Actinomycete Isolates from Arabian Sea and Bay of Bengal: Biochemical, Molecular and Functional Characterization

The thesis is comprised of seven chapters. Chapter 1 gives a general introduction to marine actinomycetes; Chapter 2 gives an account on the morphological, biochemical and physiological characterization of marine actinomycetes. Comprehensive description of molecular identification and phylogenetic analysis of actinomycetes is dealt with in Chapter 3. The antimicrobial property with special reference to antivibrio activity is described in Chapter 4. Chapter 5 explores the melanin production ability of marine actinomycetes, characterization of melanin and evaluation of its bioactivity. Chapter 6 illustrates the study on chitinolytic Streptomyces as antifungal and insecticidal agents. Summary and Conclusion of the study is presented in Chapter 7, followed by References and Appendices.The present study provides an insight into the various actinomycetes occurring in the sediments of Arabian Sea and Bay of Bengal. Streptomyces was found to be the dominant group followed by Nocardiopsis. Eventhough generic level identification is possible by traditional phenotypic methods, species level identification necessitate a polyphasic approach including both phenotypic and genotypic characterization. Antibiotic production coupled with biogranulation property helped in the effective utilization of the actinomycetes for the control of vibrios. Melanin from Streptomyces bikiniensis was proved to be a promising antioxidant and photoprotectant. Marine actinomycetes were found to be a good source of hydrolytic enzymes and the chitinolytic isolates could be explored as biocontrol agents in terms of antifungal and insecticidal property. The present study explored the potential of marine actinomycetes especially Streptomycetes as a promising source of bioactive molecules for application in aquaculture and pharmaceutical industry.

Population characteristics and taxonomy of lantern fishes of genus Diaphus (Family Myctophidae) off south west coast of India

Globally most of the conventional fish stocks have reached a state of optimum exploitation or even over-exploitation; efficient utilization of non-conventional resources is necessary to meet the supply-demand gap for protein supply. Mesopelagic fishes can be considered as one such promising resource for the future, if appropriate harvest and post-harvest technologies are developed. Increasing human population and increasing demand for cheaper food fishes has made myctophids a possible potential resource for future exploitation and utilization. Earlier studies indicated the abundance of Diaphus spp. in the eastern and northeastern Arabian Sea. The present study also indicates the dominance of Diaphus spp. in the deep sea trawling grounds of south west coast of India. Commercial viability of the myctophid fishing in the Indian waters has to be worked out. The present catch estimation is based on the Stratified Random Sampling Method from the landing data. As the coverage of sampling area was limited and the gear efficiency was not standardized, the data generated are not precise. A counter check for the estimates is also not possible due to the absence of comparable works in the study area. Fish biomass estimation by acoustics survey coupled with direct fishing would only confirm the accuracy of estimates. Exploratory surveys for new fishing areas to be continued, for gathering the distribution, abundance, biological and ecological data and map the potential fishing ground on a GIS platform and the data should be provided to the commercial entrepreneurs. Generally non-conventional and non-targeted resources are under low fishing pressure and exploitation rates. Low values of fishing mortality and exploitation rates indicate that removal from the stock by fishing was only nominal from the present fishing grounds. The results indicate that the stock is almost at virgin state and remains grossly underexploited. Since the extent of distribution and abundance of the stock in the ecosystem remains to be ascertained, sustainable yield could not be estimated. Also the impact of myctophids harvest, on other commercially important fishes, has to be studied.

Biochemical Characterization and Bio-evaluation of Collagen and Collagen Peptides Extracted and Purified from Fish Skin: In vitro and In vivo Studies on Antiarthritic and Wound Healing Properties

In fish processing plants, there is huge amount of skin that is left as the waste. When this skin is taken and processed into fish collagen, it will save large amount of money that is used for extraction of collagen from other animal s.Fish collagen can be used as an alternative to replace mammalian collagen, especially collagen extracted from bovine, when we consider the outbreak of bovine spongiform encephalopathy (BSE), transmissible spongiform encephalopathy (TSE) and the foot - and-mouth disease (FMD) issues. BSE and TSE are progressive neurological disorders affecting cattles caused by proteinacious infectious particles called prions.The study aims in producing collagen that has been extracted from fish skin to replace other animal collagen so as to overcome the problem of other animal collagen issues. Also the study utilized the abandoned fish waste produced by fish processing industry since bone, skin, fin and scales of fish can be a useful source of collagen.

