Use of soybean oil fry waste for economical biosurfactant production by isolated Pseudomonas aeruginosa using response surface methodology

The present study sought biotensoactive production from soybean oil fry waste using Pseudomonas aeruginosa ATCC 10145 and Pseudomonas aeruginosa isolated from the soil of a petroleum station having undergone gasoline and diesel oil spills. The results of the experiments were analyzed using a complete factorial experimental design, investigating the concentration of soybean oil waste, ammonia sulfate and residual brewery yeast. Assays were performed in 250-mL Erlenmeyer beakers containing 50 mL of production medium, maintained on a rotary shaker at 200 rpm and a temperature of 30±1 °C for a 48-hour fermentation period. Biosurfactant production was monitored through the determination of rhamnose, surface tension and emulsification activity. The Pseudomonas aeruginosa ATCC 10145 strain and isolated Pseudomonas aeruginosa were able to reduce the surface tension of the initial mexlium from 61 mN/m to 32.5 mN/m and 30.0 mN/m as well as produce rhamnose at concentrations of 1.96 and 2.89 g/L with emulsification indices of 96% and 100%, respectively.

Municipal solid waste management in the Caribbean: a benefit-cost analysis

Includes bibliography

Valores bioquímicos séricos de tilapia del Nilo (Oreochromis niloticus) en cultivo intensivo

The aim of the study was to evaluate the serum biochemical parameters of the Nile tilapia (Oreochromis niloticus), Thai Chitralada lineage, raised under an intensive pisciculture system and captured by the cast net technique. Blood samples from 40 individuals were obtained by caudal venopuncture. Mean body weight was 453 ± 52 g. The serum biochemical parameters evaluated were total protein, albumin, globulins, acid uric, creatinine, urea, calcium, inorganic phosphorus, Ca/P ratio, alkaline phosphatase, and magnesium. In general, the data showed similar parameters in comparison to those established for scale fish, exception of the acid uric.

Groundwater quality on a waste disposal area due to sand mining activities in São Paulo state, Brazil

This investigation reports the results of a study realized in an area related to the development of sand mining activities, which belongs to Sibelco Mineração Ltd. The site is located around Analândia municipality, nearly in the center of São Paulo State, Brazil. Hydrochemical analyses of groundwater were realized under different periods of time, with the aim of evaluating the possibility of release of several constituents to the liquid phase, which may be a source of pollution of the surface hydrological resources and of the deeper Guarani aquifer. This is because the site is located at the recharge area of Guarani aquifer and some tributaries from Corumbataí river may also be suffering contamination, implying on the impoverishment of the water quality that are very important resources in the region, as they are extensively used for drinking purposes, among others.© 2011 WIT Press.

Reproduction, food dynamics and exploitation level of Oreochromis niloticus (Perciformes: Cichlidae) from artisanal fisheries in Barra Bonita Reservoir, Brazil

Nile tilapia (Oreochromis niloticus), which is exotic to South America, is the most common species caught in artisanal fisheries at the Barra Bonita Reservoir, Southeastern Brazil. This species is of great socioeconomic importance for the region and keeps active a population of about 500 fishers. In the present study we assess reproduction, food dynamics and level of exploitation of O. niloticus, caught by artisanal fisheries in the Barra Bonita Reservoir. Specimens were collected monthly, from July 2004-June 2005, and a total of 1 715 specimens were analyzed. Each specimen was examined to obtain biological and biometric data: standard length (cm), total weight (g), reproductive data (sex and stage of maturation), and stomach contents (empty, partly full, and full). We also estimated the sex ratio (by macroscopic observation of gonads), reproductive period (by ovarian development and seasonal average of gonadosomatic index in females), and feeding habits (by stomach contents). The possible relationship between abiotic factors and the reproductive period was statistically verified using Spearman's Rank Correlation. The FiSAT (ELEFAN I) package was used to assess growth parameters, mortality rates and to infer exploitation rate from standard length frequencies. The O. niloticus population had a sex ratio of 1.3:1 (M:F). Results indicated that ripe females were captured throughout the year, with a higher frequency during the winter-2004 (with a frequency of 59%, at a mean temperature of 20.5°C), and in spring-2004 (with a frequency of 60.5% at a mean temperature of 21.18°C). The GSI mean values obtained by season were: winter-2004: 1.71; spring-2004: 1.72; summer-2005: 0.80, and autumn-2005: 1.19. The Spearman correlation indicated positive values with respect to pH, dissolved oxygen, electric conductivity, transparency and chlorophyll a, and negative values with respect to temperature, accumulated rainfall and altimetric benchmark. The main food items were phytoplankton and periphytic algae, observed in 99.6% of the analyzed stomachs. The estimated growth and mortality parameters were: L∞=33.60cm, k=0.63/year, longevity= 4.76years, Z=2.81/ year, M=1.20/year and F=1.61/year. The weight-length relationship was Ln Wt=-2.8532+2.8835 Ln Lp. The estimated yield per recruit values were as follows: E=0.570, Emax=0.776, E0.1=0.604 and E0.5=0.349. These results indicate that a well established population of O. niloticus is present at Barra Bonita Reservoir; with an active reproduction throughout the year, more intense during winter and spring, and that O. niloticus is a phytoplanktophagus species. There were no indications that this species is being overfished, we therefore recommend that, due to its exotic condition, no restrictions need to be taken on its fishing activities.

