scholarly journals Screening and Identification of Strains With High Lignocellulose-degrading Enzyme Production From Endophytic Fungi of Taxillus Chinensis

Author(s):  
Lisha Song Song ◽  
Limei Pan Pan ◽  
Ni Jiang Jiang ◽  
Jine FU FU ◽  
Lingyun Wan Wan ◽  
...  

Abstract Taxillus chinensis is an extensively used medicinal herb in the traditional as well as modern systems of medicines. It is a perennial hemiparasitic plant, which is difficult to propagate artificially because of its low parasitic rate. Successful parasitism of parasitic plants is to fuse their tissues and connect their vasculature to the host vasculature building a physiological bridge, which can efficiently withdraw water, sugars and nutrients from their host plants. It is reported that endophytic fungi play an important role in cell wall degradation and fusion, which is the key forming process of the physiological bridge. Therefore, in this study, the endophytic fungi from T. chinensis of different hosts were isolated, and then the organisms that could degrade the main components of the cell walls were screened out using a medium consisting of guaihuol and cellulose degradation capacity. The results showed that five strains with high enzyme activities for lignocellulosic degradation were screened out from 72 endophytic fungi of T. chinensis. The laccase and cellulase activities of five strains reached their peaks at day 7, and the highest enzyme activities of these two enzymes were found in strain P6, which was 117.66 and 1.66 U/mL, respectively. Manganese peroxidase of strain 4 and lignin peroxidase of strain N6 also reached their peaks at day 7 and were the highest among the 5 strains, with enzyme activities of 11.61 and 6.64 U/mL, respectively. Strains 4, 15, 31, N6 and P6 were identified as Colletotrichum acutatum, Nigerrospora sphaerica, Exserohilum rofolium, Diaporthe phaseolorum and Pestalotiopsis arceuthobii, respectively, according to their morphological and molecular biology properties.

2020 ◽  
Vol 27 (11) ◽  
pp. 1836-1854 ◽  
Author(s):  
Elena Ancheeva ◽  
Georgios Daletos ◽  
Peter Proksch

Background: Endophytes represent a complex community of microorganisms colonizing asymptomatically internal tissues of higher plants. Several reports have shown that endophytes enhance the fitness of their host plants by direct production of bioactive secondary metabolites, which are involved in protecting the host against herbivores and pathogenic microbes. In addition, it is increasingly apparent that endophytes are able to biosynthesize medicinally important “phytochemicals”, originally believed to be produced only by their host plants. Objective: The present review provides an overview of secondary metabolites from endophytic fungi with pronounced biological activities covering the literature between 2010 and 2017. Special focus is given on studies aiming at exploration of the mode of action of these metabolites towards the discovery of leads from endophytic fungi. Moreover, this review critically evaluates the potential of endophytic fungi as alternative sources of bioactive “plant metabolites”. Results: Over the past few years, several promising lead structures from endophytic fungi have been described in the literature. In this review, 65 metabolites are outlined with pronounced biological activities, primarily as antimicrobial and cytotoxic agents. Some of these metabolites have shown to be highly selective or to possess novel mechanisms of action, which hold great promises as potential drug candidates. Conclusion: Endophytes represent an inexhaustible reservoir of pharmacologically important compounds. Moreover, endophytic fungi could be exploited for the sustainable production of bioactive “plant metabolites” in the future. Towards this aim, further insights into the dynamic endophyte - host plant interactions and origin of endophytic fungal genes would be of utmost importance.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 113
Author(s):  
Lech W. Szajdak ◽  
Teresa Meysner ◽  
Marek Szczepański

The aim of this study is to comprehensively assess the change in oxidoreductive enzyme activities, due to the potential in catalyzing oxidation and reduction reactions, as the basic processes on undrained and drained peat soils. On undrained peatlands, a significant decrease of enzyme activities was observed such as xanthine oxidase, urate oxidase, phenol oxidase, and peroxidase with an increase in depth. It was connected with significantly higher porosity values, hot water extractable organic carbon, and total organic nitrogen contents, ammonium and nitrate ions concentrations, and significantly lower ash and bulk density values in the upper layers. On drained peatlands, a significant increase of enzyme activities in depth was measured. Enzyme activities such as xanthine, urate, phenol oxidase, and peroxidase were documented to be effective as new indicators and tools for changes of the moorsh-forming process in association with the oscillation of the water table caused by the drainage of the peatlands.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ermelinda Botticella ◽  
Daniel Valentin Savatin ◽  
Francesco Sestili

