Search results for: aspergillus species

Authors: Sabah Ben Fredj Melki, Yves Brygoo, Ahmed Mliki

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A 700 pb PCR-derived DNA fragment was isolated from Aspergillus carbonarius, Aspergillus niger, and Aspergillus tubingensis using degenerated primers (LC1-LC2c) and two newly designed primer pairs (KSLB-LC6) for Aspergillus niger and (AFl1F-LC2) for Aspergillus tubingensis developed for the acyl transferase (AT) and the KS domains of fungal PKSs. DNA from the most of black Aspergillus species currently recognized was tested. Herein, we report on the identification and characterisation of a part of the novel putative OTA-polyketide synthase gene in A. carbonarius “ACPks”, A. niger “ANPks” and A. tubingenis “ATPks”. The sequences were aligned and analyzed using phylogenetic methods. Primers used in this study showed general applicability and other Aspergillus species belonging to section Nigri were successfully amplified especially in A. niger and A. tubingenis. The predicted amino acid sequences “ACPks” displayed 66 to 81% similarities to different polyketide synthase genes while “ANPks” similarities varied from 68 to 71% and “ATPks” were from 81 to 97%. The AT and the KS domains appeared to be specific for a particular type of fungal PKSs and were related to PKSs involved in different mycotoxin biosynthesis pathways, including ochratoxin A. The sequences presented in this work have a high utility for the discovery of novel fungal PKS gene clusters.

Keywords: Pks genes, OTA Biosynthesis, Aspergillus Nigri, sequence analysis

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Authors: Samina Sarwar, Hajra Khalil

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Mycoremediation is emerging as a potential approach for eco-friendly and cost-effective remediation of polluted effluents collected from the dyeing unit of the textile industry was examined. This work dealt with the analyses of the bio remedial capability of some potential indigenous six fungal isolates viz., Aspergillus alliaceus, Aspergillus flavus, Aspergillus fumigatus Aspergillus niger, Penicillium sp. and Rhizopus oryzae were identified and selected for studies. All fungal species were known to bring bioremediation, which had been confirmed by measuring the percentage reduction potential in different parameters, i.e., pH, Electrical Conductivity (EC), Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Rhizopus oryzae showed the highest reduction in pH, EC, and BOD, while Aspergillus fumigatus showed the highest reduction in TDS and TSS, and COD under the optimal conditions of this study. The biodegradation potential of these fungal species was confirmed, evidenced by excellent evaluation of experimental data to propose Rhizopus oryzae and Aspergillus fumigatus as a cost-effective solution to treat the effluents from the dyeing unit of the textile industry.

Keywords: biological reduction, fungal isolates, micromycetes, mycoremediation

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Authors: Samina Sarwar, Hajra Khalil

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Mycoremediation is emerging as a potential approach for eco-friendly and cost-effective remediation of polluted effluents collected from the dyeing unit of the textile industry was examined. This work dealt with the analyses of the bio remedial capability of some potential indigenous six fungal isolates viz., Aspergillus alliaceus, Aspergillus flavus, Aspergillus fumigatus Aspergillus niger, Penicillium sp. and Rhizopus oryzae were identified and selected for studies. All fungal species were known to bring bioremediation, which had been confirmed by measuring the percentage reduction potential in different parameters, i.e., pH, Electrical Conductivity (EC), Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Rhizopus oryzae showed the highest reduction in pH, EC, and BOD, while Aspergillus fumigatus showed the highest reduction in TDS and TSS, and COD under the optimal conditions of this study. The biodegradation potential of these fungal species was confirmed, evidenced by excellent evaluation of experimental data to propose Rhizopus oryzae and Aspergillus fumigatus as a cost-effective solution to treat the effluents from the dyeing unit of the textile industry.

Keywords: biological reduction, fungal isolates, micromycetes, mycoremediation

Procedia PDF Downloads 63

Authors: S. Kumar, R. Sultana

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This study was conducted to evaluate the effect of Aspergillus species on acridid populations which are major agricultural pests of rice, sugarcane, wheat, maize and fodder crops in Pakistan. Three and replicates i.e. Aspergillus flavus, A. fumigatus and A. niger, excluding the control, were held under laboratory conditions. It was observed that consumption faecal production of acridids was significantly reduced after the pathogenic application of Aspergillus. In the control replicate, the mortality ratio for stage (N₄-N₆) was maximum on day 2^nd i.e. [F_10.7 = 18.33, P < 0.05] followed by [F_4.20 = 07.85, P < 0.05] and [F_3.77 = 06.11, P < 0.05] on 4^th and 3^rd day, respectively. Similarly, it was a minimum i.e. [F_0.48 = 84.65, P < 0.05] on the 1^st day. It was also noted that faecal production of Acridid nymphs was not significantly affected when treated with conidial concentration in H₂O formulation; however, it was significantly reduced after the contamination with conidial concentration in oil. The high morality of acridids after contamination of Aspergillus supports their use as bio-control agent for reducing pest population. The present study recommends that exploration and screening must be conducted to provide additional pathogens for evaluation as potential biological control against grasshoppers and locusts.

Keywords: acridid, agriculture, formulation, grasshoppers

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Authors: M. N. Alo, U. C. C. Egbule, J. O. Orji, C. J. Aneke

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Microbiological analysis of soil from Onu-Ebonyi Izzi local government area of Ebonyi State, Nigeria contaminated with inorganic fertilizer was carried out with a view to determine the effect of the fertilizer on the microbial flora of the soil. soil samples were analyzed for microbial burden. the result showed that the following organisms were isolated with their frequency of their occurrence as follows:pseudomonas species (33.3%) and aspergillus species (54.4%) had the highest frequncy of occurence in the whole sample of batches, while streptococcus species had 6.0% and Geotrichum species (5.3%) had the least and other predominant microorganism isolated: bacillus species,staphylococcus species and vibrio species, Escherichia species, rhzizopus species, mucor species and fusaruim species. From the result, it could be concluded that the soil was contaminated and this could affect adversely the fertility of the soil .

