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Characterization of arbuscular mycorrhizal fungal species associating with Zea mays

  • Authors: Maússe-Sitoe, Silvia , Dames, Joanna F
  • Date: 2024
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440339 , vital:73775 , https://doi.org/10.3389/fpls.2024.1345229
  • Description: Taxonomic identification of arbuscular mycorrhizal (AM) fungal spores extracted directly from the field is sometimes difficult because spores are often degraded or parasitized by other organisms. Single-spore inoculation of a suitable host plant allows for establishing monosporic cultures of AM fungi. This study aimed to propagate AM fungal spores isolated from maize soil using single spores for morphological characterization. First, trap cultures were established to trigger the sporulation of AM fungal species. Second, trap cultures were established with individual morphotypes by picking up only one spore under a dissecting microscope and transferring it to a small triangle of sterilized filter paper, which was then carefully inoculated below a root from germinated sorghum seeds in each pot and covered with a sterile substrate. All pots were placed in sunbags and maintained in a plant growth room for 120 days.
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  • Date Issued: 2024

Microbial Community Responses to Alterations in Historical Fire Regimes in Montane Grasslands

  • Authors: Gokul, Jarishma K , Matcher, Gwynneth , Dames, Joanna F , Nkangala, Kuhle , Gordijn, Paul J , Barker, Nigel P
  • Date: 2023
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440366 , vital:73777 , https://doi.org/10.3390/d15070818
  • Description: The influence of fire regimes on soil microbial diversity in montane grasslands is a relatively unexplored area of interest. Understanding the belowground diversity is a crucial stepping-stone toward unravelling community dynamics, nutrient sequestration, and overall ecosystem stability. In this study, metabarcoding was used to unravel the impact of fire disturbance regimes on bacterial and arbuscular mycorrhizal fungal community structures in South African montane grasslands that have been subjected to an intermediate (up to five years) term experimental fire-return interval gradient. Bacterial communities in this study exhibited a shift in composition in soils subjected to annual and biennial fires compared to the controls, with carbon and nitrogen identified as significant potential chemical drivers of bacterial communities. Shifts in relative abundances of dominant fungal operational taxonomic units were noted, with Glomeromycota as the dominant arbuscular mycorrhiza observed across the fire-return gradient. A reduction in mycorrhizal root colonisation was also observed in frequently burnt autumnal grassland plots in this study. Furthermore, evidence of significant mutualistic interactions between bacteria and fungi that may act as drivers of the observed community structure were detected. Through this pilot study, we can show that fire regime strongly impacts bacterial and fungal communities in southern African montane grasslands, and that changes to their usually resilient structure are mediated by seasonal burn patterns, chemical drivers, and mutualistic interactions between these two groups.
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  • Date Issued: 2023

Methods for assessing the quality of AM fungal bio-fertilizer: Retrospect and future directions

  • Authors: Agnihotri, R , Sharma, M P , Bucking, H , Dames, Joanna F , Bagyaraj, D J
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/448626 , vital:74747 , https://doi.org/10.1007/s11274-022-03288-3
  • Description: In the recent past, the mass production of arbuscular mycorrhizal (AM) fungi has bloomed into a large biofertilizer industry. Due to their obligate symbiotic nature, these fungi are propagated on living roots in substrate-based pot cultures and RiTDNA in in vitro or root organ culture systems. The quality assessment of AM inocula remains critical for the production and efficacy evaluation of AM fungi. The vigour of AM inocula are assessed through microscopic methods such as inoculum potential, infectivity potential/infection units, most probable number (MPN) and spore density. These methods marginally depend on the researcher’s skill. The signature lipids specific to AM fungi, e.g. 16:1ω5cis ester-linked, phospholipid, and neutral lipid fatty acids provide more robustness and reproducibility. The quantitative real-time PCR of AM fungal taxa specific primers and probes analyzing gene copy number is also increasingly used. This article intends to sensitize AM fungal researchers and inoculum manufacturers to various methods of assessing the quality of AM inocula addressing their merits and demerits. This will help AM producers to fulfil the regulatory requirements ensuring the supply of high-quality AM inocula to end-users, and tap a new dimension of AM research in the commercial production of AM fungi and its application in sustainable plant production systems.
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  • Date Issued: 2022

Mitigating Climate Change: The Influence of Arbuscular Mycorrhizal Fungi on Maize Production and Food Security