Cereals represent an important source of beneficial compounds for human health, such as macro- and micronutrients, vitamins, and bioactive molecules. Generally, the consumption of whole-grain products is associated with significant health benefits, due to the elevated amount of dietary fiber (DF). However, the consumption of whole-grain foods is still modest compared to more refined products. In this sense, it is worth focusing on the increase of DF fractions inside the inner compartment of the seed, the endosperm, which represents the main part of the derived flour. The main components of the grain fiber are arabinoxylan (AX), β-glucan (βG), and resistant starch (RS). These three components are differently distributed in grains, however, all of them are represented in the endosperm. AX and βG, classified as non-starch polysaccharides (NSP), are in cell walls, whereas, RS is in the endosperm, being a starch fraction. As the chemical structure of DFs influences their digestibility, the identification of key actors involved in their metabolism can pave the way to improve their function in human health. Here, we reviewed the main achievements of plant biotechnologies in DFs manipulation in cereals, highlighting new genetic targets to be exploited, and main issues to face to increase the potential of cereals in fighting malnutrition.


1930 ◽  
Vol 8 (01) ◽  
pp. 115-121
Author(s):  
Israwati Harahap ◽  
Elsie

Endophytic fungi are microorganisms living in healthy tissue of their host plants without causing disease. Endophytic fungi live in every plant, including Vetiveria zizanioides L. medicinal plant intracellulary and/or intercellulary. This plant was screened pharmacologically for antibacterial, antifungal, anticataleptic, analgesic and anti-inflammatory, rheumatism, anti oxidant and anti arthritic activity. This research aimed to isolation endophytic fungi from V. zizanioides L. and to screening their antimicrobial potency against microflora Escherichia coli, Staphylococcus aureus, and Candida albicans. Endophytic fungi isolation from V. zizanioides L. was done by surface sterilization method. A total of 33 isolates were recovered from 88 leaves and 88 root segments. Based on antimicrobial activitytest, most of the fungal extracts showed in vitro inhibition of microbes growth.


2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Yanyan Zhang ◽  
Ting Han ◽  
Qianliang Ming ◽  
Lingshang Wu ◽  
Khalid Rahman ◽  
...  

In recent years, a number of alkaloids have been discovered from endophytic fungi in plants, which exhibited excellent biological properties such as antimicrobial, insecticidal, cytotoxic, and anticancer activities. This review mainly deals with the research progress on endophytic fungi for producing bioactive alkaloids such as quinoline and isoquinoline, amines and amides, indole derivatives, pyridines, and quinazolines. The biological activities and action mechanisms of these alkaloids from endophytic fungi are also introduced. Furthermore, the relationships between alkaloid-producing endophytes and their host plants, as well as their potential applications in the future are discussed.


Weed Science ◽  
1996 ◽  
Vol 44 (2) ◽  
pp. 224-232 ◽  
Author(s):  
Imuetinyan Igbinnosa ◽  
Patrick A. Thalouarn

