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    Reconstruction of gene innovation associated with major evolutionary transitions in the kingdom Fungi
    (BioMed Central Ltd, 2022-12) Wu B; Hao W; Cox MP
    BACKGROUND: Fungi exhibit astonishing diversity with multiple major phenotypic transitions over the kingdom's evolutionary history. As part of this process, fungi developed hyphae, adapted to land environments (terrestrialization), and innovated their sexual structures. These changes also helped fungi establish ecological relationships with other organisms (animals and plants), but the genomic basis of these changes remains largely unknown. RESULTS: By systematically analyzing 304 genomes from all major fungal groups, together with a broad range of eukaryotic outgroups, we have identified 188 novel orthogroups associated with major changes during the evolution of fungi. Functional annotations suggest that many of these orthogroups were involved in the formation of key trait innovations in extant fungi and are functionally connected. These innovations include components for cell wall formation, functioning of the spindle pole body, polarisome formation, hyphal growth, and mating group signaling. Innovation of mitochondria-localized proteins occurred widely during fungal transitions, indicating their previously unrecognized importance. We also find that prokaryote-derived horizontal gene transfer provided a small source of evolutionary novelty with such genes involved in key metabolic pathways. CONCLUSIONS: The overall picture is one of a relatively small number of novel genes appearing at major evolutionary transitions in the phylogeny of fungi, with most arising de novo and horizontal gene transfer providing only a small additional source of evolutionary novelty. Our findings contribute to an increasingly detailed portrait of the gene families that define fungal phyla and underpin core features of extant fungi.
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    Monascus spp. and citrinin: Identification, selection of Monascus spp. isolates, occurrence, detection and reduction of citrinin during the fermentation of red fermented rice
    (Elsevier BV, 2022-10-16) Farawahida AH; Palmer J; Flint S
    Red fermented rice (RFR) is rice fermented using Monascus spp. This product contains monacolin K, providing health benefits including mitigation of diarrhoea and improving blood circulation. RFR can produce pigments that can act as natural colour and flavouring agents. However, Monascus spp. (a fungal starter to ferment RFR) can also produce the mycotoxin, citrinin (CIT) which is believed to have adverse effects on human health. CIT in RFR has been reported worldwide by using different methods of detection. This review focuses on the production of RFR by solid-state fermentation (SSF) and submerged fermentation (SmF), the occurrence of CIT in RFR, CIT quantification, the factors affecting the growth of Monascus spp., pigments and CIT production in RFR, and possible methods to reduce CIT in RFR. This review will help the food industries, researchers, and consumers understand the risk of consuming RFR, and the possibility of controlling CIT in RFR.
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    Flower blight of chrysanthemums : the causal fungi and their control : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University
    (Massey University, 1973) Singh, Gurmit
    The commercial chrysanthemum commonly grown in New Zealand is botanically identified as Chrysanthemum morifoliurr. Ramat. and is believed to have originated in China. As the family name Compositae suggests the individual flower ('flower head') is a composite arrangement of two types of florets, namely ray florets with well developed petals, and disc florets with tubular or poorly developed petals. Production of commercial chrysanthemums basically comprises three categories: (i) cut flowers; (ii) cuttings; (iii) container or pot plants. Chrysanthemums are probably grown by more floriculturalists than any other flower crop. Much of its popularity is attributed to the wide range of colours and forms and the fact that it can be grown either as a pot plant or for cut flowers. Another important characteristic of the chrysanthemum is the long keeping quality of the flowers, a feature which is much appreciated by retailers and consumers. In the United States of America the chrysanthemum or 'mum' is the most popular flower, surpassing both the rose and carnation in total wholesale value. [FROM INTRODUCTION]
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    The ecology of Aspergillus fumigatus and implications for wildlife conservation in modified environments : a thesis presented to Massey University in partial fulfilment of the requirements for the degree of Ph.D. in Ecology, Institute of Natural Resources, Massey University
    (Massey University, 2001) Perrott, John K.
