22 results on '"Palombo, Enzo A."'
Search Results
2. Exploring the anti-diabetic potential of Australian Aboriginal and Indian Ayurvedic plant extracts using cell-based assays.
- Author
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Gulati, Vandana, Gulati, Pankaj, Harding, Ian H., and Palombo, Enzo A.
- Subjects
TYPE 2 diabetes prevention ,GLUCOSE metabolism ,ANALYSIS of variance ,ANTINEOPLASTIC agents ,CELL culture ,CELL lines ,CELL surface antigens ,DOSE-effect relationship in pharmacology ,FAT cells ,HYPOGLYCEMIC agents ,IMMUNODIAGNOSIS ,INDIGENOUS peoples ,AYURVEDIC medicine ,STATISTICS ,PLANT extracts ,DATA analysis ,DATA analysis software ,DESCRIPTIVE statistics - Abstract
Background: Plant-derived compounds have been used clinically to treat type 2 diabetes for many years as they also exert additional beneficial effects on various other disorders. The aim of the present study was to investigate the possible mechanism of anti-diabetic activity of twelve (seven Australian Aboriginal and five Indian Ayurvedic) plant extracts. Methods: The ethanolic plant extracts were investigated for glucose uptake and adipogenesis in murine 3T3-L1 adipocytes. Cytotoxicity studies were also carried out against two cancerous cell lines, HeLa and A549, to investigate the potential anti-cancer activities of the extracts. Results: Of the seven Australian Aboriginal plant extracts tested, only Acacia kempeana and Santalum spicatum stimulated glucose uptake in adipocytes. Among the five Indian Ayurvedic plant extracts, only Curculigo orchioides enhanced glucose uptake. With respect to adipogenesis, the Australian plants Acacia tetragonophylla, Beyeria leshnaultii and Euphorbia drumondii and the Indian plants Pterocarpus marsupium, Andrographis paniculata and Curculigo orchioides reduced lipid accumulation in differentiated adipocytes. Extracts of Acacia kempeana and Acacia tetragonophylla showed potent and specific activity against HeLa cells. Conclusions: The findings suggest that the plant extracts exert their anti-diabetic properties by different mechanisms, including the stimulation of glucose uptake in adipocytes, inhibition of adipogenesis or both. Apart from their anti-diabetic activities, some of the extracts have potential for the development of chemotherapeutic agents for the treatment of cervical cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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3. Optimization of protease production by endophytic fungus, Alternaria alternata, isolated from an Australian native plant.
- Author
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Zaferanloo, Bita, Quang, Trung, Daumoo, Smita, Ghorbani, Mahmood, Mahon, Peter, and Palombo, Enzo
- Subjects
PROTEOLYTIC enzymes ,ENDOPHYTIC fungi ,ALTERNARIA alternata ,NATIVE plants ,DAIRY industry - Abstract
Endophytes are recognised as potential sources of novel secondary metabolites, including enzymes and drugs, with applications in medicine, agriculture and industry. There is a growing need for new enzymes, including proteases, for use in industry that can function under a variety of conditions. In this study, three fungal endophytes ( Alternaria alternata, Phoma herbarum and an unclassified fungus), were isolated from the Australian native plant, Eremophilia longifolia, and assessed for production of proteases. The lyophilised growth media obtained after fungal fermentation were analysed for protease production using enzyme activity assays. Protease production was optimised by assessing the effects of temperature, pH, carbon source and nitrogen source on activity. A. alternata showed the greatest protease activity in a wide range of pH (3-9). The broadest activity between 9 and 50 °C was observed at pH 7, suggesting a neutral protease. Overall, the optimum conditions were 37 °C and pH 7 with a maximum specific activity value of 69.86 BAEE units/mg. The characteristics demonstrated by this fungal endophyte showed that it is a potential source of an enzyme with particular application in the dairy industry. However, further studies of the tolerance to higher temperatures and pH will indicate whether the enzyme is suitable to such applications. [ABSTRACT FROM AUTHOR]
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- 2014
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4. Identification of a copper-responsive promoter and development of a copper biosensor in the soil bacterium Achromobacter sp. AO22.
- Author
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Ng, Shee, Palombo, Enzo, and Bhave, Mrinal
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COPPER & the environment , *HEAVY metals , *ACHROMOBACTER , *BIOAVAILABILITY - Abstract
A number of human activities result in environmental contamination with copper compounds that can cause severe detrimental effects on the ecosystem as well as human health. The physico-chemical methods of metal detection have limitations such as inability to distinguish between total versus bio-available metals and differences in metal uptake in different organisms. The heavy metal resistance-encoding genetic systems of certain bacteria provide critical tools for development of biosensors for these purposes. This study reports a copper biosensor utilizing the cop operon of the heavy metal resistant bacterial isolate, Achromobacter sp. AO22, isolated from a contaminated site in Australia. A section located between the divergently transcribed putative response regulator gene copR and multicopper oxidase gene copA that included a palindromic cop box was identified as a copper-responsive promoter using a lacZ reporter construct, pCOPRP, in E. coli. The expression was found to be enhanced by inclusion of copR. Another engineered strain, AO22(pCOPRP), showed stronger induction, and the lacZ expression in both backgrounds was enhanced significantly (250-400 fold) by copper but minimally by other metals. The construct in Achromobacter sp. AO22 thus has a high potential as biosensor for detecting copper bioavailability (hence potential toxicity) in a soil bacterial background, while the construct in E. coli is ideal for laboratory-based testing. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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5. Mercury in Vaccines from the Australian Childhood Immunization Program Schedule.
