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 co-cultures 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).

Technetium-99m-labeled deoxynivalenol from Fusarium mycotoxin alters organ toxicity in BALB/c mice by oral and intravenous route

The toxicity of deoxynivalenol, both intravenously and orally, was investigated in male and female BALB/c mice. Technetium-99m (99m Tc)-labeled deoxynivalenol was administered to mice by tail vein injection and orally dosed. Distribution of labeled deoxynivalenol at 26 hours was monitored by gamma-scintigraphy. In the evaluated organs, the accumulation of radioactive deoxynivalenol was correlated with the amount of radioactivity. In addition, the toxicity of deoxynivalenol was measured by biochemical assays followed by histopathological findings. Kidney and hepatic marker enzymes were significantly increased in intravenously administered deoxynivalenol as compared to orally treated mice. Intravenously treated mice showed severe damage in liver and kidney when compared to those orally exposed. Biodistribution of 99mTc-labeled deoxynivalenol differed between oral and intravenous treatment. In intravenously exposed mice, deoxynivalenol was distributed primarily in the liver and kidney whereas in oral exposure, it was found in the stomach and intestines after 26 hours. Deoxynivalenol toxicity, associated with its biodistribution and organ toxicity, was greatest where it had accumulated. The results show that the toxicity of deoxynivalenol is associated with organ accumulation.(AU)

Technetium-99m-labeled deoxynivalenol from Fusarium mycotoxin alters organ toxicity in BALB/c mice by oral and intravenous route

The toxicity of deoxynivalenol, both intravenously and orally, was investigated in male and female BALB/c mice. Technetium-99m (99m Tc)-labeled deoxynivalenol was administered to mice by tail vein injection and orally dosed. Distribution of labeled deoxynivalenol at 26 hours was monitored by gamma-scintigraphy. In the evaluated organs, the accumulation of radioactive deoxynivalenol was correlated with the amount of radioactivity. In addition, the toxicity of deoxynivalenol was measured by biochemical assays followed by histopathological findings. Kidney and hepatic marker enzymes were significantly increased in intravenously administered deoxynivalenol as compared to orally treated mice. Intravenously treated mice showed severe damage in liver and kidney when compared to those orally exposed. Biodistribution of 99mTc-labeled deoxynivalenol differed between oral and intravenous treatment. In intravenously exposed mice, deoxynivalenol was distributed primarily in the liver and kidney whereas in oral exposure, it was found in the stomach and intestines after 26 hours. Deoxynivalenol toxicity, associated with its biodistribution and organ toxicity, was greatest where it had accumulated. The results show that the toxicity of deoxynivalenol is associated with organ accumulation.(AU)

Effects of organic solvents on immobilized lipase in pectin microspheres.

Lipase from Brevibacillus agri 52 was found stable up to 90% diethylenglycol (DEG), glycerol (GLY), and 1,2 propanediol (1,2 PRO) at 37 degrees C for 1 h and the stability was reduced only approximately 20% after 12 h incubation, but in 40% dimethylsulfoxide (DMSO), lipase activity was stable only for 1 h. Inhibition of the biocatalysts with dimethylformamide (DMF) was detected at 20% solvent concentration. In water immiscible systems, the stability of lipase in n-hexane, n-tetradecane and n-heptane resembles the water activity, but in the presence of isobutanol, 1-hexanol, and butylbutirate, the stability was significantly reduced. Lipase 52 precipitates in the presence of 50% acetone or ethanol/water mixtures, but enzymatic activity was partially recovered by adding 20% GLY, DEG, 1,2 PRO, or DMSO to the reaction mixture. Furthermore, by increasing DEG in 70% DMF/DEG mixtures, the lipase activity was protected. Encapsulation of lipase in pectin gels cross-linked with calcium ions brings three to four times more enzymatic activity in 70% water miscible organic solvents compared to aqueous systems.

Conidia production of Beauveria sp. by solid-state fermentation for biocontrol of Ilex paraguariensis caterpillars.