Keywords: soil, bacteria, fungi, inorganic fertilizer, Onu- Ebonyi

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Authors: Nji Queenta Ngum, Mwanza Mulunda

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Introduction Most African research reports on the frequent aflatoxin contamination of various foodstuffs, with researchers rarely specifying which of the Aspergillus species are present in these commodities. Numerous research works provide evidence of the ability of fungi to grow, thrive, and interact with other crop species and focus on the fact that these processes are largely affected by climatic variables. South Africa is a water-stressed country with high spatio-temporal rainfall variability; moreover, temperatures have been projected to rise at a rate twice the global rate. This weather pattern change may lead to crop stress encouraging mold contamination with subsequent mycotoxin production. In this study, the biodiversity and distribution of Aspergillus species with their corresponding toxins in maize from six distinct maize producing regions with different weather patterns in South Africa were investigated. Materials And Methods By applying cultural and molecular methods, a total of 1028 maize samples from six distinct agro-climatic regions were examined for contamination by the Aspergillus species while the high performance liquid chromatography (HPLC) method was applied to analyse the level of contamination by aflatoxins. Results About 30% of the overall maize samples were contaminated by at least one Aspergillus species. Less than 30% (28.95%) of the 228 isolates subjected to the aflatoxigenic test was found to possess at least one of the aflatoxin biosynthetic genes. Furthermore, almost 20% were found to be contaminated with aflatoxins, with mean total aflatoxin concentration levels of 64.17 ppb. Amongst the contaminated samples, 59.02% had mean total aflatoxin concentration levels above the SA regulatory limit of 20ppb for animals and 10 for human consumption. Conclusion In this study, climate variables (rainfall reduction) were found to significantly (p<0.001) influence the occurrence of the Aspergillus species (especially Aspergillus fumigatus) and the production of aflatoxin in South Africa commercial maize by maize variety, year of cultivation as well as the agro-climatic region in which the maize is cultivated. This included, amongst others, a reduction in the average annual rainfall of the preceding year to about 21.27 mm, and, as opposed to other regions whose average maximum rainfall ranged between 37.24 – 44.1 mm, resulted in a significant increase in the aflatoxin contamination of maize.

Keywords: aspergillus species, aflatoxins, diversity, drought, food safety, HPLC and PCR techniques

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Authors: Ali Mohamadi Sani

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The aim of this study was to determine the antimicrobial effect of Helichrysum arenarium L. essential oil in "in-vitro" condition on the growth of seven microbial species including Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Saccharomyces cereviciae, Candida albicans, Aspergillus flavus and Aspergillus parasiticus using microdilution method. The minimum inhibitory concentration (MIC) and minimum bactericidal or fungicidal concentration (MBC, MFC) were determined for the essential oil at ten concentrations. Finally, the sensitivity of tested microbes to the essential oil of H. arenarium was investigated. Results showed that Bacillus subtilis (MIC=781.25 and MBC=6250 µg/ml) was more resistance than two other bacterial species. Among the tested yeasts, Saccharomyces cereviciae (MIC=97.65 and MFC=781.25 µg/ml) was more sensitive than Candida albicans, while among the fungal species, growth of Aspergillus parasiticus inhibited at lower concentration of oil than the Aspergillus flavus. The extracted essential oil exhibited the same MIC value in the liquid medium against all fungal strains (48.82 µg/ml), while different activity against A. flavus and A. parasiticus was observed in this medium with MFC values of 6250 and 390.625µg/ml, respectively. The results of the present study indicated that Helichrysum arenarium L essential oil had significant (P<0.05) antimicrobial activity; therefore, it can be used as a natural preservation to increase the shelf life of food products.

Keywords: Helichrysum arenarium, antimicrobial, essential oil, MIC

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Authors: Gafar Bamigbade, Adebunkola Omemu

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“Ogi” is a fermented cereal gruel prepared from maize (Zea mays), millet (Pennisetum typhoideum) or guinea corn (Sorghum bicolour). It could be boiled to give a thicker consistency wrapped in leaf allowed to cool and set to a gel known as “eko”. The objective of this study is to determine the amylase activities of mould associated with the spoilage of Ogi and eko. Moulds were isolated from spoilt Ogi and eko samples using standard microbiological procedures. The isolate was then screened for amylase production using starch agar medium. Positive isolates were used for amylase production by solid state fermentation (SFF) using rice bran as the medium. An alpha-amylase and glucoamylase activity of the crude enzyme was determined using the DNS method. The mean mold Population ranged from 1.15 X 105cfu/g for raw Ogi to 6.25 X 105cfu/g for Eko (wrapped in Leaves). Twenty-seven (27) moulds isolated from the sample include A. niger, A. flavus, A. fumigatus, Rhizopus species and Penicillium species. Aspergillus flavus had the highest percentage (51.9%) of incidence while Penicillium species had the least (3.7%). Out of the 27 isolates screened, 19 were found to be amylase positive by showing a clear zone around their colony after flooding with iodine solution. Diameter of clear zone ranged from 3.00mm (Aspergillus niger, C4) to 22.00mm (Aspergillus flavus, A1). Aspergillus niger isolated from spoilt Eko wrapped in leaf has the highest percentage alpha-amylase activity (30.8%) and Aspergillus flavus isolated from spoilt raw ogi has the lowest activity (11.4%). Aspergillus niger isolated from spoilt Eko wrapped in nylon produces the highest glucoamylase activity (240U/ml) while penicillium specie isolated from spoilt cooked ogi has the lowest activity (100U/ml). This study shows that moulds associated with spoilage of ogi and eko can produce amylase.

