Microbial secondary metabolites from extreme environments like hydrothermal vents are a promising source for industrial applications. In our study the protease gene from Bacillus cereus obtained from shallow marine hydrothermal vents in the East China Sea was cloned, expressed and purified. The protein sequence of 38 kDa protease SLSP-k was retrieved from mass spectrometry and identified as a subtilisin serine proteinase. The novel SLSP-k is a monomeric protein with 38 amino acid signal peptides being active over wide pH (7–11) and temperature (40–80 °C) ranges, with maximal hydrolytic activities at pH 10 and at 50 °C temperature. The hydrolytic activity is stimulated by Ca2+, Co2+, Mn2+, and DTT. It is inhibited by Fe2+, Cd2+, Cu2+, EDTA, and PMSF. The SLSP-k is stable in anionic, non-anionic detergents, and solvents. The ability to degrade keratin in chicken feather and hair indicates that this enzyme is suitable for the degradation of poultry waste without the loss of nutritionally essential amino acids which otherwise are lost in hydrothermal processing. Therefore, the proteinase is efficient in environmental friendly bioconversion of animal waste into fertilizers or value added products such as secondary animal feedstuffs.
Extreme environments are hostile for most organisms, but such habitats represent suitable settings to be inhabited by specialized microorganisms. A marine shallow-water hydrothermal vent field is located offshore in northeast Taiwan, near the shallow shore of the southeast of Kueishantao Island (121°55′ E, 24°50′ N). Research on extremophilic microorganisms makes use of the biotechnological potential associated with such microorganisms and their cellular products. With the notion that extremophiles are capable of surviving in extreme environments, it is assumed that their metabolites are adapted to function optimally under such conditions. As extremophiles, they need specific culture conditions, and only a fraction of species from the original samples are recovered in culture. We used different non-selective and selective media to isolate bacterial species associated with the hydrothermal vent crab Xenograpsus testudinatus and the sediments of its habitat. The highest number of colonies was obtained from Zobell marine agar plates with an overall number of 29 genetically distinct isolates. 16sRNA gene sequencing using the Sanger sequencing method revealed that most of the bacterial species belonged to the phylum Firmicutes and the class Bacilli. The present study indicates that hydrothermal vent bacteria and their secondary metabolites may play an important role for the reconstruction of the evolutionary history of the phylum Procaryota.
This work describes novel V 2 O 5 /ZnO hetero-structured nanomaterials providing efficient photocatalytic activities at different composite ratios (0.1:1, 1:1, 1:2, and 1:3, w/w). The V 2 O 5 /ZnO nanocomposites were prepared by a facile physico-chemical synthesis using V 2 O 5 with ZnO through a high-energy ball miller technique. The 1:1 ratio of V 2 O 5 /ZnO nanohybrid composition material showed maximum potential (99.9% of methylene blue color removal) in activating reactive hydroxyls from aqueous solutions for organic pollutant degradation. Moreover, the 1:1 ratio of V 2 O 5 /ZnO nanomaterial also showed high bacterial resistance and exhibited enhanced activity for killing a pathogenic bacterium (Staphylococcus aureus). The minimum inhibitory concentration by microdilution method for 1:1 ratio of V 2 O 5 /ZnO composite was 400 µg/mL. The experimental results proved that the developed physiochemical approach is a simple, low-cost, green methodology for synthesizing heterogenous V 2 O 5 /ZnO nanohybrid composite materials for environmental remediation and anti-microbial applications.
Wastewater emission to surface waters is a major pathway for antibacterials and antibacterial-resistant bacteria. Polluted waterbodies such as rivers provide a reservoir for bacterial resistance. We studied water quality and bacterial antibacterial resistance along the subtropical Qishan River in Taiwan as a case study of environmental resistance spread in a pristine to rural area. Human settlement densities increased generally from pristine mountain sites to the more polluted lowlands generally. Accordingly, as a working hypothesis, we expected antibacterial resistance level to increase towards downstream. We collected sediment samples from 8 stations along the Qishan river and where the Qishan river reaches the Kaoping river. The samples were processed in the lab for bacteriological and physicochemical analysis. Antibacterial resistance was tested by disk diffusion and micro-dilution with ten common antibacterials. A comparison was made among the sites where isolates began to occur at the upstream (site 1–6) with the downstream, including site 7 (Qishan town), site 8 (wastewater treatment plant) and site 9 (Kaoping river). The results of multivariate analysis for bacteriological and physicochemical parameters showed increasing water pollution levels downstream of the Qishan river. Ten bacteria including Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Enterobacter sp., Acinetobacter sp., Staphylococcus spp. and Bacillus spp. were analyzed and tested in the study. Their percentage of occurrence varied at each site. The resistance level was determined from the growth inhibition zone diameter (disk diffusion) and the minimum inhibitory concentration (micro-dilution). The results indicated that antibacterial resistance was related to certain environmental factors. Besides, the usage pattern of different classes of antibacterials in different places could alter trends of their resistance. Bacteria were found with increased resistance to antibacterials used in agriculture through the downstream sites according to the results. The WWTP emitting wastewater was demonstrated to be a hotspot of resistance in aquatic environments. In conclusion, bacterial resistance against antibacterials from the Qishan river has become a potential public health threat. This study could assist authorities by providing a reference for water quality risk assessment and management in Kaohsiung city and southern Taiwan.
Wastewater emission to surface waters is a major pathway for antibacterials and antibacterial-resistant bacteria. Polluted waterbodies such as rivers provide a reservoir for bacterial resistance. We studied water quality and bacterial antibacterial resistance along the subtropical Qishan River in Taiwan as a case study of environmental resistance spread in a pristine to rural area. Human settlement densities increased generally from pristine mountain sites to the more polluted lowlands generally. Accordingly, as a working hypothesis, we expected antibacterial resistance level to increase towards downstream. We collected sediment samples from 8 stations along the Qishan river and where the Qishan river reaches the Kaoping river. The samples were processed in the lab for bacteriological and physicochemical analysis. Antibacterial resistance was tested by disk diffusion and micro-dilution with ten common antibacterials. A comparison was made among the sites where isolates began to occur at the upstream (site 1-6) with the downstream, including site 7 (Qishan town), site 8 (wastewater treatment plant) and site 9 (Kaoping river). The results of multivariate analysis for bacteriological and physicochemical parameters showed increasing water pollution levels downstream of the Qishan river. Ten bacteria including Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Enterobacter sp., Acinetobacter sp., Staphylococcus spp. and Bacillus spp. were analyzed and tested in the study. Their percentage of occurrence varied at each site. The resistance level was determined from the growth inhibition zone diameter (disk diffusion) and the minimum inhibitory concentration (micro-dilution). The results indicated that antibacterial resistance was related to certain environmental factors. Besides, the usage pattern of different classes of antibacterials in different places could alter trends of their resistance. Bacteria were found with increased resistance to antibacterials used in agriculture through the downstream sites according to the results. The WWTP emitting wastewater was demonstrated to be a hotspot of resistance in aquatic environments. In conclusion, bacterial resistance against antibacterials from the Qishan river has become a potential public health threat. This study could assist authorities by providing a reference for water quality risk assessment and management in Kaohsiung city and southern Taiwan.
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