Dead Fungal Biomass Research Articles

Transcriptomic analyses of bacterial growth on fungal necromass reveal different microbial community niches during degradation.

Bacteria are major drivers of organic matter decomposition and play crucial roles in global nutrient cycling. Although the degradation of dead fungal biomass (necromass) is increasingly recognized as an important contributor to soil carbon (C) and nitrogen (N) cycling, the genes and metabolic pathways involved in necromass degradation are less characterized. In particular, how bacteria degrade necromass containing different quantities of melanin, which largely control rates of necromass decomposition in situ, is largely unknown. To address this gap, we conducted a multi-timepoint transcriptomic analysis using three Gram-negative, bacterial species grown on low or high melanin necromass of Hyaloscypha bicolor. The bacterial species, Cellvibrio japonicus, Chitinophaga pinensis, and Serratia marcescens, belong to genera known to degrade necromass in situ. We found that while bacterial growth was consistently higher on low than high melanin necromass, the CAZyme-encoding gene expression response of the three species was similar between the two necromass types. Interestingly, this trend was not shared for genes encoding nitrogen utilization, which varied in C. pinensis and S. marcescens during growth on high vs low melanin necromass. Additionally, this study tested the metabolic capabilities of these bacterial species to grow on a diversity of C and N sources and found that the three bacteria have substantially different utilization patterns. Collectively, our data suggest that as necromass changes chemically over the course of degradation, certain bacterial species are favored based on their differential metabolic capacities.IMPORTANCEFungal necromass is a major component of the carbon (C) in soils as well as an important source of nitrogen (N) for plant and microbial growth. Bacteria associated with necromass represent a distinct subset of the soil microbiome and characterizing their functional capacities is the critical next step toward understanding how they influence necromass turnover. This is particularly important for necromass varying in melanin content, which has been observed to control the rate of necromass decomposition across a variety of ecosystems. Here we assessed the gene expression of three necromass-degrading bacteria grown on low or high melanin necromass and characterized their metabolic capacities to grow on different C and N substrates. These transcriptomic and metabolic studies provide the first steps toward assessing the physiological relevance of up-regulated CAZyme-encoding genes in necromass decomposition and provide foundational data for generating a predictive model of the molecular mechanisms underpinning necromass decomposition by soil bacteria.

Bioremediation petroleum wastewater and oil-polluted soils by the non-toxigenic indigenous fungi.

Soil and wastewater samples contaminated by petroleum-related industries were collected from various locations in Saudi Arabia, a country known for its vast oil reserves. The samples were analyzed for their physicochemical properties, including the presence of metals, petroleum hydrocarbons, and aromatic compounds. A total of 264 fungal isolates were analyzed and categorized into eight groups of Aspergillus (194 isolates) and four groups of Penicillium (70 isolates). The potential of these fungal groups to grow in oil or its derivatives was investigated. Two isolates, Aspergillus tubingensis FA-KSU5 and A. niger FU-KSU69, were utilized in two remediation experiments-one targeting wastewater and the other focusing on polluted soil. The FA-KSU5 strain demonstrated complete removal of Fe3+, As3+, Cr6+, Zn2+, Mn2+, Cu2+ and Cd2+, with bioremediation efficiency for petroleum hydrocarbons in the wastewater from these sites ranging between 90.80 and 98.58%. Additionally, the FU-KSU69 strain achieved up to 100% reduction of Co2+, Ba2+, B3+, V+, Ni2+, Pb2+ and Hg2+, with removal efficiency ranging from 93.17 to 96.02% for aromatic hydrocarbons after 180min of wastewater treatment. After 21days of soil incubation with Aspergillus tubingensis FA-KSU5, there was a 93.15% to 98.48% reduction in total petroleum hydrocarbons (TPHs) and an 88.11% to 97.31% decrease in polycyclic aromatic hydrocarbons (PAHs). This strain exhibited the highest removal rates for Cd2+ and As3+ followed by Fe3+, Zn2+, Cr6+, Se4+ and Cu2+. Aspergillus niger FU-KSU69 achieved a 90.37% to 94.90% reduction in TPHs and a 95.13% to 98.15% decrease in PAHs, with significant removal of Ni2+, Pb2+ and Hg2+, followed by Co2+, V+, Ba2+ and B3+. The enzymatic activity in the treated soils increased by 1.54- to 3.57-fold compared to the polluted soil. Although the mixture of wastewater and polluted soil exhibited high cytotoxicity against normal human cell lines, following mycoremediation, all treated soils and effluents with the dead fungal biomass showed no toxicity against normal human cell lines at concentrations up to 500 µL/mL, with IC50 values ≥ 1000 µL/mL. SEM and IR analysis revealed morphological and biochemical alterations in the biomass of A. tubingensis FA-KSU5 and A. niger FA-KSU69 when exposed to petroleum effluents. This study successfully introduces non-toxigenic and environmentally friendly fungal strains play a crucial role in the bioremediation of contaminated environments. Both strains serve as low-cost and effective adsorbents for bio-remediating petroleum wastewater and oil-contaminated soil. Heavy metals and hydrocarbons, the primary pollutants, were either completely removed or reduced to permissible levels according to international guidelines using the dead biomass of FA-KSU5 and FA-KSU69 fungi. Consequently, the environments associated with this globally significant industry are rendered biologically safe, particularly for humans, as evidenced by the absence of cytotoxicity in samples treated with A. tubingensis FA-KSU5 and A. niger FA-KSU69 on various human cell types.

