scholarly journals Biodegradation of thiocyanate in groundwater by a native aquifer microbial consortium

Author(s):  
Liam P Spurr ◽  
Mathew P Watts ◽  
Han Ming Gan ◽  
John W Moreau

Gold ore processing typically generates large amounts of thiocyanate (SCN-)-contaminated effluent. When this effluent is stored in unlined tailings dams, contamination of the underlying aquifer can occur. The potential for bioremediation of SCN--contaminated groundwater, either in situ or through ex situ, remains largely unexplored. This study aimed to enrich and characterise SCN--degrading microorganisms from mining-contaminated groundwater under a range of culturing conditions. Mildly acidic and suboxic groundwater, containing ~135 mgL-1 SCN-, was collected from an aquifer below an unlined tailings dam. An SCN--degrading consortium was enriched from contaminated groundwater using combinatory amendments of air, glucose and phosphate. Biodegradation occurred in all oxic cultures, except with the sole addition of glucose, but was inhibited by NH4+ and did not occur under anoxic conditions. The SCN--degrading consortium was characterised using 16S and 18S rRNA gene sequencing, identifying a variety of heterotrophic taxa in addition to sulfur-oxidising bacteria. Interestingly, few recognised SCN--degrading taxa were identified in significant abundance. These results provide both proof-of-concept and the required conditions for biostimulation of SCN- degradation in groundwater by native aquifer microorganisms.

2018 ◽  
Author(s):  
Liam P Spurr ◽  
Mathew P Watts ◽  
Han Ming Gan ◽  
John W Moreau

Gold ore processing typically generates large amounts of thiocyanate (SCN-)-contaminated effluent. When this effluent is stored in unlined tailings dams, contamination of the underlying aquifer can occur. The potential for bioremediation of SCN--contaminated groundwater, either in situ or through ex situ, remains largely unexplored. This study aimed to enrich and characterise SCN--degrading microorganisms from mining-contaminated groundwater under a range of culturing conditions. Mildly acidic and suboxic groundwater, containing ~135 mgL-1 SCN-, was collected from an aquifer below an unlined tailings dam. An SCN--degrading consortium was enriched from contaminated groundwater using combinatory amendments of air, glucose and phosphate. Biodegradation occurred in all oxic cultures, except with the sole addition of glucose, but was inhibited by NH4+ and did not occur under anoxic conditions. The SCN--degrading consortium was characterised using 16S and 18S rRNA gene sequencing, identifying a variety of heterotrophic taxa in addition to sulfur-oxidising bacteria. Interestingly, few recognised SCN--degrading taxa were identified in significant abundance. These results provide both proof-of-concept and the required conditions for biostimulation of SCN- degradation in groundwater by native aquifer microorganisms.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6498 ◽  
Author(s):  
Liam P. Spurr ◽  
Mathew P. Watts ◽  
Han M. Gan ◽  
John W. Moreau

Gold ore processing typically generates large amounts of thiocyanate (SCN−)-contaminated effluent. When this effluent is stored in unlined tailings dams, contamination of the underlying aquifer can occur. The potential for bioremediation of SCN−-contaminated groundwater, either in situ or ex situ, remains largely unexplored. This study aimed to enrich and characterise SCN−-degrading microorganisms from mining-contaminated groundwater under a range of culturing conditions. Mildly acidic and suboxic groundwater, containing ∼135 mg L−1 SCN−, was collected from an aquifer below an unlined tailings dam. An SCN−-degrading consortium was enriched from contaminated groundwater using combinatory amendments of air, glucose and phosphate. Biodegradation occurred in all oxic cultures, except with the sole addition of glucose, but was inhibited by NH4+ and did not occur under anoxic conditions. The SCN−-degrading consortium was characterised using 16S and 18S rRNA gene sequencing, identifying a variety of heterotrophic taxa in addition to sulphur-oxidising bacteria. Interestingly, few recognised SCN−-degrading taxa were identified in significant abundance. These results provide both proof-of-concept and the required conditions for biostimulation of SCN− degradation in groundwater by native aquifer microorganisms.


2012 ◽  
Vol 62 (Pt_6) ◽  
pp. 1425-1433 ◽  
Author(s):  
William Orsi ◽  
Virginia Edgcomb ◽  
Jose Faria ◽  
Wilhelm Foissner ◽  
William H. Fowle ◽  
...  

