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Adsorption for heavy metals via biomaterials such as fungal biomass presents a practical remediation technique for polluted water. Among all known filamentous fungi,Penicillium chrysogenumis widespread in nature and can serve as a biosorbent for heavy metals. In the current study, the ability ofP. chrysogenumXJ-1 to remove copper (Cu2+) and chromium (Cr6+) from water was evaluated. The maximum biosorption capacity of XJ-1 for Cu2+reached 42.83 ± 0.57 mg g−1dry biomass at pH 5.0 after the equilibrium time of 1.5 h. The maximum biosorption capacity for Cr6+at pH 3.0 reached 52.69 ± 1.68 mg g−1dry biomass after the equilibrium time of 1.5 h. The biosorption data of XJ-1 biomass were well fitted to the Freundlich isotherm model and the pseudo-second-order Lagergren kinetic model. Laundry powder-treated and HCl-treated XJ-1 biomass significantly enhanced its adsorption capacity to Cu2+and Cr6+, respectively. HCl and NaOH were suitable desorbents for Cu2+/Cr6+loading biomass, respectively. Fourier transform infrared spectroscopy analyses revealed that hydroxyl, amine, and sulfonyl groups on the biosorbent contributed to binding Cu2+and Cr6+and that carbonyl and carboxyl groups were also vital binding sites of Cu2+. Scanning electron microscopy and energy-dispersive x-ray (SEM-EDX) analyses confirmed that considerable amounts of metals were precipitated on the cell surface of XJ-1. Our results suggested that XJ-1 might be used to purify multimetal-contaminated water. This low-cost and eco-friendly biomass of XJ-1 seems to have a broad use in the restoration of metal-contaminated water. [ABSTRACT FROM AUTHOR]

The biosorption of cadmium (Cd2+) and nickel (Ni2+) using living and nonliving biomass ofMucoromycotesp. XLC as a biosorbent was investigated in this study. The optimum conditions were established with batch biosorption experiments. The data from equilibrium experiments showed that all kinds of biosorbents fitted the Langmuir model. For the living and nonliving biosorbent, the predicted maximum Cd2+uptake capacity was 79.65 mg g−1and 56.51 mg g−1, while the maximum Ni2+uptake capacity was 51.26 mg g−1and 44.32 mg g−1, respectively. Acid digestion results indicated that intracellular metal ions might be the main reason for the metal uptake capacity difference between living and nonliving biosorbents. FTIR analysis and potentiometric titration indicated freeze dehydration-autoclaving treatment of nonliving biomass slightly changed the surface structure of the cell wall and the functional groups involved in biosorption were carboxylic, phosphoryl, amine and hydroxyl groups. Our results suggest the living biosorbent had a second biosorption process by intracellularly accumulating metal ions, hence possessing a higher Cd2+or Ni2+uptake capacity than nonliving biosorbent. [ABSTRACT FROM AUTHOR]

Substantial interactions of microbes with soil particles present fundamental influences on microbial activities relevant to a series of biogeochemical processes. However, how soil surface-active particles modulate microbial metabolism has received scant attention. The extent to which composition of soil colloids alter the metabolism is not well addressed. This work examined the impacts of soil colloids and minerals on the metabolic activity ofPseudomonas putidausing microcalorimetry and carbon utilization. The results showed that montmorillonite remarkably improved metabolic activity ofP. putida, whereas kaolinite, goethite and soil colloids significantly inhibited the activity. Humus may weaken the inhibition of soil colloids on bacterial metabolism via interfacial interaction rather than nutrient supplements. Soils bearing higher amount of kaolinite and iron oxide may have greater depression on bacterial activity. The thermodynamic method provides different and complementary information to that from other techniques in characterizing microbial activities. The quantity and affinity for the adhesion of bacteria onto soil components together with the detoxification of metabolites were assigned to the modifications of bacterial activities. [ABSTRACT FROM PUBLISHER]