    This thesis outlines my research since 1998 into inter-trophic interactions between pathogenic fungi, insects, birds, and the environment. Chapter One is a stand-alone investigation into fungal diseases associated with native cicadas on Mokoia Island (Lake Rotorua) and the Eastwoodhill Arboretum (Gisborne). Chapters Two through Four are specifically concerned with the natural occurrence of the pathogenic fungus Aspergillus fumigatus and its connection to hihi (or stitchbird) on Little Barrier Island (northern Hauraki Gulf), Mokoia Island, Tiritiri Matangi Island (Hauraki Gulf), and the Mt Bruce Wildlife Centre (near Masterton). The hihi (Notiomystis cincta) is a small (i.e., starling sized) cavity-nesting honeyeater endemic to New Zealand. Following European colonisation, hihi became extinct everywhere except on Little Barrier Island, making the future of this species very uncertain. In response to this situation there have been several translocations of hihi to Hen, Cuvier, Kapiti, Mokoia and Tiritiri Matangi Islands from 1980 to 1996. While hihi on Tiritiri Matangi seem to be progressing well with intensive management, all previous translocations to other islands have failed to establish self-sustaining populations. The main hypotheses given to explain these failures are insufficient year-round supply of nectar and fruit, and lack of suitable nesting cavities. Hihi were translocated to Mokoia Island in September 1994 with nest boxes provided. However, like past translocations, hihi have continued to decline on the island with high annual mortality rates above 50%. It is not clear what factors are contributing to this high mortality rate. My MSc studies carried out on Mokoia Island during 1994-1997 demonstrated that hihi had a good year-round supply of food, and were not dying as a result of starvation. Subsequent post-mortem examinations by Professor Alley of sick and dead hihi from Mokoia from 1995-1997 has revealed that the fungal disease aspergillosis, caused by Aspergillus fumigatus, is the most common cause of death among those birds. In addition, captive hihi at the Mt Bruce Wildlife Centre also suffer high rates of aspergillosis, and there is presently concern regarding the susceptibility of hihi to this fungal disease. This study suggests also that past hihi translocations have failed due, in part, to birds being exposed to elevated levels of disease-causing microorganisms. Aspergillus fumigatus is an ubiquitous fungus, and common aspergillosis-causing pathogen in birds and mammals. Infection takes place following the aspiration of fungal spores, and is primarily a respiratory disease. Aspergillus infections are usually considered to be opportunist following other primary infections, immunosuppression or stressful environmental conditions. Small numbers of spores can usually be tolerated by the immune system, but large numbers can cause disease and death. At present, prevention is the only effective method of controlling aspergillosis in wild bird populations. This project is concerned with studying the ecology of A. fumigatus, and identifying the most likely source/s of infection in hihi. Therefore, this project is directed towards identifying the most likely source/s of A. fumigatus rather than the most likely causes ot aspergillosis in hihi. In doing so, the primary aim of this project is to investigate whether previous hihi translocations from Little Barrier Island to young growth forests and forest edge habitats have been exposing birds to elevated levels of A. fumigatus, and therefore, whether A. fumigatus preventative management should be considered when planning future hihi translocations. This project aimed to, A) determine whether habitat disturbance encourages the establishment of A. fumigatus in the environment B) measure and compare A. fumigatus densities from early growth regenerating forests (i.e., Mokoia and Tiritiri Matangi Islands), a pristine mature forest (i.e., Little Barrier Island), and two mainland forest locations (i.e., Mt Bruce Wildlife Centre, and the Massey University Campus) C) measure and compare A. fumigatus densities in forest edge habitats and inner forest locations. D) investigate whether hihi nest boxes on Mokoia Island and natural tree cavity-nests on Little Barrier Island are promoting the growth of A. fumigatus and, E) investigate various types of forest disturbance events that could account for the differences in A. fumigatus densities found between study sites. Results from Chapter One describe a unique and previously unreported cicada disease caused by a Conidiobolus fungus on Mokoia Island. Results from Chapters Two and Three report elevated levels of A. fumigatus on Mokoia Island and at the Mt Bruce Wildlife Center. Low levels of A. fumigatus were recorded on Little Barrier Island, and moderate levels recorded for Tiritiri Matangi Island. Results indicate that forest disturbance promotes the abundance of A. fumigatus in the environment, and that forest edge habitats have significantly higher levels of A. fumigatus compared to inner forest locations. This suggests that forest disturbance alters natural disease dynamics, and increases bird's exposure to opportunistic disease-causing agents such as A. fumigatus. These results, in part, illustrate the functional significance of old growth forests in keeping weedy pest species like A. fumigatus in check. Results from Chapter Four report that hihi are exposed to elevated levels of airborne A. fumigatus spores while in the nest box. Additionally, results indicate that hihi re-using old nest sites would further suffer increased exposure to A. fumigatus spores. Because hihi are a vulnerable species, and seem to be particularly susceptible to aspergillosis, the conservation value of this work is high. This study was made possible by grants from the J.S.Watson Conservation Trust, Massey University Graduate Research Fund, and the World Wide Fund for Nature, and furthers our understanding of mortality factors affecting free-living birds, and provides new information on the ecology of this common wildlife disease. The broader implications of this work for managing wildlife, particularly birds in New Zealand forests are also explored. The relationship between clear-felling forest regrowth, and the incidence of aspergillosis may be the key to understanding the fate of bird populations reintroduced into forests, and determine the viability of "mainland islands".
