Project description:Kelp are the largest photosynthetic organisms in the ocean with tissue differentiation and complex life cycles. Other multicellular organisms with similar complexity such as plants and animals are well known to posses epigenetic mechanisms such as DNA methylation to control development and morphogenesis. Despite plant-like body plans and the presence of different life-cycle stages, the kelp species Saccharina japonica has only a very low level of DNA methylation, yet we have found strong evidence for differential methylation of regulatory elements and protein-coding genes which seem to contribute to the formation of life-cycle stages, tissue differentiation, growth and halogen metabolism. Thus, DNA methylation seems to play an important role in kelp, which has not been reported before.
Project description:We performed a laboratory experiment with vegetative gametophytes of the kelp Saccharina latissima and exposed the gametophytes to three temperatures (4°C, 12°C and 20°C) by sex (female, male) for 14 days.
Project description:Petroleum hydrocarbons are recalcitrant contaminants, which has caused most serious environmental problems. Acinetobacter calcoaceticus Aca13 was isolated from petroleum polluted soil for petroleum biodegradation. Hexadecane and naphthalene were used to incubate with Acinetobacter calcoaceticus Aca13. After incubation, the whole transcriptome was obtained from treated groups and control groups, and then used for RNA sequence and analysis. Obtained data in this project will help us understand the biodegradation mechanism of hexadecane and naphthalene, and will be helpful for the bioremediation of petroleum hydrocarbons.
Project description:The use of carbon labelled PBAT units allowed us to follow biodegradation of all PBAT building blocks. The presented workflow is a novel approach to study the fundamental steps in polymer biodegradation in complex systems.
Project description:Understanding the bacterial community structure, and their functional analysis for active bioremediation process is essential to design better and cost effective strategies. Microarray analysis enables us to simultaneously study the functional and phylogenetic markers of hundreds of microorganisms which are involved in active bioremediation process in an environment. We have previously described development of a hybrid 60-mer multibacterial microarray platform (BiodegPhyloChip) for profiling the bacterial communities and functional genes simultaneously in environments undergoing active bioremediation process (Pathak et al; Appl Microbiol Biotechnol,Vol. 90, 1739-1754). The present study involved profiling the status of bacterial communities and functional (biodegradation) genes using the developed 60-mer oligonucleotide microarray BiodegPhyloChip at five contaminated hotspots in the state of Gujarat, in western India. The expression pattern of functional genes (coding for key enzymes in active bioremediation process) at these sites was studied to understand the dynamics of biodegradation in the presence of diverse group of chemicals. The results indicated that the nature of pollutants and their abundance greatly influence the structure of bacterial communities and the extent of expression of genes involved in various biodegradation pathways. In addition, site specific factors also play a pivotal role to affect the microbial community structure as was evident from results of 16S rRNA gene profiling of the five contaminated sites, where the community structure varied from one site to another drastically.
Project description:We have developed a 60-mer oligonucleotide multibacterial microarray for detection and expression profiling of biodegradative genes and bacterial diversity (16S rRNA gene) in different habitats contaminated with varieties of hazardous chemicals. The genes selected were involved in biodegradation and biotransformation of various groups of compounds viz. nitroaromatic compounds (148 genes), chloroaromatic compounds (75 genes), monoaromatic compounds (373 genes), polyaromatic hydrocarbons (174 genes), pesticides/ herbicides (34 genes), alkanes/aliphatics (185 genes) and heavy metals (68 genes), which covered a total number of 133 chemicals. The efficiency (specificity, detection sensitivity) of the developed array was evaluated using the labeled genomic DNA of pure bacterial strains, Escherichia coli DH5α and Sphingomonas sp. strain NM-05 (involved in the biodegradation of γ-hexachlorohexane isolated from IPL, Lucknow) at different concentrations of 300ng, 500ng, 800ng, 1000ng and 1250ng. The specificity of the developed array was further validated using mixed cultures containing three strains (Sphingomonas sp. strain NM-05, Rhodococcus sp. strain RHA1 and Bordetella sp. strain IITR-02) involved in biodegradation of γ-hexachlorohexane, biphenyl and chlorobenzenes respectively. The mixed culture also contained non-target/non-degrader strains (E. coli DHα, E.coli BL21 and E.coli K12 NCTC50192). The developed array was applied for profiling using the total soil DNA in five contaminated habitats of north India, viz. chloroaromatic chemicals contaminated site (India Pesticide Limited, Chinhat, Lucknow), a river sediments (Gomti river sediment, Lucknow), heavy metal industry dump site (Jajmau industrial area Kanpur), a effluent treatment plant (CETP along Ganges river near Kanpur), and an oil refinery (Mathura oil refinery). Hybridization of 16S rRNA probes revealed the presence of bacteria similar to well characterized genera involved in biodegradation of pollutants. Genes involved in complete degradation pathways for hexachlorocyclohexane (lin), 1,2,4-trichlorobenzene (tcb), naphthalene (nah), phenol (mph), biphenyl (bph), benzene (ben), toluene (tbm), xylene (xyl), phthalate (pht), Salicylate (sal) and resistance to mercury (mer) were detected with highest intensity. The most abundant genes belonged to hydroxylases, monooxygenases and dehydrogenases which were present in all the five samples. Many compound specific genes which initiate the degradation pathway were also detected. Thus, the array developed and validated here may be useful in assessing the biodegradative potential and composition of environmentally useful bacteria in hazardous ecosystems.
Project description:A functional microarray targeting 24 genes involved in chlorinated solvent biodegradation pathways has been developed and used to monitor the gene diversity present in four trichloroethylene (TCE) contaminated sites under ERD (enhanced reductive dechlorination) treatment. The microarray format provided by NimbleGen and used in this study is 12x135K. 2 µg of labelled gDNA from 30 groundwater samples were hybridized on the microarrays.