Composites of sodium alginate based - Functional materials towards sustainable adsorption of benzene phenol derivatives - Bisphenol A/Triclosan

The present study evaluates the adsorption efficiency of low-cost carbonaceous adsorbents as fly ash (FA), saw dust biochar (SDB) (untreated and alkali - treated), live/dead pulverized white rot fungus Hypocrea lixii biomass encapsulated in sodium alginate (SA) against the commercially available activated carbon (AC) and graphene oxide (GO) SA beads for removal of benzene phenol derivatives - Bisphenol A (BPA)/triclosan (TCS). Amongst bi - and tri - composites SA beads, tri-composite beads comprising of untreated flyash - dead fungal biomass - sodium alginate (UFA - DB - SA) showed at par results with commercial composite beads. The tri - composite beads with point zero charge (Ppzc) of 6.2 was characterized using FTIR, XRD, surface area BET and SEM-EDX. The batch adsorption using tri - composite beads revealed removal of 93% BPA with adsorption capacity of 16.6 mg/g (pH 6) and 83.72% TCS with adsorption capacity of 14.23 mg/g (pH 5), respectively at 50 ppm initial concentration with 6 % adsorbent dose in 5 h. Freundlich isotherm favoring multilayered adsorption provided a better fit with r2 of 0.9674 for BPA and 0.9605 for TCS respectively. Intraparticle diffusion model showed adsorption of BPA/TCS molecules to follow pseudo - second order kinetics with boundary layer diffusion governed by first step of fast adsorption and intraparticle diffusion within pores by second slow adsorption step. Thermodynamic parameters (ΔH°, ΔS°, ΔG°) revealed adsorption process as exothermic, orderly and spontaneous. Methanol showed better desorbing efficiency leading to five cycles reusability. The phytotoxicity assay revealed increased germination rate of mung bean (Vigna radiata) seeds, sprinkled with post adsorbed treated water (0 h, 5 h and 7 h) initially spiked with 50 ppm BPA/TCS. Overall, UFA - DB - SA tri - composite beads provides a cost effective and eco - friendly matrix for effective removal of hydrophobic recalcitrant compounds.

Screening of White-Rot Fungi Isolates for Decolorization of Pulp and Paper Mill Effluent and Assessment of Biodegradation and Biosorption Processes.

Ten white-rot fungal isolates were evaluated for the decolorization potential of pulp and paper mill effluent. Trametes elegans PP17-06, Pseudolagarobasidium sp. PP17-33, and Microporus sp.2 PP17-20 showed the highest decolorization efficiencies between 42 and 54% in 5 d. To reveal the mechanisms involved in decolorization and assess the long-term performance, PP17-06, which showed the highest decolorization efficiency, was further investigated. It could reduce the ADMI color scale by 63.6% in 10 d. However, extending the treatment period for more than 10 d did not significantly enhance the decolorization efficiencies. The maximum MnP activity of 3.27 U L-1 was observed on the 6 d during the biodegradation. In comparison, laccase activities were low with the maximum activity of 0.38 U L-1 (24 d). No significant LiP activities were monitored during the experiment. Dead fungal biomass showed an optimum decolorization efficiency of 44.18% in 8 d employing the biosorption mechanism. No significant changes in the decolorization efficiency were observed after that, suggesting the equilibrium status was reached. These results revealed that PP17-06 has the potential to decolorize pulp and paper mill effluent by employing both biodegradation and biosorption processes.