- Author
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Austin, David W., Shandley, Kerrie A., and Palombo, Enzo A.
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MERCURY ,VACCINES ,PUBLIC health ,HUMAN services ,SAFETY ,VACCINATION ,IMMUNIZATION of children ,HEALTH - Abstract
Despite the removal of the mercury (Hg)-based preservative thimerosal from vaccines listed on the Australian Immunization Program Schedule for children, concerns remain among some researchers and parents for the safety of the present schedule, in part due to a fear of residual trace levels of Hg. The purpose of this study was to independently assess childhood vaccines for the presence of Hg. Eight vaccines administered to children under the age of 5 yr were assessed for Hg content via a DMA-80 direct mercury analyzer. Seven of the 8 vaccines contained no detectable levels of Hg (less than 1 ppb); however, 1 vaccine (Infanrix hexa) tested positive for Hg at 10 ppb. The result was confirmed and validated by retesting the original sample. Follow-up testing was conducted on three additional samples of Infanrix hexa (one from the same production lot and two from a different lot). All three tested positive for Hg (average of 9.7 ppb). Although the levels of Hg detected are substantially lower than any established exposure safety limits, the results of this study reveal that inaccuracies exist in public health messages, professional communications, and official documentation regarding Hg content in at least one childhood vaccine. In the interests of public health, it is incumbent on vaccine manufacturers and responsible agencies such as the Therapeutic Goods Administration and the Federal Department of Health and Ageing to address this issue as a matter of urgency. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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6. Characterisation of G8 human rotaviruses in Australian children with gastroenteritis
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Swiatek, Dayna L., Palombo, Enzo A., Lee, Alvin, Coventry, Michael J., Britz, Margaret L., and Kirkwood, Carl D.
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ROTAVIRUSES , *GASTROENTERITIS in children , *POLYACRYLAMIDE gel electrophoresis , *ENZYME-linked immunosorbent assay , *RNA , *NUCLEOTIDES , *AMINO acids - Abstract
Abstract: This study describes the characterisation of G8 rotavirus strains isolated from humans with acute gastroenteritis. Six G8 strains were detected in Australia between 2002 and 2008. Four were G8P[14] strains, one was G8P[8]+[14] and one was G8 P non-typeable. By polyacrylamide gel electrophoresis and enzyme immunoassay analysis, four G8 strains with visible RNA exhibited a long electropherotype and five G8 strains displayed subgroup I specificity. Sequence analysis of the VP7 gene indicated that the G8 strains exhibited the highest nucleotide and amino acid identity with a G8P[11] bovine rotavirus strain detected in Japan. VP4 sequence data of one G8P[14] strain revealed that the closest identity was to another human-bovine-like strain detected in Australia, MG6, a G6P[14] strain. The identification of G8 strains causing disease further extends the number of G8P[14] strains detected in Australian children, and indicates that there is a rare but ongoing presence of uncommon human strains within the community in Australia. [Copyright &y& Elsevier]
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- 2010
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7. Rapid identification and source-tracking of Listeria monocytogenes using MALDI-TOF mass spectrometry.
- Author
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Jadhav, Snehal, Gulati, Vandana, Fox, Edward M., Karpe, Avinash, Beale, David J., Sevior, Danielle, Bhave, Mrinal, and Palombo, Enzo A.
