scholarly journals Integration of chemosensing and carbon catabolite repression impacts fungal enzyme regulation and plant associations

2021 ◽  
Author(s):  
Wolfgang Hinterdobler ◽  
Guofen Li ◽  
David Turra ◽  
Miriam Schalamun ◽  
Stefanie Kindel ◽  
...  
Keyword(s):  
Enzyme Production ◽  
Plant Biomass ◽  
Enzyme Regulation ◽  
Strain Improvement ◽  
Living Environment ◽  
Plant Associations ◽  
Catabolite Repressor ◽  
Dead Plant ◽  
G Protein Coupled ◽  
Plant Surfaces

Fungal metabolism and enzyme production are regulated by nutrient availability and by interactions with the living environment. We investigated the mechanisms underpinning adaptation of the biotechnological fungus Trichoderma reesei to decaying plant biomass versus living plants. We found that concentration-gated response to glucose, the main molecule sensed from dead plant biomass, is mediated by a conserved signaling pathway downstream of G protein-coupled receptors (GPCRs), while the carbon catabolite repressor CRE1 is critical for glucose concentration gating. The GPCRs CSG1 and CSG2 are further required for root colonization and formation of appressorium like structures on plant surfaces. Acceleration of sexual development in the presence of plant roots and their interactions with fruiting bodies indicates preferential association with plants. Our results reveal a complex sensing network governing resource distribution, enzyme production and fungal development that explains previously observed phenomena in fermentations and opens new perspectives for industrial strain improvement and agriculture.

Bioremediation of Acid Mine Drainage in an Uranium Deposit

2007 ◽  
Vol 20-21 ◽  
pp. 248-257 ◽  
Author(s):  
Stoyan N. Groudev ◽  
Plamen S. Georgiev ◽  
Irena Spasova ◽  
Marina Nicolova
Keyword(s):  
Mine Drainage ◽  
Plant Biomass ◽  
Uranium Deposit ◽  
Water Flow Rate ◽  
Ambient Temperatures ◽  
Zinc Cadmium ◽  
Copper Zinc ◽  
Cadmium Lead ◽  
Dead Plant ◽  
The Individual

Acid drainage waters generated in the uranium deposit Curilo, Bulgaria, were treated by means of different passive systems such as natural and constructed wetlands, alkalizing limestone drains, permeable reactive multibarriers and a rock filter, used separately or in different combinations. The waters had a pH in the range of about 2 – 4 and contained radionuclides (uranium, radium), heavy metals (copper, zinc, cadmium, lead, nickel, cobalt, iron, manganese), arsenic and sulphates in concentrations usually much higher than the relevant permissible levels for waters intended for use in agriculture and/or industry. The water flow rate through the individual systems was different and not stable, and varied in the range approximately from 0.02 to 1.5 l/s. Efficient removal of pollutants was achieved by means of these systems during the different climatic seasons, even during the cold winter months at water and ambient temperatures close to 0 oC. The removal was due to different mechanisms but microbial sulphate reduction, biosorption by living and dead plant biomass and chemical neutralization played the main roles.

scholarly journals Kluyveromyces marxianus: Current State of Omics Studies, Strain Improvement Strategy and Potential Industrial Implementation

Fermentation ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 124
Author(s):  
Dung Minh Ha-Tran ◽  
Trinh Thi My Nguyen ◽  
Chieh-Chen Huang
Keyword(s):  
High Temperature ◽  
Ethanol Production ◽  
Kluyveromyces Marxianus ◽  
Plant Biomass ◽  
High Titer ◽  
Carbon Sources ◽  
Strain Improvement ◽  
Improvement Strategy ◽  
Yeast Saccharomyces Cerevisiae ◽  
Wide Range

Bioethanol is considered an excellent alternative to fossil fuels, since it importantly contributes to the reduced consumption of crude oil, and to the alleviation of environmental pollution. Up to now, the baker yeast Saccharomyces cerevisiae is the most common eukaryotic microorganism used in ethanol production. The inability of S. cerevisiae to grow on pentoses, however, hinders its effective growth on plant biomass hydrolysates, which contain large amounts of C5 and C12 sugars. The industrial-scale bioprocessing requires high temperature bioreactors, diverse carbon sources, and the high titer production of volatile compounds. These criteria indicate that the search for alternative microbes possessing useful traits that meet the required standards of bioethanol production is necessary. Compared to other yeasts, Kluyveromyces marxianus has several advantages over others, e.g., it could grow on a broad spectrum of substrates (C5, C6 and C12 sugars); tolerate high temperature, toxins, and a wide range of pH values; and produce volatile short-chain ester. K. marxianus also shows a high ethanol production rate at high temperature and is a Crabtree-negative species. These attributes make K. marxianus promising as an industrial host for the biosynthesis of biofuels and other valuable chemicals.

