Utilization of starch and clay for the preparation of superabsorbent composite

Starch and attapulgite were utilized as raw material for synthesizing starch-graft-poly(acrylic acid)/attapulgite superabsorbent composite by graft copolymerization reaction of starch and acrylic acid (AA) in the presence of attapulgite micropowder in aqueous solution. Major factors affecting on water absorbency such as weight ratio of AA to starch, initial monomer concentration, neutralization degree of AA, amount of crosslinker, initiator and attapulgite were investigated. The superabsorbent composite synthesized under optimal synthesis conditions with an attapulgite content of 10 wt% exhibit absorption of 1077 g H(2)O/g sample and 61 g H(2)O/g sample in distilled water and in 0.9 wt% NaCl solution, respectively. This superabsorbent composite with excellent water absorbency and water retention under load, being biodegradable in nature, economical and environment-friendly, could be especially useful in agricultural and horticultural applications.     

Sequential immobilization of urease to glycidyl methacrylate grafted sodium alginate

Objective of this study is to realize appropriate enzyme immobilization onto a suitable support material and to develop a model which enables reactions catalyzed with different enzymes arranged in order. Thence, this model was potential for developing a multi-enzyme system. The reactions need more than one enzyme can be realized using immobilized form of them and the enzymes will be in one support at wanted activities. In this study, sodium alginate was used as immobilization material and glycidyl methacrylate was grafted onto sodium alginate. Thus reactive epoxy groups were added to sodium alginate which also has carboxyl groups. Average molecular weight of sodium alginate was determined using Ubbelohde viscosimetri. The molecular mass of sodium alginate was calculated as 15,900 Da. Graft polymerization was made in two steps. Firstly, sodium alginate was activated with benzophenone using UV-light at 254 nm. Secondly, glycidyl methacrylate was grafted under UV-light at 365 nm onto activated sodium alginate. Grafted glycidyl methacrylate was determined gravimetric and titrimetric. Additional groups after grafting were showed with FT-IR spectrum. 1-Ethyl-3-(3-dimetylaminopropyl)-carbodiimide was used for immobilization urease from carboxyl groups at pH 5.0. Suitable 1-ethyl-3-(3-dimetylaminopropyl)-carbodiimide/–COOH ratio was found 1/10 and immobilized product activity was 197 U/g support. Reaction medium pH was 8.0 for immobilization from epoxy group. Optimum immobilization reaction time was found as 2 h and immobilized product activity was 285 U/g support. Sequential immobilization of urease to glycidyl methacrylate grafted sodium alginate was made from –COOH and epoxy groups, respectively.     

Synthesis and characterization of a novel super-absorbent based on chemically modified pulverized wheat straw and acrylic acid

In order to develop an eco-friendly polymer, the material was prepared from pulverized wheat straw by chemical methods. And a super-absorbent hydrogel has been synthesized with chemically modified pulverized wheat straw (CMPWS) and acrylic acid (AA) in aqueous solution. Factors, such as weight ratio of AA to CMPWS, the amount of initiator and cross-linker, temperature and neutralization degree of AA that influence absorbencies of super-absorbent were investigated. Moreover, the super-absorbent had been proved with expectant polymerization structure and good thermo-stability via IR spectrum and TGA analysis. The morphological features were evidenced by SEM images. The excellent product was obtained with the absorbencies of 417 g/g in distilled water and 45 g/g in 0.9 wt% NaCl solution.     

Ability of a perfluoropolymer membrane to tolerate by-products of ethanol fermentation broth from dilute acid-pretreated rice straw

A perfluoropolymer (PFP) membrane has been prepared for use in vapor permeation to separate aqueous ethanol mixtures produced from rice straw with xylose-assimilating recombinant Saccharomyces cerevisiae. PFP membranes commonly have been used for dehydration process and possess good selectivity and high permeances. The effects of by-products during dilute acid pretreatment, addition of yeast extract, and ethanol fermentation on PFP membrane performance were investigated. While feeding mixtures of ethanol (90 wt%) in water, to which individual by-products (0.1–2 g/L) were added, the PFP membrane demonstrated no clear change in permeation rate (439–507 g m⁻² h⁻¹) or separation factor (14.9–23.5) from 2 to 4 h of the process. The PFP membrane also showed no clear change in permeation rate (751–859 g m⁻² h⁻¹) or separation factor (12.5–13.8) while feeding the mixture (final ethanol conc.: 61 wt%) of ethanol and distillation of the fermentation broth using a suspended fraction of dilute acid-pretreated rice straw for 20 h. These results suggest that the PFP membrane can tolerate actual distillation liquids from ethanol fermentation broth obtained from lignocellulosic biomass pretreated with dilute acid.     

