Estudo comparativo de dois tipos de cultivo: monocultivo (camarões) versus cultivo integrado (algas/camarões)

The integrated culture of seaweed and aquatic animals is an ancient practice in Asian countries. The expansion of this practice to western countries is consequence of the recognition of this system as a sustainable alternative that allows economical diversification and mitigation of environmental impacts generated by effluents of aquaculture. This study evaluated the growth of the seaweed Gracilaria caudata and of the shrimp Litopenaeus vannamei in monoculture (shrimps) and integrated culture (shrimps and algae) systems, and accessed the effect of the seaweed in the water quality. There were two treatments in the experiment: monoculture (shrimps) and integrated culture (shrimps/ algae). The organisms were cultured in 6 aquaria (10L) filled with seawater (35.0±0.0 PSU and 28.1±0.4°C) for 28 days. The nutrients of water (PO43-, NH4+, NO2-, NO3- and DIN), the biomass and the relative growth rate (RGR, % day-1) of seaweed and shrimps were measured weekly. The parameters pH, temperature, salinity and dissolved oxygen were measured daily. The concentration of NH4+ in integrated culture (62.8±25.2µM) was lower (Mann-Whitney p<0.001) than in monoculture (85.6±24.3µM). The mean of PO4- in monoculture (10.4±4.6µM) was markedly higher (Mann-Whitney; p=0.024) than that in integrated culture (8.7±4.1µM). The level of dissolved oxygen in integrated culture (6.0±0.6mg/L) was higher (t-Student; P=0.014) than that in shrimp monoculture (5.8±0.6mg/L). The mean values of the parameters pH, NO2-, NO3- and DIN were 7.5±0.2, 10.1±12.2µM, 24.5±3.2µM and 120.17±30.76µM in monoculture, and 7.5±0.2, 10.5±13.2µM, 27.4±3.5µM and 100.76±49.59µM in integrated culture. There were not differences in these parameters between treatments. The biomass and RGR of seaweed reached 15.0±1.9g and 7.4±2.8% day-1 at the end of the experiment. The performance of shrimp was favorable in monoculture (1.5±0.8g; 5.7±1.6% dia-1) and in integrated culture (1.5±0.7g; 5.2±1.2% dia-1), and the rate of survival was 100% in both treatments. The tolerance and favorable performance of Gracilaria caudata suggest that this seaweed might be integrated into shrimp (Litopenaeus vannamei) culture systems

Resposta de Chromobacterium Violaceum cultivada em alta concentração de ferro

The Chromobacterium violaceum is a β-proteobacterium Gram-negative widely found in tropical and subtropical regions, whose genome was sequenced in 2003 showing great metabolic versatility and biotechnological and pharmaceutical potential. Given the large number of ORFs related to iron metabolism described in the genome of C. violaceum, the importance of this metal for various biological processes and due to lack of data about the consequences of excess of iron in free-living organisms, it is important to study the response mechanism of this bacterium in a culture filled with iron. Previous work showed that C. violaceum is resistant to high concentrations of this metal, but has not yet been described the mechanism which is used to this survival. Thus, to elucidate the response of C. violaceum cultured in high concentrations of iron and expecting to obtain candidate genes for use in bioremediation processes, this study used a shotgun proteomics approach and systems biology to assess the response of C. violaceum grown in the presence and absence of 9 mM of iron. The analysis identified 531 proteins, being 71 exclusively expressed by the bacteria grown in the presence of the metal and 100 just in the control condition. The increase in expression of proteins related to the TCA cycle possibly represents a metabolic reprogramming of the bacteria caused by high concentration of iron in the medium. Moreover, we observed an increase in the activity assay of superoxide dismutase and catalase as well as in Total Antioxidant Activity assay, suggesting that the metal is inducing oxidative stress in C. violaceum that increases the levels of violacein and antioxidant enzymes to better adapt to the emerging conditions. Are also part of the adaptive response changes in expression of proteins related to transport, including iron, as well as an increased expression of proteins related to chemotaxis response, which would lead the bacteria to change the direction of its movement away from the metal. Systems Biology results, also suggest a metabolic reprogramming with mechanisms coordinated by bottleneck proteins involved in transcription (GreA), energy metabolism (Rpe and TpiA) and methylation (AhcY)