Conidia production of Beauveria sp. strain LAG by solid-state fermentation (SSF) using blends of agro-industrial residues (residual potatoes and sugar-cane bagasse) was optimized with respect to cultivation conditions and the composition of substrate mixture in Erlenmeyer flasks and column-type bioreactor. With a blend of 60 % residual potatoes and 40 % sugar-cane bagasse the optimum conditions achieved were: incubation temperature 26 degrees C, initial substrate pH 6, inoculum concentration 10(7) conidia per g substrate; optimal initial moisture of the substrate was 70 % for Erlenmeyer flasks, in column-type bioreactor (with forced aeration) the optimal initial moisture of the substrate was 65 % with airflow of 60 mL/min. The highest production (1.07 x 10(10) conidia per g dry substrate) was achieved after a 10-d fermentation. The conidia were used in laboratory assays against Thelosia camina and Hylesia sp., caterpillars that are serious pests of mate plants. The mortality of T. camina was >90 % 10 d after spraying caterpillars with 1 mL conidia suspension at a concentration 10(5)-10(8)/mL. For Hylesia sp., the mortality was 70 %, 7 d after immersion in the conidia suspension containing 108 conidia per mL. Therefore, the Beauveria sp. LAG can be considered to be an important biocontrol instrument in the prospect of the Integrated Pest Management for mate plants.

Packed bed column fermenter and kinetic modeling for upgrading the nutritional quality of coffee husk in solid-state fermentation.

Studies were carried out to evaluate solid-state fermentation (SSF) for the upgradation of the nutritional quality of coffee husk by degrading the caffeine and tannins present in it. SSF was carried out by Aspergillus niger LPBx in a glass column fermenter using factorial design experiments and surface response methodology to optimize bioprocess parameters such as the substrate pH and moisture content and aeration rate. The first factorial design showed that the moisture content of the substrate and aeration rate were significant factors for the degradation of toxic compounds, which was confirmed by the second factorial design too. The kinetic study showed that the degradation of toxic compounds was related to the development of the mold and its respiration and also to the consumption of the reducing sugars present in coffee husk. From the values obtained experimentally for the oxygen uptake rate and CO(2) evolved, the system determined a biomass yield (Y(x/o)) of 3.811 (g of biomass).(g of consumed O(2))(-1) and a maintenance coefficient (m) of 0.0031 (g of consumed O(2)).(g biomass of biomass)(-1).h(-1). The best results on the degradation of caffeine (90%) and tannins (57%) were achieved when SSF was carried out with a 30 mL.min(-1) aeration rate using coffee husk having a 55% initial moisture content. The inoculation rate did not affect the metabolization of the toxic compounds by the fungal culture. After SSF, the protein content of the husk was increased to 10.6%, which was more than double that of the unfermented husk (5.2%).

Lutzomyia whitmani (Diptera: Psychodidae) as vector of Leishmania (V.) braziliensis in Paraná state, southern Brazil.

The phlebotomine sandflies in the northern areas of the state of Paraná, Brazil, particularly those in the '16a' health region, were investigated over a 3-year period. Using CDC light traps (with and without hamster bait) and Shannon traps (with lights and horse or human bait), 16 species were collected from seven municipal districts which were known foci for cutaneous leishmaniasis: Arapongas; Apucarana; Cambira; Marumbi; Faxinal; Florestópolis; and Sabáudia. Although the frequency at which each species was collected varied with the collection site, Lutzomyia whitmani predominated (62.0% of all the sandflies collected), followed by Lu. fischeri (13.3%), Lu. pessoai (10.8%), Lu. migonei (8.2%) and Lu. intermedia (2.8%). Lutzomyia monticola, Lu. shanonni, Lu. firmatoi, Lu. lanei, Lu. alphabetica, Lu. misionensis, Lu. correalimai, Lu. cortellezzii, Lu. longipenis, Brumptomyia brumpti and B. nitzulescui together represented the remaining 3.0% of the collected sandflies. Three of the 1961 female sandflies collected and dissected in the municipal district of Cambira, where a recent case of cutaneous leishmaniasis had been registered, were found to have flagellates in their guts. All three were Lu. whitmani. The parasites from each of these infections were successfully isolated in NNN and 'Tobie and Evans' media and/or by inoculation into a hind foot of a golden hamster. The results of isoenzyme electrophoresis indicated that all three isolates were of Leishmania (Viannia) braziliensis.

