Improvement in gluten-free rice bread quality by protease treatment

The wide prevalence of gluten-related disorders has led to increase in the demand for gluten-free foods. Rice is a gluten-free and less allergenic cereal. However, bread made from rice flour, i.e., gluten-free rice bread, is generally of poor quality because rice flour cannot develop a network with gluten-like properties. In this study, we investigated the effects of protease treatment on gluten-free rice to improve the quality of its bread. Bread treated with a commercial protease from Bacillus stearothermophilus (thermoase) was of higher quality, i.e., good crumb appearance, high volume, and soft texture, depending on the amount of enzyme added. Rice proteins in the protease-treated bread were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which showed that glutelins and prolamins were hardly digested by thermoase in comparison with other proteins. Scanning electron microscopy revealed that many cellular structures were formed in the thermoase-treated bread; however, these structures were rare in the untreated control. Bread crumb color was not affected by the treatment. The staling rate was much lower for the thermoase-treated bread than for the control. These results indicate that thermoase treatment can be successfully used to improve the quality of gluten-free rice bread by partial digestion of rice proteins.     

Bacillolysin,papain, and subtilisin improve the quality of gluten-free rice bread

Protease has been shown to be an effective food additive for improving the quality of gluten-free rice bread. In this study, we found that bacillolysin (Protin SD-NY10, metallo protease), papain (cysteine protease), and subtilisin (Protin SD-AY10, serine protease) increased the specific volume of gluten-free rice breads by 30–60% compared with untreated breads. These proteases also decreased crumb hardness by 10–30% compared with untreated breads. Many fine bubble cells were observed in the crumb of the protease-treated rice breads using scanning electron microscopy. Optical microscopic observation revealed fine networks of small protein aggregates stained by Coomassie Brilliant Blue (CBB) in the rice batter of the improved gluten-free rice breads. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of protein in the rice batter suggested that the amount of low molecular weight proteins (less than 10 kDa) increased with the use of Protin SD-NY10, Protin SD-AY10 and papain treatments compared with untreated rice batter. Thus, we considered that the small proteins aggregates were formed through disulfide bonds. This fine network was effective for retaining CO₂ gas during the fermentation process, resulting in an increase in the specific volume and a decrease in the crumb hardness of gluten-free rice bread.     

Quality improvement of rice-based gluten-free bread using different dietary fibre fractions of rice bran

Gluten-free (GF) breads are often characterised by low nutritional quality as they are mainly starch based and contain low amounts of vitamins, minerals and in particular dietary fibre. The objective of this study was to improve the physical, nutritional and sensory quality and shelf life of rice-based GF bread by adding different fractions of rice bran, containing different amounts of protein, fat, dietary fibre (DF) and different ratios of insoluble (IDF) to soluble (SDF) DF.     

Preparation of gluten-free bread using a meso-structured whey protein particle system

This article presents a novel method for making gluten-free bread using mesoscopically structured whey protein. The use of the meso-structured protein is based on the hypothesis that the gluten structure present in a developed wheat dough features a particle structure on a mesoscopic length scale (100 nm–100 μm). Whey protein particles were prepared by cold gelation of soluble whey protein aggregates during phase separation. The addition of a 2.4% whey protein particle suspension to wheat starch resulted in a dough that could be baked into a leavened bread with a specific volume up to 3.7 ml/g and a bubble size comparable with a normal bread. The relevance for structuring the whey protein into mesoscopic particles was confirmed by tests in which only a homogeneous whey protein gel or a whey protein solution was used. The protein particle system gave better results after proving and baking compared with these systems.     

Value added waste of Jatropha curcas residue: Optimization of protease production in solid state fermentation by Taguchi DOE methodology

The oil extraction of Jatropha curcas created the large amount of the by-product from its seeds. An application of solid-state fermentation (SSF) was considered to be of value to these raw materials. This study investigated the potential of a utilization of deoiled J. curcas seed cake as substrate for protease productions by Aspergillus oryzae. While various parameters for SSF was conventionally individually optimized, five parameters were simultaneously examined based on Taguchi method. The effect of three different levels of five factors, including moisture content of substrate, inoculums size, incubation temperature, type of porous substrate and incubation time were examined. The optimum conditions for the protease production by A. oryzae obtained from this experiment were 45% moisture content of substrate, 10% inoculums size, 30 °C incubation temperature, deoiled J. curcas seed cake mixed with cassava bagasse ratio 4:1 as porous substrate at 84 h of incubation time. By adjusting the conditions to these optimum levels, the protease production increased up to 4.6 times as many as the protease yield from the non-optimizing experiment. The use of statistical approach, Taguchi method, provided a satisfactory outcome in defining the optimum conditions for protease production by A. oryzae. Further, the utilization of deoiled J. curcas seed cake as substrate for SSF was proven as the suitable practice for this agricultural waste, in order to develop for an industrial use.     