Keywords: glucoamylase, alpha amylase, ogi, eko

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Authors: Zebiri Saliha

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Ochratoxin A (OTA) is a mycotoxin produced by certain species of the genera Aspergillus and Penicillium, primarily found in cereals, coffee, and grapevine products. Its accumulation in the body can lead to nephrotoxic, teratogenic, immunosuppressive, and carcinogenic effects. The objective of this study is to investigate the contamination of consumed wheat and its derivatives by toxic fungi in Algeria. For this purpose, an analysis of 200 samples was conducted, including 90 samples of durum wheat and common wheat and 110 samples of wheat derivatives collected from mills (semolina and flour manufacturers). The results revealed an average fungal contamination rate ranging from 60% to 100%. The identified fungal isolates primarily belonged to the genera Aspergillus (70%), Penicillium (27.5%), Alternaria (40%), and Mucor (19.4%). The density of the fungal flora was higher in products intended for animal consumption, such as durum wheat flour (2525 CFU/g), wheat scraps (3175 CFU/g), and wheat bran (2950 CFU/g). Conversely, low fungal density was observed in fine semolina (900 CFU/g) and flour (800 CFU/g) intended for human consumption. The genus Penicillium was isolated in 46% of the analyzed samples of durum wheat derivatives and in 62.7% of the analyzed samples of common wheat derivatives. The Aspergillus genus dominated the majority of the analyzed samples. Molecular identification of Aspergillus and Penicillium isolates by sequencing ITS1-5.8S-ITS2 regions of DNAr and a part of the calmodulin (CaM) gene indicated that the species involved in the production of OTA in wheat and its derivatives were mainly Aspergillus ochraceus, A. westerdijkia, A. alliaceus, A. carbonarius, and Penicillium islandicus. The amounts of OTA produced by these species were determined by HPLC-FLD and ranged between 0,8.9 and 3033μg/g. Given that food safety and quality are major concerns today, understanding the microbial biodiversity of wheat is crucial because it is a staple food in Algeria.

Keywords: wheat derivatives, Aspergillus, microbial biodiversity, OTA

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Authors: Samuel E. Okere, Anthony E. Ataga

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Introduction: The microbial ecology of Pleurotus osteratus and Pleurotus tuber–regium spent mushroom substrate (SMS) were characterized to determine other ways of its utilization. Materials and Methods: The microbiological properties of the spent mushroom substrate were determined using standard methods. This study was carried out at the Microbiology Laboratory University of Port Harcourt, Rivers State, Nigeria. Results: Quantitative microbiological analysis revealed that Pleurotus osteratus spent mushroom substrate (POSMS) contained 7.9x10⁵ and 1.2 x10³ cfu/g of total heterotrophic bacteria and total fungi count respectively while Pleurotus tuber-regium spent mushroom substrate (PTSMS) contained 1.38x10⁶ and 9.0 x10² cfu/g of total heterotrophic bacteria count and total fungi count respectively. The fungi species encountered from Pleurotus tuber-regium spent mushroom substrate (PTSMS) include Aspergillus and Cladosporum species, while Aspergillus and Penicillium species were encountered from Pleurotus osteratus spent mushroom substrate (POSMS). However, the bacteria species encountered from Pleurotus tuber-regium spent mushroom substrate include Bacillus, Acinetobacter, Alcaligenes, Actinobacter, and Pseudomonas species while Bacillus, Actinobacteria, Aeromonas, Lactobacillus and Aerococcus species were encountered from Pleurotus osteratus spent mushroom substrate (POSMS). Conclusion: Therefore based on the findings from this study, it can be concluded that spent mushroom substrate contain microorganisms that can be utilized both in bioremediation of oil-polluted soils as they contain important hydrocarbon utilizing microorganisms such as Penicillium, Aspergillus and Bacillus species and also as sources of plant growth-promoting rhizobacteria (PGPR) such as Pseudomonas and Bacillus species which can induce resistance on plants. However, further studies are recommended, especially to molecularly characterize these microorganisms.

Keywords: characterization, microorganisms, mushroom, spent substrate

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Authors: Zeynep Yazgan, Gökhan Aygün, Reyhan Çalışkan

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Objective: Invasive fungal infections are a serious threat in terms of morbidity and mortality, especially in immunocompromised patients. The most frequently isolated agents are Aspergillus genus fungi, and sensitivity to azoles, which are the first choice in treatment, decreases. In our study, we aimed to investigate the use of the agar plate screening method as a fast, easy, and practical method in determining azole resistance in Aspergillus spp. species. Methods: Our study was conducted with 125 Aspergillus spp. isolates produced from various clinical samples. Aspergillus spp. isolates were identified by conventional methods and azole resistance was determined by gradient test and agar plate screening method. Broth microdilution method was applied to resistant isolates, and CypA-L98H and CypA-M220 mutations in the cyp51A gene were investigated. Results: In our study, 55 A. fumigatus complex (44%), 42 A. flavus (33.6%), 6 A. terreus (5%), 4 A. niger (3%) and 18 Aspergillus spp. (14%) were identified. With the gradient test method, resistance to VOR and POS was detected in 1 (1.8%) of A.fumigatus isolates, and resistance to ITR was detected in 3 (5.45%). With the agar plate method, 1 of the A.fumigatus isolates (1.8%) had VOR, ITR, POS, 1 of the A.terreus isolates (16.7%) had VOR, 1 of the A.niger isolates (25%) had ITR. Resistance to VOR and POS was detected in 2 Aspergillus spp. isolates (11%), and resistance to ITR was detected in 1 (5.6%). Sensitivity and specificity were determined as 100% for VOR and POS in A. fumigatus species, 33.3% and 100% for ITR, respectively, 100% for ITR in A. flavus species, and 100% for ITR and POS in A. terreus species. By broth microdilution method in 7 isolates in which resistance was detected by gradient test and/or agar plate screening method; 1 A.fumigatus resistant to ITR, VOR, POS, 2 A.fumigatus resistant to ITR, 2 Aspergillus spp. ITR, VOR, POS MICs were determined as 2µg/ml and 8µg/ml, 8µg/ml and >32µg/ml, 0.5µg/ml and 4µg/ml, respectively. CypA-L98H mutations were detected in 5 of these isolates, CypA-M220 mutations were detected in 6, and no mutation was detected in 1. CypA-L98H and CypA-M220 mutations were detected in 1 isolate for which resistance was not detected. Conclusion: The need for rapid antifungal susceptibility screening tests is increasing in the treatment of aspergillosis. Although the sensitivity of the agar plate method was determined to be 33.3% for A.fumigatus ITR in our study, its sensitivity and specificity were determined to be 100% for ITR, VOR, and POS in other species. The low sensitivity value detected for A.fumigatus showed that agar plate drug concentrations should be updated in accordance with the latest regulations of EUCAST guidelines. The CypA-L98H and CypA-M220 mutations detected in our study suggested that the distribution of azole resistance-related mutations in different regions in our country should be investigated. In conclusion, it is thought that the agar plate method, which can be easily applied to detect azole resistance, is a fast and practical method in routine use and can contribute to both the determination of effective treatment strategies and the generation of epidemiological data.