Avaliação da biodegradabilidade de petróleo utilizando microrganismos isolados do estuário do Rio Potengi (RN)

The oil activity in the Rio Grande do Norte State (RN) is a permanent threat to coastal ecosystems, particularly mangroves, with the possibility of oil spills. In this context, the objective of this study was to evaluate the potential resistance of the mangrove environment of a possible spill. Were selected and isolated microorganisms degrading oil by the technique of enrichment cultures and formation of a bacterial consortium. The kinetic study of the consortium was held in rotary incubator shaken at 150 rpm and 30° C. Samples were taken at intervals of 4 hours for analysis of cell concentration and surface tension. The biodegradation was monitored using two methods of respirometry: manometric (OxiTop-C ®) and conductivimetry, where the biodegradation of oil was estimated indirectly by oxygen consumption and CO2 production, respectively. Furthermore, it was used a full 2² factorial design with triplicate at central point to the runs that used the conductivimetric methodology.. The technique of enrichment cultures allowed to obtain thirteen bacterial strains. Kinetic study of the consortium, we can showed the absence of the lag phase, reaching a maximum cell concentration of 2.55 g / L at 16 h of cultivation and a reduction on surface tension. When we adopted the methodology of OxiTop-C was detected a band indicating biodegradability (1% oil v/v), however when we used the conductivimetry methodology did not observe any band that would indicate effective biodegradation. By monitoring a process of biodegradation is necessary to observe the methodology will be adopted to evaluate the biodegradation process, since for the same conditions adopted different methodologies can produce different results. The oil-degrading isolates from soils of the mangrove estuary Potengi / RN are largely to be used in bioremediation strategies of these places, in the case of a possible oil spill, or it can be used in the treatment of waste oil generated in saline environments, since they are optimized the conditions of the tests so that the efficiency of biodegradation reach the minimum level suggested by the standarts

Ecogenômica de archaea e monitoramento de comunidades de procariotos redutores de sulfato: aplicações na indústria de petróleo e gás

The human activities responsible for the ambient degradation in the modern world are diverse. The industrial activities are preponderant in the question of the impact consequences for brazilian ecosystems. Amongst the human activities, the petroliferous industry in operation in Potiguar Petroliferous Basin (PPB) displays the constant risk of ambient impacts in the integrant cities, not only for the human populations and the environment, but also it reaches the native microorganisms of Caatinga ground and in the mangrove sediment. Not hindering, the elaboration of strategies of bioremediation for impacted areas pass through the knowledge of microbiota and its relations with the environment. Moreover, in the microorganism groups associated to oil, are emphasized the sulfate-reducing prokaryotes (SRP) that, in its anaerobic metabolism, these organisms participate of the sulfate reduction, discharging H2S, causing ambient risks and causing the corrosion of surfaces, as pipelines and tanks, resulting in damages for the industry. Some ancestries of PRS integrate the Archaea domain, group of microorganisms whose sequenced genomes present predominance of extremophilic adaptations, including surrounding with oil presence. This work has two correlated objectives: i) the detection and monitoring of the gene dsrB, gift in sulfate-reducing prokaryotes, through DGGE analysis in samples of mDNA of a mangrove sediment and semiarid soil, both in the BPP; ii) to relate genomic characteristics to the ecological aspects of Archaea through in silico studies, standing out the importance to the oil and gas industry. The results of the first work suggest that the petrodegraders communities of SRP persist after the contamination with oil in mangrove sediment and in semiarid soil. Comparing the populations of both sites, it reveals that there are variations in the size and composition during one year of experiments. In the second work, functional and structural factors are the probable cause to the pressure in maintenance of the conservation of the sequences in the multiple copies of the 16S rDNA gene. Is verified also the discrepancy established between total content GC and content GC of the same gene. Such results relating ribosomal genes and the ambient factors are important for metagenomic evaluations using PCR-DGGE. The knowledge of microbiota associated to the oil can contribute for a better destination of resources by the petroliferous industry and the development of bioremediation strategies. Likewise, search to lead to the best agreement of the performance of native microbiota in biogeochemical cycles in Potiguar Petroliferous Basin ecosystem

Biodegradação de hidrocarbonetos aromáticos policíclicos: prospecção metagenômica e modelagem computacional 3-D de proteínas