  • Authors: Maússe-Sitoe, Silvia N D , Dames, Joanna F
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/453465 , vital:75256 , ISBN 978-1-83768-091-7 , https://www.intechopen.com/chapters/84486
  • Description: Anthropogenic activities have contributed to the increased atmospheric concentration of greenhouse gases, which are an important contributor to climate change. From 1940 to 2004, global emissions increased by 70%, and projections suggest a continual increase by 2050 due to agriculture, forestry, and other land uses. Arbuscular mycorrhizal (AM) fungi are ubiquitous in undisturbed soils and form a symbiotic relationship with various plants. The relationship that enhances nutrient uptake and plant growth, among other benefits, is well known. Several soil management practices employed in agriculture adversely affect the symbiosis. Zea mays (maize) provides 30% of total caloric intake to 4.5 billion people worldwide and is an important staple crop, vulnerable to climate change. Higher temperatures can result in increased water demand, while changes in precipitation can result in crop failure. AM fungi can be applied as inoculants to maize. Resulting in improved plant growth, yield, and nutrient uptake and providing superior food quality properties, such as increased antioxidants, vitamins, and minerals. AM fungi are considered a crucial biotechnological tool in crop production. This review illustrates their essential role in sustainable maize production and emphasizes the need to maintain AM fungal communities in the soil to mitigate the effects of climate change.
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  • Date Issued: 2022

Partial Purification and Characterization of Endoxylanase from a fungus, Leohumicola incrustata

  • Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440393 , vital:73779 , 10.4314/br.v19i1.2
  • Description: Xylanases are glycoside hydrolases (GH) that degrade β-1, 4-xylan, a linear polysaccharide found as hemicellulose in cell wall of plants. Endoxylanase (Endo-1, 4-β-xylanase, EC 3.2. 1.8) randomly catalyses xylan to produce varying short xylooligosaccharides (XOS). This study aimed to determine the characteristics of a partially purified endoxylanase from Leohumicola incrustata. Enzyme production was carried out using beechwood (BW) xylan, after which the cell-free crude filtrate was concentrated using the ammonium sulphate precipitation method. The hydrolysed products were analysed by thin-layer chromatography (TLC) and zymography. The result showed that the enzyme produced varying smaller-sized linear xylooligosaccharides with R f values corresponding to those of xylobiose, xylotriose, xylotetraose, xylopentaose, xylohexaose and other higher oligomers. The endoxylanase had a molecular mass of 72 kDa. The enzyme is stable in the presence of K+, Na+, Ca 2+, Fe 2+, Mg 2+, Zn 2+, Co 2+, pH of 5.0 and temperature of 37 o C. However, the activity gradually decreased after 60 min at 50 o C and retained over 69% activity after 120 min, while at 60 and 70 o C, the enzyme activity sharply decreased (pre-incubation periods). Endoxylanase from L. incrustata is comparable to those of other microorganisms and should be considered an attractive candidate for future industrial applications.
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  • Date Issued: 2021

Pyrosequencing and phenotypic microarray to decipher bacterial community variation in Sorghum bicolor (L.) Moench rhizosphere

  • Authors: Kumar, Ashwani , Dubey, Anamika , Malla, Muneer A , Dames, Joanna F
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440417 , vital:73781 , https://doi.org/10.1007/s11274-022-03288-3
  • Description: Different cultivation practices and climatic conditions play an important role in governing and modulating soil microbial communities as well as soil health. This study investigated, for the first time, keystone microbial taxa inhabiting the rhizosphere of sweet sorghum (Sorghum bicolor) under extensive cultivation practices at three different field sites of South Africa (North West-South (ASHSOIL1); Mpumalanga-West – (ASHSOIL2); and Free State-North West – (ASHSOIL3)). Soil analysis of these sites revealed differences in P, K, Mg, and pH. 16S rRNA amplicon sequencing data revealed that the rhizosphere bacterial microbiome differed significantly both in the structure and composition across the samples. The sequencing data revealed that at the phylum level, the dominant group was Cyanobacteria with a relative abundance of 63.3%, 71.8%, and 81.6% from ASHSOIL1, ASHSOIL2, and ASHSOIL3, respectively. Putative metabolic requirements analyzed by METAGENassist software revealed the ASHSOIL1 sample as the prominent ammonia degrader (21.1%), followed by ASHSOIL3 (17.3%) and ASHSOIL2 (11.1%). The majority of core-microbiome taxa were found to be from Cyanobacteria, Bacteroidetes, and Proteobacteria. Functionally, community-level physiological profiling (CLPP) analysis revealed that the metabolic activity of the bacterial community in ASHSOIL3 was the highest, followed by ASHSOIL1 and ASHSOIL2. This study showed that soil pH and nutrient availability and cultivation practices played significant roles in governing the bacterial community composition in the sorghum rhizosphere across the different sites.
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  • Date Issued: 2021

