Ph.D.
Vandana K.B.
Arsenic is a toxic metalloid which severely threatens biota and human health. Consumption of arsenic-tainted water has created a public health crisis in many countries including India, Bangladesh, and USA. Our study investigates three arsenic tolerant strains, Shewanella sp. ANA-3, Micrococcus luteus BPB1 and Deinococcus indicus, for their ability to mobilize arsenic from ground water. ANA-3 serves as a good model to study the molecular basis of arsenate [As(V)] respiration in bacteria, while M.luteus BPB1 and D.indicus are indigenously isolated strains from India exhibiting high tolerance to As(V). We have developed ars mutants of the strains through conjugation with the mariner-based transposon, TnSC189. TnSC189 is a unique transposes with a high efficiency of insertional mutagenesis and ease of screening. Arsenic mutants are screened for loss of function and inverse PCR is employed to amplify transposon-flanking sequences using specific primers. Investigations are underway to elucidate the genes involved in arsenic resistance in the strains.
B. Cibichakravarthy
We focus on the molecular methods to provide knowledge about the ecology of gut flora of epigeal termites. Termites are social insects and they feed on lignocellulosic materials for their survival. The ability for the efficient degradation of recalcitrant lignocellulose has to be dependent on its multi-layered symbiotic microbiota. However, the majority of the microbial species are unculturable, thus limiting the role of individual and interrelationships among the gut microbes. Our study focuses on culture dependent and independent methods to decipher this complicated gut biogeography of termites.
S. Balaji
Aedes mosquitoes are dominant vector species for dengue virus transmission and wide spread in urban areas of India. Mostly difficult to cure post infective cases due to the lack of specific treatment and vaccine against dengue. Alternatively, vector population control is in progress to restrict it dissemination. For that, frequently used chemicals often fail because of the developed resistance and adverse effects on non-target sources. In contrast, genetic approaches are promising way to control the mosquito population. Specifically, in paratransgenic approach symbiotic bacteria are genetically modified to express effector molecule within the vector to restrict it fitness. Present work is focussed on gut bacterial diversity of Aedes mosquitoes for the identification of efficient symbiotic bacteria that can be transmitted to the subsequent generations as well as to identify the selective lethal gene to inhibit virus replication and its transmission.
S. Princy
Considering hexavalent chromium as one of the toxic heavy metal released from the tannery industries. Our current research is focused on assessing the toxicity of hexavalent chromium using bacterial cultures isolated from tannery effluent samples and trying to characterize the mechanism of chromium reduction in the selected bacterial isolates. The deposition of such hexavalent chromium in the environment from the released tannery effluents causes skin rashes and respiratory problems through its penetration to humans by their exposure. Hence, the attempts have also been made by studying the metabolic pathways of hexavalent chromium and looking for microbial strains which can be useful for biosorption of heavy metals. Our research is driven by a fascination in the complex behaviour that is observed in real environmental situations; and, is focused on experimental approaches involving advanced techniques including search for chromium reductases in bacteria from anthropogenic sources. In addition, in vitro based immunological studies may be carried out to analyse the metabolic pathways of chromium in cells.
Deepthi K.G.
A wide spectrum of ocular infections can occur when virulent microorganisms from external sources invade any part of the eye. When the eye is compromised, as in trauma or surgery, these organisms may become pathogenic, resulting in bacterial ocular infections. A rapid and accurate identification of causative agent is the basis for the effective treatment of these ocular infections. Conventional microbiological methods can confirm only 60-70% of typical clinical cases. Hence, the remaining 30-40% goes undiagnosed, which lead to clinical complications. Therefore our study is aimed to develop a highly insightful, reliable and rapid method for the identification of bacterial community in human conjunctiva of pre-operative subjects.
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D. Anand Raj
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Deinococcus indicus is a novel bacteria isolated from West Bengal, India known for its UV radiation and heavy metal tolerance. Since, this organism is reported from a region known for heavy metal contamination and earlier investigations demonstrated its radiation resistance, our study focused on the multiple stress responsive and DNA repair mechanisms. Though, most of the members of the genus Deinococcus are Gram-positive cocci, D. indicus postures Gram-negative rod shaped cells. Hence, the objectives were framed to precisely understand DNA repair pathway and stress responsive genes expression with a broader perspective.
Among those UV stress-responsive genes, UV DNA damage repair endonuclease is regarded to be the novel one which is overexpressed in D. indicus MTCC 4913 strain. Overall, our study opine the functional information on stress tolerance genes that aid to understand the DNA damage recovery mechanism towards elucidation of DNA repair pathways in near future.
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Rochelle Fernandez
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Microbial diversity which is an essential segment of biodiversity deserves greater attention since extensive knowledge on microbial taxonomy and physiology will help gain better insights into the microbial world and in identifying potential novel species. Microbial diversity is as immense as it is unknown where microorganisms signify the richest reservoir in nature vital to the ecosystem as it provides the basis for ecological processes. Shola, the tropical montane forests is an ancient forest type with valleys and edges where in between there exists extremely diverse grasslands. Grasslands and Sholas form an extraordinary ecosystem which serve as a rich repository of rare and invaluable biodiversity. Such a unique ecosystem is only found in the Southern Western Ghats. Due to human activities over centuries most of the pristine areas were disturbed leaving certain pockets like the Sholas. Among them, the remarkable ones are located in Idukki, Wayanad, Palakkad and Thrissur districts of Kerala, and the study mainly focused on the Bacterial diversity in Sholas of Idukki namely Pampadum, Mathikettan and Anamudi.
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Chandan Kumar Sahoo
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Colorectal cancer (CRC) is one among the major cause for cancer-related complication which can be challenged through altering the human gut microbiota. Besides genetic background, range of microbial dynamics and lifestyle factors play significant role in CRC etiology. Our study focus on predominant microbiota which are responsible for causing colorectal cancer (CRC) in Humans based on nutritional supplements. In addition, those which will sure for effective remedy towards prevention in our mandate. Thus, we understand the composition of the gut microbiota of sizable number of CRC patients in comparison to the healthy. This knowledge is presumed to form a base to develop new therapeutic based avenue through microbial manipulation and culture dependent and independent methods are attempted to decipher the complexity of gut biography of patients with colorectal carcinoma.