Keywords: Aspergillus, agar plate, azole resistance, cyp51A, cypA-L98H, cypA-M220

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Authors: Asad Ali, Asif Jamal

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The agriculture productivity losses due to microbial pathogens have been a serious issue in Pakistan and rest of the world. Present work was designed to isolate soil borne microorganisms having the antagonistic ability against notorious phytopathogens. From the initial collection of 23 bacterial isolates, two potent strains of Bacillus were screened on the basis of their comparative efficacy against devastating fungal pathogens. The strains AK-1 and AK-5 showed excellent inhibitory indexes against the majority of tested fungal strains. It was noted that both strains of Bacillus showed significant biocontrolling activity against Aspergillus flavus, Fusarium moniliforme, Colletotricum falcatum, Botrytis cinerea, Aspergillus niger, Fusarium oxysporum, Phythopthora capsici and Rhizopus oryzae. The strain AK-1 was efficient to suppress Aspergillus species and Rhizopus oryzae while AK-5 expressed significant antagonistic activity against Fusarium, Botrytis and Colletotricum species. On the basis of in vitro assay, it can be postulated that the Bacillus strains AK-1 and AK-5 can be used as bio-protective agent against various plant diseases. In addition, their applications as natural pesticides could be very helpful to prevent the adverse effects of chemical pesticides.

Keywords: bacillus species, biocontrol agent, biopesticides, phytopathogens

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Authors: Eszter J. Tóth, Alexandra Hoffmann, Csaba Vágvölgyi, Tamás Papp

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Members of the genera Curvularia and Bipolaris are closely related melanin producing filamentous fungi; both of them have the teleomorph states in genus Cochliobolus. While Bipolaris species infect only plants and may cause serious agriculture damages, some Curvularia species was recovered from opportunistic human infections. The human pathogenic species typically cause phaeohyphomycoses, i.e. mould infections caused by melanised fungi, which can manifest as invasive mycoses with frequent involvement of the central nervous system in immunocompromised patients or as local infections (e.g. keratitis, sinusitis, and cutaneous lesions) in immunocompetent people. Although their plant-fungal interactions have been intensively studied, there is only little information available about the human pathogenic feature of these fungi. The aim of this study was to investigate the neutrophil granulocytes’ response to hyphal forms of Curvularia and Bipolaris in comparison with the response to Aspergillus. In the present study Curvularia lunata SZMC 23759 and Aspergillus fumigatus SZMC 23245 both isolated from human eye infection, and Bipolaris zeicola BRIP 19582b isolated from plant leaf were examined. Neutrophils were isolated from heparinised venous blood of healthy donors with dextran sedimentation followed by centrifugation over Ficoll and hypotonic lysis of erythrocytes. Viability and purity of the cells were checked with trypan blue and Wright staining, respectively. Infection of neutrophils was carried out with germinated conidia in a ratio of 5:1. Production of hydrogen peroxide, superoxide anion, and nitrogen monoxide was measured both intracellularly and extracellularly in response to the germinated spores with or without the supernatant and after serum treatment. ROS and NOS production of neutrophils in interaction with the three fungi were compared. It is already known that Aspergillus species induce ROS production of neutrophils only after serum treatment. Although, in case of C. lunata, serum opsonisation also induced an intensive production of reactive species, lower level of production was measured in the lack of serum as well. After interaction with the plant pathogenic B. zeicola, amount of reactive species found to be similar with and without serum treatment. The presence of germination supernatant decreased the reactive species production in case of each fungus. Interaction with Curvularia, Bipolaris and Aspergillus species induced different response of neutrophils. It seems that recognition of C. lunata and B. zeicola is independent of serum opsonisation, albeit it increases the level of the produced reactive species in response for C. lunata. The study was supported by the grant LP2016-8/2016.

Keywords: Curvularia, neutrophils, NOS, ROS, serum opsonisation

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Authors: Dahliz Abderrahmène, Lakhdari Wassim, Bouchikh Yamina, Hammi Hamida, Soud Adila, M’lik Randa, Benglia Sara

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Devastating insects constitute one of strains for cultivate tomato. Among this vandal insects, the tomato leafminer (T. absoluta), which has been introduced in Algeria constitute a challenge for both agricultures and scientists. Firstly, this insect is introduced without their natural enemies which may reduce their damage. Secondly, this species has developed insecticide resistance to many active matters. To contribute to establish a control strategy for T. absoluta we have mad an inventory for their enthomopathogenic fungi. Two fungi were identified among others taken from adults and pupae. These fungi are Aspergillus flavus and Metarhizium sp. A study was conducted in laboratory to recognize the efficiency of these antagonists. These species had unregistered a mortality mounts of 42% and 56% respectively.

Keywords: Tuta absoluta, enthomopathogenic fungi, Aspergillus flavus, Metarhizium sp, control strategy

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Authors: A. F. Gbadebo, O. O. Atanda, M. C. Adetunji

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The study investigated the level of aflatoxin contamination of abattoir wastes in Ogun State, Nigeria, due to continued complaints of poor hygiene of abattoir centers in the states as a result of improper disposal of abattoir wastes. Wastes from the three senatorial districts of the state were evaluated for their levels of aflatoxin contamination. The moisture content, total plate count, fungal counts, percentage frequency of fungal occurrence as well as the level of aflatoxin contamination of the abattoir wastes were determined by standard methods. The moisture content of the wastes ranged between 79.10-87.46 %, total plate count from 1.37-3.27×10³cfu/ml, and fungal counts from 2.73-3.30×10²cfu/ml. Four fungal species: Aspergillus niger, Aspergillus flavus, Aspergillus ochraceus, and Penicillium citrinum were isolated from the wastes, with Aspergillus flavus having the highest percentage frequency of occurrence of 29.76%. The aflatoxin content of the samples was found to range between 3.20-4.80 µg/kg. These findings showed that abattoir wastes from Ogun State are contaminated with aflatoxins and pose a health risk to humans and animals.

