scholarly journals Morphological growth pattern of Phanerochaete chrysosporium cultivated on different Miscanthus x giganteus biomass fractions

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hassan Khalil ◽  
Estelle Legin ◽  
Bernard Kurek ◽  
Patrick Perre ◽  
Behnam Taidi

Abstract Background Solid-state fermentation is a fungal culture technique used to produce compounds and products of industrial interest. The growth behaviour of filamentous fungi on solid media is challenging to study due to the intermixity of the substrate and the growing organism. Several strategies are available to measure indirectly the fungal biomass during the fermentation such as following the biochemical production of mycelium-specific components or microscopic observation. The microscopic observation of the development of the mycelium, on lignocellulosic substrate, has not been reported. In this study, we set up an experimental protocol based on microscopy and image processing through which we investigated the growth pattern of Phanerochaete chrysosporium on different Miscanthus x giganteus biomass fractions. Results Object coalescence, the occupied surface area, and radial expansion of the colony were measured in time. The substrate was sterilized by autoclaving, which could be considered a type of pre-treatment. The fastest growth rate was measured on the unfractionated biomass, followed by the soluble fraction of the biomass, then the residual solid fractions. The growth rate on the different fractions of the substrate was additive, suggesting that both the solid and soluble fractions were used by the fungus. Based on the FTIR analysis, there were differences in composition between the solid and soluble fractions of the substrate, but the main components for growth were always present. We propose using this novel method for measuring the very initial fungal growth by following the variation of the number of objects over time. Once growth is established, the growth can be followed by measurement of the occupied surface by the mycelium. Conclusion Our data showed that the growth was affected from the very beginning by the nature of the substrate. The most extensive colonization of the surface was observed with the unfractionated substrate containing both soluble and solid components. The methodology was practical and may be applied to investigate the growth of other fungi, including the influence of environmental parameters on the fungal growth.

2020 ◽  
Author(s):  
Hassan KHALIL ◽  
Estelle LEGIN ◽  
Bernard KUREK ◽  
Patrick PERRE ◽  
Behnam TAIDI

Abstract The growth pattern of Phanerochaete chrysosporium on different Miscanthus x giganteus biomass fractions was investigated via an original method based on microscopy and image processing. The growth medium, together with image acquisition, was designed to study the mycelia growth non-invasively. Object coalescence, the colonized surface area, and radial expansion of the colony were measured. The substrate was sterilized by autoclaving, which could be considered a pre-treatment. The fastest growth rate was measured on the entire biomass, followed by the soluble fraction of the biomass, and finally, the residual solid fraction of the substrate pre-treated by autoclave. The growth rate on the different fractions of the substrate was additive, suggesting that both the solid and liquid fractions were used by the fungus, although the solid fraction of the substrate seemed to provide a richer but less accessible nutritional source. Based on the FTIR analysis, there were differences in composition between the solid and soluble fractions of the substrate, but the main components for growth were always present. We propose using this novel method for measuring initial fungal growth by following the variation of the number of objects over time. The methodology may be applied to the examination of other filamentous fungi.


Author(s):  
Ravindra Pogaku ◽  
Sripathi Kulkarni

The biosorption of eight different metals from aqueous solutions of combined industrial effluent by live or dead cells of Phanerochaete chrysosporium was investigated. Growth rate studies of P. chrysosporium were carried out in a selected medium as well as in the effluent. The specific growth rate of the fungus was in the range of 0.089–0.102 h–1 in the medium. The biosorption of metal ions increased as the initial concentration of metal ions increased in the medium. Biosorption equilibrium was established in about 1 h and the concentration of adsorbed metal ions did not change further with time. The equilibrium was well described by Langmuir, Freundlich and Reidlich – Peterson isotherms. The dead fungal biomass was more effective than living fungus for biosorption of metals. The optimum pH for the fungal growth was at 4.5 but enhanced Biosorption was at pH 6 for maximum reduction of hexavalent chromium to trivalent.