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    The hydrolysis of bile acid conjugates by selected fungi : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Biotechnology at Massey University
    (Massey University, 1980) Johns, Michael Russel
    The presence of constitutive, intracellular and extracellular enzymes catalysing the hydrolysis of glycine bile acid conjugates in the fungus Cercospora melonis CBS 162.60 was demonstrated by the use of cell-free systems. Shake flask and fermenter studies were undertaken to determine environmental factors favouring high free bile acid yields. Two major factors were observed to reduce such yields. These were the binding of the bile acid to the mycelium and the degradation of free bile acids to non-steroidal products by the fungus. Whole-cell cultures of C. melonis exhibited poor utilisation of taurine conjugates with no concomitant production of free bile acid. Incubation of synthetic bile conjugate analogues with C. melonis and the use of cell-free systems suggested that this was due to two major factors: firstly, the specificity of the extracellular enzyme for α-aminocarboxylic acid conjugates and secondly, the apparent inability of taurine conjugates to gain access to a constitutive, intracellular cholanoyl taurine hydrolase. It is proposed that the poor permeability of the fungal cell membrane is responsible. Hence, the low activity of whole-cell cultures of C. melonis on taurine conjugates suggests that an industrial process employing the fungal hydrolysis of gall is not feasible. Comparative studies with Curvularia fallax IFO 8885 showed that it possessed superior specific hydrolase activity on glycodeoxycholic acid compared to C. melonis, although this is not apparent from qualitative screening. The abilities of C. melonis, Curvularia coicis IFO 7278 and Aspergillus ochraceus IFO 4071 (Wilhelm) to 7α-dehydroxylate cholic acid and its natural conjugates were investigated. Despite the presence of an apparently constitutive, intracellular 7α-hydroxycholanoyl dehydroxylase in these organisms, only low yields of dehydroxylated products were obtained with whole-cell cultures.
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    The 19-hydroxylation of cortexolone by the fungus Pellicularia filamentosa : a thesis presented in partial fulfilment for the degree of Doctor of Philosophy in Biotechnology at Massey University
    (Massey University, 1982) Clark, Thomas Alan
    The microbiological 19-hydroxylation of steroids was studied to investigate the feasibility of a microbial process to produce 19-hydroxysteroids. These are important precursors of the valuable 19-norsteroids. At present, in industrial processes, 19-hydroxylation is performed by chemical synthesis. Fungi, selected from the genera Pestalotia (25 strains) and Pellicularia (5 strains), were screened for their steroid-hydroxylating activities. Thus, hydroxylation of the substrates progesterone, 4-androstene-3,17-dione, and cortexolone (17α ,21-dihydroxy-4-pregnene-3,20-dione) was studied. Of the organisms tested, only Pellicularia filamentosa f.sp. microsclerotia IFO 6298 and Pellicularia filamentosa f.sp. sasakii IFO 5254 were found to perform 19-hydroxylation. Thus, both fungi could produce 19-hydroxycortexolone from cortexolone, with the former organism the more active in this respect-Hydrocortisone (11β-hydroxycortexolone) was also produced by both organisms. Neither organism, however, could similarly hydroxylate progesterone nor 4-androstehe-3,17-dione. With these substrates, products other than the 19-hydroxylated derivatives were formed. Thus a degree of substrate specificity was recognised for steroidal-19-hydroxylation by these fungi. None of the Pestalotia species tested could 19-hydroxylate any of the three substrates, despite claims in the literature, but instead were very active in 11 α -hydroxylation. In particular, many species were able to 11 α-hydroxylate progesterone (0.5 g/l concentration) in greater than 90% (w/w) yield. Using P. filamentosa f.sp. microsclerotia IFO 6298, in batch fermentation, at a cortexolone concentration of 0.5 g/l yields of 19- and 11β-hydroxycortexolone totalled approximately 40% (w/w) of the consumed substrate. The ratio of the two products, typically, was approximately 1.2:1 (19:11β). Only small variations in this ratio were ever observed. The steroid losses which were observed did not proceed via the hydroxy products as intermediates, but via a degradation pathway, from cortexolone, parallel to the hydroxylation reactions. The 11β- and 19-hydroxylase enzyme-system of P. filamentosa f.sp. microsclerotia IFO 6298 was shown to be inducible by cortexolone. By using the protein synthesis inhibitor, cycloheximide, in fermenter culture the effects of dissolved oxygen tension (DOT) on enzyme induction and enzyme expression were separately investigated. For both hydroxylations, an optimum DOT for induction was shown at 15% of saturation, while the optimum for expression is at 30% of saturation. Thus, maximum rates of hydroxylation were achieved when induction was performed at low DOT, followed by elevation to ensure maximum expression. The effects of specific glucose consumption rate and specific growth rate were investigated using chemostat cultures, under automatic DOT control (at 30% of saturation). At a constant specific growth rate, the importance of glucose metabolism to the hydroxylation process was demonstrated. Thus, with glucose-limited cultures, decreasing specific hydroxylation rates were observed with decreasing specific glucose consumption rates, possibly as a result of the restricted availability of NADPH, which is required for hydroxylation to occur. Conversely, with nitrogen-limited cultures, it was observed that the hydroxylase system is subject to glucose repression. Thus, with high specific glucose consumption rates, cultures showed low levels of hydroxylation activity. Maximum activity was obtained at a point, which apparently represents a balance between sufficient glucose metabolism to maintain full expression of activity and a condition of excess glucose uptake resulting in repression of activity. This finding may be of considerable significance for fungal steroid-hydroxylation processes in general, since relief of repression, when it exists, could give several-fold increases in specific hydroxylation rates as observed in this study. Over the range of specific growth rates studied (0.028 h-l to 0.119 h-l) no significant effect on specific hydroxylation rates was observed.