- Subjects
- *
LISTERIA monocytogenes , *FOOD preservation , *FOOD industry , *MASS spectrometry , *BIOMARKERS , *PUBLIC health - Abstract
Listeria monocytogenes is an important foodborne pathogen responsible for the sometimes fatal disease listeriosis. Public health concerns and stringent regulations associated with the presence of this pathogen in food and food processing environments underline the need for rapid and reliable detection and subtyping techniques. In the current study, the application of matrix assisted laser desorption/ionisation–time-of-flight mass spectrometry (MALDI-TOF MS) as a single identification and source-tracking tool for a collection of L. monocytogenes isolates, obtained predominantly from dairy sources within Australia, was explored. The isolates were cultured on different growth media and analysed using MALDI-TOF MS at two incubation times (24 and 48 h). Whilst reliable genus-level identification was achieved from most media, identification at the species level was found to be dependent on culture conditions. Successful speciation was highest for isolates cultured on the chromogenic Agar Listeria Ottaviani Agosti agar (ALOA, 91% of isolates) and non-selective horse blood agar (HBA, 89%) for 24 h. Chemometric statistical analysis of the MALDI-TOF MS data enabled source-tracking of L. monocytogenes isolates obtained from four different dairy sources. Strain-level discrimination was also observed to be influenced by culture conditions. In addition, t -test/analysis of variance (ANOVA) was used to identify potential biomarker peaks that differentiated the isolates according to their source of isolation. Source-tracking using MALDI-TOF MS was compared and correlated with the gold standard pulsed-field gel electrophoresis (PFGE) technique. The discriminatory index and the congruence between both techniques were compared using the Simpsons Diversity Index and adjusted Rand and Wallace coefficients. Overall, MALDI-TOF MS based source-tracking (using data obtained by culturing the isolates on HBA) and PFGE demonstrated good congruence with a Wallace coefficient of 0.71 and comparable discriminatory indices of 0.89 and 0.86, respectively. MALDI-TOF MS thus represents a rapid and cost-effective source-tracking technique for L. monocytogenes . [ABSTRACT FROM AUTHOR]
- Published
- 2015
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8. Antibacterial compounds from Planchonia careya leaf extracts
- Author
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McRae, Jacqui M., Yang, Qi, Crawford, Russell J., and Palombo, Enzo A.
- Subjects
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LINOLEIC acid , *ANTIBACTERIAL agents , *ETHNIC relations - Abstract
Abstract: Aim of the study: The leaves of Planchonia careya (F. Muell.) R. Knuth (Lecythidaceae) have been traditionally implemented in the treatment of wounds by the indigenous people of northern Australia, although the compounds responsible for the medicinal properties have not been identified. In this study, antibacterial compounds from the leaf extracts were isolated and characterized, and the biological activity of each compound was assessed. Materials and methods: Compounds were isolated from the leaf extracts using HPLC-piloted activity-guided fractionation. The minimum inhibitory concentrations (MICs) were assessed with plate-hole diffusion assays, and the cytotoxicity was determined with MTT assays using monkey kidney epithelial (MA104) cells. Results: Six known compounds were isolated from the leaf extracts and were identified as 1, (+)-gallocatechin; 2, gallocatechin-(4α→8)-gallocatechin; 3, 9(S)-hydroxy-10E,12Z-octadecadienoic acid (α-dimorphecolic acid); 4, 2α,3β,24-trihydroxyolean-12-en-28-oic acid (hyptatic acid-A); 5, 3β-O-cis-p-coumaroyltormentic acid; and 6, 3β-O-trans-p-coumaroyltormentic acid. Compounds 5 and 6 were weakly selective for vancomycin-resistant Enterococcus (VRE) compared with eukaryotic cells, with an MIC of 59.4μg/mL and a 50% inhibitory concentration (IC50) of 72.0μg/mL for MA104 cells. Conclusions: The isolation of six antibacterial compounds from the leaves of Planchonia careya validates the use of this species as a topical wound-healing remedy. [Copyright &y& Elsevier]
- Published
- 2008
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9. Prevalence and Characteristics of Bacillus cereus Group Isolated from Raw and Pasteurised Milk.
- Author
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Radmehr B, Zaferanloo B, Tran T, Beale DJ, and Palombo EA
- Subjects
- Animals, Australia, Bacillus cereus genetics, Enterotoxins, Food Microbiology, Prevalence, Proteomics, Bacillus, Milk
- Abstract
The elimination of spore-forming bacteria is not guaranteed by current pasteurisation processes and is a challenging problem for the dairy industry. Given that Bacillus cereus sensu lato (B. cereus group) is an important foodborne pathogen and spoiler in the dairy industry, this study aimed at evaluating the prevalence and characteristics of B. cereus group in raw and pasteurised milk samples collected in Victoria, Australia. Isolated B. cereus group were tested for antimicrobial susceptibility, biofilm formation and virulence properties. Genetic diversity was assessed using ERIC-PCR. Proteomic profiling using MALDI-TOF MS and chemical profiling using Fourier-transform infrared (FTIR) spectroscopy were also applied for clustering of the isolates. Results showed 42.3% of milk samples contained B. cereus group, with a higher contamination level for pasteurised milk. Virulence studies identified genes nheA, nheB, hblA and nheC in most isolates and cyk gene in 46% of all isolates. Antimicrobial susceptibility testing showed a high prevalence of resistance towards ampicillin, ceftriaxone and penicillin. The biofilm-forming capacity of our isolates showed that most (53.7%) had the ability to form a biofilm. Genetic profiling using ERIC-PCR placed most B. cereus group isolates from pasteurised milk in the same cluster, indicating that they probably originated from a similar source. Raw milk isolates showed greater diversity indicating various sources. FTIR spectroscopy showed high agreement with genetic profiling. In contrast, low agreement between proteomic (MALDI-TOF MS) and genetic typing was observed. The present study showed that the FTIR spectroscopy could be adopted as a rapid tool for the typing of B. cereus group. Overall, the virulence and antimicrobial resistance characteristics, together with the ability of isolates to produce biofilm, indicate the importance of B. cereus group in the Australian dairy industry.
