Response Surface Optimization of the Critical Medium Components for Pullulan Production by <Emphasis Type="Italic">Aureobasidium pullulans</Emphasis> FB-1

Culture conditions for pullulan production by Aureobasidium pullulans were optimized using response surface methodology at shake flask level without pH control. In the present investigation, a five-level with five-factor central composite rotatable design of experiments was employed to optimize the levels of five factors significantly affecting the pullulan production, biomass production, and sugar utilization in submerged cultivation. The selected factors included concentration of sucrose, ammonium sulphate, yeast extract, dipotassium hydrogen phosphate, and sodium chloride. Using this methodology, the optimal values for concentration of sucrose, ammonium sulphate, yeast extract, dipotassium hydrogen phosphate, and sodium chloride were 5.31%, 0.11%, 0.07%, 0.05%, and 0.15% (w/v), respectively. This optimized medium has projected a theoretically production of pullulan of 4.44%, biomass yield of 1.03%, and sugar utilization of 97.12%. The multiple correlation coefficient ‘R’ was 0.9976, 0.9761 and 0.9919 for pullulan production, biomass production, and sugar utilization, respectively. The value of R being very close to one justifies an excellent correlation between the predicted and the experimental data.     

Medium optimization for polysaccharide production of Cordyceps sinensis

As a potential anticarcinogenic agent, polysaccharides from Cordyceps sinensis have been demonstrated to possess strong antioxidation activity. The aim of the present research was to study the optimal medium to produce polysaccharides of C. sinensis by using response surface methodology (RSM). The composition of optimized medium for polysaccharide production calculated from the regression model of RSM was 6.17% sucrose, 0.53% corn steep powder, 0.5% (NH₄)₂HPO₄, and 0.15% KH₂PO₄ at pH 4.44, with a predicted maximum polysaccharide production of 3.17 g/L. When applying this optimal medium, the maximum polysaccharide production was 3.05 and 3.21 g/L in a shake flask and a 5-L jar fermentor, respectively. When the pH was controlled at a higher level such as pH 5.0, both cell growth and polysaccharide production were inhibited. A low pH of 2.85 was required for maximum production of polysaccharides.     

Optimization of Levan Production by Cold-Active <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> ANT 179 and Fructooligosaccharide Synthesis by Its Levansucrase

Fructooligosaccharides (FOS) and levan attract much attention due to a wide range of applications in food technology and pharmaceutical and cosmetic industry. Bacillus licheniformis ANT 179, isolated from Antarctica soil, produced levansucrase and levan in a medium containing sucrose as carbon substrate. In this study, characterization of levansucrase and production of short-chain FOS and levan were investigated. Temperature and pH optimum of the enzyme were found to be 60 °C and pH 6.0, respectively. The optimization of fermentation conditions for levan production using sugarcane juice by response surface methodology (RSM) was carried out. Central composite rotatable design was used to study the main and the interactive effects of medium components: sugarcane juice and casein peptone concentration on levan production by the bacterium. The optimized medium with sugarcane juice at 20 % (v/v) and casein peptone at 2 % (w/v) was found to be optimal at an initial pH of 7.0 and incubation temperature of 35 °C for 48 h. Under these conditions, the maximum levan concentration was 50.25 g/L on wet weight basis and 16.35 g/L on dry weight basis. The produced inulin type FOS (kestose and neokestose) and levan were characterized by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) analysis. The study revealed that the levansucrase could form FOS from sucrose. The locally available low-cost substrate such as sugarcane juice in the form of a renewable substrate is proposed to be suitable even for scale-up production of enzyme and FOS for industrial applications. The levan and FOS synthesized by the bacterium are suitable for food applications and biomedical uses as the bacterium has GRAS status and devoid of endotoxin as compared to other Gram-negative bacteria.     

Phytase Production by a Marine Yeast <Emphasis Type="Italic">Kodamea ohmeri</Emphasis> BG3

The marine yeast strain Kodamea ohmeri BG3 isolated from the gut of a marine fish (Hexagrammes otakii) was found to secrete a large amount of phytase into the medium. The crude phytase produced by this marine yeast showed the highest activity at pH 5.0 and 65 °C. The optimal medium for phytase production contained oat 10.0 g/l, ammonium sulfate 15.0 g/l, glucose 30 g/l, and NaCl 20.0 g/l, while the optimal cultivation conditions for phytase production were pH 5.0, a temperature of 28 °C, and a shaking speed of 170 rpm. Under the optimal conditions, over 557.9 mU/ml of phytase activity was produced within 72 h of fermentation at the shake flask level. This is a very high level of phytase activity produced by yeasts. We think that the medium and process for phytase production by the marine yeast strain were very simple, and such marine yeast from the gut of natural marine fish may have a potential application in the maricultural industry and marine environmental protection. The results demonstrate that phytate was actively degraded by the crude phytase within a short period.     