Keywords: abattoir wastes, aflatoxin, microbial load, Ogun state

Procedia PDF Downloads 91

Authors: Asif Jamal, Asad Ali, Muhammad Ishtiaq Ali

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The agriculture productivity losses due to microbial pathogens have been a serious issue in Pakistan and rest of the world. Present work was designed to isolate soil borne microorganisms having the antagonistic ability against notorious phytopathogens. From the initial collection of 23 bacterial isolates, two potent strains of Bacillus were screened on the basis of their comparative efficacy against devastating fungal pathogens. The strains AK-1 and AK-5 showed excellent inhibitory indexes against the majority of tested fungal strains. It was noted that both strains of Bacillus showed significant biocontrolling activity against Aspergillus flavus, Fusarium moniliforme, Colletotricum falcatum, Botrytis cinerea, Aspergillus niger, Fusarium oxysporum, Phythopthora capsici and Rhizopus oryzae. The strain AK-1 was efficient to suppress Aspergillus species and Rhizopus oryzae while AK-5 expressed significant antagonistic activity against Fusarium, Botrytis, and Colletotricum species. On the basis of in vitro assay, it can be postulated that the Bacillus strains AK-1 and AK-5 can be used as a bio-protective agent against various plant diseases. In addition, their applications as natural pesticides could be very helpful to prevent the adverse effects of chemical pesticides.

Keywords: biological control, Bacillus spp, fungal pathogens, agriculture

Procedia PDF Downloads 239

Authors: Amr A. EL Hanafy, Yasir Anwar, Saleh A. Mohamed, Saleh Mohamed Saleh Al-Garni, Jamal S. M. Sabir , Osama A. H. Abu Zinadah, Mohamed Morsi Ahmed

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In the vicinity of the red sea about 15 fungi species were isolated from oil contaminated sites. On the basis of aptitude to degrade the crude oil and DCPIP assay, two fungal isolates were selected amongst 15 oil degrading strains. Analysis of ITS-1, ITS-2 and amplicon pyrosequencing studies of fungal diversity revealed that these strains belong to Penicillium and Aspergillus species. Two strains that proved to be the most efficient in degrading crude oil was Aspergillus niger (54 %) and Penicillium commune (48 %) Subsequent to two weeks of cultivation in BHS medium the degradation rate were recorded by using spectrophotometer and GC-MS. Hence, it is cleared that these fungal strains has the capability of degradation and can be utilized for cleaning the Saudi Arabian environment.

Keywords: fungal strains, hydrocarbon contaminants, molecular identification, biodegradation, GC-MS

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Authors: Adel Omar Ashour, Paul S. Dyer

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Aspergillus nidulans can reproduce by asexual or sexual means, producing green conidiospores or red-purple ascospores respectively. The latter one is produced in dark-purple globose ‘cleistothecia’ which are surrounded by Hülle cells. The species has a homothallic (self fertile) sexual breeding system. Given the extra metabolic costs associated with sexual compared to asexual reproduction it would be predicted that ascospore production would confer evolutionary benefits. However, due to the homothallic breeding system there is very rarely any increased genetic variation in ascospore offspring and traditionally conidia and ascospores are considered to be equally environmental resistant. We therefore examined in detail whether conidia and ascospores might exhibit as yet undetected differences in spore viability when subjected to certain environmental stressors. Spores from two strains of A. nidulans (comprising wild-type and KU mutants) were exposed to various levels of temperature (50-70°C for 30 min) and UV (350 nm for 10-60 min) stress. Results of experiments will be presented, including comparison of ‘D’ (decimal point reduction) values of conidia versus ascospores of A. nidulans. We detected that under certain exposure levels ascospores have significantly increased resistance compared to conidia. The increased environmental resistance of ascospores might be a key factor explaining the persistence of sexuality in this homothallic species, and reasons for differential survival are suggested.

Keywords: Aspergillus nidulans, asexual reproduction, conidia, ascospores, cleistothecia, d-value

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Authors: H. Malainine, A. Amrouche, H. Benmehdi

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The aim of the present work was aimed at evaluating antifungal effect of crude esters and their corresponding FAMEs isolated from Citrullus colocynthis L., Linum usitatissimum L. and Nigella sativa L. seeds against two toxigenic fungal strains namely Aspergillus flavus and Aspergillus ochraceus. The results of the antifungal activity performed radial growth on solid medium (PDA; potatoes dextrose agar) showed that the crude esters and their corresponding FAMEs have exhibited against the two strains tested. Overall, FAMEs have provided an antifungal effect more efficient than that of crude esters. Inhibition of Aspergillus ochraceus has been labeled with percentages ranging from 13.33 to 26.61% by crude esters, While FAMEs inhibition was ranged between 27.33 to 41.13%. However, the inhibition observed against the Aspergillus flavus was varying from 14.68 to 18.59% by crude esters compared with the inhibition percentages ranging from 21.5 to 33.45% by the FAMEs. The antifungal potency of esters oils seeds of the studied plants may be an alternative for consideration by the authorities interested, due to serving the public health, in reducing the fungal enormous peril.

Keywords: Citrullus colocynthis L., Linum usitatissimum L., Nigella sativa L., FAMEs, antifungal activity, Aspergillus flavus, Aspergillus ochraceus

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Authors: Digby Wrede, Stephen Gray, Syed Hussainy

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Microalgae are extremely useful organisms but notoriously hard to harvest. The use of fungal pellets has been found to be an efficient way to flocculate numerous species of algae. However, only the flocculation of single species of algae has been investigated. Algae are generally found in complex communities in the environment comprising of numerous species of algae ranging from simple single cell algae such as Chlorella to more complex or communal algae such as Dictyosphaerium. This study investigated the flocculation capabilities of Aspergillus oryzae to flocculate four species of algae; Chlorella vulgaris, Scenedesmus quadricauda, Scenedesmus acuminatus and Dictyosphaerium sp., and the algal communities in four different types of domestic effluent from a lagoon-based treatment plant; primary effluent, secondary effluent and the high rate algal pond effluent at a natural and at a lowered pH level. Spectrophotometry was used to measure the changes in algal population. C. vulgaris, S. acuminatus and S. quadricauda, had over 90% reduction of algal in suspension after 24 hours. Dictyosphaerium sp. showed a little to no removal after 24 hours. The primary, secondary, and natural pH level HRAP had roughly a 50% removal after 24 hours, the HRAP which was grown at a lower pH level had over a 90% removal after 24 hours. pH has been shown previously to affect fungal flocculation. Fungal and algae pellets have been shown to be able to treat wastewater and can be converted to biofuels in a very similar method to how algae are currently converted. The mixture of both fungi and algae has also been shown to provide a higher yield of oils then separately and are able to more efficiently treat wastewater then algae or fungi by themselves.

