [N-(phosphonomethyl)-glycine] is a broad-spectrum, non-selective, post-emergence herbicide that is widely used in agricultural. We studied, in vitro, changes in the microbial activity of typical Hapludult and Hapludox Brazilian soils, with and without applied glyphosate. Glyphosate was applied at a rate of 2.16 mg glyphosate kg(-1) of soil and microbial activity was measured by soil respiration (evolution of CO(2)) and fluorescein diacetate (FDA) hydrolysis over a period of 32 days. We found an increase of 10-15% in the CO(2) evolved and a 9-19% increase in FDA hydrolyses in the presence of glyphosate compared with the same type of soil which had never received glyphosate. Soil which had been exposed to glyphosate for several years had the strongest response in microbial activity. Most probable number (MPN) counts showed that after 32 days incubation the number of actinomycetes and fungi had increased while the number of bacteria showed a slight reduction. After the incubation period, high pressure liquid chromatography (HPLC) detected the glyphosate metabolite aminomethyl phosphonic acid (AMPA), indicating glyphosate degradation by soil microorganisms.

Citric acid production with mixed strains of Aspergillus niger

Seis linhagens de Aspergillus niger, provenientes de indústrias e 15 combinaçöes dessas linhagens, foram analisadas quantitativamente, em relaçäo à acidez total e à produçäo de ácido cítrico. O delineamento experimental permitiu determinar os efeitos da capacidade de combinaçäo e desse modo pode ser avaliada a contribuiçäo de cada linhagem nessas combinaçöes. Apenas em poucos casos, a fermentaçäo com mistura de linhagens mostrou uma tendência para uma produçäo de ácido cítrico intermediária em relaçäo à produçäo de linhagens isoladas. Dez combinaçöes de linhagens tiveram uma produçäo de ácido cítrico mais baixa do que a da linhagem combinada, de menor produçäo. Quatro combinaçöes apresentaram produçäo de ácido cítrico intermediária, e em apenas um caso, a produçäo de ácido cítrico excedeu a das linhagens combinadas