scholarly journals Insight into the Metabolic Profiles of Pb(II) Removing Microorganisms

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4008
Author(s):  
Carla Cilliers ◽  
Evans M. N. Chirwa ◽  
Hendrik G. Brink

The objective of the study was to gather insight into the metabolism of lead-removing microorganisms, coupled with Pb(II) removal, biomass viability and nitrate concentrations for Pb(II) bioremoval using an industrially obtained microbial consortium. The consortium used for study has proven to be highly effective at removing aqueous Pb(II) from solution. Anaerobic batch experiments were conducted with Luria-Bertani broth as rich growth medium over a period of 33 h, comparing a lower concentration of Pb(II) with a higher concentration at two different nutrient concentrations. Metabolite profiling and quantification were conducted with the aid of both liquid chromatography coupled with tandem mass spectroscopy (UPLC-HDMS) in a “non-targeted” fashion and high-performance liquid chromatography (HPLC) in a “targeted” fashion. Four main compounds were identified, and a metabolic study was conducted on each to establish their possible significance for Pb(II) bioremoval. The study investigates the first metabolic profile to date for Pb(II) bioremoval, which in turn can result in a clarified understanding for development on an industrial and microbial level.

The Auk ◽  
2003 ◽  
Vol 120 (2) ◽  
pp. 394-399 ◽  
Author(s):  
Richard C. Chaney ◽  
Kenneth P. Blemings ◽  
James Bonner ◽  
Hillar Klandorf

Abstract Birds have few reliable indicators of aging. Pentosidine is a product of nonenzymatic glycation that accumulates in tissues of an animal over its lifespan. The intent of this study was to determine if accumulation of skin pentosidine in birds of known ages changed as a function of time. Skin samples were obtained from the breast of 45 birds of various species obtained from the national aviary. In addition, foot webbing samples were obtained from 17 California Gulls (Larus callifornicus) of known ages. Collagen was measured by a hydroxypro-line spectrophotometric method and pentosidine was quantified using reverse phase high-performance liquid-chromatography. Pentosidine concentration in the skin and foot webbing increased linearly with age (P < 0.001). Hydroxyproline concentrations from the foot webbing were comparable to that measured in the skin; however, pentosidine concentrations were approximately one-fourth of that in skin. Knowledge regarding longevity of birds could provide information for species survival programs and insight into variations in longevity of an entire population.


2011 ◽  
Vol 77 (20) ◽  
pp. 7255-7260 ◽  
Author(s):  
Murugan Subbiah ◽  
Shannon M. Mitchell ◽  
Jeffrey L. Ullman ◽  
Douglas R. Call

ABSTRACTIt is generally assumed that antibiotic residues in soils select for antibiotic-resistant bacteria. This assumption was tested by separately adding 10 different antibiotics (≥200 ppm) to three soil-water slurries (silt-loam, sand-loam, and sand; 20% soil [wt/vol]) and incubating mixtures for 24 h at room temperature. The antibiotic activity of the resultant supernatant was assessed by culturing a sensitiveEscherichia colistrain in the filter-sterilized supernatant augmented with Luria-Bertani broth. We found striking differences in the abilities of supernatants to suppress growth of the indicatorE. coli. Ampicillin, cephalothin, cefoxitin, ceftiofur, and florfenicol supernatants completely inhibited growth while bacterial growth was uninhibited in the presence of neomycin, tetracycline, and ciprofloxacin supernatants. High-performance liquid chromatography (HPLC) analysis demonstrated that cefoxitin and florfenicol were almost completely retained in the supernatants, whereas tetracycline and ciprofloxacin were mostly removed. Antibiotic dissipation in soil, presumably dominated by adsorption mechanisms, was sufficient to neutralize 200 ppm of tetracycline; this concentration is considerably higher than reported contamination levels. Soil pellets from the tetracycline slurries were resuspended in a minimal volume of medium to maximize the interaction between bacteria and soil particles, but sensitive bacteria were still unaffected by tetracycline (P= 0.6). Thus, residual antibiotics in soil do not necessarily exert a selective pressure, and the degree to which the pharmaceutical remains bioactive depends on the antibiotic. Efforts to control antibiotic contamination would be better directed toward compounds that retain biological activity in soils (e.g., cephalosporins and florfenicol) because these are the antibiotics that could exert a selective pressure in the environment.


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