Tapping the role of microbial biosurfactants in pesticide remediation: an eco-friendly approach for environmental sustainability

  • Authors: Raj, Aman , Kumar, Ashwani , Dames, Joanna F
  • Date: 2021
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440430 , vital:73782 , https://doi.org/10.3389/fmicb.2021.791723
  • Description: Pesticides are used indiscriminately all over the world to protect crops from pests and pathogens. If they are used in excess, they contaminate the soil and water bodies and negatively affect human health and the environment. However, bioremediation is the most viable option to deal with these pollutants, but it has certain limitations. Therefore, harnessing the role of microbial biosurfactants in pesticide remediation is a promising approach. Biosurfactants are the amphiphilic compounds that can help to increase the bioavailability of pesticides, and speeds up the bioremediation process. Biosurfactants lower the surface area and interfacial tension of immiscible fluids and boost the solubility and sorption of hydrophobic pesticide contaminants. They have the property of biodegradability, low toxicity, high selectivity, and broad action spectrum under extreme pH, temperature, and salinity conditions, as well as a low critical micelle concentration (CMC). All these factors can augment the process of pesticide remediation. Application of metagenomic and in-silico tools would help by rapidly characterizing pesticide degrading microorganisms at a taxonomic and functional level. A comprehensive review of the literature shows that the role of biosurfactants in the biological remediation of pesticides has received limited attention. Therefore, this article is intended to provide a detailed overview of the role of various biosurfactants in improving pesticide remediation as well as different methods used for the detection of microbial biosurfactants. Additionally, this article covers the role of advanced metagenomics tools in characterizing the biosurfactant producing pesticide degrading microbes from different environments.
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  • Date Issued: 2021

Biological control potential of ectomycorrhizal fungi against Fusarium circinatum on Pinus patula seedlings

  • Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Grant L
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/425960 , vital:72302 , xlink:href="https://doi.org/10.1080/09583157.2020.1771542"
  • Description: The South Africa forestry industry, covering ∼1.3 million hectares, is dependent on exotic pine and Eucalyptus species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi or other beneficial microbes. Fusarium circinatum is an economically important pathogen affecting seedling survival. The purpose of this investigation was to assess the effects of ectomycorrhizal fungal inoculation on Pinus patula seedling growth and resistance to the fungal pathogen F. circinatum. Explants from ECM basidiocarps, collected from Pinus stands, were plated onto MMN medium to obtain isolates that were then verified via DNA extraction and PCR amplification and sequencing of the ITS rDNA region. These isolates were identified as Boletus edulis f. reticulatus, Lactarius quieticolor, Suillus granulatus and an unknown Suillus species. P. patula growth in the presence of the pathogen F. circinatum was significantly increased and promoted by the L. quieticolor and Suillus isolates. Preventative inoculation of seedlings in the nursery using these isolates would ensure the production of stronger, healthier plants that would be more resistant to F. circinatum infection, increasing survival in the plantation.
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  • Date Issued: 2020

Fungi and Lichens of the Limpopo Valley and Mapungubwe National Park

  • Authors: Van der Walt, Retha , Dames, Joanna F , Hawley-McMaster, Greer
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/453434 , vital:75254 , ISBN 9780620904056
  • Description: This is a 376 paged soft-cover book. With more than 1400 photographs for easy identification with disk included. With Maps, introduction glossary of terms and pictures. With descriptions and illustrations. Detailed introductory chapters for fungi and lichens sections. Information on more than 290 different local macro-fungi, lichen and slime mould species - including various novel spe-cies. Many of these may, however, occur widely in the rest of Africa and further afield. Chapters dealing with 15 different morphological groups. A succinct and descriptive text including information on the distinguishing features, ecology, distribution and edibility of species. English and Afrikaans common names. De-scription of families and genera. More than 1400 colour photographs (including a DVD) which allow detailed viewing as a further aid to identification. A detailed glossary of terms and picture glossary. A step-by-step guide to the collection of specimens. A map and background of the study area. Information on the early Mapungubwe civilization.
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  • Date Issued: 2020