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- 2020
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10. Looking for insight: The role of parasite tester opinions in farm management.
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Hedley N, Richards DG, and Palombo EA
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- Animal Husbandry economics, Animal Husbandry methods, Animals, Anthelmintics economics, Anthelmintics therapeutic use, Australia, Farmers psychology, Farms, Gastrointestinal Diseases diagnosis, Gastrointestinal Diseases parasitology, Nematode Infections diagnosis, Surveys and Questionnaires, Animal Technicians psychology, Attitude, Gastrointestinal Diseases veterinary, Nematode Infections veterinary, Parasite Egg Count psychology, Parasite Egg Count veterinary
- Abstract
Gastrointestinal nematode (GIN) infections cause millions of dollars of economic loss annually. Increasing cases of anthelmintic resistance have resulted in calls for restricted drug use and implementation of sustainable management practices to slow the rate of resistance. The limited uptake of available management systems and advice has sparked multiple surveys into the psychology and behaviours preventing uptake. These surveys have looked mainly at the farmers, the majority of whom have reported they rely on the advice of their local veterinarian or suppliers for treatment and management. However, there is little research into the psychology of veterinarians and people performing animal health testing on this topic. In the current study, a short survey of people performing faecal egg counts on animals was conducted. The survey focused on identifying areas for improving diagnosis to encourage uptake, and found other areas of interest worth further investigation. Respondents most frequently named manual labour as the main contributor to the cost of testing (65% of respondents) with analysis (42%) and sample preparation (32%) being the main contributors to time. In the survey comments, there was little consistency or commonality in the issues raised. The disparity between onsite and laboratory testers is an area worth investigation, particularly into how to co-ordinate behaviour and advice between proactive farmers and parasitology/veterinary services. Further investigation could provide better insight into how to encourage and maintain sustainable practices on farms., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
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11. Metabolites of endophytic fungi from Australian native plants as potential anticancer agents.
- Author
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Zaferanloo B, Pepper SA, Coulthard SA, Redfern CPF, and Palombo EA
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- Antineoplastic Agents metabolism, Australia, Cell Line, Tumor, Cell Survival drug effects, Endophytes genetics, Endophytes isolation & purification, Endophytes metabolism, Fungi classification, Fungi isolation & purification, Fungi metabolism, Humans, Lactones metabolism, Phylogeny, Antineoplastic Agents pharmacology, Endophytes chemistry, Eremophila Plant microbiology, Fungi chemistry, Lactones pharmacology
- Abstract
Interest in endophytes as natural sources for new medicines was inspired by the discovery of paclitaxel-producing endophytic fungi. This study investigated the anti-cancer activity of extracts of endophytes isolated from two Australian plants, Eremophila longifolia (EL) and Eremophila maculata (EM). Endophytes were isolated from surface-sterilised leaf tissue, grown as pure cultures and identified by sequencing of Internal Transcribed Spacer (ITS) regions of the ribosomal DNA. To determine cytotoxicity, two leukaemic (MOLT-4, T-cell leukaemia; PreB-697, Pre-B leukaemia), a lung cancer cell line (A549) and a normal human fibroblast cell line were treated with endophyte extracts to assess cytotoxicity in relation to alternariol monomethyl ether (AME) and alternariol (AOH). Endophyte extracts that showed cell cytotoxicity were analysed by UV-HPLC to determine the metabolites. Pure AME and AOH, three extracts form Alternaria sp. (EM-6, EM-7 and EM-9) and one from Preussia minima (EL-14) were cytotoxic to the cancer cell lines. All cytotoxic endophytes contained AME and AOH, the most cytotoxic endophyte EM-6 also contained two unique peaks. These data indicate that these four endophyte extracts may have anti-cancer properties due to the presence of AME and AOH; however, the unique compounds found in the EM-6 extract may be exclusively cytotoxic and warrant further investigation.
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- 2018
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12. Antibacterial Nerol Cinnamates from the Australian Plant Eremophila longifolia.
