Marine yeasts — a review

Yeasts are ubiquitous in their distribution and populations mainly depend on the type and concentration of organic materials. The distribution of species, as well as their numbers and metabolic characteristics were found to be governed by existing environmental conditions. Marine yeasts were first discovered from the Atlantic Ocean and following this discovery, yeasts were isolated from different sources, viz. seawater, marine deposits, seaweeds, fish, marine mammals and sea birds. Nearshore environments are usually inhabited by tens to thousands of cells per litre of water, whereas low organic surface to deep-sea oceanic regions contain 10 or fewer cells/litre. Aerobic forms are found more in clean waters and fermentative forms in polluted waters. Yeasts are more abundant in silty muds than in sandy sediments. The isolation frequency of yeasts fell as the depth of the sampling site is increased. Major genera isolated in this study were Candida, Cryptococcus, Debaryomyces and Rhodotorula. For biomass estimation ergosterol method was used. Classification and identification of yeasts were performed using different criteria, i.e. morphology, sexual reproduction and physiological/biochemical characteristics. Fatty acid profiling or molecular sequencing of the IGS and ITS regions and 28S gene rDNA ensured accurate identification.

Dynamics of Rifting Along the Southwest Continental margin of India Through Coherence and Process oriented Analysis of Gravity Data

Department of Marine Geology and Geophysics,Cochin University of Science and Technology

Marine Engineering Training in India -A Pedagogic Introspection

Indian marine engineers are renowned for employment globally due to their knowledge, skill and reliability. This praiseworthy status has been achieved mainly due to the systematic training imparted to marine engineering cadets. However, in an era of advancing technology, marine engineering training has to remain dynamic to imbibe latest technology as well as to meet the demands of the shipping industry. New subjects of studies have to be included in the curriculum in a timely manner taking into consideration the industry requirements and best practices in shipping. Technical competence of marine engineers also has to be subjected to changes depending upon the needs of the ever growing and over regulated shipping industry. Besides. certain soft skills are to be developed and improved amongst the marine engineers in order to alter or amend the personality traits leading to their career success.If timely corrective action is taken. Indian marine engineers can be in still greater demand for employment in global maritime field. In order to enhance the employability of our mmine engineers by improving their quality, a study of marine engineers in general and class IV marine engineers in particular was conducted based on three distinct surveys, viz., survey among senior marine engineers, survey among employers of marine engineers and survey of class IV marine engineers themselves.The surveys have been planned and questionnaires have been designed to focus the study of marine engineer officer class IV from the point of view of the three distinct groups of maritime personnels. As a result of this, the strength and weakness of class IV marine engineers are identified with regard to their performance on board ships, acquisition of necessary technical skills. employability and career success. The criteria of essential qualities of a marine engineer are classified as academic, technical, social, psychological. physical, mental, emergency responsive, communicative and leadership, and have been assessed for a practicing marine engineer by statistical analysis of data collected from surveys. These are assessed for class IV marine engineers from the point of view of senior marine engineers and employers separately. The Endings are delineated and graphically depicted in this thesis.Besides. six pertinent personality traits of a marine engineer viz. self esteem. learning style. decision making. motivation. team work and listening self inventory have been subjected to study and their correlation with career success have been established wherever possible. This is carried out to develop a theoretical framework to understand what leads a marine engineer to his career attainment. This enables the author to estimate the personality strengths and weaknesses of a serving marine engineer and eventually to deduce possible corrective measures or modifications in marine engineering training in India.Maritime training is largely based on International Conventions on Standard of Training. Certification and Watch keeping for Seafarers 1995. its associated Code and Merchant Shipping (STCW for Seafarers) Rules 1998. Further, Maritime Education, Training and Assessment (META) Manual was subjected to a critical scrutiny and relevant Endings of thc surveys arc superimposed on the existing rule requirement and curriculum. Views of senior marine engineers and executives of various shipping companies are taken into account before arriving at the revision of syllabus of marine engineering courses. Modifications in the pattern of workshop and sea service for graduate mechanical engineering trainees are recommended. Desirable age brackets of junior engineers and chief engineers. use of Training and Assessment Record book (TAR Book) during training etc. have also been evaluated.As a result of the pedagogic introspection of the existing system of marine engineering training in India. in this thesis, a revised pattern of workshop training of six months duration for graduate mechanical engineers. revised pattern of sea service training of one year duration and modified now diagram incorporating the above have been arrived at. Effects of various personality traits on career success have been established along with certain findings for improvement of desirable personality traits of marine engineers.