Enzymatic transformation of 2-O-α-d-glucopyranosyl-l-ascorbic acid (AA-2G) by immobilized α-cyclodextrin glucanotransferase from recombinant Escherichia coli

This work aims to produce 2-O-α-d-glucopyranosyl-l-ascorbic acid (AA-2G) from ascorbic acid and β-cyclodextrin with immobilized α-cyclodextrin glucanotransferase (α-CGTase) from recombinant Escherichia coli. Molecular sieve (SBA-15) was used as an adsorbent, and sodium alginate was used as a carrier, and glutaraldehyde (GA) was used as a cross-linker. The effects of several key variables on α-CGTase immobilization were examined, and optimal immobilization conditions were determined as the following: glutaraldehyde (GA, cross-linker) 0.01% (v/v), SBA-15 (adsorbent) 2 g/L, CaCl₂ 3 g/L, sodium alginate 20 g/L, adsorption time 3 h, and immobilization time 1 h. In comparison with free α-CGTase, immobilized α-CGTase had a similar optimal pH (5.5) and a higher optimal temperature (45 °C). The continuous production of AA-2G from ascorbic acid and β-cyclodextrin in the presence of immobilized α-CGTase was carried out, and the highest AA-2G production reached 21 g/L, which was 2-fold of that with free α-CGTase. The immobilization procedure developed here was efficient for α-CGTase immobilization, which was proved to be a prospective approach for the enzymatic production of AA-2G.     

Comparison of salinity tolerance of three Atriplex spp. in well-watered and drying soils

Members of the Chenopodiaceae are well adapted to both salt and drought stress and can serve as model species to understand the mechanisms of tolerance in plants. We grew Atriplex hortensis (ATHO), A. canescens (ATCA), and A. lentiformis (ATLE) along a NaCL salinity gradient under non-water-limited conditions and in drying soils in greenhouse experiments. The species differed in photosynthetic carbon fixation pathway, capacity for sodium uptake, and habitat preferences. Under non-water-limited conditions, ATLE (C4) maintained high growth rates up to 30 g L⁻¹ NaCl. ATHO (C3) had lower growth than ATLE at high salinities, while ATCA (C4) grew more slowly than either ATLE or ATHO and showed no net growth above 20 g L⁻¹ NaCl. ATHO and ATLE accumulated twice as much sodium in their shoots as ATCA, but all three species had increasing sodium levels at higher salinities. Potassium, magnesium and calcium levels were relatively constant over the salinity gradient. All three species showed marked accumulation of chloride across the salinity gradient, whereas nitrate, phosphorous and sulfate decreased with salinity. The effect of drought was simulated by growing plants in sealed pots with an initial charge of water plus NaCl, and allowing them to grow to the end point at which they no longer were able to extract water from the soil solution. Drought and salinity were not additive stress factors for Atriplex spp. in this experiment. NaCl increased their ability to extract water from the soil solution compared to fresh water controls. ATLE showed increased shoot dry matter production and increased water use efficiency (WUE) as initial salinity levels increased from 0 to 30 g L⁻¹ NaCl, whereas dry matter production and WUE peaked at 5 g L⁻¹ for ATHO and ATCA. Final soil moisture salinities tolerated by species were 85 g L⁻¹, 55 g L⁻¹ and 160 g L⁻¹ NaCl for ATHO, ATCA and ATLE, respectively. C4 photosynthesis and sodium accumulation in shoots were associated with high drought and salt tolerance.     

Influence of whole microalgal cell immobilization and organic solvent on the bioconversion of androst-4-en-3,17-dione to testosterone by Nostoc muscorum

The use of free, immobilized and reused immobilized cells of the microalga Nostoc muscorum was studied for bioconversion of androst-4-en-3,17-dione (AD) to testosterone in hexadecane. Among polymers such as agar, agarose, κ-carrageenan, polyacrylamide, polyvinyl alcohol, and sodium alginate that were examined for cell entrapment, sodium alginate with a concentration of 2% (w/v) proved to be the proper matrix for N. muscorum cells immobilization. The bioconversion characteristics of immobilized whole algal cells at ranges of temperatures, substrate concentrations, and shaking speeds were studied followed by a comparison with those of free cells. The conditions were 30 °C, 0.5 g/L, and 100 rpm, respectively. The immobilized N. muscorum showed higher yield (72 ± 2.3%) than the free form (24 ± 1.3%) at the mentioned conditions. The bioconversion yield did not decrease during reuse of immobilized cells and remained high even after 5 batches of bioreactions while Na-alginate 3% was used; however, reuse of alginate 2% beads did not give a satisfactory result.     