- Author
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Galappathie S, Edwards DJ, Elliott AG, Cooper MA, Palombo EA, Butler MS, and Mahon PJ
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- Acyclic Monoterpenes, Anti-Bacterial Agents chemistry, Anti-Infective Agents chemistry, Australia, Cinnamates chemistry, Coumaric Acids chemistry, Gram-Positive Bacteria drug effects, Hep G2 Cells, Humans, Microbial Sensitivity Tests, Molecular Structure, Plant Leaves chemistry, Terpenes chemistry, Terpenes isolation & purification, Terpenes pharmacology, Anti-Bacterial Agents isolation & purification, Anti-Bacterial Agents pharmacology, Anti-Infective Agents isolation & purification, Anti-Infective Agents pharmacology, Cinnamates isolation & purification, Cinnamates pharmacology, Coumaric Acids isolation & purification, Coumaric Acids pharmacology, Eremophila Plant chemistry, Plants, Medicinal chemistry
- Abstract
Two new antimicrobial agents, neryl ferulate (1) and neryl p-coumarate (2), were identified using bioassay-guided isolation from the leaves of Eremophila longifolia, which is a medicinal plant used by some Australian Aboriginal communities. Although gradual autoxidation of the nerol subunit hindered the initial attempts to purify and characterize 1 and 2, it was found that the autoxidation could be stopped through storage under argon at -20 °C. Biological evaluation showed that neryl ferulate (1) had moderate activity against various Gram-positive bacteria, while neryl p-coumarate (2) was active only against Enterococcus faecium.
- Published
- 2017
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13. Untargeted Metabolic Profiling of Winery-Derived Biomass Waste Degradation by Penicillium chrysogenum.
- Author
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Karpe AV, Beale DJ, Godhani NB, Morrison PD, Harding IH, and Palombo EA
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- Acetyl Coenzyme A metabolism, Australia, Culture Media, Conditioned chemistry, Fermentation, Fruit metabolism, Fruit microbiology, Gas Chromatography-Mass Spectrometry, Glyceric Acids metabolism, Metabolic Networks and Pathways, Vitis, Biomass, Industrial Waste, Metabolome, Penicillium chrysogenum metabolism, Wine
- Abstract
Winery-derived biomass waste was degraded by Penicillium chrysogenum under solid state fermentation over 8 days in a (2)H2O-supplemented medium. Multivariate statistical analysis of the gas chromatography-mass spectrometry (GC-MS) data resulted in the identification of 94 significant metabolites, within 28 different metabolic pathways. The majority of biomass sugars were utilized by day 4 to yield products such as sugars, fatty acids, isoprenoids, and amino acids. The fungus was observed to metabolize xylose to xylitol, an intermediate of ethanol production. However, enzyme inhibition and autolysis were observed from day 6, indicating 5 days as the optimal time for fermentation. P. chrysogenum displayed metabolism of pentoses (to alcohols) and degraded tannins and lignins, properties that are lacking in other biomass-degrading ascomycetes. Rapid fermentation (3-5 days) may not only increase the pentose metabolizing efficiency but also increase the yield of medicinally important metabolites, such as syringate.
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- 2015
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14. Untargeted metabolic profiling of Vitis vinifera during fungal degradation.
- Author
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Karpe AV, Beale DJ, Morrison PD, Harding IH, and Palombo EA
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- Aspergillus niger metabolism, Australia, Endo-1,4-beta Xylanases metabolism, Gas Chromatography-Mass Spectrometry, Lignin metabolism, Penicillium metabolism, Penicillium chrysogenum metabolism, Pentoses metabolism, Polysaccharides metabolism, Saccharomyces cerevisiae metabolism, Trichoderma metabolism, beta-Glucosidase metabolism, Biomass, Metabolome, Vitis metabolism, Vitis microbiology
- Abstract
This paper illustrates the application of an untargeted metabolic profiling analysis of winery-derived biomass degraded using four filamentous fungi (Trichoderma harzianum, Aspergillus niger, Penicillium chrysogenum and P. citrinum) and a yeast (Saccharomyces cerevisiae). Analysis of the metabolome resulted in the identification of 233 significant peak features [P < 0.05; fold change (FC) > 2 and signal-to-noise ratio >50] using gas chromatography-mass spectrometry followed by statistical chemometric analysis. Furthermore, A. niger and P. chrysogenum produced higher biomass degradation due to considerable β-glucosidase and xylanase activities. The major metabolites generated during fungal degradation which differentiated the metabolic profiles of fungi included sugars, sugar acids, organic acids and fatty acids. Although, P. chrysogenum could degrade hemicelluloses due to its high β-glucosidase and xylanase activities, it could not utilize the resultant pentoses, which A. niger and P. citrinum could do efficiently, thus indicating a need of mixed fungal culture to improve the biomass degradation. Saccharomyces cerevisiae, a non-cellulose degrader, exhibited sugar accumulation during the fermentation. Penicillium chrysogenum was observed to degrade about 2% lignin, a property not observed in other fungi. This study emphasized the differential fungal metabolic behavior and demonstrated the potential of metabolomics in optimizing degradation or manipulating pathways to increase yields of products of interest., (© FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2015
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15. Endophytes from an Australian native plant are a promising source of industrially useful enzymes.