Solid state cultivation--an efficient method to use toxic agro-industrial residues.

Studies were carried out to screen twelve strains of Lentinus edodes for their efficiency to grow on toxic agro-industrial residues of coffee industry in solid state cultivation (SSC). Based on best mycelial growth (7.57 mm/day) and biomass production (48.78 mg/plate in 12 days at 24 degrees C) in coffee husk extract medium, a strain, L. edodes LPB 02 was selected for mushroom cultivation in SSC on coffee husk (treated and untreated), coffee spent ground, and a mixed-substrate comprising coffee husk and coffee spent ground (1:1). SSC was carried out under different conditions of moisture and spawn rate. Spawn rate of 10% and moisture level of 55-60% was found suitable for all the substrates. Treatment of the coffee husk with hot water was found useful for its utilization by the fungus. Results showed that there was an increase in the protein content and decrease in the fibre content of the substrates after SSC. Fruiting bodies were obtained from the treated coffee husk, spent ground and mixed-substrate, and the biological efficiency achieved was 85.8, 88.6 and 78.4% for these substrates, respectively. However, no fruiting body was obtained with raw coffee husk was used as the substrate. Results showed that after SSC, there was a decrease of about 27, 40 and 24% in caffeine and about 18, 49 and 12% in tannin contents in the treated coffee husk, coffee spent ground and mixed substrate, respectively. No caffeine or, tannins were found in fruiting body indicating their degradation by the fungal strain.

Optimization of the production of aroma compounds by Kluyveromyces marxianus in solid-state fermentation using factorial design and response surface methodology.

Studies were carried out for the production of aroma compounds in solid-state fermentation using factorial design and response surface methodology (RSM) experiments. Five agro-industrial residues were evaluated as substrate for cultivating a strain of Kluyveromyces marxianus. The results proved the feasibility of using cassava bagasse and giant palm bran (Opuntia ficus indica) as substrates to produce fruity aroma compounds by the yeast culture. In order to test the influence of the process parameters on the culture to produce volatile compounds, two statistical experimental designs were performed. The parameters studied were initial substrate pH, addition of glucose, cultivation temperature, initial substrate moisture and inoculum size. Using a 2(5) factorial design, addition of glucose and initial pH of the substrate was found statistically significant for aroma compounds production on palm bran. Although this experimental design showed that addition of glucose did not have a significant role with cassava bagasse, 2(2) factorial design revealed that glucose addition was significant at higher concentrations. Head-space analysis of the culture by gas chromatography showed the production of nine and eleven compounds from palm bran and cassava bagasse, respectively, which included alcohols, esters and aldehyde. In both the cases, two compounds remained unidentified and ethyl acetate, ethanol and acetaldehyde were the major compounds produced. Esters produced were responsible for the fruity aroma in both the cases. With palm bran, ethanol was the compound produced in highest concentration, and with cassava bagasse (both supplemented with 10% glucose), ethyl acetate was produced at highest concentration, accumulating 418 and 1395µmoll(-1) head-spaceg(-1) substrate in 72h, respectively.

Biological detoxification of coffee husk by filamentous fungi using a solid state fermentation system.

Studies were carried out on detoxification of coffee husk in solid state fermentation using three different strains of Rhizopus, Phanerochaete, and Aspergillus sp. Fungal strains were selected by their ability to grow on a coffee husk extract-agar medium. Using R. arrizus LPB-79, the best results on the degradation of caffeine (87%) and tannins (65%) were obtained with pH 6.0 and moisture 60% in 6 days. When P. chrysosporium BK was used, maximum degradation of caffeine and tannins were 70.8 and 45%, respectively, with coffee husk having 65% moisture and pH 5.5 in 14 days. The Aspergillus strain, isolated from the coffee husk, showed best biomass formation on coffee husk extract-agar medium. Optimization assays were conducted using factorial design, and surface response experiments with Aspergillus sp. The best detoxification rates achieved were 92% for caffeine and 65% for tannins. The results showed good prospects of using these fungal strains, in particular Aspergillus sp., for the detoxification of coffee husk.