Mudanças ontogenéticas na dieta de Oreochromis niloticus and Tilapia rendalli da represa de Barra Bonita (rio Tietê, Estado de São Paulo, Brasil)

The Nile Tilapia, Oreochromis niloticus, and the Congo Tilapia, Tilapia rendalli, are important members of the African cichlids, and have been introduced to many Brazilian lakes and reservoirs. These species exhibit a large feeding flexibility and may modify their habits during their growth. In the Barra Bonita reservoir, these species are well adapted, representing more than 80% of fish. This study aimed to analyze ontogenetic variation with regard to the diet of these species in this important reservoir. Samples were taken monthly, from March 2007 to February 2008, in Anhembi, São Paulo State. Both species were analyzed by grouping individuals according to size classes. The coexistence of these species was observed in this environment, to which fish were introduced, as well as discreet differences in diet, being that Oreochromis niloticus was considered as an detritivorous, since the detritus was constant in the diet of almost all size classes, and presents some changes in its diet according to the different size classes. While T. rendalli may was defined as herbivorous, and the contribution of food resources to the diet of T. rendalli seems to be different from that of O. niloticus along the size classes.

Hemoparasite and hematological parameters in Nile tilapia

The accelerated growth of finfish aquaculture has resulted in a series of health problems, including blood disorders by hemoparasites; there are scarce studies about these agents and their impact in actual intensive farming. The aim of this study was to identify and quantify the hemoparasites present in monocytes and erythrocytes in the blood of tilapia and their correlation with the hematological profile. Blood samples were collected from caudal vessels of 15 cage-reared Nile tilapia (Oreochromis niloticus), with 70 ± 10 g weight on average, from Itambaracá Municipality, Parana State, Brazil. The total red blood cells, mean corpuscular volume, hematocrit, total and differential white blood cells counts, and the number of thrombocytes were determined in blood smears stained with May-Grünwald-Giemsa-Wright and Quick Panoptic. The results showed the presence of pleomorphic cytoplasmic inclusions with corrugated appearance and basophilic staining, mainly in monocytes, suggesting Anaplasmataceae parasitemia and inclusions with the same morphological characteristics in erythrocytes of one Nile tilapia. The hematological analysis showed no significant difference (P < 0.05) between infected and not infected fish, and therefore, there was no correlation between parasitemia and hematological profile. These observations allow us to infer that the intracytoplasmic inclusions in monocytes and erythrocytes are compatible with the family Anaplasmataceae. There was no correlation between the blood profile and low level of parasitemia. © 2012 Springer-Verlag London.