- Author
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Zaferanloo B, Virkar A, Mahon PJ, and Palombo EA
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- Australia, Endophytes classification, Endophytes genetics, Enzyme Stability, Fungal Proteins chemistry, Fungal Proteins genetics, Fungi classification, Fungi genetics, Industrial Microbiology, Kinetics, Molecular Sequence Data, Phylogeny, Plant Leaves microbiology, Endophytes enzymology, Endophytes isolation & purification, Eremophila Plant microbiology, Fungal Proteins metabolism, Fungi enzymology, Fungi isolation & purification
- Abstract
Endophytes are microorganisms that live within plant tissues that are potential sources of novel bioactive compounds, including enzymes. We have identified endophytes of the Australian native plant Eremophilia longifolia which were screened for the production of industrially useful enzymes. Seventeen fungal endophytes were isolated from the leaves of E. longifolia and enzyme production was investigated within a range of pH (3.5, 5.5, 7 and 9) and temperatures (9, 25, 37 and 50 °C). Amylase was the most common enzyme encountered with numerous isolates showing production throughout the temperature and pH ranges. Protease production was also seen over the conditions tested but was more dominant at lower pH and temperature. Activity was not observed for other enzymes including ligninase, xylanase and cellobiohydrolase. Enzymes from isolates of Preussia minima, Alternaria sp. and an unclassified fungus, which showed highest activity in screening assays, were investigated further. Enzyme production was verified by zymography and the amylase activity of P. minima was found to be significantly greater than that of Aspergillus oryzae particularly in alkaline conditions and low temperature which are desirable properties for the detergent industry. This work shows that enzymes with potential use in industry can be readily identified in fungal endophytes.
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- 2013
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16. A pilot study of the microbiological quality of culturally diverse, ready-to-eat foods from selected retail establishments in Melbourne, Australia.
- Author
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McLean SK, Dunn LA, and Palombo EA
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- Asia ethnology, Australia, Bacillus cereus growth & development, Colony Count, Microbial, Diet adverse effects, Escherichia coli growth & development, Fast Foods adverse effects, Fast Foods parasitology, Food Handling legislation & jurisprudence, Food Parasitology, Foodborne Diseases prevention & control, Gram-Negative Bacteria growth & development, Gram-Positive Bacteria growth & development, Pilot Projects, Quality Control, Salmonella typhimurium growth & development, Staphylococcus aureus growth & development, Yeasts isolation & purification, Diet ethnology, Fast Foods microbiology, Food Microbiology, Gram-Negative Bacteria isolation & purification, Gram-Positive Bacteria isolation & purification
- Abstract
In recent years, there has been an increasing number of foodborne outbreaks linked to the consumption of culturally diverse foods. This appears to be because of the increasing quantity of culturally diverse foods available and a preference to store these foods, some of which are considered potentially hazardous, at ambient temperature. This practice may contravene temperature requirements defined by the Food Standards Code. A lack of understanding of the hazardous nature of some culturally prepared foods also poses difficulties in applying the Australian food safety legislation by regulators. This pilot study examined the normal microbiota of four culturally diverse foods: nem chua, che dau trang, kueh talam, and bánh tét nhân man, which are traditionally stored and consumed at ambient temperature. Challenge testing was conducted to investigate the ability of these foods to support the growth of foodborne bacterial pathogens. Two of the products (kueh talam and che dau) were found to be microbiologically unsatisfactory because of the high standard plate counts. Challenge testing indicated that kueh talam, che dau, and bánh tét nhân man were able to support the growth of Bacillus cereus, Escherichia coli, Staphylococcus aureus, and Salmonella (1-2 log increases over 6 hours at 25 degrees C), suggesting that these foods may require temperature control during storage. However, nem chua was unable to support the growth of test bacteria, probably because of its acidic nature (pH 4.5), suggesting that ambient storage of this food may be safe. This study provided some preliminary evidence to support the need for further sampling and challenge testing of these products.
- Published
- 2010
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17. Are human P[14] rotavirus strains the result of interspecies transmissions from sheep or other ungulates that belong to the mammalian order Artiodactyla?
