Isolation of Efficient Metal-Binding Bacteria from Boreal Peat Soils and Development of Microbial Biosorbents for Improved Nickel Scavenging

Abstract

Boreal peatlands with low iron availability are a potential, but rarely studied, source for the isolation of bacteria for applications in metal sorption. The present research focused on the isolation and identification of Actinobacteria from northern Finland, which can produce siderophores for metal capture. The 16S rDNA analysis showed that isolated strains belonged to Firmicutes (Bacillus sp.) and Actinobacteria (Microbacterium sp.). The culture most efficiently producing siderophores in the widest array of the media was identified as Microbacterium sp. The most appropriate media for siderophore production by the Microbacterium strain were those prepared with glucose supplemented with asparagine or glutamic acid, and those prepared with glycerol or fructose supplemented with glutamic acid. The microorganism obtained and its siderophores were used to develop Sphagnum moss-based hybrid biosorbents. It was showed that the hybrid sorbent could bind nickel ions and that the nickel removal was enhanced by the presence of siderophores. Bacterial cells did not have a significant effect on sorption efficiency compared to the use of siderophores alone. The microbial biosorbent could be applied in the final effluent treatment stage for wastewater with low metal concentrations.

Evaluation of Piper Betle L. Extracts and Its Antivirulence Activity Towards P. Aeruginosa

“…0.5 mL of filtrate was placed in 1 mL cuvette, and 0.5 mL CAS reagent was added to the cuvette. The reading was measured using a spectrophotometer at OD630 (Optical density used to measure bacterial biofilm production) [49]. The absorbance reading is taken at t0 and t10.…”

“…Pyoverdine assay is a method to measure the capabilities of the extract to treat P. aeruginosa virulence factor [35]. This method is a quantitative method as the mixture's optical density (OD) is measured at a time interval of 0 to 10 minutes using a spectrophotometer [49]. Figure 3 shows the graph of P. aeruginosa used to determine the quorum sensing (QS) activity after adding CAS reagent.…”

“…The high affinity towards iron III during quorum sensing chemical reaction leads to detection of siderophore (Pyoverdine) using CAS reagent as an indicator [47,48]. A potent ligand such as pyoverdine removed iron III from CAS reagent causes blue colour shifting between t0 and t10 [49]. Thus, the more biofilm present, the more colour changes monitored and vice versa due to strong ligand (siderophore) to grab the iron III compound and remove the blue dyes from the mixtures.…”

Isolation and Characterization of Bacterial Endophytes from Small Nodules of Field-Grown Peanut

“…The isolates from the Enterobacteriaceae family were mostly abundant for P-solubilization by the YMA media, whereas the isolates from the genera Pseudomonas and Pantoea predominantly solubilized P on the PVK media. Only the bacteria from the Pantoea group were observed to undergo P-solubilization on both the YMA and PVK media, and a single isolate (38) showed the highest amount of PSI activity when using these two media types. In addition to the genera Pseudomonas and Pantoea, a single isolate from Rhizobium (16), Herbaspirillum (27), and Mitsuaria (43) were also observed to have PSI activity due to the PVK media.…”

Biological sulfate removal with low-cost carbon sources using cold-acclimated bacteria

“…However, a sulfate removal rate of only 13.8% was observed, probably because the carbon of such a complex material is poorly bioavailable. Since peat is known as an efficient biosorbent for several contaminants (Zhou et al 2012;Gogoi et al 2018Gogoi et al , 2019Leiviskä et al 2018;Zhang et al 2019), and exploiting peat soils for development of biosorbents has been extensively investigated (Bartczak et al 2018;Virpiranta et al 2020), the role of adsorption in sulfate removal also merits study. In addition, there is a lack of knowledge on the utilization of whey and sewage sludge under cold conditions.…”