Substitution of corn and soybean oil by cassava meal and African palm tree oil in diets of laying hens

Fourty-two White Leghorns laying hens, from the commercial Cuban hybrid L-33, were used for eight weeks during the laying peak (36 to 43 weeks of age), to assess the substitution of corn by cassava root meal (Manihot esculenta Crantz) and the crude soybean oil by crude oil of African palm tree (Elaeis guineensis J.) in the diets of laying hens. Analysis of variance was conducted, according to simple classification design, with three treatments and 14 repetitions (a cage with a hen). The treatments consisted of three diets (1- corn meal + soybean oil; 2- 25 % cassava meal + African palm tree oil; 3- 53 % cassava meal + African palm tree oil), with 15.71 % CP; 3.83 % Ca and 0.36 % P available. The viability was of 100 % in all treatments. No differences were found for laying (92.21, 92.09 and 91.59 %), which surpassed the potential of this hybrid during the laying peak (90 %), conversion (118g feedstuff/egg in the three treatments), egg mass produced (3066, 3114 and 3071 g/bird) and mass conversion (1.99, 1.95 y 1.98 feed consumed/egg mass). The pigmentation of the egg yolk was reduced as the level of cassava meal increased in the diets (6, 4 and 3 at Roche's scale), as well as the cost of the feed consumed in 56 d per hen (2.56, 2.15 and 1.83 USD/bird). The possibility of substituting, totally, corn meal by that of cassava and soybean oil by that of the African palm tree in the diets of laying hens during the laying peak was determined, with positive economic effect and without damaging the productive performance of birds.

Blood Cues Induce Antipredator Behavior in Nile Tilapia Conspecifics

In this study, we show that the fish Nile tilapia displays an antipredator response to chemical cues present in the blood of conspecifics. This is the first report of alarm response induced by blood-borne chemical cues in fish. There is a body of evidence showing that chemical cues from epidermal 'club' cells elicit an alarm reaction in fish. However, the chemical cues of these 'club' cells are restricted to certain species of fish. Thus, as a parsimonious explanation, we assume that an alarm response to blood cues is a generalized response among animals because it occurs in mammals, birds and protostomian animals. Moreover, our results suggest that researchers must use caution when studying chemically induced alarm reactions because it is difficult to separate club cell cues from traces of blood. © 2013 Barreto et al.

Effect of ricinoleic acid esters from castor oil (Ricinus communis) on the oocyte yolk components of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

Rhipicephalus sanguineus are bloodsucking ectoparasites, whose main host is the domestic dog, thus being present in urban areas and closely located to people. Eventually, this tick species parasitize humans and can become a potential vector of infectious diseases. Methods to control this type of pest have been the focus of many research groups worldwide. The use of natural products is increasingly considered nowadays, due to the low toxicity levels to the host and low waste generation to the environment. This study tested the effect of ricinoleic acid esters from castor oil (as an potential acaricide) on the reproductive system of R sanguineus females, more specifically on the vitellogenesis process. For this, two groups were established: the control group (CG) and the treatment group (TG) with five rabbits in each (New Zealand White), used as hosts. NaCl and ester were added to rabbits' food and offered to the hosts. After full engorgement, the females were collected and had their ovaries extracted. The ticks ovaries were submitted to histochemical techniques so the effects of esters could be observed over polysaccharides, proteins and lipids yolk. Changes in the deposition of yolk components were observed. This caused modifications on elements of polysaccharide origin and on glycoprotein compounds, interfering in the final yolk synthesis and compromising the development of the future embryo. © 2012.

Optimization of the surimi production from Mechanically Recovered Fish Meat (MRFM) using response surface methodology

The by-products generated from industrial filleting of tilapia surimi can be used for the manufacture of surimi. The surimi production uses large amounts of water, which generates a wastewater rich in organic compounds (lipids, soluble proteins and blood). Optimizing the number of washing cycles will contribute to a more sustainable production. A mathematical model of mechanically recovered tilapia meat (Oreochromis niloticus) for the processing of surimi (minced fish washing cycles and tapioca starch addition) based on two quality parameters (texture and moisture) was constructed by applying the response surface methodology (RSM). Each factor had an important effect on the moisture and texture of surimi. This study found that the optimal formulation for producing the best surimi using the by-products of tilapia filleting in manufacturing fish burger were the addition of 10% tapioca starch and three minced fish washing cycles. A microstructural evaluation supported the findings of the mathematical model. Practical Applications: The use of mechanically recovered fish meat (MRFM) for the production of surimi enables the utilization of the by-products of filleting fish. However, the inferior quality of the surimi produced from MRFM in relation to that produced with fillets necessitates the addition of starch; secondly, surimi production consumes a large volume of water. RSM provides a valuable means for optimizing the number of washing cycles and starch amounts utilized in fish burger production. Tapioca starch, widely produced in Brazil, has desirable characteristics (surface sheen, smooth texture, neutral taste and clarity in solution) for use in MRFM-produced surimi. © 2013 Wiley Periodicals, Inc.