Production of isomaltulose using Erwinia sp. D12 cells: Culture medium optimization and cell immobilization in alginate

Isomaltulose is a structural isomer of sucrose commercially used in food industries. Glucosyltransferase produced by Erwinia sp. D12 catalyses an intramolecular transglucosylation of sucrose giving isomaltulose. An experimental Design and Response Surface Methodology were applied for the optimization of the nutrient concentration in the culture medium for enzyme production in shaken flasks at 200 rpm and 30 °C. A higher production of glucosyltransferase (7.47 Uml⁻¹) was observed in the culture medium containing sugar cane molasses (160 gl⁻¹), bacteriological peptone (20 gl⁻¹) and yeast extract Prodex Lac SD^® (15 gl⁻¹) after 8 h, at 30 °C. The highest production of glucosyltransferase in the 6.6-l bioreactor (14.6 Uml⁻¹) was obtained in the optimized culture medium after 10 h at 26 °C. When Erwinia sp. D12 cells were immobilized in sodium alginate, it was verified that sodium alginate solution A could be substituted by a cheaper one, sodium alginate solution B. Using a 40% cell suspension and 2% sodium alginate solution B for cell immobilization in a packed-bed reactor, 64.1% conversion of sucrose to isomaltulose was obtained. The packed-bed reactor with immobilized cells plus glutaraldehyde and polyethylenimine solutions remained in a pseudo-steady-state for 180 h.     

A novel mono- and diacylglycerol lipase highly expressed in Pichia pastoris and its application for food emulsifier preparation

A mono- and diacylglycerol lipase (MDL) was cloned from Penicillium cyclopium and expressed in Pichia pastoris strain GS115. The recombinant enzyme was named Lipase GH1. High cell density fermentation was performed by culture in a 7.5-L fermenter using BSMG medium, in which the phosphate in basal salt medium was replaced by sodium glycerophosphate (Na₂GP). The maximal lipase activity detected was 18,000 U per mL, and total protein content in the fermentation supernatant was 3.94 g per L. The activity of the liquid enzyme remained stable under alkaline conditions at 4 °C for 6 months and was 50% after one year. Lipase GH1 was used for the synthesis of mono- and diacylglycerols (MAGs and DAGs), which are commonly used emulsifiers for industrial applications. A conversion rate of 84% after 24 h of reaction was obtained using glycerol/oleic acid molar ratio 11:1, water content 1.5 wt%, enzyme dosage 80 U per g, and reaction temperature 35 °C. Lipase GH1 was more efficient for the synthesis of MAGs and DAGs than was Lipase G50 (a similar, commercially available lipase derived from Penicillium camemberti) when oleic acid was used as an acyl donor. Lipase GH1 has potential for food emulsifier preparation.     

Validation of a simple,rapid and cost effective method for the estimation of caprylic acid and sodium caprylate from biological products using NEFA-C kit

The method for the determination of caprylic acid and sodium caprylate from biological products was systematically validated using NEFA-C kit. The results obtained demonstrated that the kit method was simple, rapid, reliable, sensitive, reproducible and cost effective in comparison to the current methods i.e. colorimetric, High Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) methods. The assay exhibited excellent linearity, accuracy, precision and robustness. Mean recoveries ranged between 95 and 101.3% (n = 6). The proposed method was linear over the concentration range of 0.05–10 mM of caprylate with values of coefficient of regression being >0.99. Method showed sensitivity of 0.05 mM (7.21 μg/ml for caprylic acid and 8.31 μg/ml for sodium caprylate). The % Relative standard Deviation (%RSD) for intra and interprecision studies was less than 5%. In conclusion the validated method was successfully used in monitoring of processed bulk and final products generated during production of biological products thus laying emphasis on strict control of release criteria for biological products fractionated using caprylic acid.     