Ear rot,aflatoxin accumulation,and fungal biomass in maize after inoculation with Aspergillus flavus

Aflatoxin, a toxin produced by the fungus Aspergillus flavus Link: Fries, occurs naturally in maize (Zea mays L.). Aflatoxin is a potent human carcinogen and is also toxic to livestock, pets, and wildlife. When contaminated with aflatoxin, the value of maize grain is markedly reduced. This investigation was conducted to compare ear rot, aflatoxin accumulation, and fungal biomass in maize single crosses with varying degrees of resistance to aflatoxin accumulation and to determine the relative importance of general combining ability (GCA) and specific combining ability (SCA) in the inheritance of resistance to ear rot, aflatoxin accumulation, and fungal biomass. Eight germplasm lines with different levels of resistance to aflatoxin accumulation were used as parents of a diallel cross. The cross was evaluated for visible ear rot, aflatoxin accumulation, and A. flavus infection in the grain. A. flavus infection was determined by quantitative real-time polymerase chain reaction (qRT-PCR) assays. Both GCA and SCA were significant sources of variation in the inheritance of the three traits although GCA accounted for a greater portion of the variation among single crosses. The interactions of GCA and SCA with years were highly significant for aflatoxin accumulation, but not significant for A. flavus infection. Estimates of GCA effects were highly significant for both reduced A. flavus infection and reduced aflatoxin accumulation for Mp313E, Mp715, and Mp717. Conversely, GCA effects associated with GA209 were significant for reduced levels of A. flavus infection and ear rot, but high levels of aflatoxin accumulation. Mp313E, Mp715, and Mp717 should be useful in breeding programs targeting both reduced levels of fungal infection and aflatoxin accumulation.     

Crucial role of amylose in the rising of gluten- and additive-free rice bread

Gluten- and additive-free rice bread is suitable for consumption by individuals who are sensitive to gluten and prefer to avoid additives. Here, we prepared 100% rice bread, which is a gluten-free rice bread prepared in the absence of additives, using 19 rice flour samples containing amylose contents ranging from 9.6 to 22.3%. The amylose content was positively correlated with the specific volume of the 100% rice bread, whereas no correlation was observed between the protein content and the specific volume. The amylose content was also positively correlated with the specific volume of gluten-free rice bread prepared following protease treatment of the dough. The dough of 100% rice bread prepared from rice flour containing higher amylose contents was better stabilized during leavening than that prepared from rice flour containing a lower amylose content. It was therefore apparent that amylose plays an important role in the preparation of 100% rice bread with a high loaf volume through stabilization of the dough.     

Effect of the thermostable xylanase B (XynB) from Thermotoga maritima on the quality of frozen partially baked bread

The effect of the recombinantly produced xylanase B (XynB) from Thermotoga maritima MSB8 on the quality of frozen partially baked bread (FPBB) was investigated. Addition of XynB to wheat flour dough resulted in a significant increase in dough extensibility (L), swelling (G), and a decrease in dough resistance to deformation (P), configuration. Bread crumb characteristics were studied by differential scanning calorimeter (DSC) and dynamic-mechanical analysis (DMA). The results show that addition of XynB leads to improvements in the bread quality of FPBB and retards bread staling compared to the control. The greatest improvements were obtained in specific volume (+35.2%) and crumb firmness (−40.0%). The control FPBB was significantly firmer in texture and higher in amylopectin recrystallization than the bread with XynB. During frozen storage of FPBB with and without XynB for 8 weeks, the crumb firmness increased gradually and the specific volume slightly decreased with the frozen storage time. The ΔH values of freezable water (FW) endothermic transitions increased with frozen storage time for all samples. However, addition of XynB lowered the ΔH values indicating a decrease in FW. Therefore, XynB is useful in improving the quality of FPBB. DMA was also used to monitor the shrinking behavior of the samples. Addition of XynB increased the contraction during chilling but significantly diminished the total shrinking and frozen-state shrinking of the bread crumb during the freezing process.     