Construcción de una filogenia molecular para las especies de los géneros Klebsiella y Raoultella basada en los genes ARNr 16S y ARN polimerasa subunidad

Las bacterias de los géneros Raoultella y Klebsiella son patógenos oportunistas para las cuales no existe un sistema uniforme de clasificación taxonómica internacional. En el presente estudio se propone una filogenia molecular basada en el gen ribosomal 16S (ADNr 16S) y el gen codificante de la subunidad de la ARN polimerasa (rpoB) de los géneros Klebsiella y Raoultella con el fin de establecer relaciones evolutivas entre dichos géneros. Los resultados evidencian una agrupación acorde con la taxonomía y las propiedades bioquímicas características, reportadas en el Genbank. Se estableció una bifurcación en los árboles, lo cual confirma la separación de los géneros Klebsiella y Raoultella. Adicionalmente, se confirmó el carácter polifilético de K. aerogenes por el gen ADNr 16S y la agrupación de R. terrigena y K. oxytoca de acuerdo con el gen rpoB. La comparación entre los árboles obtenidos permitió determinar relaciones evolutivas entre las especies, a partir de los genes evaluados, lo cual refleja cambios aparentes a nivel taxonómico y corrobora la importancia del análisis a nivel de multilocus. Este tipo de estudios permite monitorear la estabilidad de los genotipos microbianos sobre la escala temporal y espacial, mejorar la precisión de las anotaciones taxonómicas (mejor descripción de taxones o subdivisiones genéticas) y evaluar la diversidad genética y adaptabilidad en términos de virulencia o resistenciaa drogas.

Biochemical differentiation between Ophidion Barbatum and o. Rochei (Pisces, Ophidiidae)

El gènere Ophidion esta representat al Mediterrani per dues espècies, 0. barbatum L. i O. rochei Müller. Són dues espècies molt similars en aspecte i difícils d'identificar només a partir dels seus caràcters morfològics externs. El treball descriu en primer lloc, i a partir de dades obtingudes per tècniques electroforètiques, alguns marcadors bioquímics que permeten diferenciar les dues espècies. En segon lloc, i a partir del càlcul de la 'Distància Genètica de Nei', es fa una estimació del temps de divergència entre O. barbatum i 0. rochei

Theoretical studies of systems of biochemical interest containing Fe and Cu transition metals

La presència de la química teòrica i computacional està augmentant en quasi tots els camps de la recerca en química. Els càlculs teòrics poden ajudar a entendre millor l'estructura, les propietats i la reactivitat de compostos metàl·lics d'àrees tan diferents com la química inorgànica, organometàl·lica i bioinorgànica. No obstant això, és imprescindible utilitzar la metodologia adequada per obtenir resultats teòrics fiables. Els estudis d'aquesta tesi es poden dividir en dos grups diferents. El primer grup inclou l'estudi teòric del mecanisme de reacció de diversos sistemes que contenen coure i tenen diferents estructures Cun-O2. Aquests estudies s'han dut a terme amb l'objectiu de profunditzar en la natura dels processos oxidants químics i biològics promoguts per sistemes que contenen coure. En la segona part de la tesi, s'estudia la fiabilitat de diferents tècniques utilitzades per estudiar l'estructura electrònica i la reactivitat de sistemes que contenen coure, ferro i altres metalls de transició.

ARX, model thinking: taxonomy and operativity of an architectural process

The purpose of this work was to establish a taxonomy of hand made model construction as a platform for an approach to project an operative method in architecture. It was therefore studied and catalogued in a systematic approach a broad model production in the work of ARX. A wide range of families and sub-families of models were found, with different purposes according to each phase of development, from searching steps for a new possible configuration to detailed refined decisions. This working method revealed as most relevant characteristics, the grounds for a potential personal reflection and open discussion on project method, its flexibility on space modeling, an accuracy on the representation of real construction situations and its constant and stimulating opening to new suggestions. This research helped on a meta-reflection about this method, having been useful on creating a consciousness of processes that pretend to become an autonomous language, knowledge that might become useful to those who pretend to implement a haptic modus operandi in the work of an architectural project.