scholarly journals Efficient Degradation of Feather by Keratinase ProducingBacillussp.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
P. Jeevana Lakshmi ◽  
Ch. M. Kumari Chitturi ◽  
V. V. Lakshmi
Keyword(s):  
Culture Filtrate ◽  
Enzyme Production ◽  
Strain Improvement ◽  
Physical Parameters ◽  
Total Free Amino Acids ◽  
Bean Meal ◽  
Soya Bean Meal ◽  
Poultry Feather ◽  
Native Strains ◽  
Hydrolysis Of

Keratinase producing microorganisms are being increasingly utilized for degradation and recycling of poultry feather waste. Two native strains BF11 (Bacillus subtilis) and BF21 (Bacillus cereus) degrading keratin completely were characterized. The native strains produced more than 10 KU/mL of enzyme. Strain improvement resulted in isolation of MBF11 and MBF21 from BF11 and BF21 isolates, respectively. Optimization of nutritional and physical parameters of these MBF isolates at laboratory scale increased the overall keratinase activity by 50-fold resulting in a yield of 518–520 KU/mL. Fermentation media designed with starch as carbon source and soya bean meal as nitrogen source supported high levels of enzyme production. The optimum conditions for enzyme production were determined to be pH 8.5 and temperatures of 45–55°C for MBF11 and 37°C for MBF21, respectively. Culture filtrate showed a significant increase in the amounts of cysteine, cystine, methionine, and total free amino acids during the fermentation period. The ratio of organic sulphur concentration was also considerably higher than that of the inorganic sulphate in the culture filtrate suggesting the hydrolysis of disulphide by the isolates.

scholarly journals Myceliophthora thermophila Xyr1 is predominantly involved in xylan degradation and xylose catabolism

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Ana Carolina dos Santos Gomes ◽  
Daniel Falkoski ◽  
Evy Battaglia ◽  
Mao Peng ◽  
Maira Nicolau de Almeida ◽  
...  
Keyword(s):  
Plant Biomass ◽  
Strain Improvement ◽  
Basic Knowledge ◽  
Myceliophthora Thermophila ◽  
Wild Type ◽  
Degrading Enzymes ◽  
Biomass Saccharification ◽  
Regulatory Systems ◽  
Genes Encoding ◽  
Pentose Transport

Abstract Background Myceliophthora thermophila is a thermophilic ascomycete fungus that is used as a producer of enzyme cocktails used in plant biomass saccharification. Further development of this species as an industrial enzyme factory requires a detailed understanding of its regulatory systems driving the production of plant biomass-degrading enzymes. In this study, we analyzed the function of MtXlr1, an ortholog of the (hemi-)cellulolytic regulator XlnR first identified in another industrially relevant fungus, Aspergillus niger. Results The Mtxlr1 gene was deleted and the resulting strain was compared to the wild type using growth profiling and transcriptomics. The deletion strain was unable to grow on xylan and d-xylose, but showed only a small growth reduction on l-arabinose, and grew similar to the wild type on Avicel and cellulose. These results were supported by the transcriptome analyses which revealed reduction of genes encoding xylan-degrading enzymes, enzymes of the pentose catabolic pathway and putative pentose transporters. In contrast, no or minimal effects were observed for the expression of cellulolytic genes. Conclusions Myceliophthora thermophila MtXlr1 controls the expression of xylanolytic genes and genes involved in pentose transport and catabolism, but has no significant effects on the production of cellulases. It therefore resembles more the role of its ortholog in Neurospora crassa, rather than the broader role described for this regulator in A. niger and Trichoderma reesei. By revealing the range of genes controlled by MtXlr1, our results provide the basic knowledge for targeted strain improvement by overproducing or constitutively activating this regulator, to further improve the biotechnological value of M. thermophila.

scholarly journals Ant Community in Neotropical Agrosystems: A Four-Year Study in Conventional and No-Tillage Systems