Production of Raw Starch-Saccharifying Thermostable and Neutral Glucoamylase by the Thermophilic Mold <Emphasis Type="Italic">Thermomucor indicae-seudaticae</Emphasis> in Submerged Fermentation

Among physical and nutritional parameters optimized by “one variable at a time” approach, four cultural variables (sucrose, MgSO₄ ^.7H₂O, inoculum size, and incubation period) significantly affected glucoamylase production. These variables were, therefore, selected for optimization using response surface methodology. The p-values of the coefficients for linear effect of sucrose and inoculum size were less than 0.0001, suggesting them to be the key experimental variables in glucoamylase production. The enzyme production (34 U/ml) attained under optimized conditions (sucrose, 2%; MgSO₄ ^.7H₂O, 0.13%; yeast extract, 0.1%; inoculum size, 5 × 10⁶ spores per 50 ml production medium; incubation time, 48 h; temperature, 40°C; and pH 7.0) was comparable with the value predicted by polynomial model (34.2 U/ml). An over all 3.1-fold higher enzyme titers were attained due to response surface optimization. The experimental model was validated by carrying out glucoamylase production in shake flasks of increasing capacity (0.25–2.0 l) and 22-l laboratory bioreactors (stirred tank and airlift), where the enzyme production was sustainable. Furthermore, the fermentation time was reduced from 48 h in shake flasks to 32 h in bioreactors.     

Multiple Responses Optimization and Modeling of Lipase Production by <Emphasis Type="Italic">Rhodotorula mucilaginosa</Emphasis> MTCC-8737 Using Response Surface Methodology

Response surface methodology was employed to optimize culture medium for production of lipase with Rhodotorula sp. MTCC 8737. In the first step, a Plackett–Burman design was used to evaluate the effects of different inducers qualitatively. Of all the seven inducers tested, soybean oil showed significant influence on the lipase production. Further, response surface studies were conducted to quantitatively optimize by considering linear, interactive, and quadratic effects of test variables. A novel approach was proposed to optimize the lipase production system by optimizing the responses in terms of yield kinetics rather than optimizing the direct responses like lipase titer and biomass growth. The coefficient of determination (R ²) calculated for Y _P/S (0.769), Y _P/X (0.799), and Y _X/S (0.847) indicated that the statistical model could explain 76.9%, 79.99%, and 84.7% of variability in the response.     

Modelling Growth and Bacteriocin Production by <Emphasis Type="Italic">Pediococcus acidilactici</Emphasis> PA003 as a Function of Temperature and pH Value

To investigate the effect of pH and temperature on the cell growth and bacteriocin production of Pediococcus acidilactici PA003, a lactic acid bacterium isolated from traditionally fermented cabbage, the kinetic behaviour of P. acidilactici PA003 was simulated in vitro during laboratory fermentations by making use of MRS broth. Firstly, primary models were developed for cell growth, glucose consumption, lactic acid and bacteriocin production for a given set of environmental conditions. Based on primary models, further study was undertaken to fit secondary models to describe the influence of temperature and pH on microbial behaviour. The models were validated successfully for all components. The results from the cell yield coefficient for lactic acid production reflected the homofermentative nature of P. acidilactici PA003. Both cell growth and bacteriocin production were very much influenced by changes in temperature and pH. The optimal condition for specific growth rate and biomass concentration was almost the same at pH 6.5 and 35 °C. At 35 °C and pH 6.1, the maximal bacteriocin activity was also achieved. The kinetic models provide useful tools for elucidating the mechanisms of temperature and pH on the kinetic behaviour of P. acidilactici PA003. The information obtained in this paper may be very useful for the selection of suitable starter cultures for a particular fermentation process and is a first step in the optimization of food fermentation processes and technology as well.     