Optimization and immobilization of amylase obtained from halotolerant bacteria isolated from solar salterns

The objective of the present study was to isolate halotolerant bacteria from the sediment sample collected from Marakanam Solar Salterns, Tamil Nadu, India using NaCl supplemented media and screened for amylase production. Among the 22 isolates recovered, two strains that had immense potential were selected for amylase production and designated as P1 and P2. The phylogenetic analysis revealed that P1 and P2 have highest homology with Pontibacillus chungwhensis (99%) and Bacillus barbaricus (100%). Their amylase activity was optimized to obtain high yield under various temperature, pH and NaCl concentration. P1 and P2 strain showed respective, amylase activity maximum at 35 °C and 40 °C; pH 7.0 and 8.0; 1.5 M and 1.0 M NaCl concentration. Further under optimized conditions, the amylase activity of P1 strain (49.6 U mL^?1) was higher than P2 strain. Therefore, the amylase enzyme isolated from P. chungwhensis P1 was immobilized in sodium alginate beads. Compared to the free enzyme form (49.6 U mL^?1), the immobilized enzyme showed higher amylase activity as 90.3 U mL^?1. The enzyme was further purified partially and the molecular mass was determined as 40 kDa by SDS–PAGE. Thus, high activity of amylase even under increased NaCl concentration would render immense benefits in food processing industries.     

Kinetics of cellulose hydrolysis by halostable cellulase from a marine Aspergillus niger at different salinities

Kinetics of cellulose hydrolysis with halostable cellulase from a marine Aspergillus niger was analyzed at different salinities. Cellulase activity in 8% NaCl solution was 1.43 folds higher than that in NaCl free solution. Half saturation constant, K_m (15.6260 g/L) and the rate constant of deactivation, K_de (0.3369 g/L h) in 8% NaCl solution was lower than that (18.6364 g/L), 0.3754 (g/L h) in NaCl free solution. The maximum initial hydrolysis velocity, V_max (25.5295 g/L h), in 8% NaCl solution was higher than that in NaCl free solution (25.0153 g/L h). High salinity increased affinity to the cellulase to the substrate and thermostability. Halostable cellulase from a marine Aspergillus niger was valuable for cellulose hydrolysis under high salinity conditions.     

Retinoid compounds associated with water blooms dominated by Microcystis species

Retinoic acids play a critical role in vital physiological processes and vertebrate development, and their derivatives can be produced by some cyanobacterial species into surface waters. This study presents important environmentally-relevant information on total retinoid-like activity of field cyanobacterial biomasses and their surrounding waters. Intracellular and extracellular levels of total retinoid-like activity and retinoic acids have been investigated at a set of independent sites with the occurrence of water bloom dominated by widespread species Microcystis aeruginosa. Twelve samples of biomass and surrounding water from seven localities affected by blooms were studied in comparison with samples from M. aeruginosa laboratory cultures. The method for biomass extraction was optimized and final extracts and samples of surrounding water concentrated by solid phase extraction were assessed using in vitro reporter gene bioassay and chemical analyses for all-trans-retinoic acid (ATRA), 9-cis retinoic acid (9-cis RA) and microcystins RR, LR and YR. Methanol was the most efficient solvent for the extraction of compounds with retinoid-like activity. An in vitro bioassay with the P19/A15 transgenic cell line revealed retinoid-like activity in all cyanobacterial biomasses in the range of 356–2838 ng of retinoid acid equivalents (REQ)/g dry mass (dm), while only three of surrounding water samples exhibited detectable retinoid-like activity, in the range of 12.8–28.7 ng REQ/L. Microcystins were detected in all samples, but they elicited no detectable retinoid-like activity up to 10 mg/L. Chemical analyses detected concentrations up to 340 ng/g dm of all-trans-retinoic acid (ATRA) and 84 ng/g dm 9-cis retinoic acid (9-cis RA) in bloom extracts, and up to 19 ng/L ATRA and 2.2 ng/L 9-cis RA in surrounding water. In most samples, ATRA and 9-cis RA contributed relatively little to the total REQs, which indicates the presence of significant amounts of other compounds with retinoic acid receptor-mediated modes of action. The impact of retinoid-like cyanobacterial metabolites could be of importance namely in smaller water bodies with dense water blooms and low dilution.     