Novel allelic variants encoded at the Glu-D3 locus in bread wheat

Low-molecular weight glutenin subunits (LWM-GS) are important components of wheat (Triticum aestivum L.) gluten, with important effects on end-use quality. The LMW-GS are encoded at Glu-3 loci (Glu-A3, Glu-B3 and Glu-D3, on the short arms of chromosomes 1A, 1B and 1D), each of which exhibits extensive allelic variation. Each locus encodes numerous LMW-GS, some of which have similar electrophoretic mobilities, making it difficult to distinguish among Glu-3 loci. Alleles of the Glu-D3 locus of bread wheat are considered the most problematic to assign. To date, six Glu-D3 alleles, designated a, b, c, d, e and f, have been reported. We report five previously undescribed alleles (g, h, i, j and k), and describe a method for characterizing them using a combination of SDS-PAGE and multiplexed PCR-based DNA markers. This method could be used for accurate identification of Glu-D3 alleles, permitting the estimation of the effects of these alleles on end-use quality and the selection of desirable alleles and allelic combinations in wheat breeding.     

Resistance to Penicillium allii in accessions from a National Plant Germplasm System Allium collection

Multiple Allium accessions (garlic, and wild and ornamental Allium species) were screened for resistance using Penicillium allii and A. sativum (positive control). Single accessions of A. aflatunense, A. atroviolaceum, A. stipitatum, and Allium sp. remained asymptomatic. Single accessions of A. roseum and A. senescens, two accessions each of A. acuminatum and A. ampeloprasum and a single accession of A. moly displayed lesion expansion rates not exceeding 22%, 26%, 46%, 50%, 61%, 67% and 67%, respectively, of positive controls. Single accessions of A. sativum var. ophioscordon and A. scorodoprasum displayed rates not exceeding 68% and 55%, respectively, of positive controls with deep wounding, but did not consistently differ with shallow wounding. Accessions of A. canadense, A. sativum or A. longicuspis did not differ, differed inconsistently, or differed insubstantially from positive controls. Lesion expansion rates for A. acuminatum, A. ponticum and A. scorodoprasum were significantly less than in positive controls, but their small bulbs often rotted completely. Results document publicly available germplasm possessing significant resistance to P. allii.     

High level of resistance to Sclerotinia sclerotiorum in introgression lines derived from hybridization between wild crucifers and the crop Brassica species B. napus and B. juncea

Sclerotinia rot caused by the fungus Sclerotinia sclerotiorum is one of the most serious and damaging diseases of oilseed rape and there is keen worldwide interest to identify Brassica genotypes with resistance to this pathogen. Complete resistance against this pathogen has not been reported in the field, with only partial resistance being observed in some Brassica genotypes. Introgression lines were developed following hybridization of three wild crucifers (viz. Erucastrum cardaminoides, Diplotaxis tenuisiliqua and E. abyssinicum) with B. napus or B. juncea. Their resistance responses were characterized by using a stem inoculation test. Seed of 54 lines of B. napus and B. juncea obtained from Australia, India and China through an Australian Centre for International Agricultural Research (ACIAR) collaboration programme were used as susceptible check comparisons. Introgression lines derived from E. cardaminoides, D. tenuisiliqua and E. abyssinicum had much higher levels (P < 0.001) of resistance compared with the ACIAR germplasm. Median values of stem lesion length of introgression lines derived from the wild species were 1.2, 1.7 and 2.0 cm, respectively, as compared with the ACIAR germplasm where the median value for stem lesion length was 8.7 cm. This is the first report of high levels of resistance against S. sclerotiorum in introgression lines derived from E. cardaminoides, D. tenuisiliqua and E. abyssinicum. The novel sources of resistance identified in this study are a highly valuable resource that can be used in oilseed Brassica breeding programmes to enhance resistance in future B. napus and B. juncea cultivars against Sclerotinia stem rot.     