- Author
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Matthijnssens J, Potgieter CA, Ciarlet M, Parreño V, Martella V, Bányai K, Garaicoechea L, Palombo EA, Novo L, Zeller M, Arista S, Gerna G, Rahman M, and Van Ranst M
- Subjects
- Australia, Child, Preschool, Europe, Evolution, Molecular, Humans, Infant, Molecular Sequence Data, Phylogeny, Sequence Analysis, DNA, Sequence Homology, Gastroenteritis virology, RNA, Viral genetics, Rotavirus genetics, Rotavirus isolation & purification, Rotavirus Infections virology
- Abstract
A limited number of human G6P[14] rotavirus strains that cause gastroenteritis in humans have been isolated in Europe and Australia. The complete genome sequences were determined for five of these human strains--B10925-97 (isolated in Belgium in 1997), 111/05-27 (Italy, 2005), PA169 (Italy, 1987), MG6 (Australia, 1993), and Hun5 (Hungary, 1997)--and their genetic relatedness to animal rotavirus strains was evaluated by sequencing the complete genome of the sheep rotavirus OVR762 (G8P[14]; Spain, 2002), the guanaco (Lama guanicoe) rotavirus strains Arg/Chubut/99 and Arg/Río Negro/98 (G8P[14] and G8P[1], respectively; Argentina, 1999 and 1998), the sable antelope strain RC-18/08 (G6P[14]; South Africa, 2008), and the bovine rotavirus strain Arg/B383/98 (G15P[11]; Argentina, 1998). These analyses revealed an overall consensus genomic constellation (G6/G8)-P[14]-I2-(R2/R5)-C2-M2-(A3/A11)-N2-T6-(E2/E12)-H3, together with a few gene reassortments, and the phylogenetic analyses confirmed that the P[14] human strains evaluated in this study were closely related to rotavirus strains isolated from sheep, cattle, goats, guanacos, and antelopes and to rabbits (albeit to a lesser extent), suggesting that one (or more) of these animal species might be the source of the human G6P[14] strains. The main feature of the genotype and phylogenetic analyses was the close overall genomic relatedness between the five human G6P[14] rotavirus strains and the ovine and antelope rotavirus strains. Taken together, these data strongly suggest a common origin for the human P[14] strains and those of the even-toed ungulates belonging to the mammalian order Artiodactyla, with sheep probably playing a key role in the interspecies transmission responsible for the introduction of P[14] rotavirus strains into the human population.
- Published
- 2009
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18. Genetic variation of NSP1 and NSP4 genes among serotype G9 rotaviruses causing hospitalization of children in Melbourne, Australia, 1997-2002.
- Author
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Shah K, Kirkwood CD, Bhave M, and Palombo EA
- Subjects
- Amino Acid Sequence, Australia epidemiology, Humans, Molecular Sequence Data, Phylogeny, Genetic Variation, Glycoproteins genetics, Rotavirus Infections epidemiology, Rotavirus Infections virology, Toxins, Biological genetics, Viral Nonstructural Proteins genetics
- Abstract
Serotype G9 rotaviruses have emerged as one of the leading causes of gastroenteritis in children worldwide. We examined 29 representative G9 rotavirus isolates from a 6-year collection (1997-2002) and determined the level of variation in genes encoding non-structural proteins, NSP1 and NSP4. Northern hybridization analysis with a whole genome probe derived from the prototype G9 strain, F45, revealed that the NSP1 gene (gene 5) of two isolates (R1 and R14) did not exhibit significant homology. Complementary DNA probes of R1 and R14 genes 5 were used in Northern blot hybridization and indicated the presence of at least two gene 5 alleles among Melbourne G9 rotaviruses. Nucleotide sequence analysis revealed that isolates carrying the R14 gene 5 shared 94-98% sequence identities with one another, while sequence identity to R1 was 78%. Surprisingly, R1 displayed 96% nucleotide identity with the prototype serotype G1 strain, Wa. The detection of different alleles of NSP1 genes prompted us to investigate the level of variation in another non-structural protein, NSP4, a multifunctional protein and the first viral-encoded enterotoxin. Phylogenetic analysis indicated that while all isolates clustered into one group containing the Wa NSP4 allele (genotype 1), isolate R1 was most closely related to Wa. This study reveals new information about the diversity of non-structural proteins of G9 rotaviruses., (2006 Wiley-Liss, Inc.)
- Published
- 2006
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19. Characterisation of antibacterial Australian medicinal plant extracts by investigation of the mechanism of action and the effect of interfering substances.
- Author
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Tomlinson S and Palombo EA
- Subjects
- Animals, Anti-Bacterial Agents, Australia, Cell Membrane drug effects, Cell Membrane metabolism, Microbial Sensitivity Tests, Milk, Permeability, Plant Extracts metabolism, Saccharomyces cerevisiae, Sodium Chloride metabolism, Staphylococcus aureus metabolism, Eremophila Plant, Plant Extracts pharmacology, Plants, Medicinal metabolism, Staphylococcus aureus drug effects
- Abstract
Propidium iodide (PI) uptake and salt tolerance assays were used to investigate the mechanism of antibacterial action of an extract of the leaves of Eremophila duttonii, a traditional Australian medicinal plant previously shown to have potent bactericidal activity against Gram positive bacteria. The extract compromised the integrity of the cytoplasmic membrane of Staphylococcus aureus , leading to increased membrane permeability (indicated by uptake of PI) and a decrease in ability to exclude NaCl. The bactericidal action of the E. duttonii extract was concluded to be due to its membrane-active properties. The effect of contaminants on the efficacy of this extract and other medicinal plant extracts was also investigated. Organic contaminants (bakers' yeast and skim milk powder) decreased the efficacy of all extracts investigated, while hard water had no effect. Greater understanding of the biocidal properties of the plant extracts investigated may determine if they have medical, industrial or environmental applications. ((c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).