Knowledge of the native prokaryotes in hazardous locations favors the application of biotechnology for bioremediation. Independent strategies for cultivation and metagenomics contribute to further microbiological knowledge, enabling studies with non-cultivable about the "native microbiological status and its potential role in bioremediation, for example, of polycyclic aromatic hydrocarbons (HPA's). Considering the biome mangrove interface fragile and critical bordering the ocean, this study characterizes the native microbiota mangrove potential biodegradability of HPA's using a biomarker for molecular detection and assessment of bacterial diversity by PCR in areas under the influence of oil companies in the Basin Petroleum Geology Potiguar (BPP). We chose PcaF, a metabolic enzyme, to be the molecular biomarker in a PCR-DGGE detection of prokaryotes that degrade HPA s. The PCR-DGGE fingerprints obtained from Paracuru-CE, Fortim-CE and Areia Branca-RN samples revealed the occurrence of fluctuations of microbial communities according to the sampling periods and in response to the impact of oil. In the analysis of microbial communities interference of the oil industry, in Areia Branca-RN and Paracuru-CE was observed that oil is a determinant of microbial diversity. Fortim-CE probably has no direct influence with the oil activity. In order to obtain data for better understanding the transport and biodegradation of HPA's, there were conducted in silico studies with modeling and simulation from obtaining 3-D models of proteins involved in the degradation of phenanthrene in the transport of HPA's and also getting the 3-D model of the enzyme PcaF used as molecular marker in this study. Were realized docking studies with substrates and products to a better understanding about the transport mechanism and catalysis of HPA s

Rhamnolipid produced from agroindustrial wastes enhances hydrocarbon biodegradation in contaminated soil

A crude biosurfactant solution was produced by Pseudomonas aeruginosa growing on agroindustrial wastes as the substrate and used to study its effect on hydrocarbon biodegradation by the indigenous soil microflora under laboratory conditions. Two concentrations were studied at first and 1 mg of biosurfactant/g of soil showed to be the most efficient for the total petroleum hydrocarbon reduction, which reached 85% at the first 20 days in soil microcosms. Respirometric and microbial analyses showed that the biosurfactant added did not have toxic effects over the microbial population. The use of a biosurfactant for bioremediation has been limited because of its high cost production. Biosurfactants produced from cost-free by-products combines waste minimization with economic potential bioremediation process.

Estudos ecogenômicos e bioprospectivos de Shewanella ssp

Bacteria trom Shewanella and Geobacter ganera are the most studied iron-reducing microorganisms particularly due to their electron transport systems and contribution to some industrial and environmental problems, including steel corrosion, bioenergy and bioremediation of petroleum-impacted sites. The present study was focused in two ways: the first is an in silico comparative ecogenomic study of Shewanella spp. with sequenced genomes, and the second is an experimental metagenomic work to detect iron-reducing Shewanella through PCR-DGGE of a metabolic gene. The in silico study resulted in positive correIation between copy number of 16S rDNA and genome size in Shewanella spp., with clusters of rrn near lhe origin of replication. This way, the genus is inferred as opportunist. There are no compact genomes and their sequences length varied, ranging from 4306142 nt in S. amazonensis SB2B to 5935403 nt in S. woodyi ATCC 51908, without correIation to temperature range characteristic of each specie. Intragenomic 16S rDNA sequences possess little divergence, but reasonable to resuIt in different phyIogenetic trees, depending on the sequence that is chosen to compare. For moIecuIar detection of iron-reducing Shewanella, it is proposed the mtrB gene as new biomarker. because it codes to a fundamental protein at Fe (III)-reduction. The specific primers were designed and evaluated in silico and resulted in a fragment of 360 pb. In the second study, these primers were tested in a genomic sample from S. oneidensis MR-1, amplifying the expected region. After this successfuI resuIt, the primer set was used as a tool to assess the iron-reducing communities of ShewaneIla genus under an environmental stress, i.e. crude oil contamination in mangrove sediment in Rio Grande do Norte State (Brazil). The primers presented high specificity and the reactions performed resulted in one single band of ampIification in the metagenomic samples. The fingerprinting obtained at DGGE reveaIed temporal variation of Shewanella spp. in analyzed samples. The resuIts presented show the detection of a biotechnological important group of microorganisms, the iron-reducing Shewanella spp. using a metabolic gane as target. It is concluded there are eight or more 16S rDNA sequences in Shewanella genus, with little divergence among them that affects the phylogeny; the pair of primers designed to ampIify mtrB sequences is a viable alternative to detect iron-reducing ShewanelIa in metagenomic approaches; such bacteria are present in the mangrove sediment anaIyzed, with temporal variations in the samples. This is the first experimental study that screened the iron-reducing Shewanella genus in a metagenomic experiment of mangrove sediments subjected to oil contamination through a key metabolic gene