Keywords: algae harvesting, Aspergillus oryzae, fungal flocculation, wastewater treatment

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Authors: Abderahim Ahmadou, Alfredo Napoli, Noel Durand, Didier Montet

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Biochar is a microporous and adsorbent solid carbon product obtained from the pyrolysis of various organic materials (biomass, agricultural waste). Biochar is distinguished from vegetable charcoal by its manufacture methods. Biochar is used as the amendment in soils to give them favorable characteristics under certain conditions, i.e., absorption of water and its release at low speed. Cashew nuts shell from Mali is usually discarded on land by local processors or burnt as a mean for waste management. The burning of this biomass poses serious socio-environmental problems including greenhouse gas emission and accumulation of tars and soot on houses closed to factories, leading to neighbor complaints. Some mycotoxins as aflatoxins are carcinogenic compounds resulting from the secondary metabolism of molds that develop on plants in the field and during their conservation. They are found at high level on some seeds and nuts in Africa. Ochratoxin A, member of mycotoxins, is produced by various species of Aspergillus and Penicillium. Human exposure to Ochratoxin A can occur through consumption of contaminated food products, particularly contaminated grain, as well as coffee, wine grapes. We showed that cashew shell biochars produced at 400, 600 and 800°C adsorbed aflatoxins (B1, B2, G1, G2) at 100% by filtration (rapid contact) as well as by stirring (long contact). The average percentage of adsorption of Ochratoxin A was 35% by filtration and 80% by stirring. The duration of the biochar-mycotoxin contact was a significant parameter. The effect of biochar was also tested on two strains of toxigenic molds: Aspergillus parasiticus (producers of Aflatoxins) and Aspergillus carbonarius (producers of Ochratoxins). The growth of the strain Aspergillus carbonarius was inhibited at up to 60% by the biochar at 600°C. An opposite effect to the inhibition was observed on Aspergillus parasiticus using the same biochar. In conclusion, we observed that biochar adsorbs mycotoxins: Aflatoxins and Ochratoxin A to different degrees; 100% adsorption of aflatoxins under all conditions (filtration and stirring) and adsorption of Ochratoxin A varied depending on the type of biochar and the experiment conditions (35% by filtration and 85% by stirring). The effects of biochar at 600 °C on the toxigenic molds: Aspergillus parasiticus and Aspergillus carbonarius, varied according to the experimental conditions and the strains. We observed an opposite effect on the growth with an inhibition of Aspergillus carbonarius up to 60% and a stimulated growth of Aspergillus parasiticus.

Keywords: biochar, cashew nut shell, mycotoxins, toxicogenic molds

Procedia PDF Downloads 139

Authors: J. Y. Ijato, A. Adewumi, H. O Yakubu, O. O. Olajide, B. O. Ojo, B. A. Adanikin

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Post-harvest fruit rot pathogens are one of the major factors that are responsible for food security challenges in developing countries like Nigeria. These pathogens also cause fruit food poisoning. Biocidal effects of ethanolic extracts of Khaya grandifoliola, Hyptis suaveolens, Zingiber officinale, Calophyllum inophyllum, Datura stramonium on the mycelia growth of fungal rot pathogens of pineapple fruit was investigated, the ethanolic extracts of these test plants exhibited high significant inhibitory effects on the rot pathogens, the highest ethanolic extract inhibition of Zingiber officinale was on Aspergillus flavus (38.40%) at 1.0g/ml while the least inhibitory effect was on Aspergillus fumigatus (23.10%) at 1.0g/ml, the highest ethanol extract inhibition of Datura stramonium was on Aspergillus tubingensis (24.00%) at 1.0g/ml while the least inhibitory effect was 10.00% on Colletotrichum fruticola at 1.0g/ml, the highest ethanol extract inhibition of Calophyllum inophyllum was on Trichoderma harzianum (18.50%) at 1.0g/ml while the least inhibitory effect was on Aspergillus flavus (15.00%) at 1.0g/ml, the highest ethanol extract inhibition of Hyptis suaveolens was on Aspergillus fumigatus (35.00%) at 1.0g/ml while the least inhibitory effect was on Aspergillus niger (20.00%) at 1.0g/ml, the highest ethanol extract inhibition of Khaya grandifoliola was on Aspergillus flavus (35.00%) at 1.00g/ml while the least inhibitory effect was on Aspergillus fumigates (22.00%) at 1.0g/ml, the antifungal capacity of these test plant extracts on rot causing fungi on pineapple fruit reveals the possibility of their use by farmers and fruit traders as alternative to chemical fungicide that portends great threat to human and environmental health.