Lead biosorption profiling of endophytic Aspergillus flavus SGE34 isolated from Cleome viscosa Linn.

ABSTRACT Lead is an environmental pollutant that causes remarkable damage to various organs in the human body, especially the nervous system. Removal of lead by conventional methods is costly, and therefore, in the current scenario, biosorption using fungi is extensively explored as they provide good metal uptake systems. The present study evaluated the Pb (II) biosorption potential of endophytic fungi Aspergillus flavus SGE34. The fungal isolate was obtained from the root of an indigenous medicinal plant of the Chhattisgarh region named Cleome viscosa Linn. The biosorption potential of dead fungal biomass was optimized at different operating parameters like contact time, pH, and temperature. The maximum biosorption values were found at pH 6.0 with an equilibrium time of 150 minutes at 350C. The Fourier transform infrared spectroscopy study revealed that the pattern of new absorption bands, altered absorption intensity, and shift in wavenumber of functional groups was deduced, due to interaction between metal ions and active sites of biosorbent. The present study concluded that A. flavus SGE34 has high metal tolerance and biosorption capacity; it could effectively remove lead from industrial effluents.

Bio-Leaching of Heavy Metals by Aspergillus niger from Mobile-Phone Scrap

The current study aimed to bioleach heavy metals from mobile phone scraps wastes (MPSs) which achieved by environmentally friendly method by employing Aspergillus nigur biomass which isolated from locally eroded mineral sites. Biological parameters of the experiment were: pH (5-2.5), temperature (28°C), ground mineral particle size (75-150 μm) and mineral particle amounts of (MPSs) were 0.1, 0.5, 1.0 grams/litter. The mineral content was analyzed for the recovery of heavy metals The results showed the highest values of the elements at a concentration of 0.5 g/L and pH 3.1 on day 28 of the experiment. The dead fungal biomass was also efficient in removing various heavy metals which charecterized by using XRF device and FT-IR technology was used to find out the active groups in fungal biomass. Electron microscopic imaging also showed the accumulation of metal particles within the fungal hyphae. The results of the current study indicate the possibility of applying Aspergillus niger for its ability to convert (MPSs) metals from solid to liquid phase, as an environmentally friendly and cost-efficient way of biologically leaching heavy metals.

Biosorption performance of the multi-metal tolerant fungus Aspergillus sp. for removal of some metallic nanoparticles from aqueous solutions

The wide spread of nanotechnology applications currently carries with it the possibility of polluting the environment with the residues of these nanomaterials, especially those in the metallic form. Therefore, it is necessary to study the possibility of treating and removing various nanoscale metal pollutants in environmentally friendly ways. The present study focused on the isolation of multi-metal tolerant fungi to be applied in the bioremoval of Zn, Fe, Se, and Ag nanoparticles as potential nanoscale metal pollutants. Aspergillus sp. has been isolated as multi-metal tolerant fingus and investigated in the bioremoval of targeted nanometals from their aquoues solutions. The effect of biomass age, pH, and contact time was studied to determine the optimal biosorption conditions for fungal pellets towards metal NPs. The results showed a high percentage of fungal biosorption on the of two-day-old cells, which amounted to 39.3, 52.2, 91.7, and 76.8% of zinc, iron, selenium, and silver, respectively. The pH 7 was recorded the highest percentage of NPs removal for the four studied metals i.e. 38.8, 68.1, 80.4, and 82.0% of Zn-, Fe-, Se- and Ag-NPs, respectively. The contact time required between Aspergillus sp. and the metal nanoparticles to obtain the best adsorption was only 10 min in the case of Zn and Ag, but it was 40 min for both Fe and Se NPs. The efficiency of living fungal pellets in removing the four metallic NPs exceeded that of dead biomass by 1.8, 5.7, 2.5, and 2.5 folds for Zn, Fe, Se and Ag, respectively. However, utilization of dead fungal biomass for metallic NPs removal could be considered more applicable to the actual environmental applications.

