Department of Microbiology
The research at the department of Microbiology at NCU is multidisciplinary and has 5 major broad areas of emphasis: microbe-host interactions, applied microbiology and biotechnology, microbial ecology and physiology, molecular microbiology and bioinformatic /-omics. We are currently working with bacteria, fungi and plant viruses.
The Department of Microbiology is home to the following research activities:
- Identification of mycorrhizal symbionts and exploring its potential in plant growth improvement
Mycorrhizae is a mutualistic symbiotic association between mycorrhizal fungi and plant roots. The plant obtains phosphate, other minerals and water through the fungus, while the fungus obtains sugars from the plant root. This relationship is very common in ecosystems and concerns about 80% of all known vascular plants. Two main types of mycorrhizae are known: endomycorrhizae and ectomycorrhizae. In the case of endomycorrhizae, e.g. vesicular-arbuscular mycorrhizae, fungal mycelium is embedded within the root tissue and form arbuscules and vesicules. Ectomycorrhizal fungi form so-called mantle around the plant roots and Hartig net between cortex cells. Our research is concern on the observation of mycorrhizal symbionts in natural forest ecosystem and impact of fungal inoculation on the growth and tolerance of abiotic stresses, e.g. salinity, by host plant. Moreover, our researches concern on taxonomic and functional analysis of these fungal community.
- Characterization of endophytes from extreme environments and deciphering their role in crop improvement.
Endophytes are organisms often fungi and bacteria, that live in and between living plant cells. The relationship that they establish with the plant varies from symbiotic to neutral. Of all of the world’s plants, only a few plant species are explored for endophytes. Hence the opportunity to find new and interesting endophytes among the myriad of plants is great. Our research objectives investigate on how and why the plant endophytic microbiome is so different from each other. Which environmental factors determine these differences and what are the consequences for ecosystem sustainability? Why this diversity exists and how it persists are the key questions that drive our research. Sometimes extremely unusual and valuable organic substances are produced by these endophytes that are sources of novel chemistry and biology to assist in helping solve not only plant health, but also human and animal health problems.
- Study on novel actinobacteria species from extreme environments and their application potential
Actinobacteria are abundant in soil environment. This versatile group of bacteria has adapted to diverse ecological habitats, which has drawn considerable attention of the scientific community in recent times, as it has opened up new possibilities for novel metabolites that may help in solving some of the most challenging problems of the day, for example, novel drugs for drug-resistant human pathogens, affordable means to maintain ecological balance in various habitats, and alternative practices for sustainable agriculture. Traditionally, free dwelling soil actinobacteria inhabiting common, well explored habitats have been the subject of intensive research. Of late, actinobacteria of harsh or extreme environments have generated immense interest as potential source of novel compounds, which may find applications in medicine, agriculture, and environment.
- Study on interactions between pathogenic viruses and plant symbiotic microorganisms co-infecting the same host
Plant Viruses are obligate intracellular phytopathogens affecting various plants including crops. Their transmission from one plant to another usually involves animal vectors (e.g. insects, nematodes, mites), however viruses can also be spread via sap exchange during mechanical damage of plant tissue. Viral infections can cause serious plant diseases with a wide range of symptoms, most often yellowing, mosaic or necrotic spots, growth distortion and abnormalities in fruit formation. Therefore viruses cause huge economical losses in crop production, having negative impact on plant yield quality and quantity. The objectives of our studies are interactions between pathogenic viruses and plant symbiotic microorganisms (e.g. endomycorrhizal fungi) co-infecting the same host. As plant symbionts increase host fitness and modulate host defence mechanisms, we aim to establish if they can be used as bioprotective factors against viruses. We study symbiont-dependent mechanisms underlying alleviation of virus-induced stress responses in plants.
- Biological synthesis of microbial nanoparticles
To date, different types of nanoparticles have been synthesized and being used in different fields for various applications including medicine and agriculture. In the recent years, metal and nonmetal nanoparticles have attracted much attention owing to their excellent high activity against many species of bacteria and fungi, including multi-resistant ones and cancer cells. For synthesis of bimetallic silver-gold and nonmetallic – selenium nanoparticles actinobacteria and fungi will be used as they are known from high metabolic activity, secretion of high amount of proteins and secondary metabolites. Moreover, biological synthesis of nanoparticles by using bacteria, fungi or plants is fast, cheap and eco-friendly when compared to chemical methods, and synthesized nanoparticles capped with molecules of natural origin.
- Application of plant growth-promoting bacteria (PGPB) against human pathogenic microorganisms (HPMO)
HPMOs have high survival strategies in environment. They can migrate via root system and colonize various plant parts such as roots, shoots, flowers and fruits. Washing step reduces the level of the human pathogens or spoilage organisms only marginal therefore, the major concern is how to get rid of the attached and internal bacteria which are difficult to wash off. Contamination of raw vegetables may occur during cultivation, harvesting, handling or distribution. In past few years, consumption of unprocessed vegetables has resulted in increased number of disease outbreaks caused by HPMOs. Bearing all this in mind, our research objectives investigate the use of plant growth-promoting bacteria (PGPB) against HPMO’s.
- Investigation of phosphate solubilizing microbes (PSMs)
Phosphate solubilizing microbes (PSMs) are a group of beneficial microorganisms capable of hydrolyzing organic and inorganic insoluble phosphorus compounds to soluble P form that can easily be assimilated by plants. Because the reserves of phosphorus on our planet are depleting quickly since the introduction of modern agriculture PSM became a hot topic among scientists from around the globe. Did you know that only 30% of phosphorus in artificial fertilizers applied to fields is uptaken by plants? The rest of phosphorus is quickly fixed to ions like Ca, F, or Al and becomes unavailable for plants contributing to the eutrophication process of surface waters. PSM with their ability to solubilize phosphate may be used to retain a significantly higher amount of P in the cycle. Research on our Department focuses on isolation, identification, and characterization of bacterial and fungal PSM.
- Assessing the effect of antibacterial agents on bacterial cell
Bacterial adhesion to surfaces is a complex process, involves specific and non-specific interactions related to the physicochemical properties of cells, surface and environmental conditions. Many bacteria exhibit the ability for adhesion to the surface of various materials. Adhesion and friction are closely related and play a predominant role in many natural processes. The direction in which forces are applied has shown to influence the bond strength of certain systems tremendously and can mean the difference between adhesion and detachment. By probing friction forces and the adhesion forces lateral to the surface, specific information can be obtained that possibly provide new clues for antiadhesive, or easy to clean surfaces. Discovery of new antibacterial agents requires the investigation the mechanism of action. Antibiotics cause a number of morphological changes in bacteria, which could modify the physicochemical cell properties, affecting the hydrophobicity, adhesion, biofilm formation or mobility. Our research objectives investigate on the effect of antibacterial agents on morphology and adhesive properties of Gram-positive and Gram-negative bacteria, using atomic force microscopy (AFM).