Bioremediation of nickel (Ni2+) from the contaminated environments using thermophilic bacterial biomass: a comparative study

Distinguishing between live and dead standing tree biomass on the North Rim of Grand Canyon National Park, USA using small-footprint lidar data

Daily industrial activities especially in developing countries produce and discharge wastes containing heavy metals into the water resources making them polluted, threatening human health and the ecosystem. One such heavy metal is Chromium, the hexavalent form of which is extremely toxic and carcinogenic. Biosorption, the process of passive cation binding by dead or living biomass, represents a potentially cost-effective way of eliminating toxic heavy metals from industrial wastewater. The potential of microorganisms to remove metal ions in solution has been extensively studied; in particular, live and dead fungi have been recognized as a promising class of low-cost adsorbents for the removal of heavy metal ions. Fungal biomass has various advantages; hence, it needs to be explored further to take its maximum advantage in wastewater treatment. In this study, we discuss the live and dead fungi characteristics of sorption, factors influencing heavy metal removal. Biosorption studies were performed with both dead and live biomass and the effectiveness of Cr (VI) biosorption was compared for each parameter. It was observed that biosorption was maximum (approximately): 82% while using sulfuric acid as the pre-treatment agent (hence only dead biomass) and also maximum of 96.5% at 1 N. The optimum pH for maximum biosorption was 6 when dead biomass was used, while it was 2 when live biomass was used. Maximum Chromium removal of 86% was obtained using 2 g live biomass whereas 0.5 g of dead biomass was enough to obtain the maximum efficiency.96% chromium was removed at 25° C using dead biomass, whereas, maximum removal of about 84% was obtained when live biomass was used for biosorption and it took place at 35° C. Maximum Cr (VI) removal of about 95% was obtained when dead biomass was used and 69% when live biomass was used, both at 1mg/L metal concentration. 0.5 g of dead biomass in 100 ml, 1 mg/L solution, was optimum for Cr (VI) removal, while for live biomass, maximum Cr (VI) biosorption of 63% was obtained when 1.5 g of it was used in 300 ml solution. It was finally concluded that dead fungal biomass has better biosorption potentials and also some other inherent advantages over live biomass.

Batch and column approach on biosorption of fluoride from aqueous medium using live, dead and various pretreated Aspergillus niger (FS18) biomass

The removal of lead(II) from artificial aqueous solution using live and dead biomass of Saccharomyces cerevisiae AUMC 3875 was investigated. The minimum inhibitory concentration (MIC) value of S. cerevisiae AUMC 3875 for lead(II) was 600 mg/l. For live and dead biomass, maximum lead(II) uptake capacities were achieved at pH 5.0, initial metal ion concentration 300 mg/l, and biomass dosage 3 g/l. Maximum biosorption capacities were reached after 3 h and 20 min for live and dead cells, respectively. Fourier Transform Infrared spectroscopy (FTIR) results revealed the important role of C = O,ـ OH,ـ NH, protein amide II band, $$ \mathrm{PO}_2^{-} $$ , mannans, sulphur and sulphur-oxygen compounds in lead(II) uptake. Scanning electron microscopy analysis (SEM) showed that the cell surface morphology and surface area/volume ratio changed greatly after lead(II) uptake. Transmission electron microscopy analysis (TEM) confirmed the involvement of both extracellular adsorption and intracellular penetration through the cell wall. X-ray powder diffraction (XRD) analysis revealed the presence of Pb(SO4),Pb2OSO4 by dead biomass and Pb3O2(SO4),Pb2OSO4 by live biomass. Energy dispersive X-ray microanalysis (EDAX) confirmed the occurrence of sulphur, oxygen and lead(II) on the cell wall. The removal of lead(II) from storage battery industry wastewater was performed by dead biomass efficiently.

The removal of lead(II) from artificial aqueous solution using live and dead biomass of Saccharomyces cerevisiae AUMC 3875 was investigated. The minimum inhibitory concentration (MIC) value of S. cerevisiae AUMC 3875 for lead(II) was 600 mg/l. For live and dead biomass, maximum lead(II) uptake capacities were achieved at pH 5.0, initial metal ion concentration 300 mg/l, and biomass dosage 3 g/l. Maximum biosorption capacities were reached after 3 h and 20 min for live and dead cells, respectively. Fourier Transform Infrared spectroscopy (FTIR) results revealed the important role of C = O,ـ OH,ـ NH, protein amide II band, $$ \mathrm{PO}_2^{-} $$ , mannans, sulphur and sulphur-oxygen compounds in lead(II) uptake. Scanning electron microscopy analysis (SEM) showed that the cell surface morphology and surface area/volume ratio changed greatly after lead(II) uptake. Transmission electron microscopy analysis (TEM) confirmed the involvement of both extracellular adsorption and intracellular penetration through the cell wall. X-ray powder diffraction (XRD) analysis revealed the presence of Pb(SO4),Pb2OSO4 by dead biomass and Pb3O2(SO4),Pb2OSO4 by live biomass. Energy dispersive X-ray microanalysis (EDAX) confirmed the occurrence of sulphur, oxygen and lead(II) on the cell wall. The removal of lead(II) from storage battery industry wastewater was performed by dead biomass efficiently.