Variable Volume Fed-Batch Fermentation for Nisin Production by <Emphasis Type="Italic">Lactococcus lactis</Emphasis> subsp<Emphasis Type="Italic">. lactis W28</Emphasis>

A feeding technology that was suitable for improving the nisin production by Lactococcus lactis subsp. lactis W28 was established. The effects of initial sucrose concentration (ISC) in the fermentation broth, feeding time, and feeding rate on the fermentation were studied. It was observed that a fed-batch culture (ISC = 10 g l⁻¹) with 100 ml sucrose solution (190 g l⁻¹) being evenly fed (9–10 ml h⁻¹) into the fermenter after 3-h fermentation gave the best performance in terms of biomass and nisin yield. Under these conditions, the total biomass and the total nisin yield were approximately 23% and 51% higher than those in batch fermentation, respectively. When the sucrose concentration was controlled at 5–10 g l⁻¹ in variable volume intermittent fed-batch fermentation (VVIF) with ISC = 10 g l⁻¹, the total biomass and the total nisin yield were 29% and 60% above those in batch fermentation, respectively. The VVIF proved to be effective to eliminate the substrate inhibition by maintaining sucrose at appropriate levels. It is also easy to be scaled up, since various parameters involved in industrial production were taken into account.     

Response of Cellulase Activity in pH-Controlled Cultures of the Filamentous Fungus <Emphasis Type="Italic">Acremonium cellulolyticus</Emphasis>

Cellulase production was investigated in pH-controlled cultures of Acremonium cellulolyticus. The response to culture pH was investigated for three cellulolytic enzymes, carbomethyl cellulase (CMCase), avicelase, and β-glucosidase. Avicelase and β-glucosidase showed similar profiles, with maximum activity in cultures at pH 5.5–6. The CMCase activity was highest in a pH 4 culture. At an acidic pH, the ratios of CMCase and avicelase activity to cellulase activity defined by filter paper unit were high, but at a neutral pH, the β-glucosidase ratio was high. The pH 6.0 culture showed the highest cellulase activity within the range of pH 3.5–6.5 cultures. The saccharification activity from A. cellulolyticus was compared to those of the cellulolytic enzymes from other species. The A. cellulolyticus culture broth had a saccharification yield comparable to those of the Trichoderma enzymes GC220 and Cellulosin T2, under conditions with the same cellulase activity. The saccharification yields from Solka floc, Avicel, and waste paper, measured as the percent of released reducing sugar to dried substrate, were greater than 80% after 96 h of reaction. The yields were 16% from carboxymethylcellulose and 26% from wood chip refiner. Thus, the A. cellulolyticus enzymes were suitable for converting cellulolytic biomass to reducing sugars for biomass ethanol production. This study is a step toward the establishment of an efficient system to reutilize cellulolytic biomass.     

Rhamnolipid Production by <Emphasis Type="Italic">Pseudomonas Aeruginosa</Emphasis> GIM 32 Using Different Substrates Including Molasses Distillery Wastewater

A rhamnolipid production strain newly isolated from oil-contaminated soil was identified as Pseudomonas aeruginosa GIM32 by its morphology and 16S rDNA sequence analysis. The effect of carbon source and carbon to nitrogen (C/N) ratio on rhamnolipids production was investigated. Palm oil was favorable as a carbon source for rhamnolipid production. The maximum biomass and rhamnolipid concentration were 8.24 g/L and 30.4 g/L, respectively, with an optimization medium containing 50 g/L palm oil and 5 g/L sodium nitrate. Molasses distillery wastewater as an unconventional substrate for rhamnolipid production was investigated. It was found that 2.6 g/L of rhamnolipids was produced; this amount was higher than that of past reports using wastewater as a substrate. In addition, 44% of the chemical oxygen demand of wastewater was removed at the same time under the optimization condition. Eleven kinds of different molecular weight rhamnolipid homologues were identified in the rhamnolipids obtained from molasses distillery wastewater by P. aeruginosa GIM32 by LC–MS analysis.     