Sulfhydryl oxidase enhances the effects of ascorbic acid in wheat dough

Various enzyme families such as sulfhydryl oxidase have been successfully applied to bread production although their mechanism of action has not been fully described yet. In this study, we investigated the effects of the recently characterized fungal sulfhydryl oxidase AoSOX1 in fresh and frozen dough alone and in combination with ascorbic acid. The addition of AoSOX1 to an additive-free dough resulted in a weaker and more extensible dough while opposite effects were detected in the presence of ascorbic acid. The hardening of the doughs registered upon the combined use of AoSOX1 and ascorbic acid was dependent on the amount of enzyme used and not on the amount of ascorbic acid. The ability of the sulfhydryl oxidase to enhance the effects of the ascorbic acid system suggests their combined use as a valuable tool to stabilize the structure of fresh and frozen dough.     

Identification of a GDSL-motif carboxylester hydrolase from rice bran (Oryza sativa L.)

A major esterase (designated OsEST1) showing high activity using 1-naphthyl acetate as a substrate was identified from rice bran and purified approximately 239-fold to near-homogeniety. The purified enzyme migrated as a single polypeptide band on native and SDS-polyacrylamide gels and had a molecular mass of 25 kDa under denaturing conditions. Analysis of its tryptic peptides by MALDI-TOF-MS and subsequent data mining identified a corresponding cDNA OsEST1 consisting of 714 nucleotides and encoding a 238 amino acid protein. Analysis of its primary sequence indicated that OsEST1 is a GDSL-motif carboxylester hydrolase belonging to the SGNH protein subfamily in containing the putative catalytic triad of Ser¹¹, Asp¹⁸⁷, and His¹⁹⁰. OsEST1 showed the highest catalytic activity at approximately pH 8.0–8.5 and at 45 °C with K_m and V_max values for 1-naphthyl acetate of 172 μM and 63.7 μmol/min/mg protein, respectively. However, OsEST1 showed no activity with triacylglycerol. Alignment of the primary sequence of OsEST1 and other rice GDSL-motif esterases/lipases showed that OsEST1 aligns with a specific family of plant SGNH esterases involved in response to dehydration and cuticle formation. These results suggest that OsEST1 is not a lipase but an esterase activity which has some other function in rice, especially during seed development.     

Utilization of pretreated bagasse for the sustainable bioproduction of cellulase by Aspergillus nidulans MTCC344 using response surface methodology

Response surface methodology (RSM) was used to optimize the conditions for the production of endo β-1,4 glucanase, a component of cellulase by Aspergillus nidulans MTCC344 under solid state fermentation, using bagasse as the chief substrate. A four-factor-five-level central composite design was employed for experimental design and analysis of the results. Maximum cellulase activity (CMCase was 28.96 U g⁻¹) can be attained at the optimum conditions, 16.8 mm bagasse bed height, 60% moisture content, pH 4.25 and temperature 40 °C in the solid state fermenter. These data were rather close to the experimental results obtained (CMCase was 28.84 U g⁻¹). A. nidulans MTCC344 was able to hydrolyze pretreated bagasse completely after 8 days of incubation with significant endo β-1,4 glucanase activities. The results of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) of bagasse showed structural changes through pretreatment, in favor of enzymatic hydrolysis. Bagasse with alkali pretreatment using sodium hydroxide is a source of lignocelluloses able to improve the yield of endo β-1,4 glucanase by the strain of A. nidulans. The endo β-1,4 glucanase produced during the bioconversion of cellulose to glucose by A. nidulans MTCC344 is strongly dependent on the pretreatment given before hydrolysis.     

Development of simple and co-dominant PCR markers to genotype puroindoline a and b alleles for grain hardness in bread wheat (Triticum aestivum L.)

Grain hardness is one of the most important quality characteristics of cultivated bread wheat (Triticum aestivum L.). A large deletion in the puroindoline a (Pina) gene or single nucleotide polymorphisms (SNPs) in the puroindoline b (Pinb) gene results in hard grain texture. So far, nine Pina alleles (Pina-D1a–Pina-D1b, Pina-D1k–Pina-D1q) and seventeen Pinb alleles (Pinb-D1a–Pinb-D1g, Pinb-D1p–Pinb-D1ab) have been identified in bread wheat. The major Pina and Pinb alleles identified in hard wheat cultivars are Pina-D1b, Pinb-D1b, Pinb-D1c and Pinb-D1d. In this study, a three-primer PCR system was employed to develop nine co-dominant STS markers for genotyping Pina-D1a and Pina-D1b, whereas temperature-switch (TS) PCR was used to develop six co-dominant SNP markers for genotyping the Pinb-D1a, Pinb-D1b, Pinb-D1c and Pinb-D1d alleles. These STS and TS-PCR markers were used to verify the grain hardness genotype of 100 wheat cultivars. The reliability and genotyping accuracy of TS-PCR markers were confirmed through sequencing of PCR products and a comparison with previously published results. Therefore, STS and TS-PCR markers offer a simple, cost-effective and reliable method for high-throughput genotyping Pina and Pinb alleles to select grain hardness in wheat quality breeding programs and for wheat market classification.     