Sociobiology ◽  
2018 ◽  
Vol 65 (2) ◽  
pp. 130 ◽  
Author(s):  
Wedson Desidério Fernandes ◽  
Denise Lange ◽  
Janser Moura Pereira ◽  
Josué Raizer
Keyword(s):  
Soil Fauna ◽  
Plant Biomass ◽  
Agricultural Practices ◽  
Conventional Tillage ◽  
No Tillage ◽  
Environmental Complexity ◽  
Ant Communities ◽  
Ant Community ◽  
Tillage System ◽  
Dead Plant

Studies comparing agricultural practices that maintain a better quality and a healthy soil fauna consider the no-tillage farming as the most effective practice when compared to other planting techniques. In order to evaluate the influence of the no-tillage and conventional tillage methods (with and without manipulation of the soil before planting, respectively) on ant communities, we monitored two areas with these two types of practice (conventional and no-tillage) over the period of four years. We collected ants once per month along 10 transects randomly distributed using three pitfall traps in each area. In addition, we collected the dead plant biomass present at each point sampled as a parameter for measuring the environmental complexity of the areas. In total, we captured 27,480 individuals belonging to 26 species in the no-tillage area and 24,570 individuals belonging to 24 species in the conventional tillage area. The generalised linear model analysis showed that the no-tillage system had the highest abundance of individuals, as well as richness and diversity of species, during most of the study period, as compared to conventional tillage areas. We also found a significant positive correlation between species richness and dead plant biomass. Thus, it is possible to infer that the no-tillage area is a more complex environment with a greater diversity of ants and, therefore, a more sustainable agrosystem as compared to conventional tillage areas.

scholarly journals Enzyme Activities at Different Stages of Plant Biomass Decomposition in Three Species of Fungus-Growing Termites

2017 ◽  
Vol 84 (5) ◽  
Author(s):  
Rafael R. da Costa ◽  
Haofu Hu ◽  
Bo Pilgaard ◽  
Sabine M. E. Vreeburg ◽  
Julia Schückel ◽  
...  
Keyword(s):  
Plant Material ◽  
Plant Biomass ◽  
Fungal Spores ◽  
Decomposition Process ◽  
Old World ◽  
Content Type ◽  
Substrate Conversion ◽  
Fungus Comb ◽  
Dead Plant ◽  
Plant Polymer

ABSTRACTFungus-growing termites rely on mutualistic fungi of the genusTermitomycesand gut microbes for plant biomass degradation. Due to a certain degree of symbiont complementarity, this tripartite symbiosis has evolved as a complex bioreactor, enabling decomposition of nearly any plant polymer, likely contributing to the success of the termites as one of the main plant decomposers in the Old World. In this study, we evaluated which plant polymers are decomposed and which enzymes are active during the decomposition process in two major genera of fungus-growing termites. We found a diversity of active enzymes at different stages of decomposition and a consistent decrease in plant components during the decomposition process. Furthermore, our findings are consistent with the hypothesis that termites transport enzymes from the older mature parts of the fungus comb through young worker guts to freshly inoculated plant substrate. However, preliminary fungal RNA sequencing (RNA-seq) analyses suggest that this likely transport is supplemented with enzymes producedin situ. Our findings support that the maintenance of an external fungus comb, inoculated with an optimal mixture of plant material, fungal spores, and enzymes, is likely the key to the extraordinarily efficient plant decomposition in fungus-growing termites.IMPORTANCEFungus-growing termites have a substantial ecological footprint in the Old World (sub)tropics due to their ability to decompose dead plant material. Through the establishment of an elaborate plant biomass inoculation strategy and through fungal and bacterial enzyme contributions, this farming symbiosis has become an efficient and versatile aerobic bioreactor for plant substrate conversion. Since little is known about what enzymes are expressed and where they are active at different stages of the decomposition process, we used enzyme assays, transcriptomics, and plant content measurements to shed light on how this decomposition of plant substrate is so effectively accomplished.

scholarly journals Penicillium subrubescens adapts its enzyme production to the composition of plant biomass

2020 ◽  
Vol 311 ◽  
pp. 123477
Author(s):  
Adiphol Dilokpimol ◽  
Mao Peng ◽  
Marcos Di Falco ◽  
Thomas Chin A Woeng ◽  
Rosa M.W. Hegi ◽  
...  
Keyword(s):  
Enzyme Production ◽  
Plant Biomass

scholarly journals Symbiont-Mediated Digestion of Plant Biomass in Fungus-Farming Insects