Constitutive Expression and Optimization of Nutrients for Streptokinase Production by <Emphasis Type="Italic">Pichia pastoris</Emphasis> Using Statistical Methods

The Pichia pastoris clone producing streptokinase (SK) was optimized for its nutritional requirements to improve intracellular expression using statistical experimental designs and response surface methodology. The skc gene was ligated downstream of the native glyceraldehyde 3-phosphate dehydrogenase promoter and cloned in P. pastoris. Toxicity to the host was not observed by SK expression using YPD medium. The transformant producing SK at level of 1,120 IU/ml was selected, and the medium composition was investigated with the aim of achieving high expression levels. The effect of various carbon and nitrogen sources on SK production was tested by using Plackett–Burman statistical design and it was found that dextrose and peptone are the effective carbon and nitrogen sources among all the tested. The optimum conditions of selected production medium parameters were predicted using response surface methodology and the maximum predicted SK production of 2,136.23 IU/ml could be achieved with the production medium conditions of dextrose (x1), 2.90%; peptone (x2), 2.49%; pH, 7.2 (x3), and temperature, 30.4 (x4). Validation studies showed a 95% increase in SK production as compared to that before optimization at 2,089 IU/ml. SK produced by constitutive expression was found to be functionally active by plasminogen activation assay and fibrin clot lysis assay. The current recombinant expression system and medium composition may enable maximum production of recombinant streptokinase at bioreactor level.     

Assessment of Physical Process Conditions for Enhanced Production of Novel Glutaminase-Free L-Asparaginase from <Emphasis Type="BoldItalic">Pectobacterium carotovorum</Emphasis> MTCC 1428

Statistically based experimental design was applied to maximize the production of glutaminase-free L-asparaginase from Pectobacterium carotovorum MTCC 1428. The effect of physical process parameters (initial pH of the medium, temperature, rpm of the shaking incubator, and inoculum size) on the production of L-asparaginase from P. carotovorum MTCC 1428 was studied using central composite design technique. The individual optimum levels of initial pH of the medium, temperature, rpm of shaking incubator, and inoculum size were found to be 6.90, 29.8 °C, 157 rpm, and 2.61% (v/v), respectively, for the production of L-asparaginase. After physical process parameters optimization, the production and productivity of L-asparaginase was enhanced by 26.39% (specific activity) and 10.19%, respectively. Maximization of L-asparaginase production was achieved at 12 h under optimal levels of physical process parameters in shake flask level.     

Effect of Concentration and Substrate Flow Rate on Isomaltulose Production from Sucrose by <Emphasis Type="Italic">Erwinia</Emphasis> sp. Cells Immobilized in Calcium-Alginate Using Packed Bed Reactor

Isomaltulose was obtained from sucrose solution by immobilized cells of Erwinia sp. D12 using a batch and a continuous process. Parameters for sucrose conversion into isomaltulose were evaluated using both experimental design and response surface methodology. Erwinia sp. D12 cells were immobilized in different alginates, and the influence of substrate flow rate and concentration parameters to produce isomaltulose from sucrose were observed. Response surface methodology demonstrated that packed bed columns containing cells immobilized in low-viscosity sodium alginate (250 cP) presented a mean isomaltulose conversion rate of 47%. In a continuous process, both sucrose substrate concentration and substrate flow rate parameters had a significant effect (p < 0.05) and influenced the conversion of sucrose into isomaltulose. Higher conversion rates of sucrose into isomaltulose, from 53–75% were obtained using 75 g of immobilized cells at a substrate flow rate of 0.6 mL/min.     

Effects of pH and Carbon Source on <Emphasis Type="Italic">Synechococcus</Emphasis> PCC 7002 Cultivation: Biomass and Carbohydrate Production with Different Strategies for pH Control

Synechococcus PCC 7002 is an interesting species in view of industrial production of carbohydrates. The cultivation performances of this species are strongly affected by the pH of the medium, which also influences the carbohydrate accumulation. In this work, different methods of pH control were analyzed, in order to obtain a higher production of both Synechococcus biomass and carbohydrates. To better understand the influence of pH on growth and carbohydrate productivity, manual and automatic pH regulation in CO₂ and bicarbonate system were applied. The pH value of 8.5 resulted the best to achieve both of these goals. From an industrial point of view, an alternative way to maintain the pH practically constant during the entire period of cultivation is the exploitation of the bicarbonate-CO₂ buffer system, with the double aim to maintain the pH in the viability range and also to provide the amount of carbon required by growth. In this condition, a high concentration of biomass (6 g L^?1) and carbohydrate content (around 60 %) were obtained, which are promising in view of a potential use for bioethanol production. The chemical equilibrium of C-N-P species was also evaluated by applying the ionic balance equations, and a relation between the sodium bicarbonate added in the medium and the equilibrium value of pH was discussed.     