Synthesis and characterization of a novel cellulose-g-poly(acrylic acid-co-acrylamide) superabsorbent composite based on flax yarn waste

A new, low-cost, and eco-friendly cellulose-based superabsorbent was successfully prepared from flax yarn waste. The method used was a free-radical graft copolymerization of AA and AM onto a cellulose backbone in a homogeneous aqueous solution. APS was used as the initiator in the presence of a crosslinker, MBA. The effects of various factors on water absorbency were discussed. The factors included reaction temperature, initiator amount, monomer amount, salt solution type, and solution pH. Under the optimized conditions, the water absorbencies of the obtained superabsorbent composite were 875 g/g distilled water, 490 g/g natural rainwater, and 90 g/g 0.9 wt% aqueous NaCl solution. The product also had excellent water retention and salt resistance properties. Fourier-transform infrared spectroscopy and scanning electron microscopy were employed to examine the structure of the prepared superabsorbent.     

Fermentative production of succinic acid from straw hydrolysate by Actinobacillus succinogenes

In this work, straw hydrolysates were used to produce succinic acid by Actinobacillus succinogenes CGMCC1593 for the first time. Results indicated that both glucose and xylose in the straw hydrolysates were utilized in succinic acid production, and the hydrolysates of corn straw was better than that of rice or wheat straw in anaerobic fermentation of succinic acid. However, cell growth and succinic acid production were inhibited when the initial concentration of sugar, which was from corn straw hydrolysate (CSH), was higher than 60 g l^?1. In batch fermentation, 45.5 g l^?1 succinic acid concentration and 80.7% yield were attained after 48 h incubation with 58 g l^?1 of initial sugar from corn straw hydrolysate in a 5-l stirred bioreactor. While in fed-batch fermentation, concentration of succinic acid achieved 53.2 g l^?1 at a rate of 1.21 g l^?1 h^?1 after 44 h of fermentation. Our work suggested that corn straw could be utilized for the economical production of succinic acid by A. succinogenes.     

Efficacy of some antioxidants supplementation in reducing oxidative stress post sodium tungstate exposure in male wistar rats

This study aimed to evaluate the protective efficacy of some antioxidants against sodium tungstate induced oxidative stress in male wistar rats. Animals were sub-chronically exposed to sodium tungstate (100 ppm in drinking water) for three months except for control group. In the same time, many rats were supplemented orally with different antioxidants (alpha-lipoic acid (ALA), n-acetylcysteine (NAC), quercetin or naringenin (0.30 mM)) for five consecutive days a week for the same mentioned period before. Exposure to sodium tungstate significantly (P < 0.05) inhibit blood δ-aminolevulinic acid dehydratase (ALAD) activity, liver and blood reduced glutathione (GSH) levels and an increase in oxidized glutathione (GSSG) and thiobarbituric acid reactive species (TBARS) levels in tissues. ALA acid and NAC supplementation post sodium tungstate exposure increased GSH and also, was beneficial in the recovery of altered superoxide dismutase and catalase activity, besides, significantly reducing blood and tissue reactive oxygen species and TBARS levels. The results suggest a more pronounced efficacy of ALA acid and NAC supplementation than quercetin or naringenin supplementation post sodium tungstate exposure in preventing induced oxidative stress in rats.     

Enhanced extraction genistein from pigeon pea [Cajanus cajan (L.) Millsp.] roots with the biotransformation of immobilized edible Aspergillus oryzae and Monacus anka and antioxidant activity evaluation

A new method of enhanced extraction genistein from pigeon pea [Cajanus cajan (L.) Millsp.] roots with the biotransformation of immobilized edible Aspergillus oryzae and Monacus anka, was investigated. It showed that immobilized Aspergillus oryzae and Monacus anka on sodium alginate effectively supported the highest genistein extraction yield by screening microorganism tests. After biotransformation process with immobilized Aspergillus oryzae and Monacus anka under 30 °C, pH 6.0, 2 days, liquid-solid ratio 12: 1 (mL/g), the extraction yield of genistein reached 1.877 mg/g, which was 2.65-fold to that of normal extraction yield. Moreover, IC₅₀ values of the extracts measured by DPPH-radical scavenging test and β-Carotene-linoleic acid bleaching test were 0.737 mg/mL and 0.173 mg/mL (control sample 1.117 mg/mL and 0.216 mg/mL), respectively. SOD (Super Oxygen Dehydrogenises) activity of the extracts treated with immobilized microorganism which was stronger than that of the untreated pigon pea roots (1.44 U/mg) at the concentration of protein (0.9375 μg/mL) was 1.83 U/mg. The developed method could be an alternative method for the enhanced extraction of genistein from plants and could be potentially applied in the food industry     