Toxicological evaluation of vegetable oils and biodiesel in soil during the biodegradation process

Vegetable oils and their derivatives, like biodiesel, are used extensively throughout the world, thus posing an environmental risk when disposed. Toxicity testing using test organisms shows how these residues affect ecosystems. Toxicity tests using earthworms (Eisenia foetida. are widespread because they are a practical resource for analyzing terrestrial organisms. For phytotoxicological analysis, we used seeds of arugula (Eruca sativa and lettuce (Lactuca sativa. to analyze the germination of seeds in contaminated soil samples. The toxicological experiment was conducted with four different periods of biodegradation in soil: zero days, 60 days, 120 days and 180 days. The studied contaminants were soybean oil (new and used) and biodiesel (B100). An evaluation of the germination of both seeds showed an increased toxicity for all contaminants as the biodegradation occurred, biodiesel being the most toxic among the contaminants. on the other hand, for the tests using earthworms, the biodiesel was the only contaminant that proved to be toxic. Therefore, the higher toxicity of the sample containing these hydrocarbons over time can be attributed to the secondary compounds formed by microbial action. Thus, we conclude that the biodegradation in soil of the studied compounds requires longer periods for the sample toxicity to be decreased with the action of microorganisms.

Biosurfactant synthesis by Pseudomonas aeruginosa LBI isolated from a hydrocarbon-contaminated site

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

Biodegradability of commercial and weathered diesel oils

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

Investigation about the efficiency of the bioaugmentation technique when applied to diesel oil contaminated soils

Este trabalho investigou a eficiência da técnica do bioaumento quando aplicada a solos contaminados com óleo diesel coletados em três postos de combustíveis. Experimentos de biodegradação foram realizados em frascos de Bartha (250 mL), usados para medir a produção microbiana de CO2. A eficiência de biodegradação também foi quantificada pela concentração de hidrocarbonetos. Conjuntamente aos experimentos de biodegradação, a capacidade das culturas estudadas e dos microrganismos nativos em biodegradar óleo diesel comprado de um posto de combustíveis local, foi verificada utilizando-se a técnica baseada no indicador redox 2,6 - diclorofenol indofenol (DCPIP). Resultados obtidos com esse teste mostraram que os inóculos empregados nos experimentos de biodegradação foram capazes de biodegradar óleo diesel e os testes com os microrganismos nativos indicaram que estes solos previamente apresentavam uma microbiota adaptada para degradar hidrocarbonetos. em suma, nenhum ganho foi obtido com a adição dos microrganismos ou mesmo efeitos negativos foram observados nos experimentos de biodegradação.

The Allium cepa bioassay to evaluate landfarming soil, before and after the addition of rice hulls to accelerate organic pollutants biodegradation

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

Structure, properties and applications of rhamnolipids produced by Pseudomonas aeruginosa L2-1 from cassava wastewater

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

Effect of culture conditions on the biomass determination by ergosterol of Lentinus crinitus and Psilocybe castanella

Estimating fungal growth is important in processes of soil bioremediation. It has been demonstrated that ergosterol is a good indicator of fungal biomass in solid substrata. In the present study were evaluated the effects upon the ergosterol rate of Lentinus crinitus Berk. and Psilocybe castanella Peck through the culture conditions of these fungi, which are evaluated for the bioremediation of soils contaminated by organochlorates. A good correlation between fungal biomass and ergosterol was observed for both species. The culture conditions did not influence the ergosterol rate of L. crinitus. Yet the ergosterol rate of P. castanella was influenced from 35 days of culture and when grown in the presence of 15.00 g hexachlorobenzene l(-1) of culture medium. So it is possible to estimate growth of both species using ergosterol as indicator in processes of soil bioremediation since the influences observed in the ergosterol rate of P. castanella are considered.

Toxicity and Biodegradation in Sandy Soil Contaminated by Lubricant Oils

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