Effect of certain chemical compounds on secondary metabolites of Penicillium janthinellum and P. duclauxii

The secondary metabolites of Penicillium janthinellum and P. duclauxii were affected by different concentrations of cadmium nitrate, sodium chloride, and sucrose. The fungal culture characteristics including mycelial fresh and dry weight, colony diameter, colony spore mass and reverse color, number of spores, and secondary metabolites were affected as well. Cyclopenin, carlosic acid, erythroskyrin, kojic acid, and patulin were produced by P. janthinellum on cadmium nitrate-free medium. However, cyclopenin, carlosic acid, frequentin, and islandicin were produced at 100 ppm, and cyclopenin at 500 ppm. On the other hand, the secondary metabolites produced by P. duclauxii were 9 on cadmium nitrate-free medium, 7 on medium containing 100 and 500 ppm of cadmium nitrate, and 4 at 1000 ppm cadmium nitrate concentration. Secondary metabolite brevianamide A was produced in the presence and absence of cadmium nitrate. The duclauxin, patulin, terrestic acid, and xanthomegin were produced only on cadmium nitrate-free medium. However, mycophenolic acid was produced only on cadmium nitrate-containing medium. The kojic acid was produced by P. janthinellum at 0.0%, 0.5%, 1.0%, 2.0%, 3.0%, and 5.0% concentrations of sodium chloride. The carlosic acid, erythroskyrin, and patulin were produced only at 0.0% and 1.0%. While carolic acid and islandicin were produced at 1%, 2%, and 3% and frequentin was produced only at 2% and 3%. On the other hand, 8 secondary metabolites were produced by P. duclauxii at 0.0%, 0.5%, 1.0%, and 2.0% concentration of sodium chloride and only 4 were produced at 3%. The secondary metabolites produced by P. janthinellum were 7 at 10% and 20%, 6 at 30%, and 2 only at 40% concentrations of sucrose. However, 8 secondary metabolites were produced by P. duclauxii at 10%, 20%, 30% and 3 at 40% concentrations of sucrose.     

<Emphasis Type="Italic">Rhizopus stolonifer</Emphasis> LAU 07: a novel source of fructosyltransferase

Increasing awareness of the importance of fructooligosaccharides (FOS) as ingredients of functional foods has led to intensive search of new sources of fructosyltransferases (FTase), enzymes responsible for the conversion of sucrose to fructooligosaccharides. A local strain of Rhizopus stolonifer isolated from spoilt orange fruit with high fructosyltransferase activity (U _t) of 12.31–45.70 U mL⁻¹ during a fermentation period of 24–120 h is herein reported. It showed low hydrolytic activity (U _h) in the range of 0.86–1.78 U mL⁻¹ during the same period. FOS yield of 34 % (1-kestose, GF₂, nystose, GF₃) was produced by FTase obtained from a 72 h-old culture using 60 g of sucrose per 100 mL of the substrate. When the isolate was grown in a defined submerged medium, its pH dropped sharply from the intial value of 5.5 to 1.0 within 24 h, and this value was maintained throughout the fermentation. The biomass content ranged from 8.8 g L⁻¹ at 24 h of fermentation to reach the maximum of 10 g L⁻¹ at 72 h. It was reduced to 5.6 g L⁻¹ at the end of 120 h of fermentation. This report represents the first reference to a strain of Rhizopus as a source of FTase for the production of FOS. The high U _t/U _h ratio shown by this isolate indicates that it may be a good strain for the industrial and commercial production of FOS. However, there is a need of further optimization of the bioprocess to increase the conversion efficiency of sucrose to FOS by the enzyme.     

Assessment of various carbon sources and nutrient feeding strategies for Panax ginseng cell culture

Ginseng (root of Panax ginseng C. A. Meyer) cells were cultivated on medium supplemented with various carbohydrates including sucrose, glucose, and fructose, at initial concentrations ranging from 10 to 110 g/L. Sucrose was shown to be the superior carbon source to the monosaccharides for ginseng cell growth and the optimal concentration was between 30 and 50 g/L. An increase in the initial concentration within this range increased the maximum cell density and growth index significantly, whereas much higher concentrations inhibited cell growth. Feeding of sucrose and some other medium components during the growth (fed-batch mode) was more effective in enhancing the cell growth and biomass productivity, increasing the growth index by more than 60–70% and biomass productivity by more than 50%.     