Molecular Characterization and Gene Expression Profiling of Antimicrobial Peptides in Penaeid Shrimps

The constitutive production of AMPs in shrimps ensures that animals are able to protect themselves from low-level assaults by pathogens present in the environment. As these molecules play important roles in the shrimp immune defense system, the expression level of these AMPs are possible indicators of the immune state of shrimps. The present study also indicates the antiviral property of AMPs, especially ALF, stressing the importance of their up-regulation through the application of immunostimulants/probiotics as a prophylactic strategy in aquaculture. The present study shows that shrimp defense system is equipped enough to evade WSSV infection to a certain extent, when the animals were maintained on marine yeast and probiotic diet, whereas the control diet fed group succumbed to WSSV infection. This study reveals that marine yeast and probiotic supplemented diet can delay the process of WSSV infection and confer greater protection to the animals. Particularly, the protection conferred by marine yeast, C. haemulonii S27 and Bacillus MCCB101 were highly promising imparting greater hope to the aquaculture community to overcome the prevailing disease problems in aquaculture. It may be inferred from the present study that up-regulation of AMP genes could be effected by the application of immunostimulants and probiotics. Also, AMP expression profile could be used as an effective tool for screening immunostimulants and probiotics for application in shrimp culture. Ultimately, it is likely that no single compound or strategy will provide a solution to the problem of disease within aquaculture and that, in reality, a suite of techniques will be required including the manipulation of the rearing environment, addition of probionts as a matter of routine during culture, and the use of immunostimulants and other supplements during vulnerable growth phases. Finally, the development of good management practices, the control of environmental variables, genetic improvement in the penaeid species, understanding of host-virus interaction, modulation of the shrimp immune system, supported by functional genomics and proteomics of this crustacean, as a whole suggests that the control of WSSV is not far.

Chitinase production by.marine fungi

In this thesis an attempt is made to explore the potential of marine fungi for the production of chitinolytic enzymes and to recognize the ability to hydrolyse native chitin through submerged as well as solid substrate fermentation culture conditions, using wheat bran and shellfish processing waste such as ‘prawn waste’ as solid substrates. Attempt was made to isolate a potential chitinase producing fungus from marine environment and to develop an ideal bioprocess for the production ofchitolytic enzymes.Present study indicate scope for utilization of B. bassiana for industrial production of chitinase using prawn waste as solid substrate employing solid substrate fermentation.

Coastal and ground water pollution in Kavaratti island, Lakshadweep sea

The tiniest Union territory of India, Lakshadweep, is an archipelago, with an area of 32 Sq. km. consisting of 12 atolls, three reefs and five submerged banks, lies between 8° and 12°30'N latitudes and 71° and 74" E longitudes. It is one of the most important and critical territories of India from economic and defence point of view. Specialised environment having typical geological set up, Lakshadweep is ecologically sensitive to even slight climatic or anthropogenic interference. Pollution of coastal seas, over exploitation and contamination of the fresh water sources are thus become great concerns to the existence of the island. Typical geological set up and interference cause threat to the ecology of the fragile environment and resources of the island as well as its resources. Marine pollution and ground water contamination are concerns in this regard. Even though attentions were made to assess the physico—chemical and bacteriological status of the marine and groundwater systems separately, an integrated approach has not been evolved. The present study with its broad objectives is attempted for an integrated assessment of microbiological, physicochemical and biological characteristics of the surrounding seawater and microbiological and physico—chemical characteristics of the ground water in Kavaratti island. The entire study has been organised in 4 chapters

Preparation of useful raw materials from Refinery sludge and its utilisation in rubber processing

Petroleum, a mixture of organic compounds, comes from underground rock formations ranging in age from ten to several hundred million years. The process by which it is formed and developed is not yet completely known. Studies indicate that petroleum is formed mainly from microscopic-sized marine animals and plants. When these organisms died in water of low oxygen content, they did not decompose. Thus their remains sank to the bottom to be buried under accumulations of sediment. Their conversion to petroleum remains a subject of research even today.

"Geochemistry and Petrogenesis of Perinthatta Anorthosite, Northern Kera|a

This report deals essentially with the geochemistry and petrogenesis of Perinthatta anorthosite. The work also addresses the geological setting of the pluton in terms of its field relationships and petrography and the structure and metamorphism of the region and examines its relation with the associated plutons. For the sake of convenience, the thesis is divided into six chapters

Hydrogeological, Geophysical And Geochemical Studies In Parts Of Coastal And Midland Areas, Central Kerala - A Gis Approach

The present study deals with the different hydrogeological characteristics of the coastal region of central Kerala and a comparative analysis with corresponding hard rock terrain. The coastal regions lie in areas where the aquifer systems discharge groundwater ultimately into the sea. Groundwater development in such regions will require a precise understanding of the complex mechanism of the saline and fresh water relationship, so that the withdrawals are so regulated as to avoid situations leading to upcoming of the saline groundwater bodies as also to prevent migration of sea water ingress further inland. Coastal tracts of Kerala are formed by several drainage systems. Thick pile of semi-consolidated and consolidated sediments from Tertiary to Recent age underlies it. These sediments comprise phreatic and confined aquifer systems. The corresponding hard rock terrain is encountered with laterites and underlined by the Precambrian metamorphic rocks. Supply of water from hard rock terrain is rather limited. This may be due to the small pore size, low degree of interconnectivity and low extent of weathering of the country rocks. The groundwater storage is mostly controlled by the thickness and hydrological properties of the weathered zone and the aquifer geometry. The over exploitation of groundwater, beyond the ‘safe yield’ limit, cause undesirable effects like continuous reduction in groundwater levels, reduction in river flows, reduction in wetland surface, degradation of groundwater quality and many other environmental problems like drought, famine etc.

