José Luis Parada

Universidade Positivo (UP), Curityba, Paraná, Brazil

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Publications (9)9.16 Total impact

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    ABSTRACT: Phytase production by Aspergillus niger F3 by solid state fermentation (SSF) on citrus peel was evaluated at pilot scale under different aeration conditions. The best airflow intensity was 1 VkgM (Lair kg medium(-1) min(-1)), which allowed to produce 65 units of phytases per gram in dry basis (65 Ug(-1) d.b.) as it removed the metabolic heat generated by the microorganism, Agitation did not improve heat removal. Airflow intensity was considered as scale-up criterion. When the airflow intensity was maintained at 1 VkgM for SSF with 2 and 20 kg of medium, the kinetics parameters for biomass and enzyme concentration at the end of fermentation differed by less than 2. The air flow intensity was required to maintain the temperature and cool the SSF and to provide oxygen for microbial growth. Air flow intensity is a key a factor that must be considered when scale-up of SSF is attempted.
    Bioresource Technology 05/2012; 118:603-6. · 5.04 Impact Factor
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    ABSTRACT: Lactobacillus reuteri LPB P01-001 was isolated from the gastrointestinal tract of wild swine and was characterised by biochemical testing and sequencing of gene 16S rRNA. A simple and low-cost culture medium based on cane sugar (2.5% p/v) and yeast extract (1% p/v) was used in the production of this probiotic. The fermentative conditions were a) pH control at 6.5 and b) no pH control; both were set at 37°C in a 12 L slightly stirred tank bioreactor. Fermentation parameters such as the specific growth rate, productivity and yield of biomass, lactic and acetic acid levels were determined. L. reuteri LPB P01-001 behaves as an aciduric bacteria because it grows better in a low pH medium without pH control. However, the lactic acid production yield was practically half (9.22 g.L(-1)) of that obtained under a constant pH of 6.5, which reached 30.5 g.L(-1) after 28 hours of fermentation. The acetic acid production was also higher under pH-controlled fermentation, reaching 10.09 g.L(-1)after 28 hours of fermentation. These parameters may raise the interest of those committed to the efficient production of a probiotic agent for swine.
    Brazilian Journal of Microbiology 01/2012; 43(1):135-47. · 0.76 Impact Factor
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    ABSTRACT: A study from cows with mastitis was performed and Staphylococcus aureus was the predominant pathogen in 46.4 % among 153 studied strains from 276 milk samples of infected cows. Antibiotic resistance of 71 S. aureus isolates was determined in order to search resistant strains to antibiotics of clinical interest, as well as to determine their degree of multi-resistance. It was found that 60% of the S. aureus strains presented resistance to β-lactams, but none to oxacillin, teicoplamin or vancomycin. On the other hand, with the aim of reducing the use of current antibiotics and their associated resistance, a new formulation was introduced. The antimicrobial compounds (P22-P32), demonstrated to be effective in 55% of the 76 mastitis cases studied. The use of P22-P32 reduced the number of somatic cell to less than 300,000 SCC/mL-1 in 75.2 % of milk samples analyzed, normalizing the milk quality, fat and lactose levels and increasing the volume of production in 10.1 %.
    Brazilian Archives of Biology and Technology 08/2011; 54(4):709-716. · 0.47 Impact Factor
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    ABSTRACT: The extraction of phytase produced by solid-state fermentation of citrus peel was studied employing a multistage leaching process. It was observed that the extracts containing EDTA retained over 90% of phytase activity at room temperature after 24 h after the leaching. A fractional design 22 (with 4 replicates at the central point) was carried out for testing the pH and agitation as process independent factors. Only the interaction between the pH and agitation showed a significant influence. These factors were optimized with a central composite design. Agitation at 300 rpm and pH at 5.0 were the best conditions to extract the enzyme from solid matrix. The modeling of the process indicated that diffusivity of the enzyme in the solvent was the controlling mechanism. The corresponding kinetic constant and saturation concentration in this process were 0.89 min-1 and 4.0 IU/mL, respectively. The multistage process indicated that after two steps, it was possible to recover 85% of total enzyme produced.
    Brazilian Archives of Biology and Technology 12/2010; 53(6):1487-1496. · 0.47 Impact Factor
