scholarly journals Chitinases from Bacteria to Human: Properties, Applications, and Future Perspectives

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Abhishek Singh Rathore ◽  
Rinkoo D. Gupta

Chitin is the second most plenteous polysaccharide in nature after cellulose, present in cell walls of several fungi, exoskeletons of insects, and crustacean shells. Chitin does not accumulate in the environment due to presence of bacterial chitinases, despite its abundance. These enzymes are able to degrade chitin present in the cell walls of fungi as well as the exoskeletons of insect. They have shown being the potential agents for biological control of the plant diseases caused by various pathogenic fungi and insect pests and thus can be used as an alternative to chemical pesticides. There has been steady increase in demand of chitin derivatives, obtained by action of chitinases on chitin polymer for various industrial, clinical, and pharmaceutical purposes. Hence, this review focuses on properties and applications of chitinases starting from bacteria, followed by fungi, insects, plants, and vertebrates. Designing of chitinase by applying directed laboratory evolution and rational approaches for improved catalytic activity for cost-effective field applications has also been explored.

Author(s):  
Arpitha Shankar

AMF (Arbuscular Mychorhizal Fungi) are very well known due to their importance in promoting growth and developments of plants especially vegetables. These fungi can be grown easily, stored and multiplied with simple means, also the application of these fungi is generally on the layer of the soil or near the roots in the inner layers of the soils. The growth of the amf fungi is very easy and they are highly adjustable to any soil and environmental conditions. In this review our main focus is on the use of amf for production of vegetables and also the effect of amf against insects and pests. The amf is known to reduce several symptoms caused by different insect pests and also plant diseases thereby promoting healthy growth of the plants. Also use of this amf will increase the uptake of nutrient from the soils through symbiotic relationships between plants and fungi. The uptake of important minerals which are drawn from deeper layers of soils is observed with the help pf amf. This study reveals the benefits of the use of amf under severe disease and pest incidences thereby known as an alternate for harmful chemical pesticides and fungicides.


1990 ◽  
Vol 62 (4) ◽  
pp. 295-307
Author(s):  
Asko O. Hannukkala ◽  
Jukka Korva ◽  
Eeva Tapio

The effects of four conventional and four organic cropping systems on the crop yield and yield quality, on the microbial activity of soil, on weeds, plant diseases, insect pests and earthworms were compared in a field experiment on the Suitia Experimental Farm in Southern Finland in 1982—1988. In the conventional cropping systems, industrial fertilisers and chemical pesticides were used according to practices adopted on actual farms in Southern Finland. In the organic cropping systems, plant nutrition was based on biological N fixation by legumes and organic manures. No chemical pesticides were used. The average yield of barley in organic cropping varied between one quarter and half of that in conventional cropping. The yields of winter wheat, oats and potato were about 40 % of those obtained conventionally. The yields of clover-grass leys in organic farming were similar to those of grass-leys in the conventional system. Unfortunately, the clover-grass leys outwintered after the first year. The primary reason for the poor crop growth in the organic cropping systems was apparently the acute N deficiency caused by poor performance of legumes, low N content of organic manures and N losses in anaerobic conditions often occurring during winter and early spring. Pronounced soil compaction and anaerobic conditions in organic cropping systems had a harmful effect on the microbiological activity of soil as well as on earthworms. Weeds, plant diseases and insects were not a remarkable problem in any of the cropping systems.


2019 ◽  
Vol 56 (Special Issue) ◽  
pp. 136-142 ◽  
Author(s):  
RK Tanwar ◽  
S Singh ◽  
SP Singh ◽  
Vikas Kumar Kanwar ◽  
Rakesh Kumar ◽  
...  

