THE USE OF COADJUTANTS IN TANK MIX WITH FUNGICIDES IN ORDER TO IMPROVE THEIR EFFECTIVENESS EVEN AT LOW DOSAGES

One of the most important items of modern agriculture is the reduction of environmental impact thanks to the integration of new cultivation and protection techniques. Therefore it is important to optimise the use of chemicals and pesticides. We found that some coadjutants applied in tank mix with fungicides on sugar beet protection improve the effectiveness of active principles in cercospora leafspot (Cercospora bieticola sacc.) control

Improvement of environmental quality in intensive pig farming through an integrated bioactivation program for the control and prevention of swine mycoplasmal pneumonia

The decline of pig health status is the effect of a bad air quality inside breeding facilities related to the concentration of biogases derived from the action of faecal microbial flora on urine nitrogen. Bioactivation of the environment with bacterialenzymatic mixtures is able to reduce this chemical emanation. An experimental trial has been performed to evaluate the efficacy of the bioactivation treatment to prevent mycoplasmal pneumonia in finishing pigs. Treated and untreated groups, different treatment schemes and different floors have been compared. The ammonia concentration was checked by a chemical method. M. hyopneumoniae infection was evaluated through seroprevalence and by a quantitative lung-scoring system. For all slaughter-lots average carcass weight was recorded. The decrease of the environmental ammonia concentration resulted in lower lungscores and higher carcass weight

Biostimulation of in situ microbial degradation processes in organically-enriched sediments mitigates the impact of aquaculture

Abstract Fish farm deposition, resulting in organic matter accumulation on bottom sediments, has been identified as among the main phenomena causing negative environmental impacts in aquaculture. An in situ bioremediation treatment was carried out in order to reduce the organic matter accumulation in the fish farm sediments by promoting the natural microbial biodegradation processes. To assess the effect of the treatment, the concentration of organic matter in the sediment and its microbial degradation, as well as the response of the benthic prokaryotic community, were investigated. The results showed a significant effect of the treatment in stimulating microbial degradation rates, and the consequent decrease in the concentration of biochemical components beneath the cages during the treatment. During the bioremediation process, the prokaryotic community in the fish farm sediment responded to the overall improvement of the sediment conditions by showing the decrease of certain anaerobic taxa (e.g. Clostridiales, Acidaminobacteraceae and Caldilinaceae). This suggested that the bioactivator was effective in promoting a shift from an anaerobic to an aerobic metabolism in the prokaryotic community. However, the larger importance of Lachnospiraceae (members of the gut and faecal microbiota of the farmed fishes) in treated compared to non-treated sediments suggested that the bioactivator was not efficient in reducing the accumulation of faecal bacteria from the farmed fishes. Our results indicate that bioremediation is a promising tool to mitigate the aquaculture impact in fish farm sediments, and that further research needs to be oriented to identifying more successful interventions able to specifically target also fish-faeces related microbes

Trichoderma longibrachiatum Evx1 is a fungal biocatalyst suitable for the remediation of soils contaminated with diesel fuel and polycyclic aromatic hydrocarbons

Trichoderma sp. strain Evx1 was isolated from a semi-deciduous forest soil in Southern Italy. It decolorizes polynuclear organic dyes and tolerates high concentrations of phenanthrene, anthracene, fluoranthene, and pyrene. The ability of this ascomycete fungus to degrade polycyclic aromatic hydrocarbons was verified in vitro and confirmed by its strong phenoloxidase activity in the presence of gallic acid. Phylogenetic characterization of Trichoderma sp. Evx1 positioned this strain within the species Trichoderma longibrachiatum. The potential use of this species for the bioremediation of contaminated environmental matrices was tested by inoculating diesel-spiked soil with a dense mycelial suspension. The biodegradation percentage of the C12-40 hydrocarbon fraction in the inoculated soil rose to 54.2 ± 1.6 %, much higher than that in non-inoculated soil or soil managed solely by a combination of watering and aeration. The survival and persistence of T. longibrachiatum Evx1 throughout the bioremediation trial was monitored by PCR-DGGE analysis. The fungal strain was still present in the soil 30 days after bioaugmentation. These findings indicate that T. longibrachiatum Evx1 may be a suitable inoculum in bioremediation protocols for the reclamation of soils contaminated by complex mixtures of hydrocarbons

Bioaugmentation and biostimulation as strategies for the bioremediation of a burned woodland soil contaminated by toxic hydrocarbons: A comparative study

In this work, the natural attenuation strategy (no soil amendments done) was compared with two different bioremediation approaches, namely bioaugmentation through soil inoculation with a suspension of Trichoderma sp. mycelium and biostimulation by soil addition with a microbial growth promoting formulation, in order to verify the effectiveness of these methods in terms of degradation efficiency towards toxic hydrocarbons, with particular attention to the high molecular weight (HMW) fraction, in a forest area impacted by recent wildfire in Northern Italy. The area under investigation, divided into three parcels, was monitored to figure out the dynamics of decay in soil concentration of C12-40 hydrocarbons (including isoalkanes, cycloalkanes, alkyl-benzenes and alkyl-naphthalenes besides PAHs) and low molecular weight (LMW) PAHs, following the adoption of the foregoing different remediation strategies. Soil hydrocarbonoclastic potential was even checked by haracterizing the autochthonous microbial cenoses. Field experiments proved that the best performance in the abatement of HMW hydrocarbons was reached 60 days after soil treatment through the biostimulation protocol, when about 70% of the initial concentration of HMW hydrocarbons was depleted. Within the same time, about 55% degradation was obtained with the bioaugmentation protocol, whilst natural attenuation allowed only a 45% removal of the starting C12-40 hydrocarbon fraction. Therefore, biostimulation seems to significantly reduce the time required for the remediation, most likely because of the enhancement of microbial degradation through the improvement of nutrient balance in the burned soil