Reutilization of waste fungal biomass for concomitant production of proteochitinolytic enzymes and their catalytic products by Alcaligenes faecalis SK10

Fungal biomass, being organic waste, could be an excellent source of protein, carbohydrate and minerals. However, it has not been exploited fully until now. Efficient management of this waste can not only address the environmental impact on its disposal but also yield value-added metabolites. In the present study, in order to explore its potential, we subjected dead fungal biomass of Aspergillus niger SKN1 as substrate for both fermentative and enzymatic biodegradation, respectively by potent proteo-chitinolytic bacteria Alcaligenes faecalis SK10 and its enzyme cocktail. The results revealed that reasonable amount of protease and chitinase could be biosynthesized by the fermentative mode of utilization, while a mixture of amino acid, peptides and low-molecular weight amino-sugar (mono and oligomeric form of N-acetylglucosamine) could be generated through enzymatic hydrolysis. The physicochemical condition of both the bioprocess was subsequently optimized through statistical approach. The projected utilization of waste zero-valued fungal biomass offer a sustainable and environmentally sound method for production of microbial metabolites and large scale execution of the same could be proficient and in tune with the principle of circular economy.

Mycostimulator of chitinolytic activity: Thermodynamic studies and its activity against human and food-borne microbial pathogens

Chitinolytic activity and antibiosis are gaining prominence in various biotechnological fields. Dead fungal biomass (DFB) was used as a mycostimulator of chitinase production and antibiosis by Aspergillus fumigatus. The presence of DFB stimulated the synthesis of various secondary metabolites by A. fumigatus that were detected by gas chromatography-mass spectrometry analysis such as 6,8-Di-C-á-glucosylluteolin; bistrimethylsilyl N-acetyl eicosasphinga-4,11-dienine; curan-17-oic acid, 19,20-dihydroxy-, methyl ester, (19S)-; spiro[5à-androstane-3,2′-thiazolidine; retinal; Androsta-1,4-dien-3-one; Panaxydol; Costunolide; Cyclo-(glycyl-L-tyrosyl); and 2-amino ethane thiolsulfuric acid. Chitinase activity was 42.9 Units/mL with the presence DFB, where it was 10.3 Units/mL without DFB. The maximum activity of chitinase was observed at 1.5 g of dead fungal biomass, at 4 h, 50 °C and pH 6. Thermodynamic properties showed ∆H° and ∆S° values of 126 KJ mol-1 and 432 J mol-1 K-1, respectively, indicating an endothermic reaction up to 60 °C. Deviation in ∆G° values confirmed that the reaction at 10 to 20 °C is a nonspontaneous reaction, and at 30 to 60 °C the reaction has a spontaneous nature. DFB encouraged the antimicrobial activity against Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Aspergillus fumigatus, Mucor circinelloides, and Candida albicans with 2.3, 2.2, 2.8, 0.8, 0.7, and 2.2 mm inhibition zones, respectively.

Comparative Analysis of Hexavalent Chromium Biosorption Efficiency Using Dead and Live Aspergillus nomius Biomass

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.

English

Efficiency of biosorbent from chitosan coated dead fungal biomass of Aspergillus niger for dye removal with its impact on metals and physicochemical parameters of textile industry wastewater were assessed. Dye and metal concentrations of wastewater were determined using UV and Atomic Absorption Spectrophotometers respectively, before and after column biosorption using simulation optimized parameters with biosorbent. Physicochemical parameters were determined using standard methods. Simulated and industrial wastewaters data were analysed statistically with one way ANOVA and T-test. Biosorption of dye was classified with Langmuir and Freundlich isotherms. Results showed that at dye concentration of 100 mg/L, 6.90 mg/g of indigo dye adsorbed per mass (qe); in 1.87 mg/L of wastewater, 0.07 mg/g of dye adsorbed per unit mass (qe). Isotherm model fitted well to Freundlich with constant 0.04 and 8.45 mg/g in textile and simulated wastewater respectively. Metals in wastewater ranged from 0.071 to 1.102 mg/L. Acidity, COD Zn, Pb, Fe, Ni, Mn, Cu, Cd, Cr, Co, Mg ions were reduced by 32.94, 39.02, 84.95, 34.57, 44.19, 42.19, 49.09, 25.13, 43.66 and 32.03% respectively after treatment while TDS, conductivity, alkalinity, turbidity, pH increased. Chitosan coated A. niger could be effective in removing dyes and heavy metals from textile wastewater. Key words: Aspergillus niger, biosorbent, physico-chemical, heavy metals, textile wastewater.