Evaluation of actinomycete isolates obtained from herbal vermicompost for the biological control of Fusarium wilt of chickpea

A total of 137 actinomycetes cultures, isolated from 25 different herbal vermicomposts, were characterized for their antagonistic potential against Fusarium oxysporum f. sp. ciceri (FOC) by dual-culture assay. Of the isolates, five most promising FOC antagonistic isolates (CAI-24, CAI-121, CAI-127, KAI-32 and KAI-90) were characterized for the production of siderophore, cellulase, protease, hydrocyanic acid (HCN), indole acetic acid (IAA) and antagonistic potential against Rhizoctonia bataticola, which causes dry root rot in chickpea (three strains viz. RB-6, RB-24 and RB-115) and sorghum (one strain). All of the five FOC antagonistic isolates produced siderophore and HCN, four of them (except KAI-90) produced IAA, KAI-32 and KAI-90 produced cellulase and CAI-24 and CAI-127 produced protease. In the dual-culture assay, three of the isolates, CAI-24, KAI-32 and KAI-90, also inhibited all three strains of R. bataticola in chickpea, while two of them (KAI-32 and KAI-90) inhibited the tested strain in sorghum. When the FOC antagonistic isolates were evaluated further for their antagonistic potential in the greenhouse and wilt-sick field conditions on chickpea, 45-76% and 4-19% reduction of disease incidence were observed, respectively compared to the control. The sequences of 16S rDNA gene of the isolates CAI-24, CAI-121, CAI-127, KAI-32 and KAI-90 were matched with Streptomyces tsusimaensis, Streptomyces caviscabies, Streptomyces setonii, Streptomyces africanus and an identified species of Streptomyces, respectively using the BLAST searching. This study indicated that the selected actinomycete isolates have the potential for biological control of Fusarium wilt disease in chickpea.     

Mycoparasitic Trichoderma viride as a biocontrol agent against Fusarium oxysporum f. sp. adzuki and Pythium arrhenomanes and as a growth promoter of soybean

Trichoderma viride was proved as an effective biocontrol agent against two fungal pathogens, Fusarium oxysporum f. sp. adzuki and Pythium arrhenomanes, infecting soybean. During an in vitro biocontrol test, Trichoderma showed mycoparasitism and destructive control against the tested fungal pathogens. Both the pathogens significantly influence the germination and P. arrhenomanes had a severe effect (only 5% germination). The root system of the soybean plant was poorly developed due to the infection and it exerted a negative influence on the nodulation and further growth phases of the plant. During pot assay along with biocontrol activity, Trichoderma showed growth promoting action on the soybean plant. Trichoderma enhanced growth of shoot and root systems and fruit yield after 12 weeks of growth. Pythium and Fusarium infected plants treated with Trichoderma had ∼194% and 141% more height than pathogens alone. The fruit yield treated with Trichoderma was ∼66 per plant whereas the yield was only 41 for a control plant. The plants infected with Pythium and Fusarium and treated with Trichoderma had fruit yields of 43 and 53 respectively and those were 5 and 1.6 times higher than plants infected with pathogens.     