Bioremediation of diesel contamination at an underground storage tank site: a spatial analysis of the microbial community

The present study reports on a real case of contamination due to the chronic leakage of diesel fuel from an underground tank at a dismissed service station. Speciation of the microbial community according to both lateral and vertical gradients from the origin of the contaminant release was analyzed by means of the PCR-DGGE technique. Moreover, the effects of a landfarming treatment on both the microbial community structure and the abatement of contamination were analyzed. The concentration of total petrol hydrocarbons (TPHs) decreased along the horizontal gradient (from 7042.2 ± 521.9 to 112.2 ± 24.3 mg kg(-1)), while increased downwards from the position of the tank (from 502.6 ± 43.7 to 4972.5 ± 275.3 mg kg(-1)). PCR-DGGE analyses and further statistical treatment of the data indicated a correlation between structure of the bacterial communities and amount of diesel fuel contamination. On the other hand, level of contamination, soil texture and depth were shown to affect the fungal community. Chloroflexi and Ascomycota were the most abundant microbes ascertained through culture-independent procedures. Landfarming promoted 91.6 % reduction of TPHs in 75 days. Furthermore, PCR-DGGE analyses evidenced that both bacterial and fungal communities of the treated soil were restored to the pristine conditions of uncontaminated topsoil. The present study demonstrated that bacterial and fungal communities were affected differently by soil factors such as level of hydrocarbon contamination as well as soil depth and texture. This report shows that a well-planned landfarming treatment can drive the restoration of the soil in terms of both abatement of the contaminants and resilience of the microbial community structure

Combination of sediment washing and bioactivators as a potential strategy for dredged marine sediment recovery

Dredging of potentially contaminated sediments from ports and waterways is an inevitable operation in order to maintain adequate depths for ship navigation. The fate of these sediments is an issue discussed worldwide due to their impact on human and environmental health. In this scenario, the aim of the present study is to provide an innovative eco-friendly and adaptable solution for dredged sediment decontamination and rehabilitation based on sediment washing followed by a biological treatment. The sediment washing, conducted at pilot scale, split the raw dredged sediment into two fractions of homogeneous particle size (silt-clay fraction and sand fraction). Sand fraction was characterized by a significant lower values of heavy metals and total petroleum hydrocarbons (TPH) with respect to the silt-clay and raw sediment samples. The biological treatment, carried out at mesoscale level, consisted in the addiction of a mixture of micro- organisms (with hydrocarbon degrading ability), enzymes, and nutrients (bioactivator product) to the three matrices (raw sediment, silt-clay and sand). After three months, in raw sediment and sand fraction, the bioac- tivator product allowed a 46% and 55% removal of TPH, respectively; instead, in silt-clay fraction this treatment was not able to degrade significant amount of organic pollutants (reduction percentage of TPH lower than 5%). Culture-dependent analysis showed higher concentration of microbial cells immediately after addition of the bioactivator product and a general increasing of microbial biomass in both treated and untreated samples at the end of the experimentation. Moreover, PCR-DGGE analysis evidenced that the composition of microbial popu- lation varied in relation to the different granulometric characteristics of the sediment and to the application of the bioactivator product. Thus, the results here reported showed that bacterial and fungal communities re- sponded differently to the bioremediation treatment. These results seem very promising considering the complexity of the material to be decontaminated and the apparent difficulty of creating acceptable habitat for the operation of a biological active system

Bioremediation of diesel contamination at an underground storage tank site: a spatial analysis of the microbial community

The present study reports on a real case of contamination due to the chronic leakage of diesel fuel from an underground tank at a dismissed service station. Speciation of the microbial community according to both lateral and vertical gradients from the origin of the contaminant release was analyzed by means of the PCR-DGGE technique. Moreover, the effects of a landfarming treatment on both the microbial community structure and the abatement of contamination were analyzed. The concentration of total petrol hydrocarbons (TPHs) decreased along the horizontal gradient (from 7042.2 ± 521.9 to 112.2 ± 24.3 mg kg(-1)), while increased downwards from the position of the tank (from 502.6 ± 43.7 to 4972.5 ± 275.3 mg kg(-1)). PCR-DGGE analyses and further statistical treatment of the data indicated a correlation between structure of the bacterial communities and amount of diesel fuel contamination. On the other hand, level of contamination, soil texture and depth were shown to affect the fungal community. Chloroflexi and Ascomycota were the most abundant microbes ascertained through culture-independent procedures. Landfarming promoted 91.6 % reduction of TPHs in 75 days. Furthermore, PCR-DGGE analyses evidenced that both bacterial and fungal communities of the treated soil were restored to the pristine conditions of uncontaminated topsoil. The present study demonstrated that bacterial and fungal communities were affected differently by soil factors such as level of hydrocarbon contamination as well as soil depth and texture. This report shows that a well-planned landfarming treatment can drive the restoration of the soil in terms of both abatement of the contaminants and resilience of the microbial community structure