A basic IPM module for basmati rice as a part of integrated crop management accounting the pest prevalence and the information available from literature has been developed. As the module is location specific and dynamic, therefore needs regular updating and fine tuning depending on the location and pest prevalence. The technology has been successfully validated and implemented during 1998 to 2019 in Pusa Basmati 1, Taraori Basmati, Dehraduni Basmati, Pusa Basmati 1121 in Haryana, Uttar Pradesh and Uttarakhand with little modification and fine tuning. Implementation of the technology resulted in increase in rice grain yield i.e., 21.6% in Pusa Basmati 1 at Shikohpur, in Uttar Pradesh 21.5% in Taraori Basmati at Chhajpur in Haryana, 19.5% in Type 3 in Uttarakhand, 14.5 to 22.7% in Pusa Basmati 1121 in Haryana and 38.2% in Pusa Basmati 1121 in Uttar Pradesh over farmer's practices (FP). In all the basmati rice trials, higher yield as well as Benefit - Cost (B-C) ratio was obtained in IPM as compared to FP. Implementation of IPM led to significant reduction in uses of chemical pesticides. In case of IPM, only 1.46 application of chemical pesticides (103.2 g a.i./ha) were undertaken in Pusa Basmati 1121 against 2.8 application in FP (1214.4 g a.i./ha) at Bambawad, Uttar Pradesh. ICAR-NRRI, Cuttack developed and validated IPM module at Sigmapur (Cuttack, Odisha) non-Basmati rice variety Pooja for four kharif seasons i.e 2010-2013 using standard agronomic practices. The trial resulted in an enhancement of 47.1% yield and 26.47 % B-C ratio over FP. Additional income of Rs. 9857/- per ha was also obtained in IPM over FP. On-Farm trial on validation of IPM module in non-Basmati rice (Pooja variety) under semi deep water conditions conducted in 10 ha during rabi 2017 at Nagapur and Basudeipur villages in Khurda district of Odisha resulted in reduction in the incidence of insect pests and diseases with higher population of natural enemies as compared to FP. Rice yield was recorded 5600 kg ha-1 in IPM as against 4900 kg ha-1 in FP. Recently, ICT based e-pest monitoring and advisory has become an important component for area wise implementation of IPM at state and national level. The programme has been successfully implemented in Odisha during 2010 and 2011 under RKVY. Implementation of the programme had resulted successful management of swarming caterpillar in 13 rice growing districts of Odisha during kharif 2010 and 2011.


2021 ◽  
Vol 7 (3) ◽  
pp. 202
Author(s):  
Johannes Delgado-Ospina ◽  
Junior Bernardo Molina-Hernández ◽  
Clemencia Chaves-López ◽  
Gianfranco Romanazzi ◽  
Antonello Paparella

Background: The role of fungi in cocoa crops is mainly associated with plant diseases and contamination of harvest with unwanted metabolites such as mycotoxins that can reach the final consumer. However, in recent years there has been interest in discovering other existing interactions in the environment that may be beneficial, such as antagonism, commensalism, and the production of specific enzymes, among others. Scope and approach: This review summarizes the different fungi species involved in cocoa production and the cocoa supply chain. In particular, it examines the presence of fungal species during cultivation, harvest, fermentation, drying, and storage, emphasizing the factors that possibly influence their prevalence in the different stages of production and the health risks associated with the production of mycotoxins in the light of recent literature. Key findings and conclusion: Fungi associated with the cocoa production chain have many different roles. They have evolved in a varied range of ecosystems in close association with plants and various habitats, affecting nearly all the cocoa chain steps. Reports of the isolation of 60 genera of fungi were found, of which only 19 were involved in several stages. Although endophytic fungi can help control some diseases caused by pathogenic fungi, climate change, with increased rain and temperatures, together with intensified exchanges, can favour most of these fungal infections, and the presence of highly aggressive new fungal genotypes increasing the concern of mycotoxin production. For this reason, mitigation strategies need to be determined to prevent the spread of disease-causing fungi and preserve beneficial ones.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthew J. Byrne ◽  
Matthew G. Iadanza ◽  
Marcos Arribas Perez ◽  
Daniel P. Maskell ◽  
Rachel M. George ◽  
...  

AbstractInsect pests are a major cause of crop losses worldwide, with an estimated economic cost of $470 billion annually. Biotechnological tools have been introduced to control such insects without the need for chemical pesticides; for instance, the development of transgenic plants harbouring genes encoding insecticidal proteins. The Vip3 (vegetative insecticidal protein 3) family proteins from Bacillus thuringiensis convey toxicity to species within the Lepidoptera, and have wide potential applications in commercial agriculture. Vip3 proteins are proposed to exert their insecticidal activity through pore formation, though to date there is no mechanistic description of how this occurs on the membrane. Here we present cryo-EM structures of a Vip3 family toxin in both inactive and activated forms in conjunction with structural and functional data on toxin–membrane interactions. Together these data demonstrate that activated Vip3Bc1 complex is able to insert into membranes in a highly efficient manner, indicating that receptor binding is the likely driver of Vip3 specificity.


Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2682 ◽  
Author(s):  
Francis J. Osonga ◽  
Ali Akgul ◽  
Idris Yazgan ◽  
Ayfer Akgul ◽  
Gaddi B. Eshun ◽  
...  

Plant-based pathogenic microbes hinder the yield and quality of food production. Plant diseases have caused an increase in food costs due to crop destruction. There is a need to develop novel methods that can target and mitigate pathogenic microbes. This study focuses on investigating the effects of luteolin tetraphosphate derived silver nanoparticles (LTP-AgNPs) and gold nanoparticles (LTP-AuNPs) as a therapeutic agent on the growth and expression of plant-based bacteria and fungi. In this study, the silver and gold nanoparticles were synthesized at room temperature using luteolin tetraphosphate (LTP) as the reducing and capping agents. The synthesis of LTP-AgNPs and LTP-AuNP was characterized by Transmission Electron Microscopy (TEM) and size distribution. The TEM images of both LTP-AgNPs and LTP-AuNPs showed different sizes and shapes (spherical, quasi-spherical, and cuboidal). The antimicrobial test was conducted using fungi: Aspergillus nidulans, Trichaptum biforme, Penicillium italicum, Fusarium oxysporum, and Colletotrichum gloeosporioides, while the class of bacteria employed include Pseudomonas aeruginosa, Aeromonas hydrophila, Escherichia coli, and Citrobacter freundii as Gram (−) bacteria, and Listeria monocytogenes and Staphylococcus epidermidis as Gram (+) bacterium. The antifungal study demonstrated the selective size and shape-dependent capabilities in which smaller sized spherical (9 nm) and quasi-spherical (21 nm) AgNPs exhibited 100% inhibition of the tested fungi and bacteria. The LTP-AgNPs exhibited a higher antimicrobial activity than LTP-AuNPs. We have demonstrated that smaller sized AgNPs showed excellent inhibition of A. nidulans growth compared to the larger size nanoparticles. These results suggest that LTP-AuNP and LTP-AgNPs could be used to address the detection and remediation of pathogenic fungi, respectively.


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Sardul Singh Sandhu ◽  
Anil K. Sharma ◽  
Vikas Beniwal ◽  
Gunjan Goel ◽  
Priya Batra ◽  
...  

The growing demand for reducing chemical inputs in agriculture and increased resistance to insecticides have provided great impetus to the development of alternative forms of insect-pest control. Myco-biocontrol offers an attractive alternative to the use of chemical pesticides. Myco-biocontrol agents are naturally occurring organisms which are perceived as less damaging to the environment. Their mode of action appears little complex which makes it highly unlikely that resistance could be developed to a biopesticide. Past research has shown some promise of the use of fungi as a selective pesticide. The current paper updates us about the recent progress in the field of myco-biocontrol of insect pests and their possible mechanism of action to further enhance our understanding about the biological control of insect pests.


Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 639
Author(s):  
Yiling Sun ◽  
Ayelen Tayagui ◽  
Sarah Sale ◽  
Debolina Sarkar ◽  
Volker Nock ◽  
...  

Pathogenic fungi and oomycetes give rise to a significant number of animal and plant diseases. While the spread of these pathogenic microorganisms is increasing globally, emerging resistance to antifungal drugs is making associated diseases more difficult to treat. High-throughput screening (HTS) and new developments in lab-on-a-chip (LOC) platforms promise to aid the discovery of urgently required new control strategies and anti-fungal/oomycete drugs. In this review, we summarize existing HTS and emergent LOC approaches in the context of infection strategies and invasive growth exhibited by these microorganisms. To aid this, we introduce key biological aspects and review existing HTS platforms based on both conventional and LOC techniques. We then provide an in-depth discussion of more specialized LOC platforms for force measurements on hyphae and to study electro- and chemotaxis in spores, approaches which have the potential to aid the discovery of alternative drug targets on future HTS platforms. Finally, we conclude with a brief discussion of the technical developments required to improve the uptake of these platforms into the general laboratory environment.


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