Tributyltin (TBT) is one of the most toxic xenobiotics ubiquitous in the aquatic environment. Several reports have described the negative impact of TBT in living organisms, from bacteria to mammals. Over the world, TBT contamination has being described as a serious problem. Thus, it is imperative to decontaminate TBT polluted sites. Bioremediation strategies may constitute an alternative to conventional decontamination methods, benefiting from the microorganisms potential to metabolize xenobiotics. Several microorganisms among bacteria, fungus, and algae have been reported to possess the ability to resist and, in certain cases, degrade TBT in their simple and less toxic derivatives. Due their characteristics, some of those microorganisms have been used for bioremediation studies and to construct bioreporters to detect TBT in the environment. This review provides an overview regarding microbial TBT resistance, while focusing on TBT degradation and bioremediation. A comprehensive revision on the several applications of organotin compounds, adverse biological effects on living organisms, and information regarding the available TBT bioreporters is also included.

Tributyltin (TBT) is one of the most toxic xenobiotics ubiquitous in the aquatic environment. Several reports have described the negative impact of TBT in living organisms, from bacteria to mammals. Over the world, TBT contamination has being described as a serious problem. Thus, it is imperative to decontaminate TBT polluted sites. Bioremediation strategies may constitute an alternative to conventional decontamination methods, benefiting from the microorganisms potential to metabolize xenobiotics. Several microorganisms among bacteria, fungus, and algae have been reported to possess the ability to resist and, in certain cases, degrade TBT in their simple and less toxic derivatives. Due their characteristics, some of those microorganisms have been used for bioremediation studies and to construct bioreporters to detect TBT in the environment. This review provides an overview regarding microbial TBT resistance, while focusing on TBT degradation and bioremediation. A comprehensive revision on the several applications of organotin compounds, adverse biological effects on living organisms, and information regarding the available TBT bioreporters is also included.

The accurate reliable detection and identification of microorganisms in food is critical to public safety. Consequently, it is extremely important to develop rapid and inexpensive methods for the detection of food microorganisms in order to minimize or even replace the traditional analysis methods that are expensive and time-consuming. In this study, the potential of mid-infrared spectroscopy was evaluated, for the first time, to detect changes in colony forming units of microorganisms in freshly cut ham along the time. A partial least squares regression model was performed and a good linear relationship was obtained between spectra information and microbial load. It was concluded that infrared spectroscopy easily and quickly allows the separation of ham samples according to their microbial content and could be used to predict the microbial concentration from the spectra, using the fingerprint region (1,200–950 cm−1), without sample preparation or handling. Practical Applications As it is essential to avoid infections caused by foodborne bacteria, it is important to develop a rapid, low cost and easy to perform technique to face the increasing demands of the food industry. Mid-infrared spectroscopy, coupled to multivariate analysis, has potential to be used as a first-screening approach and to assess the microbial concentration in ham samples, avoiding the traditional plating methods that are time-consuming.

The accurate reliable detection and identification of microorganisms in food is critical to public safety. Consequently, it is extremely important to develop rapid and inexpensive methods for the detection of food microorganisms in order to minimize or even replace the traditional analysis methods that are expensive and time‐consuming. In this study, the potential of mid‐infrared spectroscopy was evaluated, for the first time, to detect changes in colony forming units of microorganisms in freshly cut ham along the time. A partial least squares regression model was performed and a good linear relationship was obtained between spectra information and microbial load. It was concluded that infrared spectroscopy easily and quickly allows the separation of ham samples according to their microbial content and could be used to predict the microbial concentration from the spectra, using the fingerprint region (1,200–950 cm⁻¹), without sample preparation or handling. PRACTICAL APPLICATIONS: As it is essential to avoid infections caused by foodborne bacteria, it is important to develop a rapid, low cost and easy to perform technique to face the increasing demands of the food industry. Mid‐infrared spectroscopy, coupled to multivariate analysis, has potential to be used as a first‐screening approach and to assess the microbial concentration in ham samples, avoiding the traditional plating methods that are time‐consuming.