Advances in microbial amylases.

This review makes a comprehensive survey of microbial amylases, i.e. alpha-amylase, beta-amylase and glucoamylase. Amylases are among the most important enzymes and are of great significance in present-day biotechnology. Although they can be derived from several sources, such as plants, animals and micro-organisms, the enzymes from microbial sources generally meet industrial demands. Microbial amylases could be potentially useful in the pharmaceutical and fine-chemical industries if enzymes with suitable properties could be prepared. With the advent of new frontiers in biotechnology, the spectrum of amylase application has widened in many other fields, such as clinical, medicinal and analytical chemistries, as well as their widespread application in starch saccharification and in the textile, food, brewing and distilling industries. In this review, after a brief description of the sources of amylases, we discuss the molecular biology of amylases, describing structures, cloning, sequences, and protoplast fusion and mutagenesis. This is followed by sections on their production and finally the properties of various amylases.

Production and shelf-life studies of low cost beverage with soymilk, buffalo cheese whey and cow milk fermented by mixed cultures of Lactobacillus casei ssp. shirota and Bifidobacterium adolescentis.

A study was performed to develop a fermented milk beverage with the aim to increase the potential application of buffalo cheese whey and soymilk. A mixed substrate was prepared by selective combination, which contained buffalo cheese whey 35%, soymilk 30% and cow milk 35%. The substrate mixture was fermented by a mixed culture of Lactobacillus casei shirota and Bifidobacterium adolescentis at 37 degrees C for 8 h keeping a 1:1.5 proportion between the lactic and bifidobacteria within a 5% (v/v) inoculum size. The fermented beverage was lightly extra-flavoured with vanilla essence and subjected to chemical, microbiological and sensory evaluations during storage for 28 days at 4 degrees C. Except a slight variation in the acidity, no other properties changed even after 28 days. There were no contaminating organisms (Salmonella and coliforms), which indicated the sanitary and hygienic conditions of the processing and the viable cells of the bacterial strains was well within recommended limits (6.8 x 10(8) cells for L. casei and 2.3 x 10(7) cells for Bifidobacterium). No negative changes were found in the sensory characteristics of the beverage allowing its good acceptability in all during the storage period.

Recent developments in microbial inulinases. Its production, properties, and industrial applications.

Microbial inulinases are an important class of industrial enzymes that have gained much attention recently. Inulinases can be produced by a host of microorganisms, including fungi, yeast, and bacteria. Among them, however, Aspergillus sp. (filamentous fungus) and Kluyveromyces sp. (diploid yeast) are apparently the preferred choices for commercial applications. Among various substrates (carbon source) employed for their production, inulin-containing plant materials offer advantages in comparison to pure substrates. Although submerged fermentation has been universally used as the technique of fermentation, attempts are being made to develop solid-state fermentation technology also. Inulinases catalyze the hydrolysis of inulin to D-fructose (fructose syrup), which has gained an important place in human diets today. In addition, inulinases are finding other newer applications. This article reviews more recent developments, especially those made in the past decade, on microbial inulinases--its production using various microorganisms and substrates. It also describes the characteristics of various forms of inulinases produced as well as their applications.

The realm of microbial lipases in biotechnology.

In this review, a comprehensive and illustrious survey is made of the applied aspects of microbial lipases in modern biotechnological practices. Lipases are the most versatile biocatalyst and bring about a range of bioconversion reactions such as hydrolysis, interesterification, esterification, alcoholysis, acidolysis and aminolysis. After a brief description of the microbial sources of lipases, the pivotal role of lipases in the processes and products of the food and flavourings industry is illustrated. An illustration is presented of biomedical applications. The panorama of lipases in the manufacture of fine chemicals is depicted with special emphasis on pharmaceuticals, pesticides, cosmetics, biosensors and detergents. Widening applications such as those in waste management and improved tanning techniques are other novel aspects of lipase utilization that are discussed in this review.