Immersive Projection for biochemical pattern matching

In all biological processes, protein molecules and other small molecules interact to function and form transient macromolecular complexes. This interaction of two or more molecules can be described by a docking event. Docking is an important phase for structure-based drug design strategies, as it can be used as a method to simulate protein-ligand interactions. Various docking programs exist that allow automated docking, but most of them have limited visualization and user interaction. It would be advantageous if scientists could visualize the molecules participating in the docking process, manipulate their structures and manually dock them before submitting the new conformations to an automated docking process in an immersive environment, which can help stimulate the design/docking process. This also could greatly reduce docking time and resources. To achieve this, we propose a new virtual modelling/docking program, whereby the advantages of virtual modelling programs and the efficiency of the algorithms in existing docking programs will be merged.

Microbial perchlorate reduction: A precise laboratory determination of the chlorine isotope fractionation and its possible biochemical basis

Perchlorate-reducing bacteria fractionate chlorine stable isotopes giving a powerful approach to monitor the extent of microbial consumption of perchlorate in contaminated sites undergoing remediation or natural perchlorate containing sites. This study reports the full experimental data and methodology used to re-evaluate the chlorine isotope fractionation of perchlorate reduction in duplicate culture experiments of Azospira suillum strain PS at 37 degrees C (Delta Cl-37(Cr)--ClO4-) previously reported, without a supporting data set by Coleman et al. [Coleman, M.L., Ader, M., Chaudhuri, S., Coates,J.D., 2003. Microbial Isotopic Fractionation of Perchlorate Chlorine. Appl. Environ. Microbiol. 69, 4997-5000] in a reconnaissance study, with the goal of increasing the accuracy and precision of the isotopic fractionation determination. The method fully described here for the first time, allows the determination of a higher precision Delta Cl-37(Cl)--ClO4- value, either from accumulated chloride content and isotopic composition or from the residual perchlorate content and isotopic composition. The result sets agree perfectly, within error, giving average Delta Cl-37(Cl)--ClO4- = -14.94 +/- 0.15%omicron. Complementary use of chloride and perchlorate data allowed the identification and rejection of poor quality data by applying mass and isotopic balance checks. This precise Delta Cl-37(Cl)--ClO4-, value can serve as a reference point for comparison with future in situ or microcosm studies but we also note its similarity to the theoretical equilibrium isotopic fractionation between a hypothetical chlorine species of redox state +6 and perchlorate at 37 degrees C and suggest that the first electron transfer during perchlorate reduction may occur at isotopic equilibrium between art enzyme-bound chlorine and perchlorate. (C) 2008 Elsevier B.V. All rights reserved.

Microbial and biochemical soil quality indicators and their potential for differentiating areas under contrasting agricultural management regimes

The aim of this study was to examine interrelationships between functional biochemical and microbial indicators of soil quality, and their suitability to differentiate areas under contrasting agricultural management regimes. The study included five 0.8 ha areas on a sandy-loam soil which had received contrasting fertility and cropping regimes over a 5 year period. These were organically managed vegetable, vegetable -cereal and arable rotations, an organically managed grass clover ley, and a conventional cereal rotation. The organic areas had been converted from conventional cereal production 5 years prior to the start of the study. All of the biochemical analyses, including light fraction organic matter (LFOM) C and N, labile organic N (LON), dissolved organic N and water-soluble carbohydrates showed significant differences between the areas, although the nature of the relationships between the areas varied between the different parameters, and were not related to differences in total soil organic matter content. The clearest differences were seen in LFOM C and N and LON, which were higher in the organic arable area relative to the other areas. In the case of the biological parameters, there were differences between the areas for biomass-N, ATP, chitin content, and the ratios of ATP: biomass and basal respiration: biomass. For these parameters, the precise relationships between the areas varied. However, relative to the conventionally managed area, areas under organic management generally had lower biomass-N and higher ATP contents. Arbuscular mycorrhizal fungus colonization potential was extremely low in the conventional area relative to the organic areas. Further, metabolic diversity and microbial community level physiological profiles, determined by analysis of microbial community metabolism using Biolog GN plates and the activities of eight key nutrient cycling enzymes, grouped the organic areas together, but separated them from the conventional area. We conclude that microbial parameters are more effective and consistent indicators of management induced changes to soil quality than biochemical parameters, and that a variety of biochemical and microbial analyses should be used when considering the impact of management on soil quality. (C) 2004 Elsevier Ltd. All rights reserved.