Immobilization of Naringinase in PVA–Alginate Matrix Using an Innovative Technique

A synthetic polymer, polyvinyl alcohol (PVA), a cheap and nontoxic synthetic polymer to organism, has been ascribed for biocatalyst immobilization. In this work PVA–alginate beads were developed with thermal, mechanical, and chemical stability to high temperatures (<80 °C). The combination of alginate and bead treatment with sodium sulfate not only prevented agglomeration but produced beads of high gel strength and conferred enzyme protection from inactivation by boric acid. Naringinase from Penicillium decumbens was immobilized in PVA (10%)–alginate beads with three different sizes (1–3 mm), at three different alginate concentrations (0.2–1.0%), and these features were investigated in terms of swelling ratio within the beads, enzyme activity, and immobilization yield during hydrolysis of naringin. The pH and temperature optimum were 4.0 and 70 °C for the PVA–alginate-immobilized naringinase. The highest naringinase activity yield in PVA (10%)–alginate (1%) beads of 2 mm was 80%, at pH 4.0 and 70 °C. The Michaelis constant (K _Mapp) and the maximum reaction velocity (V _maxapp) were evaluated for both free (K _Mapp = 0.233 mM; V _maxapp = 0.13 mM min⁻¹) and immobilized naringinase (K _Mapp = 0.349 mM; V _maxapp = 0.08 mM min⁻¹). The residual activity of the immobilized enzyme was followed in eight consecutive batch runs with a retention activity of 70%. After 6 weeks, upon storage in acetate buffer pH 4 at 4 °C, the immobilized biocatalyst retained 90% of the initial activity. These promising results are illustrative of the potential of this immobilization strategy for the system evaluated and suggest that its application may be effectively performed for the entrapment of other biocatalysts.     

Chemical evaluation of seeded fruit biomass of oil pumpkin (<Emphasis Type="Italic">Cucurbita pepo</Emphasis> L. var. <Emphasis Type="Italic">Styriaca</Emphasis>)

Oil pumpkin (Cucurbita pepo L. var. Styriaca) is an economically important horticultural plant cultivated for oil production. After harvesting seeds, the residual biomass has a limited application and is usually left in the field. An experimental study was performed to evaluate the chemical composition of the seeded fruit oil pumpkin biomass (OP) dried by solvent-exchange using ethanol. The sugar composition of polysaccharides obtained by sequential extraction with water and dilute alkali indicated the prevalence of pectic polysaccharides. Hemicelulloses were released in higher amounts in the alkaline step. The chemical composition of OP and its individual tissues (peel, flesh and hairy flesh) was investigated and compared to the corresponding preparations of standard pumpkin (SP, Cucurbita pepo L.). The content of components (on oven-dry basis), calculated from the analysis data of the individual tissues, was estimated for OP: 7.9 % ash, 7.6 % Klason lignin, 19.3 % pectin (as uronic acids), 34.1 % neutral carbohydrates, and 27.4 % α-cellulose and for SP: 6.4 % ash, 4.0 % Klason lignin, 20.9% pectin (as uronic acids), 38.1% neutral carbohydrates, and 29.2 % α-cellulose, respectively. The OP biomass showed a higher proportion of hemicelluloses.     

Modified <Emphasis Type="Italic">Rhizopus arrhizus</Emphasis> biomass for sorption of <Superscript>241</Superscript>Am and other radionuclides

The improvement and the refinement of non-viable Rhizopus arrhizus biomass were investigated via immobilization. Immobilization was carried out by using sodium alginate/CaCl₂ solution and formaldehyde/HCl cross-linking with dead Rhizopus arrhizus biomass and were used for the sorption of radionuclides from low level effluent wastes. The sodium alginate/CaCl₂ immobilized biomass (ratio 1:2) showed about 86% sorption for ²⁴¹Am activity but due to its soft nature and tendency to undergo distortion in shape, is unsuitable for practical applications. The biomass cross-linked with 15% formaldehyde/0.1 M HCl solution has a relatively high mechanical strength and rigidity. It was showing a sorption of >99% for ²⁴¹Am activity and has the sorption capacity of ~65 mg/g for americium and uranium. Hence, it can be utilized for the removal of radionuclides from radioactive waste effluents.