Biomedical subjects

C R Soccol

Publications and source records attributed to C R Soccol.

10 recordsLinked to original sources

PubMed2005

Continuous aerobic phenol degradation by defined mixed immobilized culture in packed bed reactors.

A defined mixed culture of Pseudomonas putida, Commamonas testosteroni and Candida tropicalis was immobilized by adsorption on polyurethane foam, cocoa-fibers, expanded slate and sintered glass. Packed bed reactors were used for long-term continuous phenol biodegradations. Loading experiments were done to study the impact of the following parameters: (1) hydraulic retention time, (2) dissolved oxygen concentration, and (3) elimination of the oxygen limitation. After the acclimation period (approximately 10 d), the loading test with the individual packings showed the following maximum degradation rates: sintered glass 34, polyurethane foam 12, expanded slate 11.5, and cocoa-fibers 7.7 kg m(-3) d(-1). All these values were reached at a removal efficiency >99 % and with oxygen in excess. Under these conditions, the pH of the diluted unbuffered medium in the reactor effluent was 3.2-4.0 and no incompletely oxidized metabolic intermediates were found. The free cell concentration in the effluent increased after the phenol overloading time period.

Aerobiosis↗

PubMed2004

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.

Animals↗

PubMed2001

Production, purification and properties of microbial phytases.

Phytases (myo-inositol hexakisphosphate phosphohydrolase, EC 3.1.3.8) catalyse the release of phosphate from phytate (mycoinositol hexakiphosphate). Several cereal grains, legumes and oilseeds, etc., store phosphorus as phytate. Environmental pollution due to the high-phosphate manure, resulting in the accumulation of P at various locations has raised serious concerns. Phytases appear of significant value in effectively controlling P pollution. They can be produced from a host of sources including plants, animals and micro-organisms. Microbial sources, however, are promising for their commercial exploitations. Strains of Aspergillus sp., chiefly A. ficuum and A. niger have most commonly been employed for industrial purposes. Phytases are considered as a monomeric protein, generally possessing a molecular weight between 40 and 100 kDa. They show broad substrate specificity and have generally pH and temperature optima around 4.5-6.0 and 45-60 degrees C. The crystal structure of phytase has been determined at 2.5 A resolution. Immobilization of phytase has been found to enhance its thermostability. This article reviews recent trends on the production, purification and properties of microbial phytases.

6-Phytase↗

PubMed2000

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.

Biodegradation, Environmental↗

PubMed2000

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.

Amylases↗

PubMed2000

Lactobacillus plantarum amylase acting on crude starch granules. Native isoforms and activity changes after limited proteolysis.

The microheterogeneous native amylolytic complex secreted by the isolate A6 of Lactobacillus plantarum revealed a selective enzyme specificity loss when submitted to a limited proteolysis under a suboptimum pH condition. A clear electrophoretic profile change toward just one shorter, more acidic, and equally active polypeptide fragment resulted from the pronase E pretreatment. Although the whole enzyme activity remained apparently unaffected for soluble starch, the native parallel activity on intact and non-gelatinized starch granules either from cereals or tubers was dramatically reduced. This phenomenon was more clearly documented by scanning electron microscopy using the easiest accessible native substrate: wheat starch granules. The anion-exchange-purified native enzymes from L. plantarum displayed a different optimum pH curve when compared with the thermotolerant alpha-amylase from Bacillus licheniformis. The alpha-amylases from the lactic-acid-producing A6 isolate presented an electrophoretic profile easily distinguishable from those from B. liqueniformis and B. subtilis species.

Amylases↗

PubMed1999

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.

Animals↗

PubMed1999

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.

Aspergillus↗

PubMed1999

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.

Bacteria↗

PubMedDate not supplied

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%).

Algorithms↗