Co-culture of microalgae, cyanobacteria, and macromycetes for exopolysaccharides production: process preliminary optimization and partial characterization.

In this study, the biomass and exopolysaccharides (EPS) production in co-cultures of microalgae/cyanobacteria and macromycetes was evaluated as a technology for producing new polysaccharides for medical and/or industrial application. Based on biomass and EPS productivity of monocultures, two algae and two fungi were selected and cultured in different co-culture arrangements. The hydrosoluble EPS fractions from mono- and cocultures were characterized by ¹³C NMR spectroscopy and gas chromatography coupled to mass spectrometry and compared. It was found that co-cultures resulted in the production of an EPS different from those produced by monocultures, showing fungal predominance with microalgal/cyanobacterial traces. Co-cultures conditions were screened (temperature, agitation speed, fungal and microalgae inoculation rate, initial pH, illumination rate, and glucose concentration) in order to achieve maximum biomass and EPS production, resulting in an increase of 33 and 61% in exopolysaccharides and biomass productions, respectively (patent pending)

Screening of fungal strains for cellulolytic and xylanolytic activities production and evaluation of brewers’ spent grain as substrate for enzyme production by selected fungi

Brewer’s spent grain (BSG), the solid residue of beer production, is attracting significant attention as raw material for the production of added value substances, since until recently it was mainly used as animal feed or deposited in landfills, causing serious environmental problems. Therefore, this work aimed at developing a bioprocess using BSG as a substrate for the production of cellulases and xylanases for waste saccharification and bioenergy production. Different fungi were analyzed for their cellulolytic and xylanolytic abilities, through a first screening on solid media by assessment of fungal growth and enzyme production on agar containing carboxylmethylcellulose or xylan as the sole carbon source, respectively. The best cellulase and xylanase producers were subjected to quantitative evaluation of enzyme production in liquid cultures. Aspergillus niger LPB-334 was selected for its ability to produce cellulase and xylanase at high levels and it was cultivated on BSG by solid state fermentation. The cellulase production reached a maximum of 118.04 8.4 U/g of dry substrate after 10 days of fermentation, while a maximum xylanase production of 1315.15 37.5 U/g of dry substrate was reached after 4 days. Preliminary characterization of cellulase and xylanase activities and identification of the enzymes responsible were carried out

Milk kefir: Composition, microbial cultures, biological activities, and related products

In recent years, there has been a strong focus on beneficial foods with probiotic microorganisms and functional organic substances. In this context, there is an increasing interest in the commercial use of kefir, since it can be marketed as a natural beverage that has health promoting bacteria. There are numerous commercially available kefir based-products. Kefir may act as a matrix in the effective delivery of probiotic microorganisms in different types of products. Also, the presence of kefir's exopolysaccharides, known as kefiran, which has biological activity, certainly adds value to products. Kefiran can also be used separately in other food products and as a coating film for various food and pharmaceutical products. This article aims to update the information about kefir and its microbiological composition, biological activity of the kefir's microflora and the importance of kefiran as a beneficial health substance.Facultad de Ciencias Exacta

MARCADORES PARASITOLÓGICOS E HEMATOLÓGICOS PARA A SELEÇÃO DE BOVINOS RESISTENTES À DERMATOBIOSE

O presente trabalho foi desenvolvido na UFPR - Campus Palotina e em três propriedades rurais do município de Palotina, Paraná, durante o período de setembro de 1997 a agosto de 1999. O experimento foi delineado com o objetivo de estudar possíveis marcadores (parasitológicos e hematológicos) que refletem a habilidade do gado de leite (raça Holandesa Preto e Branco) em resistir à parasitose por larvas de Dermatobia hominis (Linnaeus Jr., 1781). Um total de 1050 larvas de D. hominis foram expulsas por meio de compressão digital. Os maiores valores de contagem total de leucócitos foram observados nos animais que apresentaram o menor número de nódulos de larvas de D. hominis. Study of parasitological and hematological markers for the selection of dermatobiose resistant bovines Abstract The present research work has been carried out from September 1997 through August 1999 at Federal University of Paraná Palotina Campus and in three farms from the same County. The main aim of this study was to analyze the possible parasitological and hematological markers that reflect Black and White Holstein dairy cattle resistance towards parasitism by Dermatobia hominis (Linnaeus Jr, 1781) larvae. From the group of 14 experimental animals a total of 1050 D. hominis were collected by manual compression during the period of time of the experiment. From the hematological data it was possible to conclude that there was an inverse relationship between the total leucocytes counting values and the number of larvae nodules, so that the highest the number of leucocytes per l of blood, the lowest the number of larvae nodules

Bioconversion of potato-processing wastes into an industrially-important chemical lactic acid

Lactic acid (LA) is an important biomolecule applied in food, pharmaceutical and chemical areas, mainly to produce biodegradable polymers, such as poly–lactic acid (PLA). In this work, an efficient fermentative process for LA production was developed using potato processing waste (PPW) hydrolysate with Lactobacillus pentosus. After optimization and kinetics studies, LA production reached 150 g/L with a productivity of 1.6 g/L.h in Erlenmeyer flasks. LA production was also conducted in STR where 110 g/L were reached with a productivity of 2.4 g/L.h. LA recovery consisted of a clarification step, with powdered activated carbon, with further precipi- tation at low temperature and acidification of calcium lactate for conversion to LA. The process was effective for contaminants’ removal and clarification, and LA concentration to 416 g/L. Good perspectives for LA production, recovery and clarification were observed. Future studies will be carried out for LA purification and polymeri- zation for PLA synthesis

Statistical optimization for lipase production from solid waste of vegetable oil industry

<p>The production of biofuel using thermostable bacterial lipase from hot spring bacteria out of low-cost agricultural residue olive oil cake is reported in the present paper. Using a lipase enzyme from <i>Bacillus licheniformis</i>, a 66.5% yield of methyl esters was obtained. Optimum parameters were determined, with maximum production of lipase at a pH of 8.2, temperature 50.8°C, moisture content of 55.7%, and biosurfactant content of 1.693 mg. The contour plots and 3D surface responses depict the significant interaction of pH and moisture content with biosurfactant during lipase production. Chromatographic analysis of the lipase transesterification product was methyl esters, from kitchen waste oil under optimized conditions, generated methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate.</p

RESPOSTA IMUNE HUMORAL DE COELHOS FRENTE A EXTRATOS DE LARVAS DE Dermatobia hominis

O presente experimento teve como objetivo avaliar a resposta imune humoral de coelhos frente a extrato de larvas (L2 e L3) de D. hominis. Vinte e quatro coelhos foram imunizados com três diferentes extratos de larvas de D. hominis. Foram estabelecidos três grupos imunizados da seguinte forma: grupo A, com extrato solúvel; grupo B, com extrato bruto; e grupo C, com extrato solúvel e extrato bruto. Uma dose de reforço foi aplicada no 135o dia após a primeira inoculação, nos animais dos grupos A, B e C. Amostras de soro foram coletadas quinzenalmente do dia 0 aos 150 dias após a primeira imunização (DPI) para verificar a cinética de produção de anticorpos por meio do ensaio de imunoadsorção enzimática (ELISA). Anticorpos circulantes foram encontrados em níveis máximos a partir de 45 DPI. A dose de reforço induziu o aparecimento imediato de uma resposta secundária. O extrato solúvel foi mais eficaz na estimulação da resposta imune humoral de machos e fêmeas. Constatou-se diferença significativa (