Keywords: fruit rot, pathogens, plant extracts, pineapple, food poisoning

Procedia PDF Downloads 72

Authors: Suphalucksana, Wichai, Sangsoponjit Settasit, Soytong Kasem

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A study on the efficiency for enzyme production of fungi isolated from stomach of buffalo was conducted. The fungi were collected from 4 parts of stomach as rumen, reticulum, omasum and abomasums. The objective to study the efficiency of fungi from stomach of buffalo had effected to produced enzyme and to selected fungi for their ability to produced enzyme cellulase, hemicellulase and ligninase. Results shown that the fungi isolated from rumen were: Eupenicillium sp. (B-RU-01-1), Eupenicillium sp. (B-RU-02-3G), Rhyzopus stolonifer (B-RU-01-4) and Trichoderma sp. (B-RU-01-2). From the reticulum, Aspergillus glaucus (B-RET-02-3), Aspergillus orchraceus (B-RET-02-2) and Penicillium sp. (B-RET-02-4) were found. In the omasum Aspergillus fumigatus (B-OMA-01-1G), Eurotium sp. (B-OMA-01-4) and Rhizopus stolonifer (B-OMA-02-3) were isolated and in the abomasums Aspergillus flavas (B-ABO-02-3), Aspergillus fumigatus (B-ABO-02-1), Aspergillus niger (B-ABO-01-3G), Aspergillius terreus (B-ABO-02-4) and Mucor sp. (B-ABO-02-4G). Results of enzyme analysis revealed that cellulase was produced by isolated: Eupenicillium sp. (B-RU-02-3G), Eupenicillium sp. (B-RU-01-1), Penicillium sp. (B-RET-02-4), Aspergillius glaucus (B-RET-02-3), Aspergillus ochraceus (B-RET-02-2), Aspergillius fumigatus (B-OMA-01-1G), Eurotium sp. (B-OMA-01-4), Aspergillius flavus (B-ABO-02-3), Aspergillius fumigatus (B-ABO-02-1), Aspergillius niger (B-ABO-01-3G), Aspergillius terreus (B-ABO-02-4). Hemicellulase was produced Eupenicillium sp. (B-RU-02-3G), Eupenicillium sp. (B-RU-01-1), Rhizopus stolonifer (B-RU-01-4), Trichoderma sp. (B-RU-01-2), Aspergillius glaucus (B-RET-02-3), Aspergillus ochraceus (B-RET-02-2), Penicillium sp. (B-RET-02-4), Aspergillius fumigatus (B-OMA-01-1G), Eurotium sp. (B-OMA -01-4), Aspergillius flavus (B-ABO-02-3), Aspergillius fumigatus (B-ABO-02-1) Aspergillius niger (B-ABO-01-3G), Aspergillius terreus (B-ABO-02-4), Mucor sp. (B-ABO-02-4G). For the enzyme ligninase, two isolates were found to produced this enzyme namely : Trichoderma sp. (B-RU-01-2) and Mucor sp. (B-ABO-02-4G).

Keywords: enzyme production from fungi, enzyme production, fungi, agricultural technology

Procedia PDF Downloads 349

Authors: Walaa Al-Maghraby

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Endophytes are organisms that colonize internal plant tissues without causing apparent harm to their host. Almost all groups of microorganisms have been found in endophytic association with plants may be fungi. They stimulate the production of secondary metabolites with a diverse range of biological activities. Leptadenia pyrotechnica is a more or less leafless, erect shrub with straight stems which is highly distributed in Saudi Arabia. Four endophytes fungi were isolated from Leptadenia pyrotechnica and identified using 18S ribosomal RNA sequences, which revealed four fungi genuses, namely Aspergillus terreus; Aspergillus welwitschiae; Aspergillus fumigatus and Aspergillus flavus. In this present study, four endophytic fungi from Leptadenia pyrotechnica were used for obtaining crude aqueous and ethyl acetate extracts for antimicrobial screening against 6 human pathogens, the antibacterial tests presented satisfactory results, where the pathogenic bacteria were inhibited by the four extracts tested, except for Escherichia coli that was inhibited by all extracts except ethyl acetate extract of Aspergillus terreus. Analysis of variance showed that the extract produced by endophyte Leptadenia pyrotechnica was the most effective against all bacteria, either gram-negative or positive. However, the extract was not efficient against pathogenic fungi. Therefore, this study indicates that endophytes from medicinal plant Leptadenia pyrotechnica could be potential sources of antibacterial substances.

Keywords: antimicrobial activity, Aspergillus sp, endophytes, Leptadenia pyrotechnica

Procedia PDF Downloads 116

Authors: H. Necef, A. Benayad

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Fungi are becoming more and more important in our life. Therefore, as a start for the symposium on filamentous fungi in biotechnology a short survey of the role of fungi in biotechnology. Salin soils occupy about 7% of land area; they are characterized by unsuitable physical conditions for the growth of living organisms. However, researches showed that some microorganisms especially fungi are able to grow and adapt to such extreme conditions; it is due to their ability to develop different physiological mechanisms in their adaptation. This is the first study on the physiological and biological characteristics of El-Beida marsh. Nine soil samples were taken at different points in two steps, the first was in winter (low temperature), and the second was in summer (high temperature). The physicochemical analyses of the soil were conducted, then the isolation process was applied using two methods, direct method and dilution method (10-1, 10-2, 10-3, 10-4). Different species of fungi were identified belong to 21 genera in addition to 3 yeast species, Aspergillus showed the highest proportion by 43%, then Penicillium by 20% then Alternaria by 7%, in addition to various genera in different proportions. As for the sampling periods, it was observed that the spread of fungi in winter was higher than in summer with the proportion 75.47% and 24.53% respectively. Some halotolerant fungi have a biotechnological importance especially if the salinity of the medium is necessary for the fermentation, and if the halotolerance genes of the fungus will define, this will open the research to study and improve this property for the industrial important micro-organisms.

Keywords: salinity, identification, aspergillus oryzae, halotolerance, fungi

Procedia PDF Downloads 364

Authors: W. Lakhdari, B. Doumendji-Mitich, A. Dahliz, S. Doumendji, Y. Bouchikh, R. M'lik, H. Hammi, A. Soud

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This work was done in order to fight against Brachytrupes megacephalus, a major pest in the Algerian oasis and promote one aspect of biological control against it. He wears a hand on the isolation and identification of indigenous fungi on imagos of this insect harvested in the station of INRAA Touggourt and secondly, the study of the pathogenicity of these strains fungal on this orthoptère adults. The results obtained showed the presence of six different species of entomopathogenic fungi, it is: Aspergillus flavus, Fusarium sp, Beauveria bassiana, Penicillium sp, Metharizium anisopliae and Aspergillus Niger. The pathogenicity test using fungi Beauveria bassiana strains and Metharizium anisopliae. On adult of B. megacephalus highlights the effectiveness of these strains of predatory adults, with a mortality rate approaching 100% after 11 days.