2021 ◽  
Vol 66 (1) ◽  
pp. 297-316 ◽  
Author(s):  
Hongjie Li ◽  
Soleil E. Young ◽  
Michael Poulsen ◽  
Cameron R. Currie
Keyword(s):  
Plant Material ◽  
Plant Biomass ◽  
Herbivorous Insects ◽  
Bacterial Symbionts ◽  
Seminal Work ◽  
Carbohydrate Active Enzyme ◽  
Plant Feeding ◽  
Enzyme Discovery ◽  
Genomic Studies ◽  
Dead Plant

Feeding on living or dead plant material is widespread in insects. Seminal work on termites and aphids has provided profound insights into the critical nutritional role that microbes play in plant-feeding insects. Some ants, beetles, and termites, among others, have evolved the ability to use microbes to gain indirect access to plant substrate through the farming of a fungus on which they feed. Recent genomic studies, including studies of insect hosts and fungal and bacterial symbionts, as well as metagenomics and proteomics, have provided important insights into plant biomass digestion across insect–fungal mutualisms. Not only do advances in understanding of the divergent and complementary functions of complex symbionts reveal the mechanism of how these herbivorous insects catabolize plant biomass, but these symbionts also represent a promising reservoir for novel carbohydrate-active enzyme discovery, which is of considerable biotechnological interest.

scholarly journals Appressorium: The Breakthrough in Dikarya

2019 ◽  
Vol 5 (3) ◽  
pp. 72 ◽  
Author(s):  
Alexander Demoor ◽  
Philippe Silar ◽  
Sylvain Brun
Keyword(s):  
Filamentous Fungi ◽  
Mycorrhizal Fungi ◽  
Large Range ◽  
Plant Biomass ◽  
Podospora Anserina ◽  
Evolutionary Origin ◽  
Saprotrophic Fungi ◽  
Mutualistic Fungi ◽  
Dead Plant

Phytopathogenic and mycorrhizal fungi often penetrate living hosts by using appressoria and related structures. The differentiation of similar structures in saprotrophic fungi to penetrate dead plant biomass has seldom been investigated and has been reported only in the model fungus Podospora anserina. Here, we report on the ability of many saprotrophs from a large range of taxa to produce appressoria on cellophane. Most Ascomycota and Basidiomycota were able to form appressoria. In contrast, none of the three investigated Mucoromycotina was able to differentiate such structures. The ability of filamentous fungi to differentiate appressoria no longer belongs solely to pathogenic or mutualistic fungi, and this raises the question of the evolutionary origin of the appressorium in Eumycetes.

Range of variability in boreal aspen plant communities after wildfire and clear-cutting

2004 ◽  
Vol 34 (2) ◽  
pp. 274-288 ◽  
Author(s):  
Sybille Haeussler ◽  
Yves Bergeron
Keyword(s):  
Plant Communities ◽  
Populus Tremuloides ◽  
Plant Biomass ◽  
Spatial Scales ◽  
Basal Area ◽  
Structural Diversity ◽  
Clear Cutting ◽  
Dead Plant ◽  
Live Tree ◽  
Canadian Boreal Forest

Composition, structure, and diversity of vascular and nonvascular plant communities was compared 3 years after wildfire and clear-cutting in mesic trembling aspen (Populus tremuloides Michx.) forests of the southern Canadian boreal forest. We examined mean response to disturbance and variability around the mean across four to five spatial scales. Four 1997 wildfires were located near Timmins, Ontario, and ten 1996–1997 clearcuts were located adjacent to the wildfires. We randomly located plots within mesic, aspen-dominated stands selected to minimize predisturbance environmental differences. Correspondence analysis separated wildfire and clearcut samples based on community composition: wildfires had more aspen suckers, Diervilla lonicera Mill., and pioneering mosses; clearcuts had more under story tall shrubs, forbs, bryophytes, and lichens. Live tree basal area averaged 1.7 m2/ha in wildfires and 1.8 m2/ha in clearcuts (p = 0.59), and understory community structure (the horizontal and vertical distribution of live and dead plant biomass) was not markedly different. Clearcuts had higher species richness with greater variance than wildfires across all spatial scales tested, but differences in beta and structural diversity varied with spatial scale. Generally, clearcut–wildfire differences were more evident and wildfire variability greater at larger analytical scales, suggesting that plant biodiversity monitoring should emphasize cumulative effects across landscapes and regions.

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