Feeding on fungi: genomic and proteomic analysis of the enzymatic machinery of bacteria decomposing fungal biomass

Dead fungal biomass is an abundant source of nutrition in both litter and soil of temperate forests largely decomposed by bacteria. Here, we have examined the utilization of dead fungal biomass by the five dominant bacteria isolated from the in situ decomposition of fungal mycelia using a multiOMIC approach. The genomes of the isolates encoded a broad suite of carbohydrate-active enzymes, peptidases and transporters. In the extracellular proteome, only Ewingella americana expressed chitinases while the two Pseudomonas isolates attacked chitin by lytic chitin monooxygenase, deacetylation and deamination. Variovorax sp. expressed enzymes acting on the side-chains of various glucans and the chitin backbone. Surprisingly, despite its genomic potential, Pedobacter sp. did not produce extracellular proteins to decompose fungal mycelia but presumably feeds on simple substrates. The ecological roles of the five individual strains exhibited complementary features for a fast and efficient decomposition of dead fungal biomass by the entire bacterial community.

Coupling Laccase production from Trametes pubescence with heavy metal removal for Economic Waste Water Treatment

The objective of this work is to evaluate simultaneously the impact of nickel and lead on the fungus Trametes pubescence growth and laccase production, and their removal efficiency by T. pubescence. Here laccase activity and production were investigated in both in vitro and in vivo fungal growth conditions at the presence of either Pb or Ni, with the results showing inhibitory effects of Pb and Ni on T. pubescence growth and laccase activity. In particular, T. pubescence was seen to be able to withstand 1000 mg L−1 of Pb and Ni, while the fungus was capable of removing 99 % of Pb and 8.6 % of Ni, respectively. Most importantly, it was found that although only live cells will secrete laccase, both live and dead fungal biomass can accumulate heavy metals in the aqueous solutions. The laccase production can thus be coupled with heavy metal removal for potential waste water treatment.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

Dead Rhizophagus irregularis biomass mysteriously stimulates plant growth.

Arbuscular mycorrhizal (AM) fungi establish symbiotic associations with many plant species, transferring significant amounts of soil nutrients such as phosphorus to plants and receiving photosynthetically fixed carbon in return. Functioning of AM symbiosis is thus based on interaction between two living partners. The importance of dead AM fungal biomass (necromass) in ecosystem processes remains unclear. Here, we applied either living biomass or necromass (0.0004 potting substrate weight percent) of monoxenically produced AM fungus (Rhizophagus irregularis) into previously sterilized potting substrate planted with Andropogon gerardii. Plant biomass production significantly improved in both treatments as compared to non-amended controls. Living AM fungus, in contrast to the necromass, specifically improved plant acquisition of nutrients normally supplied to the plants by AM fungal networks, such as phosphorus and zinc. There was, however, no difference between the two amendment treatments with respect to plant uptake of other nutrients such as nitrogen and/or magnesium, indicating that the effect on plants of the AM fungal necromass was not primarily nutritional. Plant growth stimulation by the necromass could thus be either due to AM fungal metabolites directly affecting the plants, indirectly due to changes in soil/root microbiomes or due to physicochemical modifications of the potting substrate. In the necromass, we identified several potentially bioactive molecules. We also provide experimental evidence for significant differences in underground microbiomes depending on the amendment with living or dead AM fungal biomass. This research thus provides the first glimpse into possible mechanisms responsible for observed plant growth stimulation by the AM fungal necromass.

Functional convergence in the decomposition of fungal necromass in soil and wood.

Understanding the post-senescent fate of fungal mycelium is critical to accurately quantifying forest carbon and nutrient cycling, but how this organic matter source decomposes in wood remains poorly studied. In this study, we compared the decomposition of dead fungal biomass (a.k.a. necromass) of two species, Mortierella elongata and Meliniomyces bicolor, in paired wood and soil plots in a boreal forest in northern Minnesota, USA. Mass loss was quantified at four time points over an 8-week incubation and the richness and composition of the fungal communities colonizing fungal necromass were characterized using high-throughput sequencing. We found that the structure of fungal decomposer communities in wood and soil differed, but, in both habitats, there was relatively rapid decay (∼30% remaining after 56 days). Mass loss was significantly faster in soil and for high-quality (i.e. high nitrogen and low melanin) fungal necromass. In both habitats, there was a clear trajectory of early colonization by opportunistic fungal taxa followed by colonization of fungi with greater enzymatic capacities to degrade more recalcitrant compounds, including white-rot and ectomycorrhizal fungi. Collectively, our results indicate that patterns emerging regarding substrate quality effects on fungal necromass decomposition in soil and leaf litter can be largely extended to fungal necromass decomposition in wood.

