Cobalt and copper recovery from aqueous Co （II） and Cu（II） is one critical step for cobalt and copper wastewaters treatment. Previous tests have primarily examined Cu（II） and Co（II） removal in microbial electr...Cobalt and copper recovery from aqueous Co （II） and Cu（II） is one critical step for cobalt and copper wastewaters treatment. Previous tests have primarily examined Cu（II） and Co（II） removal in microbial electro- lysis cells （MECs） with abiotic cathodes and driven by microbial fuel cell （MFCs）. However, Cu（II） and Co（II） removal rates were still slow. Here we report MECs with biocathodes and driven by MFCs where enhanced removal rates of 6.0＋0.2mg·L^-1·h^-1 for Cu（II） at an initial concentration of 50 mg·L^-1 and 5.3~0.4mg·L^-1·h^-1 for Co（II） at an initial 40 mg· L^-1 were achieved, 1.7 times and 3.3 times as high as those in MECs with abiotic cathodes and driven by MFCs. Species of Cu（II） was reduced to pure copper on the cathodes of MFCs whereas Co（II） was removed associated with microorganisms on the cathodes of the connected MECs. Higher Cu（II） concentrations and smaller working volumes in the cathode chambers of MFCs further improved removal rates of Cu（II） （115.7 mg·L^-1·h^-1） and Co（II） （6.4 mg·L^-1·h^-1） with concomi- tantly achieving hydrogen generation （0.054-0.00 mol·mol^-1 COD）. Phylogenetic analysis on the bio- cathodes indicates Proteobacteria dominantly accounted for 67.9% of the total reads, followed by Firmicutes （14.0%）, Bacteroidetes （6.1%）, Tenericutes （2.5%）, Lentisphaerae （1.4%）, and Synergistetes （1.0%）. This study provides a beneficial attempt to achieve simultaneous enhanced Cu（II） and Co（II） removal, and efficient Cu（II） and Co（II） wastewaters treatment without any external energy consumption.展开更多
We tested the recent hypothesis that the"fly factor"phenomenon(food cur-rently or previously fed on by flies attracts more flies than the same type of food kept inccessible to flies)is mediated by bacterial ...We tested the recent hypothesis that the"fly factor"phenomenon(food cur-rently or previously fed on by flies attracts more flies than the same type of food kept inccessible to flies)is mediated by bacterial symbionts deposited with feees or regur-gitated by feeding flies.We allowed laboratory-reared black blow flies,Phormia regina(Meigen),to feed and de fecate on bacterial Luria-Bertani medium solidified with agar,and isolated seven morphologically distinct bacterial colonies.We identified these us-ing matrix-assisted laser desorption/ionization mass spectrometry and sequencing of the 165 rRNA gene.In two-choice laboratory experiments,traps baited with cultures of Pro-teus mirabilis Hauser,Morganella morganii subsp.sibonii Jensen,or Serratia marcescens Bizio,captured significantly more flies than corresponding control jars baited with tryptic soy agar only.A mixture of seven bacterial strains as a trap bait was more attractive to flies than a single bacterial isolate(M.m.siboni).In a field experiment,traps baited with agar cultures of P:mirabilis and M.m siboni in combination captured significantly more flies than lraps baited with either bacterial isolate alone or the agar control.As evident by gas chromatography-mass spectrometry,the odor profiles of bacterial isolates differ,which may explain the additive effect of bacteria to the attractiveness of bacterial trap baits.As"generalist bacteria,"P mirabilis and M.m.sibonii growing on animal protein(beef liver)or plant protein(tofu)are similarly effective in attracting flies.Bacteria-derived airborne semiochemicals appear to mediate foraging by flies and to inform their feeding and oviposition decisions.展开更多
文摘Cobalt and copper recovery from aqueous Co （II） and Cu（II） is one critical step for cobalt and copper wastewaters treatment. Previous tests have primarily examined Cu（II） and Co（II） removal in microbial electro- lysis cells （MECs） with abiotic cathodes and driven by microbial fuel cell （MFCs）. However, Cu（II） and Co（II） removal rates were still slow. Here we report MECs with biocathodes and driven by MFCs where enhanced removal rates of 6.0＋0.2mg·L^-1·h^-1 for Cu（II） at an initial concentration of 50 mg·L^-1 and 5.3~0.4mg·L^-1·h^-1 for Co（II） at an initial 40 mg· L^-1 were achieved, 1.7 times and 3.3 times as high as those in MECs with abiotic cathodes and driven by MFCs. Species of Cu（II） was reduced to pure copper on the cathodes of MFCs whereas Co（II） was removed associated with microorganisms on the cathodes of the connected MECs. Higher Cu（II） concentrations and smaller working volumes in the cathode chambers of MFCs further improved removal rates of Cu（II） （115.7 mg·L^-1·h^-1） and Co（II） （6.4 mg·L^-1·h^-1） with concomi- tantly achieving hydrogen generation （0.054-0.00 mol·mol^-1 COD）. Phylogenetic analysis on the bio- cathodes indicates Proteobacteria dominantly accounted for 67.9% of the total reads, followed by Firmicutes （14.0%）, Bacteroidetes （6.1%）, Tenericutes （2.5%）, Lentisphaerae （1.4%）, and Synergistetes （1.0%）. This study provides a beneficial attempt to achieve simultaneous enhanced Cu（II） and Co（II） removal, and efficient Cu（II） and Co（II） wastewaters treatment without any external energy consumption.
文摘We tested the recent hypothesis that the"fly factor"phenomenon(food cur-rently or previously fed on by flies attracts more flies than the same type of food kept inccessible to flies)is mediated by bacterial symbionts deposited with feees or regur-gitated by feeding flies.We allowed laboratory-reared black blow flies,Phormia regina(Meigen),to feed and de fecate on bacterial Luria-Bertani medium solidified with agar,and isolated seven morphologically distinct bacterial colonies.We identified these us-ing matrix-assisted laser desorption/ionization mass spectrometry and sequencing of the 165 rRNA gene.In two-choice laboratory experiments,traps baited with cultures of Pro-teus mirabilis Hauser,Morganella morganii subsp.sibonii Jensen,or Serratia marcescens Bizio,captured significantly more flies than corresponding control jars baited with tryptic soy agar only.A mixture of seven bacterial strains as a trap bait was more attractive to flies than a single bacterial isolate(M.m.siboni).In a field experiment,traps baited with agar cultures of P:mirabilis and M.m siboni in combination captured significantly more flies than lraps baited with either bacterial isolate alone or the agar control.As evident by gas chromatography-mass spectrometry,the odor profiles of bacterial isolates differ,which may explain the additive effect of bacteria to the attractiveness of bacterial trap baits.As"generalist bacteria,"P mirabilis and M.m.sibonii growing on animal protein(beef liver)or plant protein(tofu)are similarly effective in attracting flies.Bacteria-derived airborne semiochemicals appear to mediate foraging by flies and to inform their feeding and oviposition decisions.