2004 ◽  
Vol 4 (4) ◽  
pp. 175-182 ◽  
Author(s):  
K. Rojek ◽  
F.A. Roddick ◽  
A. Parkinson

Phanerochaete chrysosporium was shown to rapidly decolorise a solution of natural organic matter (NOM). The effect of various parameters such as carbon and nitrogen content, pH, ionic strength, NOM concentration and addition of Mn2+ on the colour removal process was investigated. The rapid decolorisation was related to fungal growth and biosorption rather than biodegradation as neither carbon nor nitrogen limitation, nor Mn2+ addition, triggered the decolorisation process. Low pH (pH 3) and increased ionic strength (up to 50 g L‒1 added NaCl) led to greater specific removal (NOM/unit biomass), probably due to increased electrostatic bonding between the humic material and the biomass. Adsorption of NOM with viable and inactivated (autoclaved or by sodium azide) fungal pellets occurred within 24 hours and the colour removal depended on the viability, method of inactivation and pH. Colour removal by viable pellets was higher under the same conditions, and this, combined with desorption data, confirmed that fungal metabolic activity was important in the decolorisation process. Overall, removals of up to 40–50% NOM from solution were obtained. Of this, removal by adsorption was estimated as 60–70%, half of which was physicochemical, the other half metabolically-dependent biosorption and bioaccumulation. The remainder was considered to be removed by biodegradation, although some of this may be ascribed to bioaccumulation and metabolically-dependent biosorption.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Petra G. Šimková ◽  
Gerhard W. Weber ◽  
Fernando V. Ramirez Rozzi ◽  
Lotfi Slimani ◽  
Jérémy Sadoine ◽  
...  

AbstractThe Baka Pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-Pygmy populations. However, the Baka’s dental morphology, like several other aspects of their biology, is still understudied. Here, we explore the variation of the Baka’s deciduous upper and lower second molars (dm2s) in comparison to a geographically heterogeneous human sample by means of 3D geometric morphometrics and analysis of dental traits. Our results show that the different populations largely overlap based on the shape of their dm2s, especially the lower ones. Their distal region and the height of the dentinal crown differ the most, with the Baka showing the most extreme range of variation. Upper and lower dm2s covary to a great extent (RV = 0.82). The Baka’s and South Americans’ dm2s were confirmed among the largest in our sample. Despite the Baka’s unique growth pattern, long-lasting isolation, and extreme dental variation, it is not possible to distinguish them from other populations based on their dm2s’ morphology only.


Author(s):  
Holger Pettersson ◽  
Dempsey S. Springfield ◽  
William F. Enneking

2021 ◽  
Author(s):  
Dalel Daâssi ◽  
Fatimah Qabil Almaghribi

Abstract The aim of this work was to isolate indigenous PAH degrading-fungi from petroleum contaminated soil and exogenous ligninolytic strains from decaying-wood, with the ability to secrete diverse enzyme activity. A total of ten ligninolytic fungal isolates and two native strains, has been successfully isolated, screened and identified. The phylogenetic analysis revealed that the indigenous fungi (KBR1 and KB8) belong to the genus Aspergillus niger and tubingensis. While the ligninolytic exogenous PAH-degrading strains namely KBR1-1, KB4, KB2 and LB3 were affiliated to different genera like Syncephalastrum sp, Paecilomyces formosus, Fusarium chlamydosporum, and Coniochaeta sp., respectively. Basis on the taxonomic analysis, enzymatic activities and the hydrocarbons removal rates, single fungal culture employing the strain LB3, KB4, KBR1 and the mixed culture (LB3+KB4) were selected to be used in soil microcosms treatments. The Total petroleum hydrocarbons (TPH), fungal growth rates, BOD5/COD ratios and GC-MS analysis, were determined in all soil microcosmos treatments (SMT) and compared with those of the control (SMU). After 60 days of culture incubation, the highest rate of TPH degradation was recorded in SMT[KB4] by approximately 92±2.35% followed by SMT[KBR1] then SMT[LB3+KB4] with 86.66±1.83% and 85.14±2.21%, respectively.