Dried alginate-entrapped enzymes (DALGEEs) and their application to the production of fructooligosaccharides

A modification of the classical calcium alginate enzyme entrapment technique is described aiming to overcome some of the limitations of the former gel-based biocatalysts. Dried alginate entrapped enzymes (DALGEEs) were obtained dehydrating calcium alginate gel beads containing entrapped enzymes. A fructosyltransferase from Aspergillus aculeatus, present in Pectinex Ultra SP-L, was entrapped using this technique. The resulting DALGEEs were successfully tested both operating batchwise and in a continuous fixed-bed reactor for fructooligosaccharides (FOS) synthesis from sucrose. Interestingly, DALGEEs did not re-swell upon incubation in concentrated (600 g/L) sucrose solutions, probably due to the lowered water activity (a_w) of such media. Confocal laser scanning microscopy of DALGEEs revealed that the enzyme molecules accumulated preferably in the shell of the particles. DALGEEs showed an approximately 30-fold higher volumetric activity (300 U/mL) compared with the calcium alginate gel beads. Moreover, a significant enhancement (40-fold) of the space-time-yield of fixed-bed bioreactors was observed when using DALGEEs as biocatalyst compared with gel beads (4030 g/day L of FOS vs. 103 g/day L). The operational stability of fixed-bed reactors packed with DALGEEs was extraordinary, providing a nearly constant FOS composition of the outlet during at least 700 h. It was also noticeable their resistance against microbial attack, even after long periods of storage at room temperature. The DALGEEs immobilisation strategy may also be useful for other biotransformations, in particular when they take place in low a_w media.     

Surfactant-mediated permeabilization of Pseudomonas putida KT2440 and use of the immobilized permeabilized cells in biotransformation

Surfactants were used to permeabilize cells of Pseudomonas putida KT2440 so as to maximize retention of the arginine deiminase (ADI) activity within the treated cells. The surfactants cetyltrimethylammoniumbromide (CTAB), sodium dodecyl sulfate (SDS) and Triton X100 were tested separately. Statistical models were developed for the effects on the ADI activity of the following factors: the concentration of the surfactant, the length of the treatment period and the concentration of the cells. For all surfactants, the concentration of cells was the most significant factor in influencing permeabilization. All permeabilization treatments used mild conditions (pH 7, 37 °C). The permeabilized cells were immobilized in alginate beads for the biotransformation of arginine to citrulline. The optimal conditions for immobilization and biotransformation were as follows: 2% (w/v, g/100 mL) sodium alginate, 100 g/L of treated cells, 40 mM arginine, pH 6.0, a temperature of 35 °C and an agitation speed of 150 rpm. The immobilized biocatalyst retained nearly 90% of its initial activity after nine cycles of repeated use in batch operations. In contrast, the freely suspended cells were barely active after the second use cycle.     

Alginate embedding and subsequent sporulation of in vitro-produced Conidiobolus thromboides hyphae using a pressurised air-extrusion method

Conidiobolus thromboides is an entomophthoralean fungus with potential as a biological control agent of aphids. However, its application in biological control is limited due to its formulation requirements. The objective of this study was to develop and optimise a novel air-extrusion method to embed C. thromboides hyphae at high density in alginate pellets. An orthogonal experimental design was used to investigate selected combinations of parameters known to affect hyphal density within pellets. The diameter of pellets produced, and the calculated density of hyphae within them, ranged from 0.18 ± 0.09 to 3.17 ± 0.06 mm and from 0.02 to 350.56 mg/mm³ respectively. These data were used to predict the optimal parameter combination to deliver the greatest density of hyphae of C. thromboides per pellet: 1% sodium alginate, a 1:2 ratio of hyphae to sodium alginate, an orifice diameter of 0.232 mm and an air pressure of 0.05 MPa. Pellets made under the optimal conditions predicted produced a mean total of 4.3 ± 0.6 × 10⁵ conidia per pellet at 100% relative humidity which was significantly greater than the mean total number of conidia produced from infected aphid cadavers of comparable size (9.35 ± 0.85 × 10⁴) (p < 0.001). In conclusion, air-extrusion embedding appears to be a promising method for formulating in vitro-produced hyphae of C. thromboides for use in biological control.