Mycorrhizal Interventions for Sustainable Potato Production in Africa

  • Authors: Chifetete, Varaidzo W , Dames, Joanna F
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/426021 , vital:72307 , xlink:href="https://doi.org/10.3389/fsufs.2020.593053"
  • Description: The potato (Solanum tuberosum L.) is an important tuber crop with high dietary value that could potentially help to alleviate malnutrition and hunger in Africa. However, production is expensive, with high fertilizer and pesticide demands that lead to environmental pollution, and tillage practices that negatively affect soil structure. Microorganisms of different types have increasingly been found to be useful as biofertilizers, and arbuscular mycorrhizal (AM) fungi are an important crop symbiont. AM fungi have been shown to increase tolerance of crop plants to drought, salinity and disease by facilitating water and nutrient acquisition and by improving overall soil structure. However, the establishment and maintenance of the symbioses are greatly affected by agricultural practices. Here, we review the benefits that AM fungi confer in potato production, discuss the role and importance of mycorrhiza helper bacteria, and focus on how AM fungal diversity and abundance can be affected by conventional agricultural practices, such as those used in potato production. We suggest approaches for maintaining AM fungal abundance in potato production by highlighting the potential of conservation tillage practices augmented with cover crops and crop rotations. An approach that balances weed control, nutrient provision, and AM fungal helper bacterial populations, whilst promoting functional AM fungal populations for varying potato genotypes, will stimulate efficient mycorrhizal interventions.
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  • Date Issued: 2020

Screening of ectomycorrhizal and other associated fungi in South African forest nurseries

  • Authors: Chartier FitzGerald, Veronique C , Dames, Joanna F , Hawley, Greer L
  • Date: 2020
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/426058 , vital:72310 , xlink:href="https://hdl.handle.net/10520/ejc-soufor-v82-n4-a8"
  • Description: The South African forestry industry covers approximately 1.3 million hectares and is dependent on exotic pine and eucalypt species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi. This investigation assessed levels of naturally occurring ECM colonisation of Pinus patula seedlings from 10 different South African forestry nurseries using a grid line intersect method. Fungi from colonised roots were identified using morphological characteristics and Illumina sequencing. Colonisation of seedlings in production nurseries was low (2-21%). Morphologically, the ECM fungi Thelophora terrestris, Suillus sibiricus, and the genera Russula and Pseudotomentella were identified. Molecularly, the ECM fungi T. terrestris, Inocybe jacobi and the genus Sphaerosporella, as well as several other ECM-containing families were identified, along with many saprotrophic/ endophytic fungi belonging to genera such as Penicillium, Ramasonia and Talaromyces. As can be seen, a combination of both molecular and morphological identification techniques are needed as neither is able to give a full picture of the species present in isolation. This study reveals an initial insight into the root microbiome community associated with Pinus patula seedlings, which should be taken into account when inoculation with beneficial microbes is considered. It determined that natural ECM fungal root colonisation levels are very low throughout the South African nurseries investigated, indicating the need for ECM fungal inoculation, which can increase seedling growth, viability and resistance to pathogens.
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  • Date Issued: 2020

Development of high yielding strain of Pleurotus tuber-regium fructification, nutritional and phylogenetic studies

  • Authors: Bamigboye, Comfort O , Oloke, Julius K , Dames, Joanna F
  • Date: 2019
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/448595 , vital:74745 , https://doi.org/10.1007/s13197-019-03786-7
  • Description: Mushrooms are nutritionally rich, healthy and medicinal. Pleurotus tuber-regium (Fr.) is one of the nutritious medicinal mushroom found in the tropics and subtropics, but with history of slow growth and low sclerotia yield. In this study, mutants were created by mycelia exposure to ultraviolet irradiation (at a wavelength of 254 nm and a distance of 45 cm), for 3 h and sub-cultured at 30 min interval. The DNA from the wild and mutant strains were extracted, PCR amplified and sequenced. A phylogenetic tree was constructed to show the degree of similarity and differences between the wild and the mutant strains. Fructification studies were conducted on Rhodes grass straw and sawdust to determine the viability of the mutant strains and any nutritional improvement. The wild strain of P. tuber-regium and mutant produced at 30 min (Pt30) cultivated on sawdust and Rhodes straw, yielded sclerotia with biological efficiency of 8.8 and 47.6% respectively. Proximate analysis of the sclerotium showed that the mutant, Pt30, had improved nutritional compositions compared to the wild strain with a total non-structural carbohydrate concentration of 2.41 g as against 0.93 g. Conclusively in this study, better strains of P. tuber-regium were produced with faster growth rate, higher mycelia ramification rate on lignocellulosic substrate and a higher sclerotia yield than the wild P. tuber-regium. It was also established that mutagenesis is capable of improving P. tuber-regium for a successful commercial venture in sclerotia production.
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  • Date Issued: 2019