2021 ◽  
Vol 62 (4) ◽  
pp. 333-339
Author(s):  
Imo Okorie ◽  
Romanus Nwokorie

The growth of fungi on the surface of metals has great influence on their structural integrity and failure. Their growth on metal surfaces is determined by their secreted metabolites which enable them to adapt to new environmental and nourishment conditions. Although information on the capacity of fungi to adapt to metal surfaces is scarce, most fungi growing on metal surfaces alter the composition of the metals involving it in the process of functional growth and metabolism. Changes in the composition and colour of the metals are some of the evidences confirming that fungus has penetrated the metal surfaces and use it to satisfy its nutritional need with resultant corrosion. In this work we tried to explain different mechanisms of fungal influenced corrosion from different perspectives ranging from the role of biofilms, corrosive media generation by fungal metabolism processes to electrochemical processes generated by fungal growth on metal surfaces. Finally, no single mechanism can conclusively explain all forms of fungal influenced corrosion because every mechanism is unique and applies to individual fungus, its metabolic biproducts or the growth pattern.


2020 ◽  
Author(s):  
Natalia Schiefermeier-Mach ◽  
Susanne Perkhofer ◽  
Lea Heinrich ◽  
Thomas Haller

Abstract Aspergillus fumigatus is an opportunistic fungal pathogen with small airborne spores (conidia) that may escape clearance by upper airways and directly impact the alveolar epithelium. Consequently, innate alveolar defense mechanisms are being activated, including professional phagocytosis by alveolar macrophages, recruitment of circulating neutrophils and probably enhanced secretion of pulmonary surfactant by the alveolar type II (AT II) cells. However, no data are available in support of the latter hypothesis. We therefore used a coculture model of GFP-Aspergillus conidia with primary rat AT II cells and studied fungal growth, cellular Ca2+ homeostasis, and pulmonary surfactant exocytosis by live cell video microscopy. We observed all stages of fungal development, including reversible attachment, binding and internalization of conidia as well as conidial swelling, formation of germ tubes and outgrowth of hyphae. In contrast to resting conidia, which did not provoke immediate cellular effects, metabolically active conidia, fungal cellular extracts (CE) and fungal culture filtrates (CF) prepared from swollen conidia caused a Ca2+-independent exocytosis. Ca2+ signals of greatly varying delays, durations and amplitudes were observed by applying CE or CF obtained from hyphae of A. fumigatus, suggesting compounds secreted by filamentous A. fumigatus that severely interfere with AT II cell Ca2+ homeostasis. The mechanisms underlying the stimulatory effects, with respect to exocytosis and Ca2+ signaling, are unclear and need to be identified.


1988 ◽  
Vol 18 (2) ◽  
pp. 188-194 ◽  
Author(s):  
Roberto Calamassi ◽  
Mauro Falusi ◽  
Laura Mugnai

The process of primary growth in 2-year-old seedlings of six Pinusbrutia Ten. provenances is described. At the end of the first growing season, two types of shoot morphology were observed: type 1, a terminal winter bud, and type 2, a terminal rosette of primary needles protecting the meristematic apex. During the 2nd year the seedlings exhibited a succession of shoots (varying in number from one to five), each of which was due to the elongation of a new apical bud. Morphological observations along with an anatomical examination of the winter bud led to the conclusion that the growth pattern in juvenile P. brutia is monocyclic with a variable number of summer shoots (using the terminology proposed by Lanner (Lanner, R.M. 1976. In Tree physiology and yield improvement. Editedby M.G.R. Cannell and F.T. Last. Academic Press, London, pp. 223-243)). The provenances studied differed both in growth potential and in seasonal growth pattern (differences in number of shoots, ratio of spring shoot to total growth, growth rate). Two groups could be identified: (i) the provenances of the island of Crete, which had a low growth potential and short growing season, and (ii) the high-altitude provenances of inland Turkey, with high growth potential and a growth rate that peaked in summer.


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