The majority of environmental micro-organisms identified with the rRNA approach have never been visualized. Thus, their reliable classification and taxonomic assignment is often difficult or even impossible. In our preliminary 18S rRNA gene sequencing work from the world’s largest anoxic marine environment, the Cariaco Basin (Caribbean Sea, Venezuela), we detected a ciliate clade, designated previously as CAR_H [Stoeck, S., Taylor, G. T. & Epstein, S. S. (2003). Appl Environ Microbiol 63, 5656–5663]. Here, we combine the traditional rRNA detection method of fluorescent in situ hybridization (FISH) with scanning electron microscopy (SEM) and confirm the phylogenetic separation of the CAR_H sequences from all other ciliate classes by showing an outstanding morphological feature of this group: a unique, archway-shaped kinety surrounding the oral apparatus and extending to the posterior body end in CAR_H cells. Based on this specific feature and the molecular phylogenies, we propose a novel ciliate class, Cariacotrichea nov. cl.


2018 ◽  
Author(s):  
Julie Lattaud ◽  
Frédérique Kirkels ◽  
Francien Peterse ◽  
Chantal V. Freymond ◽  
Timothy I. Eglinton ◽  
...  

Abstract. Long chain diols (LCDs) occur widespread in marine environments and also in lakes and rivers. Transport of LCDs from rivers may impact the distribution of LCDs in coastal environments, however relatively little is known about the distribution and biological sources of LCDs in river systems. In this study, we investigated the distribution of LCDs in suspended particulate matter (SPM) of three river systems (Godavari, Danube, and Rhine) in relation with season, precipitation, temperature, and source catchments. The dominant long-chain diol is the C32 1,15-diol followed by the C30 1,15-diol in all studied river systems. In regions influenced by marine waters, such as delta systems, the fractional abundance of the C30 1,15-diol is substantially higher than in the river itself, suggesting different LCD producers in marine and freshwater environments. A change in the LCD distribution along the downstream transects of the rivers studied was not observed. However, an effect of river flow is observed, i.e. the concentration of the C32 1,15-diol is higher in stagnant waters, such as reservoirs and during seasons with river low stands. A seasonal change in the LCD distribution was observed in the Rhine, likely due to a change in the producers. Eukaryotic diversity analysis by 18S rRNA gene sequencing of SPM from the Rhine showed extremely low abundances of sequences (i.e.


Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 586
Author(s):  
Manuel Alejandro Borquez-Román ◽  
Luis Fernando Lares-Jiménez ◽  
Libia Zulema Rodriguez-Anaya ◽  
Jose Reyes Gonzalez-Galaviz ◽  
Paul A. Fuerst ◽  
...  

Two amoeboid organisms were obtained from water samples taken from a thermal spring, "Agua Caliente", in Northwestern Mexico. The isolates were obtained when samples were cultivated at 37 °C on non-nutrient agar coated with Escherichia coli. The initial identification of the isolates was performed morphologically using light microscopy. The samples were found to have trophozoite morphology consistent with members of the genus Stenamoeba, a genus derived in 2007 from within the abolished polyphyletic genus Platyamoeba. Further analysis was performed by sequencing PCR products obtained using universal eukaryotic primers for the small subunit ribosomal ribonucleic acid (SSU rRNA) gene. Sequencing primers were designed to allow the comparison of the 18S rRNA gene sequences of the new isolates with previous sequences reported for Stenamoeba. Phylogenetic relationships among sequences from Stenamoeba were determined using Maximum Likelihood analysis. The results showed the two "Agua Caliente" sequences to be closely related, while clearly separating them from those of other Stenamoeba taxa. The degrees of sequence differentiation from other taxa were considered sufficient to allow us to propose that the Mexican isolates represent a new species.


2020 ◽  
Vol 32 (4) ◽  
pp. 2561-2573
Author(s):  
Wenlei Wang ◽  
Lei Wu ◽  
Kai Xu ◽  
Yan Xu ◽  
Dehua Ji ◽  
...  