N fertilizers suppress witchweed plant growth and development, thus reducing the severity of parasite attack and increasing host yield simultaneously. However, the underlying physiological mode of N action occurring within the parasite cells remains largely unknown. This study aims at screening for the effects of N forms and different growth conditions on some N assimilation enzymes in witchweed seedlings grown aseptically without host plant, and in pots with host plants. Results show that supply of N in NH4+or urea forms resulted in 83 to 92% reduction in nitrate reductase activity (NRc), compared with control. Increasing NO3−concentrations from 0 mM to 100 mM, led to a corresponding increase in NRc in giant witchweed. NRc of giant witchweed seedlings grown under light and dark cycles were about 270 times higher than seedlings grown in continuous darkness. A combination of NH4+and NO3−, resulted in increased giant witchweed NRc, compared with NH4+or NO3−supplied singly. Highest shoot development and NRc was at NH4+and NO3−ratio 1:1, followed by ratios 1:3, 3:1, 0:1, and 1:0, respectively. Addition of N in soils resulted in increased NRc, followed by rapid deterioration and death of giant witchweed plants. NRc, GSc, and GDHc in witchweed, maize, cowpea, and tobacco were affected by diurnal fluctuations with higher enzyme activities occurring during the day than at night. Higher GSc than GDHc suggests that NH4+assimilation occurs mainly through the GS pathway in witchweed plants. NRc and GDHc were two and four times higher in giant witchweed grown in aseptic media without host plant, than that grown in potted soils with host plants. These findings provide insight into the physiological mode of N action and their implications on witchweed control.


2008 ◽  
Vol 3 (8) ◽  
pp. 1934578X0800300 ◽  
Author(s):  
Abimbola A. Sowemimo ◽  
RuAngelie Edrada-Ebel ◽  
Rainer Ebel ◽  
Peter Proksch ◽  
Olanrewaju R. Omobuwajo ◽  
...  

In a chemical screening of fungal strains endophytic to Nigerian plants, Diaporthe phaseolorum, the endophyte of Bryophyllum pinnatum, gave cytochalasin D and (3 R,4 R)-3,4,5-trihydroxy-1-tetralone, Neurospora discreta from Morinda lucida yielded multiforisin I and 4-hydroxyphenylacetic acid, while Aspergillus japonicus from Jatropha gossypiifolia gave (+)-eupenoxide and microsphaerone C, a new 4-pyridone derivative. When tested for cytotoxic activity, cytochalasin D displayed strong activity towards the mouse lymphoma cell line L5178Y, while the remaining compounds, except 4-hydroxyphenylacetic acid, were found to be moderately active.


2009 ◽  
Vol 4 (11) ◽  
pp. 1934578X0900401 ◽  
Author(s):  
Vijay C. Verma ◽  
Ravindra N. Kharwar ◽  
Gary A. Strobel

This review describes examples of naturally occurring bioactive compounds obtained from fungal endophytes from various host plants. The main topics addressed are sources, identification, biological activity, biosynthesis, and ecological and chemosystematic significance of those bioactive compounds whose sources were well defined.


2010 ◽  
Vol 76 (12) ◽  
pp. 4063-4075 ◽  
Author(s):  
Michele T. Hoffman ◽  
A. Elizabeth Arnold

ABSTRACT Both the establishment and outcomes of plant-fungus symbioses can be influenced by abiotic factors, the interplay of fungal and plant genotypes, and additional microbes associated with fungal mycelia. Recently bacterial endosymbionts were documented in soilborne Glomeromycota and Mucoromycotina and in at least one species each of mycorrhizal Basidiomycota and Ascomycota. Here we show for the first time that phylogenetically diverse endohyphal bacteria occur in living hyphae of diverse foliar endophytes, including representatives of four classes of Ascomycota. We examined 414 isolates of endophytic fungi, isolated from photosynthetic tissues of six species of cupressaceous trees in five biogeographic provinces, for endohyphal bacteria using microscopy and molecular techniques. Viable bacteria were observed within living hyphae of endophytic Pezizomycetes, Dothideomycetes, Eurotiomycetes, and Sordariomycetes from all tree species and biotic regions surveyed. A focus on 29 fungus/bacterium associations revealed that bacterial and fungal phylogenies were incongruent with each other and with taxonomic relationships of host plants. Overall, eight families and 15 distinct genotypes of endohyphal bacteria were recovered; most were members of the Proteobacteria, but a small number of Bacillaceae also were found, including one that appears to occur as an endophyte of plants. Frequent loss of bacteria following subculturing suggests a facultative association. Our study recovered distinct lineages of endohyphal bacteria relative to previous studies, is the first to document their occurrence in foliar endophytes representing four of the most species-rich classes of fungi, and highlights for the first time their diversity and phylogenetic relationships with regard both to the endophytes they inhabit and the plants in which these endophyte-bacterium symbiota occur.


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