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    ABSTRACT: Beans are important sources of proteins and other nutrients. However, stachyose and other oligosaccharides (RFOs) are present in this legume causing flatulence (H2, CO2 and CH4), abdominal pain, and diarrhea. The problematic digestibility of these sugars in the small intestine is attributed to a lack of α-galactosidase, which is essential for the hydrolysis of α-1,6 linkages. The aim of the present work was to reduce the stachyose of black bean slurry by lactic acid fermentation using a selected Lactobacillus LPB56, an α-galactosidase producer. The bean slurry (6L) was fermented in a bioreactor with 1.3% (w/v) of CaCO3, at 37 °C and 160 rpm. Bacterial cells increased from 2.4 × 107 to 7.0 × 108 CFU/mL, and the stachyose and other sugars were totally consumed after 18 h of fermentation. The maximum activity of α-galactosidase was 0.162 U/mL after 6 h. The fermentative process did not cause significant changes on the composition of the bean product.
    Food Research International. 01/2009; 42(4):425-429.
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    ABSTRACT: This work presents a statistical model of survival analysis for three pathogenic bacterial strains (Escherichia coli, Listeria monocytogenes and Staphylococcus aureus), when treated with neutralized and non-neutralized filtered supernatants broth from cultures of Lactobacillus acidhophilus, Lactobacillus rhamnosus and Lactobacillus sake. Survival analysis is a method employed to determine the period of time from an initial stage up to the occurrence of a particular event of interest, as death or a particular culture growth failure. In order to evaluate the potential efficacy of the ahead mentioned lactic acid bacteria when used as bioprotective starters in foods, experimental data were statistically treated and expressed by simple representative curves. Following the methodology of Cox and Kaplan-Meier, it was possible to make the selection of the best bioprotective lactic starter, as a predictive tool for evaluation of shelf life and prevention of eventual risks in fresh sausages and other similar food products.
    Brazilian Archives of Biology and Technology 01/2009; 52. · 0.47 Impact Factor
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    ABSTRACT: Propionic acid (PA) is widely used as additive in animal feed and also in the manufacturing of cellulose-based plastics, herbicides, and perfumes. Salts of propionic acid are used as preservative in food. PA is mainly produced by chemical synthesis. Nowadays, PA production by fermentation of low-cost industrial wastes or renewable sources has been an interesting alternative. In the present investigation, PA production by Propionibacterium acidipropionici ATCC 4965 was studied using a basal medium with sugarcane molasses (BMSM), glycerol or lactate (BML) in small batch fermentation at 30 and 36 degrees C. Bacterial growth was carried out under low dissolved oxygen concentration and without pH control. Results indicated that P. acidipropionici produced more biomass in BMSM than in other media at 30 degrees C (7.55 g l(-1)) as well as at 36 degrees C (3.71 g l(-1)). PA and biomass production were higher at 30 degrees C than at 36 degrees C in all cases studied. The best productivity was obtained by using BML (0.113 g l(-1) h(-1)), although the yielding of this metabolite was higher when using glycerol as carbon source (0.724 g g(-1)) because there was no detection of acetic acid. By the way, when using the other two carbon sources, acetic acid emerged as an undesirable by-product for further PA purification.
    Applied biochemistry and biotechnology 05/2008; 151(2-3):333-41. · 1.94 Impact Factor
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    ABSTRACT: In recent times, there has been an increased interest to adapt healthy diets, which help in preventing diseases, and as a consequence, the study and development of new functional foods has gained much importance. Food additives as probiotics and prebiotics may exert positive effects on the composition of gut microbiota and are subject of intensive research. The allergy to dairy products affect negatively some persons. Lactose intolerance and the cholesterol content are two major drawbacks related to the fermented dairy products. Traditions and economic reasons that limit the use of dairy fermented products in some developing countries promote the idea of reduction of milk components as vehicles for the probiotic agents. At present, some non-dairy probiotic beverages are being commercialized and are discussed in this review. Probably, beverages such as fruit and vegetable juices would be the next food category where the healthy probiotic bacteria will make their mark.
    Food Research International. 01/2008;
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    J. L. PARADA