Comparative susceptibility of Ostrinia furnacalis, Ostrinia nubilalis and Diatraea saccharalis (Lepidoptera: Crambidae) to Bacillus thuringiensis Cry1 toxins

Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) are highly effective against the European corn borer, Ostrinia nubilalis (Hübner), and the closely related Asian corn borer, Ostrinia furnacalis (Guenée). Since the registration of Bt corn hybrids in the U.S. in 1996, there has been a great deal of information generated on O. nubilalis. However, relatively little information exists for O. furnacalis. To help determine whether the information generated for O. nubilalis can be leveraged for decisions regarding the use of transgenic Bt corn against O. furnacalis, experiments were designed to determine whether the pattern of sensitivity to various Bt Cry1 toxins is similar between the two species. Test insects included laboratory-reared O. furnacalis originating from Malaysia, a Bt-susceptible laboratory colony of O. nubilalis maintained at the University of Nebraska-Lincoln (UNL) and an out-group consisting of the sugarcane borer, Diatraea saccharalis (F.), from Louisiana which represents a different genus from the same family. O. furnacalis and O. nubilalis exhibited a similar pattern of susceptibility to all the Cry1 toxins and were highly susceptible to the range of Bt toxins tested including Cry1Aa, Cry1Ab, Cry1Ac and Cry1F. Both of the Ostrinia species were more tolerant to Cry1Ba compared with D. saccharalis, although sensitivity of O. furnacalis was intermediate and did not differ significantly from that of O. nubilalis and D. saccharalis. D. saccharalis was also susceptible to the range of toxins tested but unlike the two Ostrinia species, was more tolerant to Cry1F and more susceptible to Cry1Ba. These results indicate that both of the Ostrinia corn borer species are similar in sensitivity to the Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ba and Cry1F toxins, thus suggesting shared toxin receptors and mechanisms of toxicity for the two species.     

Insecticidal effect of recombinant endophytic bacterium containing Pinellia ternata agglutinin against white backed planthopper, Sogatella furcifera

White backed planthopper (WBPH; Sogota furcifera Horvath) has become the major threat to rice crops throughout Asia, damaging plants both through its feeding behavior and by acting as a virus vector. Here, we developed a novel method for biologically controlling WBPH by using endophytic bacterium to express anti-pest plant lectins. Strain SJ-10 of an endophytic bacterium, characterized as Enterobacter cloacae by morphological, physiological, biochemical and 16s rDNA characteristics, was isolated from rice seedlings. The Pinellia ternate agglutinin (PTA) gene was cloned into SJ-10 for expression. The positive transformant, selected by antibiotic resistance, was evaluated using PCR, SDS-PAGE and Western blot assay. After inoculation, rSJ-10 could colonize rice plants so that they expressed PTA, and then the rice was shown to have insecticidal activity against WBPH. The results showed that rSJ-10 could significantly decrease the survival and fecundity of WBPH fed on rice seedlings (p < 0.01). At day 19, the fecundity of WBPH inoculated with rSJ-10, or with wild-type SJ-10 was decreased by 86.1%, and 25.6%, respectively. At day 22, numbers of WBPH on rice in the control were 19.4 times greater than on rice inoculated with rSJ-10. At day 26, the rice seedlings all died in the control group, but the seedlings inoculated with rSJ-10 grew well. The results showed that the rice seedlings inoculated with rSJ-10 expressing PTA protein were endowed with the anti-pest activity against WBPH. Further work is needed to investigate whether the rice plants expressing rPTA are toxic to mammals. This research highlights a way to biologically control planthoppers by recombinant endophytic bacteria expressing plant lectins.     

Endophytic Lecanicillium lecanii and Beauveria bassiana reduce the survival and fecundity of Aphis gossypii following contact with conidia and secondary metabolites

Lecanicillium lecanii and Beauveria bassiana are important entomopathogens of Aphis gossypii. Their capacity to colonize crop plants is also becoming widely recognized. Their presence in crop plants indicates the possibility of a much greater potential for contact between insect and fungus than previously recognized. The present experiment aimed to study the effects of endophytic strains of these fungi on the survival, and reproduction of A. gossypii. Contact with conidia of both fungi significantly reduced the rate and period of reproduction of A. gossypii. The culture filtrates of L. lecanii and B. bassiana significantly increased mortality and feeding-choice experiments indicate that insects may be able to detect metabolites of the fungi. The culture filtrate of L. lecanii also significantly reduced the reproduction of the aphid. The ethyl acetate and methanolic fractions of the culture filtrate and of mycelia of L. lecanii also caused significant mortality and reduced fecundity of A. gossypii. The methanolic fractions of mycelia of B. bassiana caused significant mortality of A. gossypii. The present investigations indicated that A. gossypii is affected by contact with both conidia and fungal metabolites. This broad influence indicates that these fungi may have a role in regulating insect pest populations.