- Published
- 2005
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20. Identification of the antibacterial component of an ethanolic extract of the Australian medicinal plant, Eremophila duttonii.
- Author
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Shah A, Cross RF, and Palombo EA
- Subjects
- Anti-Bacterial Agents administration & dosage, Anti-Bacterial Agents therapeutic use, Australia, Humans, Medicine, Traditional, Microbial Sensitivity Tests, Plant Extracts administration & dosage, Plant Extracts therapeutic use, Anti-Bacterial Agents pharmacology, Eremophila Plant, Gram-Positive Bacteria drug effects, Phytotherapy, Plant Extracts pharmacology
- Abstract
Activity-guided fractionation was used to determine the antibacterial component of an ethanolic extract of the leaves of an Australian native medicinal plant, Eremophila duttonii F. Muell. (Myoporaceae). The extract, previously shown to have activity against Gram positive bacteria, was shown to have activity against additional Gram positive bacteria, including Clostridium perfringens, C. sporogenes and Listeria monocytogenes. Thin layer chromatography (TLC) was used to separate the extract into seven coloured fractions in visible light, one of which was shown by bioautography to contain antibacterial activity. Recovery of the component from the TLC plate and testing for antibacterial activity using a plate-hole diffusion assay supported this result. The purity of the component was verified by high-performance liquid chromatography and a time-kill experiment indicated that the purified component showed identical bactericidal activity to the whole extract. TLC spray reagents indicated that the component was a sterol, terpene or sugar but not a flavonoid, while the pigmented nature suggested a carotenoid., (Copyright (c) 2004 John Wiley & Sons, Ltd.)
- Published
- 2004
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21. Antibacterial activity of Australian plant extracts against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE).
- Author
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Palombo EA and Semple SJ
- Subjects
- Anti-Bacterial Agents isolation & purification, Australia, Gram-Positive Bacteria drug effects, Methicillin Resistance, Plant Extracts metabolism, Plants, Medicinal classification, Plants, Medicinal metabolism, Vancomycin Resistance, Anti-Bacterial Agents pharmacology, Enterococcus faecalis drug effects, Plant Extracts pharmacology, Staphylococcus aureus drug effects
- Abstract
Ethanolic extracts of five traditional Australian medicinal plants, previously shown to display antibacterial activity against laboratory strains of the Gram positive bacteria Staphylococcus aureus and Enterococcus faecalis, were investigated for their abilities to inhibit clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Using plate-hole diffusion assays, the following results were obtained: (a) extract from the leaves of Eremophila alternifolia (Myoporaceae) showed activity against MRSA; (b) extract from the leaves of Acacia kempeana (Mimosaceae) showed incomplete inhibition of VRE; (c) extracts from the leaves of Amyema quandong (Loranthaceae) and Eremophila duttonii (Myoporaceae) were active against both types of bacteria; (d) extract from the stem base of Lepidosperma viscidum (Cyperaceae) was active against MRSA and exhibited incomplete inhibition of VRE. All active extracts were evaluated using time-kill assays. Most of the extracts showed bactericidal effects and reduced the number of viable cells by 4-6 logs within four hours, while the extracts from Acacia kempeana leaves and Lepidosperma viscidum stem base exhibited bacteriostatic activity against VRE. The extract from the leaves of Eremophila duttonii was the most active and reduced the number of viable cells of MRSA and VRE to undetectable levels within 1 hour.
- Published
- 2002
- Full Text
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22. Expanding distribution of human serotype G6 rotaviruses in Australia.
- Author
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Diwakarla S, Clark R, and Palombo EA
- Subjects
- Amino Acid Sequence, Animals, Australia, Capsid Proteins genetics, Capsid Proteins immunology, Cattle, Child, Humans, Molecular Sequence Data, Phylogeny, Rotavirus genetics, Sequence Homology, Amino Acid, Serotyping, Swine, Antigens, Viral, Gastroenteritis virology, Rotavirus classification, Rotavirus isolation & purification, Rotavirus Infections virology
- Abstract
Serotype G6 rotaviruses are common pathogens of cattle but are rarely found in humans. In Australia, human G6 isolates have previously been detected in two major southern population centres. A new isolate, ASG6.02, was detected in central Australia (Alice Springs) in 1997. Comparison of the deduced amino acid sequence of the major neutralizing antigen, VP7, indicated that ASG6.02 was related to human G6 viruses isolated from children in Italy and Australia. Phylogenetic analysis supported the close relationship between ASG6.02 and other Australian isolates and indicated that G6 VP7 sequences generally clustered according to the species of origin (human, bovine or porcine). The VP4 type of ASG6.02 was determined as P-type [14], in common with other isolates from Australia and Italy. The detection of ASG6.02 indicates that the distribution of this serotype is increasing in this country and may have implications for successful vaccine development.
- Published
- 2002
- Full Text
- View/download PDF
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