Abstract Microorganisms play important roles in the growth and development of macroalgae. Still, the biodiversity of the epiphytic microbial community associated with the economically important red alga Pyropia haitanensis during the cultivation period remains uncharacterized, especially the effects of P. haitanensis cultivation on the microbial community of surrounding seawater. Here, we isolated epiphytic microbes from P. haitanensis during the thallus stage during oceanic cultivation and the conchocelis stage during industrial cultivation. The dynamic diversity patterns, as determined by 16S and 18S rRNA gene sequencing of the bacterial and fungal communities, respectively, associated with P. haitanensis and seawater in the presence and absence of algal cultivation were investigated. A notable distinction was observed between the microbial communities of seawater with and without P. haitanensis cultivation. Additionally, the alpha-diversity of seawater with P. haitanensis cultivation was significantly greater than without P. haitanensis cultivation. Cyanobacteria were the dominant species in the latter, while Rhodobacteraceae was enriched in the former. Furthermore, there were significant differences in the microbial community of P. haitanensis at the thallus and conchocelis stages. Seawater properties had significant direct effects on the microbial diversity of P. haitanensis and cultivation seawater, but not on non-cultivation seawater. The enriched microbial presence might promote thallus morphogenesis and be beneficial for the growth and development of both the thallus and conchocelis stages. These findings expand our knowledge of the bacteria and fungi that are beneficial for Pyropia nursery seeding and cultivation, as well as the effects of P. haitanensis cultivation on the seawater microbial community.


2018 ◽  
Vol 15 (13) ◽  
pp. 4147-4161 ◽  
Author(s):  
Julie Lattaud ◽  
Frédérique Kirkels ◽  
Francien Peterse ◽  
Chantal V. Freymond ◽  
Timothy I. Eglinton ◽  
...  

Abstract. Long-chain diols (LCDs) occur widespread in marine environments and also in lakes and rivers. Transport of LCDs from rivers may impact the distribution of LCDs in coastal environments, however relatively little is known about the distribution and biological sources of LCDs in river systems. In this study, we investigated the distribution of LCDs in suspended particulate matter (SPM) of three river systems (Godavari, Danube, and Rhine) in relation with precipitation, temperature, and source catchments. The dominant long-chain diol is the C32 1,15-diol followed by the C30 1,15-diol in all studied river systems. In regions influenced by marine waters, such as delta systems, the fractional abundance of the C30 1,15-diol is substantially higher than in the river itself, suggesting different LCD producers in marine and freshwater environments. A change in the LCD distribution along the downstream transects of the rivers studied was not observed. However, an effect of river flow is observed; i.e., the concentration of the C32 1,15-diol is higher in stagnant waters such as reservoirs and during seasons with river low stands. A seasonal change in the LCD distribution was observed in the Rhine, likely due to a change in the producers. Eukaryotic diversity analysis by 18S rRNA gene sequencing of SPM from the Rhine showed extremely low abundances of sequences (i.e., < 0.32 % of total reads) related to known algal LCD producers. Furthermore, incubation of the river water with 13C-labeled bicarbonate did not result in 13C incorporation into LCDs. This indicates that the LCDs present are mainly of fossil origin in the fast-flowing part of the Rhine. Overall, our results suggest that the LCD producers in rivers predominantly reside in lakes or side ponds that are part of the river system.


2019 ◽  
Vol 131 ◽  
pp. 01043 ◽  
Author(s):  
Bo Peng ◽  
Yuannan Wang ◽  
Hengjun Zhang ◽  
Chen Chen ◽  
Hailin Luo ◽  
...  

Monitoring phytoplankton community underpins our understanding of water quality and ecological functions. In this study, we approached phytoplankton abundance, community composition, and diversity by both microscopy and 18S rRNA gene sequencing. Environmental variances influencing the phytoplankton were evaluated as well. There were 6 phyla and 62 species identified by microscopy, and the diversity index Shannon-Wiener and evenness index Pielou index indicated phytoplankton community had high diversity; however, the high density of dominance genus suggested that our research region had potential red tide effects. The canonical correspondence analysis illustrated that suspended solids, phosphate and temperature were three major factors that affected the distribution and components of phytoplankton community. The DNA barcoding sequencing of 18S rRNA gene supported the main results via microscopic methods while providing more identified community components, which implied that 18S rRNA gene sequencing can be used as a supplemental method for fast ecological assessment of phytoplankton community.


2019 ◽  
Vol 366 (6) ◽  
Author(s):  
Robert Wilson ◽  
Kjartan Østbye ◽  
Inga Leena Angell ◽  
Knut Rudi

ABSTRACT The association between diet and the rumen microbiota for wild animals remains largely unexplored. Here, we explored this association using a combination of 16S rRNA gene sequencing to determine the prokaryote microbiota and 18S rRNA gene sequencing to determine the dietary components for wild roe deer. These analyses revealed a wide diversity of dietary components, with over-representation of Bacteroidetes for the diet-correlating bacteria. Ruminococcus, on the other hand, dominated the stable diet-independent part of the microbiota. Taken together, the combination of 16S and 18S rRNA gene analyses provide novel insight into rumen microbiota ecology.


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