Dead plant biomass from foundation plant species is fundamental for the survival of coastal salt marshes because dead biomass aids in the vertical accretion of the ecosystem. Fungi regulate the decomposition of dead biomass, and thus play an essential role for marsh survival. Despite their importance, little is known about the compositional and functional changes of fungal communities in plant matter throughout senescence and litter decomposition. Here, we analyzed how fungal communities and their functionality change in the foundation plant species Spartina patens, which builds vast amounts of dead plant biomass (thatch) on the soil surface. We analyzed the chemical and fungal properties of live biomass, standing dead biomass (dead biomass shortly after senescence), upper thatch (top layer of litter on the soil surface), and lower thatch (bottom layer of litter on the soil surface) during September and November of 2021. We found that the chemical and fungal properties of different S. patens biomass types followed a predictable litter decomposition pattern. Notably, live biomass, standing dead biomass, upper thatch, and lower thatch all hosted unique fungal communities and litter chemistry. Functional groups present in live biomass (pathogens, epiphytes, and mycoparasites) were lost during senescence and later replaced by diverse saprotrophs. The abundance of lignocellulose saprotrophs increased throughout decomposition, with the highest abundance occurring in lower thatch. These results suggest a predictable succession of fungal communities through the senescence and decomposition of the foundation species S. patens. Our study highlights the diversity of fungal communities in a disappearing foundation species.

Measurements of mid‐season live and dead aboveground biomass are reported for a 10‐yr period (1975–84) in a northeast Kansas tallgrass prairie. Study sites included shallow, rocky upland and deep, non‐rocky lowland soils in annually burned (April) and unburned watersheds. Lowland sites had significantly greater live biomass than upland sites for both burned and unburned prairie for the 10‐yr period. Moreover, live biomass was greater on burned than unburned lowland sites, but was not significantly increased by fire on the upland sites. Averaged across upland and lowland sites, mid‐season live biomass was 422 g m–2 on annually burned and 364 g m–2 on unburned sites for the 10‐yr period. Each site had its lowest live biomass value during the severe drought year of 1980 (range = 185–299 g m–2). During the study period, live biomass was most strongly correlated with seasonal pan water evaporation (r = –0.45 to –0.82), whereas dead biomass was correlated with the previous yr's precipitation (r = 0.61 and 0.90 for upland and lowland sites, respectively). When aboveground biomass was sampled throughout the 1984 season and separated into several components, biomass of the graminoids was 40% lower, whereas that of forbs and woody plants was 200–300% greater in the unburned than in the annually burned site.

Measurements of mid-season live and dead aboveground biomass are reported for a 10-yr period (1975-84) in a northeast Kansas tallgrass prairie. Study sites included shallow, rocky upland and deep, non-rocky lowland soils in annually bumed (April) and unbumed watersheds. Lowland sites had significantly greater live biomass than upland sites for both bumed and unbumed prairie for the 10-yr period. Moreover, live biomass was greater on burned than unburned lowland sites, but was not significantly increased by fire on the upland sites. Averaged across upland and lowland sites, mid-season live biomass was 422 g m-2 on annually burned and 364 g m-2 on unburned sites for the 10-yr period. Each site had its lowest live biomass value during the severe drought year of 1980 (range = 185-299 g m-2). During the study period, live biomass was most strongly correlated with seasonal pan water evaporation (r = -0.45 to -0.82), whereas dead biomass was correlated with the previous yr's precipitation (r = 0.61 and 0.90 for upland and lowland sites, respectively). When aboveground biomass was sampled throughout the 1984 season and separated into several components, biomass of the graminoids was 40% lower, whereas that of forbs and woody plants was 200-300% greater in the unburned