Keywords: biological control, brachytrupes megacephalus, entomopathogenic fungi, Southeastern Algeria

Procedia PDF Downloads 385

Authors: Dina Helmy El-Ghonemy, Thanaa Hamed Ali

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The aim of this study was to purify and characterize a keratinolytic enzyme produced by Aspergillus sp. DHE7 cultured in basal medium containing chicken feather as substrate. The enzyme was purified through ammonium sulfate saturation of 60%, followed by gel filtration chromatography in Sephadex G-100, with a 16.4-purification fold and recovery yield of 52.2%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the purified enzyme is a monomeric enzyme with an apparent molecular mass of 30 kDa — the purified keratinase of Aspergillus sp. DHE7 exhibited activity in a broad range of pH (7- 9) and temperature (40℃-60℃) profiles with an optimal activity at pH eight and 50℃. The keratinolytic activity was inhibited by protease inhibitors such as phenylmethylsulfonyl fluoride and ethylenediaminetetraacetate, while no reduction of activity was detected by the addition of dimethyl sulfoxide (DMSO). Bivalent cations, Ca²⁺ and Mn²⁺, were able to greatly enhance the activity of keratinase by 125.7% and 194.8%, respectively, when used at one mM final concentration. On the other hand, Cu²⁺ and Hg²⁺ inhibited the enzyme activity, which might be indicative of essential vicinal sulfhydryl groups of the enzyme for productive catalysis. Furthermore, the purified keratinase showed significant stability and compatibility against the tested commercial detergents at 37ºC. Therefore, these results suggested that the purified keratinase from Aspergillus sp. DHE7 may have potential use in the detergent industry and should be of interest in the processing of poultry feather waste.

Keywords: Aspergillus sp. DHE7, biochemical characterization, keratinase, purification, waste management

Procedia PDF Downloads 90

Authors: Nora Laref, Bettache Guessas

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Preservation of foods mainly depends on delaying or inhibiting the growth of spoilage microorganisms, and antifungal activity of lactic acid bacteria is one of the technological properties researched. The antifungal activity was screened with overlay method of six strains of lactic acid bacteria (Lactobacillus plantarum LB54, LB52, LB51, LB20, LB24 Lactobacillus farciminis LB53) isolated from silage, camel milk and carrot against Aspergillus sp. Lactobacillus plantarum and farciminis inhibit spore germination and mycelia growth of Aspergillus sp., the production of antifungal compounds by these strains was detectable after 4h of incubation at 30°C and show total inhibition after 24h in liquid media, but in solid media showed a good inhibition after 96h of incubation, these compounds cause malformations in the thalle, conidiophore and conidia. These strains could be used as agents of biopreservation since have the ability to retard Aspergillus sp., growth in apricot juice with and without sugar conserved in refrigerator but not in bread.

Keywords: lactobacillus, antifungal substances, aspergillus, biopreservation

Procedia PDF Downloads 313

Authors: Qaiser Akram, Ahsan Naeem, Hafiz Muhammad Rizwan, Waqas Ahmad, Rubeena Yasmeen

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Aspergillus has good secretory potential for phytases. Morphologically and microscopically identified Aspergillus terreus (A. terreus) (n=20) were screened for phytase production and non-toxicity. Phytases produced by non-toxigenic A. terreus under optimum conditions were quantified. Phytases of highest producer A. terreus were evaluated for stability after exposure to temperature (35, 55, 75 and 95ºC) and pH (2, 4, 6 and 8). Effect of metal ions (Fe⁺³, Ba⁺², Ca⁺², Cu⁺², Mg⁺², Mn⁺², K⁺¹ and Na⁺¹) was assessed on phytase activity. Log reduction in phytase activity was calculated. The highest activity units of phytase produced by A. terreus were 271.49 ± 8.14 phytase unit / mL (FTU/ mL). The lowest reduction in phytase activity was 50.20 ± 7.36 (18.5%) and 68.22 ± 10.3 FTU/mL (25.13%) at 35ºC and pH 6, respectively for 15 minutes. The highest reduction 259 ± 0.84 (95.5%) and 211.99 ± 4.39 FTU/mL (78.1%) was recorded at 95ºC for 60 minutes and pH 2.0 for 45 minutes exposure, respectively. All metal ions negatively affected phytase activity. Phytase activity was inhibited minimum (45.32 ± 28.54 FTU/mL, 16.69%) by K⁺¹(1 mM) and maximum (231.48 ± 3.68 FTU/mL, 80.8%) by Cu⁺² (10 mM). It was concluded that A. terreus phytase stability and activity was dependent on physio-chemical factors.

Keywords: stability, phytase, aspergillus terreus, physio-chemical factors and metal ions

Procedia PDF Downloads 240

Authors: Sidra Pervez, Afsheen Aman, Shah Ali Ul Qader

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The importance of attaining an optimum performance of an enzyme is often a question of devising an effective method for its immobilization. Cross-linked enzyme aggregate (CLEAs) is a new approach for immobilization of enzymes using carrier free strategy. This method is exquisitely simple (involving precipitation of the enzyme from aqueous buffer followed by cross-linking of the resulting physical aggregates of enzyme molecules) and amenable to rapid optimization. Among many industrial enzymes, amyloglucosidase is an important amylolytic enzyme that hydrolyzes alpha (1→4) and alpha (1→6) glycosidic bonds in starch molecule and produce glucose as a sole end product. Glucose liberated by amyloglucosidase can be used for the production of ethanol and glucose syrups. Besides this amyloglucosidase can be widely used in various food and pharmaceuticals industries. For production of amyloglucosidase on commercial scale, filamentous fungi of genera Aspergillus are mostly used because they secrete large amount of enzymes extracellularly. The current investigation was based on isolation and identification of filamentous fungi from genus Aspergillus for the production of amyloglucosidase in submerged fermentation and optimization of cultivation parameters for starch saccharification. Natural isolates were identified as Aspergillus niger KIBGE-IB36, Aspergillus fumigatus KIBGE-IB33, Aspergillus flavus KIBGE-IB34 and Aspergillus terreus KIBGE-IB35 on taxonomical basis and 18S rDNA analysis and their sequence were submitted to GenBank. Among them, Aspergillus fumigatus KIBGE-IB33 was selected on the basis of maximum enzyme production. After optimization of fermentation conditions enzyme was immobilized on CLEA. Different parameters were optimized for maximum immobilization of amyloglucosidase. Data of enzyme stability (thermal and Storage) and reusability suggested the applicability of immobilized amyloglucosidase for continuous saccharification of starch in industrial processes.

Keywords: aspergillus, immobilization, industrial processes, starch saccharification

Procedia PDF Downloads 465