In the last decades, 3-bromopyruvate (3BP) has been intensively studied as a promising anticancer and antimicrobial agent. The transport of this drug inside the cell is a critical step for its toxicity in cancer and microorganisms. The Cryptococcus neoformans is the most sensitive species of microorganisms toward 3BP. Its cells exhibit the highest uptake rate of 3BP among all tested fungal strains. In Saccharomyces cerevisiae cells, the Jen1 transporter was found to be responsible for 3BP sensitivity. The deletion of Jen1 resulted in the abolishment of 3BP mediated transport. We functionally characterized the Jen4 protein, a Jen1 homologue of C. neoformans, and its role in the phenotypic 3BP sensitivity. The deletion of the CNAG_04704 gene, which encodes Jen4, was found to impair the mediated transport of 3BP and decrease 3BP sensitivity. Further heterologous expression of Jen4 in the S. cerevisiae jen1 Delta ady2 Delta strain restored the mediated transport of 3BP. The application of a green fluorescent protein fusion tag with the CNAG_04704, revealed the Jen4 labeled on the plasma membrane. The identification of 3BP transporters in pathogen cells is of great importance for understanding the mechanisms of 3BP action and to anticipate the application of this compound as an antimicrobial drug. | This work was supported by the Ministry of Science and Higher Education (Poland) via 'Statutory Research 2018/S/IGM', the strategic program UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) and was also co-financed by the Polish National Science Center (grant number 2015/19/N/NZ7/00956), by the project PTDC/BIAMIC/5184/2014 funded by national funds through the Fundacao para a Ciencia e Tecnologia (FCT) I.P. and by the European Regional Development Fund (ERDF) through the COMPETE 2020-Programa Operacional Competitividade e Internacionalizacao (POCI). DR acknowledges FCT for the SFRH/BD/96 166/2013 PhD grant.

In the last decades, 3-bromopyruvate (3BP) has been intensively studied as a promising anticancer and antimicrobial agent. The transport of this drug inside the cell is a critical step for its toxicity in cancer and microorganisms. The Cryptococcus neoformans is the most sensitive species of microorganisms toward 3BP. Its cells exhibit the highest uptake rate of 3BP among all tested fungal strains. In Saccharomyces cerevisiae cells, the Jen1 transporter was found to be responsible for 3BP sensitivity. The deletion of Jen1 resulted in the abolishment of 3BP mediated transport. We functionally characterized the Jen4 protein, a Jen1 homologue of C. neoformans, and its role in the phenotypic 3BP sensitivity. The deletion of the CNAG_04704 gene, which encodes Jen4, was found to impair the mediated transport of 3BP and decrease 3BP sensitivity. Further heterologous expression of Jen4 in the S. cerevisiae jen1Δ ady2Δ strain restored the mediated transport of 3BP. The application of a green fluorescent protein fusion tag with the CNAG_04704, revealed the Jen4 labeled on the plasma membrane. The identification of 3BP transporters in pathogen cells is of great importance for understanding the mechanisms of 3BP action and to anticipate the application of this compound as an antimicrobial drug.

Bacterial communities of the surface microlayer (SML) of the estuary Ria de Aveiro (Portugal) were characterized in terms of abundance and activity during a 2-year survey at two sites with distinct hydrodynamic properties (marine and brackish water zones). The hydrodynamic conditions were simulated using a bidimensional numerical model and related to the microbiological observations. The pattern of variation of bacterial biomass productivity (BBP) was distinct between the two sampling sites. At the outer site, BBP was significantly lower at the SML, whereas at the inner site, it was significantly enhanced at the SML. Although the total bacterial abundance was similar in the SML and underlying water (UW), the fraction of cells attached to particles was significantly higher at the SML (two to three times). The integration of microbiological results with environmental and hydrological variables shows that strong currents in the marine zone promote the vertical mixing, inhibiting the establishment of an SML bacterial community distinct from that of UW. In contrast, in the brackish water zone, lower current velocities provide conditions for enhancing the bacterial activity in the enriched SML. Estuarine dynamics influence the distribution and activity of microorganisms at the SML and in the water column, with anticipated impacts for the carbon cycle in the estuarine environment.