Photoelectrocatalysis based on Ti/TiO2 nanotubes removes toxic properties of the azo dyes Disperse Red 1, Disperse Red 13 and Disperse Orange 1 from aqueous chloride samples

This work describes the efficiency of photoelectrocatalysis based on Ti/TiO2 nanotubes in the degradation of the azo dyes Disperse Red 1, Disperse Red 13 and Disperse Orange 1 and to remove their toxic properties, as an alternative method for the treatment of effluents and water. For this purpose, the discoloration rate, total organic carbon (TOC) removal, and genotoxic, cytotoxic and mutagenic responses were determined, using the comet, micronucleus and cytotoxicity assays in HepG2 cells and the Salmonella mutagenicity assay. In a previous study it was found that the surfactant Emulsogen could contribute to the low mineralization of the dyes (60% after 4h of treatment), which, in turn, seems to account for the mutagenicity of the products generated. Thus this surfactant was not added to the chloride medium in order to avoid this interference. The photoelectrocatalytic method presented rapid discoloration and the TOC reduction was ≥87% after 240min of treatment, showing that photoelectrocatalysis is able to mineralize the dyes tested. The method was also efficient in removing the mutagenic activity and cytotoxic effects of these three dyes. Thus it was concluded that photoelectrocatalysis was a promising method for the treatment of aqueous samples. © 2013 Elsevier Ltd.

Meal size effects on the postprandial metabolic response of Bothrops alternatus (Serpentes: Viperidae)

We examined the effects of meal size on the postprandial metabolic response of the lancehead Bothrops alternatus (Duméril, Bibron & Duméril, 1894), fed mice equaling to 5, 10, 20, and 40% of the snake's body mass. The maximum O2 consumption rates measured during digestion increased with meal size, reaching levels up to 2.8-7.8-fold higher than the metabolic rate measured during fasting. Specific Dynamic Action (SDA) duration also increased with meal size, lasting from 54 to 212 hours to complete. Under our experimental conditions, 30°C, the majority of our snakes failed to completely digest prey with a relative size of 40%. The SDA coefficient ranged from 17 to 27% of the energy content of the meal and was not affected by meal size. © 2013 Sociedade Brasileira de Zoologia All rights reserved.

Lipase production by Botryosphaeria ribis EC-01 on soybean and castorbean meals: Optimization, immobilization, and application for biodiesel production

The effects of soybean and castorbean meals were evaluated separately, and in combinations at different ratios, as substrates for lipase production by Botryosphaeria ribis EC-01 in submerged fermentation using only distilled water. The addition of glycerol analytical grade (AG) and glycerol crude (CG) to soybean and castorbean meals separately and in combination, were also examined for lipase production. Glycerol-AG increased enzyme production, whereas glycerol-CG decreased it. A 24 factorial design was developed to determine the best concentrations of soybean meal, castorbean meal, glycerol-AG, and KH2PO4 to optimize lipase production by B. ribis EC-01. Soybean meal and glycerol-AG had a significant effect on lipase production, whereas castorbean meal did not. A second treatment (22 factorial design central composite) was developed, and optimal lipase production (4,820 U/g of dry solids content (ds)) was obtained when B. ribis EC-01 was grown on 0.5 % (w/v) soybean meal and 5.2 % (v/v) glycerol in distilled water, which was in agreement with the predicted value (4,892 U/g ds) calculated by the model. The unitary cost of lipase production determined under the optimized conditions developed ranged from US$0.42 to 0.44 based on nutrient costs. The fungal lipase was immobilized onto Celite and showed high thermal stability and was used for transesterification of soybean oil in methanol (1:3) resulting in 36 % of fatty acyl alkyl ester content. The apparent K m and V max were determined and were 1.86 mM and 14.29 μmol min -1 mg-1, respectively. © 2013 Springer Science+Business Media New York.

Branchial O2 chemoreceptors in Nile tilapia Oreochromis niloticus: Control of cardiorespiratory function in response to hypoxia

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)