Biological treatment of azo dyes on effluent by Neurospora sp isolated and adopted from dye contaminated site

Application of fungal agents to develop eco-friendly and cost-effective dye removal from textile effluent was studied. A fungal strain Neurospora sp has been isolated from effluent site and tested for its ability to biosorption and biodegrade azodyes. Biosorption of azo dyes by live and dead fungal biomass was evaluated. Percentage of decolorization was found to be effective against all tested azodyes and ranges between 33 and 76%. Nearly 72% of azo dyes were removed by dead Neurospora sp biomass and 86% respectively by live active biomass. Biodegradation of textile effluent by Neurospora sp showed changes in BOD, COD and TOC indicates that isolated Neurospora sp effectively degrade and utilize the dye as a sole carbon source. The initial TOC of 2600 mg/L was approximately reduced to almost its three fourth within a week. Research works on application of fungal biomass on textile effluent treatment have proven decolorizing potential among a wide range of anionic and cationic dyes. Based on the results, the biosorption mechanism by Neurospora sp was observed as effective, economic and eco-friendly decontaminant.

Production of \u03b2-1,3-glucanase and chitosanase from clostridial strains isolated from the soil subjected to biological disinfestation

Biological soil disinfestation (BSD) or anaerobic (reductive) soil disinfestation (ASD/RSD) is a bioremediation method used to eliminate soil-borne plant pathogens by exploiting the activities of anaerobic bacteria in soil. In this study, two obligate anaerobic bacterial strains isolated from BSD-treated soil and identified as Clostridium beijerinckii were examined for their abilities to suppress the spinach wilt disease pathogen (Fusarium oxysporum f. sp. spinaciae) as a representative soil-borne fungal plant pathogen. Both strains degraded β-1,3-glucan and chitosan, two major polysaccharide components of ascomycetes fungal cell wall, supplemented in the medium. β-1,3-Glucanase was detected in the supernatants of cultures supplemented with different types of glucan. Similarly, chitosanase was detected in cultures supplemented with chitosan. Both the enzyme activities were also detected in cultures containing glucose as a substrate. Live cells of F. oxysporum f. sp. spinaciae that were co-incubated with each anaerobic strain under anaerobic conditions using glucose as a substrate died during incubation. Freeze-dried dead fungal biomass of the pathogen, when added to the culture, supported good growth of both anaerobes and production of both enzymes. Severe and nearly complete degradation of both live and dead fungal cells during incubation with anaerobic bacteria was observed by fluorescence microscopy. When individual anaerobic bacterial strain was co-incubated with live pathogenic fungal cells in wheat bran, a popular material for BSD-treatment, both the strains grew well and killed the fungal pathogen promptly by producing both enzymes. These results indicate that both the bacterial strains attack the fungal cells by releasing extracellular fungal cell wall-degrading enzymes, thereby eliminating the pathogen.

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

In this study, Aspergillus niger (FS18) was used to remove the fluoride from aqueous medium. Batch and column mode studies were carried out to investigate the effect of different conditions such as live biomass, dead biomass, various pretreated biomass and immobilized fungal biomass on the removal of fluoride removal. The results showed that the maximum removal of fluoride was attained at 30–80 min using dead fungal biomass when compared to live and various pretreated biomass. The fluoride removal was noted somewhat in the aqueous medium using formaldehyde and acid treated biomass when compared to calcium treated fungal biomass. The experimental data was fitted with pseudo second order when compared to pseudo first order. In column study, the maximum fluoride adsorption capacity of 89% was observed. Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) with energy-dispersive X-ray spectroscopy (EDXA) techniques were used to elucidate the adsorption mechanism of dead fungal biosorbent. Findings of this work suggested that dead fungal biomass could be a suitable sorbent for the removal of fluoride in aqueous solution.

Dead biomass of thermophilic Aspergillus fumigatus for Congo red biosorption

Decolorization of congo red with growing and dead biomass of thermophilic Aspergillus fumigatus was studied. The biosorption percent by dead biomass increases with increasing pH up to 6 at dye initial concentration 10,60 and 70 mg/100ml , and up to pH7 at dye initial concentration 20,30,40,50 and 60 mg/100ml. The mount of congo red biosorbed onto dead biomass increases with increasing temperature from 10 to 30°C then decreases at 40 °C and sharply at 50°C. Increase in dead biomass concentration above 0.8 (g/100ml) did not effective in biosorption of congo red. Maximum decolourization was observed at 180min of contact time. The study concluded that dead fungal biomass possesses various advantages such as absence of nutrient needs, therefore the findings offer potential for the development of a cost effective for biosorption of congo red.