Molecular identification and antibacterial properties of an ericoid associated mycorrhizal fungus

  • Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
  • Date: 2019
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440378 , vital:73778 , https://doi.org/10.1186/s12866-019-1555-y
  • Description: The quest for novel sources of antibacterial compounds have necessitated the inclusion of ericoid mycorrhizal fungi (ERM) commonly found within the root of ericaceous plants. Agar-well diffusion method was used to detect antibacterial activity and was followed by the microbroth diffusion method [minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)].
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  • Date Issued: 2019

Arbuscular mycorrhizal fungi persist in dying Euphorbia ingens trees

  • Authors: Vivas, M , Crous, C J , Dames, Joanna F , Van der Linde, J A , Coetzee, M P A , Roux, J
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440465 , vital:73784 , https://doi.org/10.1016/j.sajb.2017.12.009
  • Description: Forest declines have been reported with increasing regularity during the last decade and are expected to increase due to the ongoing environmental changes. During adverse environmental conditions, plant symbioses with mycorrhizas can help to reduce plant stress. Mycorrhizas are symbiotic associations between fungi and roots of living plants. Plants offer carbohydrates to the fungus and the fungus improves the acquisition of nutrients and water to the plant. Specifically, arbuscular mycorrhizal (AM) fungi are the most abundant mycorrhizas. In South Africa, there are increasing reports describing the decline of native Euphorbia ingens trees. This study analysed the presence and abundance of AM fungal colonisation in the roots of E. ingens trees, and the number of AM fungal spores in the surrounding soil, with the aim to improve the understanding of the rapid decline of these trees. AM fungal colonisation and spores in relation to the soil properties were also analysed. Soil and root samples were collected from different rates of declining E. ingens trees at three sites in South Africa. AM fungal colonisation of the roots was assessed and fungal spores in the surrounding soil were enumerated. Soil phosphorus, mineral nitrogen and pH were analysed from the soil samples. The results showed that AM fungi are associated with E. ingens trees. AM abundance was influenced by site specific properties and not by E. ingens health. Moreover, the level of soil NO3− and soil texture significantly influenced AM colonisation in roots and the number of spores enumerated. These preliminary findings provide background information for further research into the large-scale decline of E. ingens populations in South Africa.
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  • Date Issued: 2018

Morphological and symbiotic root modifications for mineral acquisition from nutrient-poor soils

  • Authors: Kleinert, Aleysia , Benedito, V A , Morcillo, R J L , Dames, Joanna F , Cornejo-Rivas, P , Zuniga-Feest, A , Delgado, Mabel , Muñoz, Gaston
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/448640 , vital:74748 , https://doi.org/10.1007/978-3-319-75910-4_4
  • Description: Plants have the ability to form vast root systems with lengths measuring up to several kilometers and branch roots numbering in millions. These expansive root systems provide plants with a large surface area for water and nutrient uptake from the surrounding soil. Roots also have further equally important functions to fulfil such as vegetative reproduction, hormone biosynthesis, photoassimilate storage, and the establishment of symbiotic relationships with microorganisms. Root systems have evolved several adaptations to aid them in maximizing nutrient uptake. These adaptations can be morphological such as changes in the root architecture or formation of cluster roots or may be symbiotic associations with mycorrhizae or nitrogen-fixing bacteria. Improvement of nutrient acquisition and use by plants is imperative for economic, humanitarian, and environmental reasons, and a better understanding of the processes governing root adaptations would enable us to adapt fertilizer and pesticide programs. In this chapter, we will focus on both morphological (cluster roots) and symbiotic root adaptations (associations with ectomycorrhizae, arbuscular mycorrhizae, and nitrogen-fixing bacteria) to soil nutrient deficiencies.
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  • Date Issued: 2018

Purification and characterization of an amyloglucosidase from an ericoid mycorrhizal fungus (Leohumicola incrustata)

  • Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440405 , vital:73780 , https://doi.org/10.1186/s13568-018-0685-1
  • Description: This study aimed to purify and characterize amyloglucosidase (AMG) from Leohumicola incrustata. AMG was purified to homogeneity from cell-free culture filtrate of an ERM fungus grown in a modified Melin–Norkrans liquid medium. The molecular mass of the AMG was estimated to be 101 kDa by combining the results of Sephadex G-100 gel filtration, sodium dodecyl sulphate–polyacrylamide gel electrophoresis, and zymography. The Km and kcat values were 0.38 mg mL−1 and 70 s−1, respectively, using soluble starch as a substrate. The enzyme was stable at 45 °C (pH 5.0), retaining over 65% activity after a pre-incubation period of 24 h. The metal inhibition profile of the AMG showed that Mn2+ and Ca2+ enhanced activity, while it was stable to metals ions, except a few (Al3+, Co2+, Hg2+ and Cd2+) that were inhibitory at a concentration higher than 5 mM. Thin layer chromatography revealed that only glucose was produced as the product of starch hydrolysis. The amylase from L. incrustata is a glucoamylase with promising characteristics such as temperature stability over an extended period, high substrate affinity and stability to a range of chemicals. Also, this study reports for the first time the possibility of using some culturable ERM fungi to produce enzymes for the bio-economy.
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  • Date Issued: 2018

The potential use of treated brewery effluent as a water and nutrient source in irrigated crop production

  • Authors: Taylor, Richard P , Jones, Clifford L W , Laing, Mark D , Dames, Joanna F
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440476 , vital:73785 , https://doi.org/10.1016/j.wri.2018.02.001
  • Description: Brewery effluent (BE) needs to be treated before it can be released into the environment, reused or used in down-stream activities. This study demonstrated that anaerobic digestion (AD) followed by treatment in an integrated tertiary effluent treatment system transformed BE into a suitable solution for crop irrigation. Brewery effluent can be used to improve crop yields: Cabbage (Brassica oleracea cv. Star 3301), grew significantly larger when irrigated with post-AD, post-primary-facultative-pond (PFP) effluent, compared with those irrigated with post-constructed-wetland (CW) effluent or tap water only.
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  • Date Issued: 2018

Improved endoglucanase production and mycelial biomass of some ericoid fungi

  • Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
  • Date: 2017
  • Language: English
  • Type: article , text
  • Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
  • Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
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  • Date Issued: 2017

Improved endoglucanase production and mycelial biomass of some ericoid fungi

  • Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
  • Date: 2017
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
  • Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
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  • Date Issued: 2017

Physiology and Spatio-temporal Relations of Nutrient Acquisition by Roots and Root Symbionts

  • Authors: Valentine, Alex J , Kleinert, Aleysia , Thuynsma, Rochelle , Chimphango, Samson , Dames, Joanna F , Benedito, V A
  • Date: 2017
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/448652 , vital:74749 , https://doi.org/10.1007/124_2016_11
  • Description: Among the various functions of roots, nutrient acquisition (via soil uptake or through symbiotic relationships) is one of the most essential for land plants. Soil from natural and agricultural ecosystems may impede plant nutrient acquisition, by many factors such as mineral availabilities either in excess or deficient supply, depletion of organic matter, extreme variations in water supply, and many other physical and chemical features. In order to survive, plants need to undergo developmental and physiological mechanisms to cope with these extreme soil situations. Here we review how plants control nutrient acquisition by dynamically changing root architecture for improved soil space exploration, as well as altering cellular-level function for enhanced nutrient uptake, via apoplastic acidification, exudation of enzymes and metabolites (organic acids, secondary metabolites) and constantly changing the composition of transporters at the plasma membrane. These changes start with environmental cues which induce cell signaling and involve hormones and coordinated regulatory genes networks that drive the root’s developmental plasticity as well as the cell’s biochemical dynamics. Mutualistic root symbioses, such as mycorrhizae and rhizobial-induced nodulation, are also important to provide essential nutrients to the plant, which are tightly regulated in order to only occur at plant’s benefit. We also explore molecular mechanisms which roots have evolved to cope with nutritional, as well as other soil stresses, such as aluminium toxicity and heavy metals. Overall, understanding root dynamics under several environmental variables at different perspectives, from root architecture to biochemistry to genetic levels will allow us to better explore the spatial and temporal relations of roots with their mineral nutrient environment.
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  • Date Issued: 2017
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