Bacterial communities of the surface microlayer (SML) of the estuary Ria de Aveiro (Portugal) were characterized in terms of abundance and activity during a 2-year survey at two sites with distinct hydrodynamic properties (marine and brackish water zones). The hydrodynamic conditions were simulated using a bidimensional numerical model and related to the microbiological observations. The pattern of variation of bacterial biomass productivity (BBP) was distinct between the two sampling sites. At the outer site, BBP was significantly lower at the SML, whereas at the inner site, it was significantly enhanced at the SML. Although the total bacterial abundance was similar in the SML and underlying water (UW), the fraction of cells attached to particles was significantly higher at the SML (two to three times). The integration of microbiological results with environmental and hydrological variables shows that strong currents in the marine zone promote the vertical mixing, inhibiting the establishment of an SML bacterial community distinct from that of UW. In contrast, in the brackish water zone, lower current velocities provide conditions for enhancing the bacterial activity in the enriched SML. Estuarine dynamics influence the distribution and activity of microorganisms at the SML and in the water column, with anticipated impacts for the carbon cycle in the estuarine environment.

Staphylococcus aureus is responsible for a large spectrum of diseases, including staphylococcal food poisoning (SFP), due to its ability to produce enterotoxins. To prevent the development of SFP, effective food preservation methods are needed. High pressure processing (HPP) uses pressures, between 100 and 600 MPa, to inactivate pathogenic and spoilage microorganisms. In this study, HPP treatments (450 MPa and 600 MPa, both for 15 and 30 min, at 20 C) were applied in three different strains of S. aureus in the stationary growth phase and reduction effectiveness was assessed. A non-enterotoxic strain ATCC 6538 and two enterotoxic strains 2153 MA (with enterotoxin A) and 2065 MA (with enterotoxin A, G, I) were used. It was verified that the non-enterotoxic strain was the most resistant to HPP, not being completely inactivated within 30 min at 600 MPa. Additionally, it was demonstrated that HPP had no effect on virulence factors (enterotoxins, b-hemolysin, lipase, lecithinase, coagulase, thermonuclease, catalase), and also in mannitol fermentation capacity and methicillin susceptibility. HPP treatments also proved to be less effective in the strain with higher carotenoids content (non-enterotoxic strain). The results of this study show that S. aureus HPP barotolerance might be related not only to the presence of enterotoxins but also to carotenoids level, although these two factors may not be the only mechanisms responsible for the distinct sensitivity/resistance to HPP shown by different strains of S. aureus.

Staphylococcus aureus is responsible for a large spectrum of diseases, including staphylococcal food poisoning (SFP), due to its ability to produce enterotoxins. To prevent the development of SFP, effective food preservation methods are needed. High pressure processing (HPP) uses pressures, between 100 and 600 MPa, to inactivate pathogenic and spoilage microorganisms. In this study, HPP treatments (450 MPa and 600 MPa, both for 15 and 30 min, at 20 °C) were applied in three different strains of S. aureus in the stationary growth phase and reduction effectiveness was assessed. A non-enterotoxic strain ATCC 6538 and two enterotoxic strains 2153 MA (with enterotoxin A) and 2065 MA (with enterotoxin A, G, I) were used. It was verified that the non-enterotoxic strain was the most resistant to HPP, not being completely inactivated within 30 min at 600 MPa. Additionally, it was demonstrated that HPP had no effect on virulence factors (enterotoxins, β-hemolysin, lipase, lecithinase, coagulase, thermonuclease, catalase), and also in mannitol fermentation capacity and methicillin susceptibility. HPP treatments also proved to be less effective in the strain with higher carotenoids content (non-enterotoxic strain). The results of this study show that S. aureus HPP barotolerance might be related not only to the presence of enterotoxins but also to carotenoids level, although these two factors may not be the only mechanisms responsible for the distinct sensitivity/resistance to HPP shown by different strains of S. aureus.