Field measurements of canopy reflectance of wetland vegetation in the blue (450 ran), green (548 nm), red (655 nm) and NIR (805 nm) wavebands were correlated with plant biomass variables. Negative relationships, asymptotic in nature, were observed between visible wavebands, canopy reflectance and total live biomass as well as green biomass, with correlation coefficients r between -0·52 and -0·93. Curvilinear relations were observed between NIR canopy reflectance and total live biomass as well as green biomass, with r between 0·39 and 0·88. Different normalization indices (NIR blue-1 , NIR red-1 , VI, PI and NIRlbio ) were tested and positive relations between these indices and total live biomass and green biomass were observed, with r between 0·69 and 0·96. Inverse relations of an asymptotic nature were observed between dead biomass as a percentage of total biomass and of green biomass, with r between 0·90 and 0·91. A model discriminating live and dead above-ground biomass was developed to improve correlations between canopy reflectance and biomass variables. The model nearly doubled the correlation coefficient between reflectance and green biomass for a canopy containing large amounts of interfering dead biomass, but did not change this correlation for a canopy containing small amounts of dead biomass.

Our study highlights that fungal biosorption capacity is highly dependent on the sampling area (roadside vs jungle) with roadside fungal strains showing significantly higher copper (Cu) biosorption capacities using living biomass compared to fungal strains originating from plants collected in virgin jungle (P<0·05). It also highlights that different biosorption mechanisms (alive - metabolic dependent and dead biomass - metabolic independent) result in different amounts of Cu being removed from the solutions. The living biomass possessed a better biosorption capacity than the dead biomass (P<0·05).

Biosorption of nickel by Lysinibacillus sp. BA2 native to bauxite mine

Heavy-metal removal from aqueous solution by fungus Mucor rouxii

Shoot mortality and dynamics of live and dead biomass in a stand of Salix viminalis

Manganese (Mn) contamination in groundwater is a global concern due to its harmful effects. The high concentration of Mn2+ in humans creates memory issues, decreased fertility, appetite loss, sleeplessness, sperm abnormalities, and ‘Manganism’. In this study, the isolation of thermophiles was followed by their assessment for MIC (minimum inhibitory concentration) and Mn bioremediation. We have isolated a total of 11 Mn-resistant bacterial strains of thermophiles with the identification of their bioremediation potential from the Tapt Kund, Soldhar, and Gauri Kund hot springs of Uttarakhand, India. Out of 11 strains, three isolates (TA8, SA9, and GA7) were identified with the highest metal resistance properties for toxic Mn2+. The metal tolerance capabilities of the strains were evaluated through MIC and the metal biosorption rate was estimated by the live cells bioremediation through thermophilic bacteria. ICP-MS (inductively coupled plasma mass spectrometry) was used to assess the Mn2+ removal rate of bacterial bioremediation. It turned out that every strain exhibited promising bioremediation potential and proved Mn-resistant. The bacterial strain TA8 exhibits the highest MIC (600 µg.L-1.) with a bioremediation rate of 98.34% for Mn2+. The bacterial strain SA9 has a MIC value of 525 µg.L-1, with a biosorption rate of 77.74% for Mn2+. The bacterial strain GA7 has a MIC of 475 µg.L-1, with an efficiency rate of 61.17% for Mn2+ removal. The most promising strain of thermophilic bacteria for Mn2+ bioremediation is the TA8, which has demonstrated the highest potential (98.34%) out of all the tested strains. The findings may have public health implications, as reducing manganese levels in groundwater can help mitigate health risks associated with Mn exposure. Also, this research enriches our knowledge of microbial bioremediation and its potential applications in environmental management. Ultimately, this research could offer a novel, economical, and environmentally beneficial approach to managing metal toxicity

Bioaccumulation and biosorption characteristics of Mn2+ions by both dead and living, non-growing biomass of Gram-positive bacteriaKocuria palustrisandMicrococcus luteusisolated from spent nuclear fuel pools were compared. The radioindicator method using radionuclide54Mn was applied to obtain precise and reliable data characterizing both processes as well as manganese distribution in bacterial cells. Manganese was mainly found on the surface (biosorption) of live cells of both bacteria and surface sorption capacity increased with Mn concentration in solution. Only 10.0% (M. luteus) and 6.3% (K. palustris) of uptaken Mn were localized in the cytoplasm (bioaccumulation). Biosorption of Mn by dead bacterial biomass was a rapid process strongly affected by solution pH. Maximum sorption capacitiesQmaxcalculated from the Langmuir isotherm and characterizing Mn binding represented 316±15 μmol/g forM. luteusand 282±16 μmol/g forK. palustris.Results indicate that living, non-growing cells showed a higher efficiency of Mn removal than dead biomass. Based on FTIR spectra examination with aim to characterize the surface ofK. palustrisandM. luteuscells, we confirmed that the phosphate and carboxyl functional groups are involved in manganese sorption onto cell surface by both live and dead bacterial biomass.