Role of sea-surface wind and transport on enhanced aerosol optical depth observed over the Arabian Sea

The objective of this study is to understand the reasons for the enhancement in aerosol optical depth (AOD) over the Arabian Sea observed during June, July and August. During these months, high values of AOD are found over the sea beyond 10◦ N and adjacent regions. The Arabian Sea is bounded by the lands of Asia and Africa on its three sides. So the region is influenced by transported aerosols from the surroundings as well as aerosols of local origin (marine aerosols). During the summer monsoon season in India, strong surface winds with velocities around 15 m s−1 are experienced over most parts of the Arabian Sea. These winds are capable of increasing sea spray activity, thereby enhancing the production of marine aerosols. The strong winds increase the contribution of marine aerosols over the region to about 60% of the total aerosol content. The main components of marine aerosols include sea salt and sulphate particles. The remaining part of the aerosol particles comes from the western and northern land masses around the sea, of which the main component is transported dust particles. This transport is observed at higher altitudes starting from 600 m. At low levels, the transport occurs mainly from the Indian Ocean and the Arabian Sea itself, indicating the predominance of marine aerosols at these levels. The major portion of the total aerosol loading was contributed by coarse-mode particles during the period of study. But in the winter season, the concentration of coarse-mode aerosols is found to be less. From the analysis, it is concluded that the increase in marine aerosols and dust particles transported from nearby deserts results in an increase in aerosol content over the Arabian Sea during June, July and August.

Planning And Operation Problems Of Indian Major Ports With Special Emphasis On Cochin Port

Rapid changes in the technological environment of marine logistics and the increasing integration of waterborne, air and land transport systems have fostered a revolution in the design and operations of transport vehicles, cargo handling technology, and terminal facilities. This in turn has caused major changes in the functions of and uses of ports. From literature, it was found that these changes were very slow in case of Indian ports and the performances of port operations were poor when compared with similar ports in the same region. It was also found that a very few studies were conducted to identify the reasons for slow improvements in the performances of Indian major ports. In this thesis, an attempt is made to find out the operational problems of Indian major ports and to analyze the reasons for it. Some solutions have also been found out using management tools

Ornamental Fish Diseases And Their Management Measures

CMFRI - Winter School Course Manual on “Recent Advances in Breeding and Larviculture of Marine Finfish and Shellfish”. 30.12.2008 - 19.1.2009

Impact of process parameters on chitinase production by an alkalophilic marine Beau6eria bassiana in solid state fermentation

A chitinolytic fungus, Beau6eria bassiana was isolated from marine sediment and significant process parameters influencing chitinase production in solid state fermentation using wheat bran were optimised. The organism was strongly alkalophilic and produced maximum chitinase at pH 9·20. The NaCl and colloidal chitin requirements varied with the type of moistening medium used. Vegetative (mycelial) inoculum was more suitable than conidial inoculum for obtaining maximal enzyme yield. The addition of phosphate and yeast extract resulted in enhancement of chitinase yield. After optimisation, the maximum enzyme yield was 246·6 units g 1 initial dry substrate (U gIDS 1). This is the first report of the production of chitinase from a marine fungus.

Hydrogeology and hydrochemistry of the aquifer systems of Kuttanad area, Kerala: Their role in understanding the evolution of groundwaters

This is an attempt to understand the important factors that control the occurrence, development and hydrochemical evolution of groundwater resources in sedimentary multi aquifer systems. The primary objective of this work is an integrated study of the hydrogeology and hydrochemistry with a view to elucidate the hydrochemical evolution of groundwater resources in the aquifer systems. The study is taken up in a typical coastal sedimentary aquifer system evolved under fluvio-marine environment in the coastal area of Kerala, known as the Kuttanad. The present study has been carried out to understand the aquifer systems, their inter relationships and evolution in the Kuttanad area of Kerala. The multi aquifer systems in the Kuttanad basin were formed from the sediments deposited under fluvio-marine and fluvial depositional environments and the marine transgressions and regressions in the geological past and palaeo climatic conditions influenced the hydrochemical environment in these aquifers. The evolution of groundwater and the hydrochemical processes involved in the formation of the present day water quality are elucidated from hydrochemical studies and the information derived from the aquifer geometry and hydraulic properties. Kuttanad area comprises of three types of aquifer systems namely phreatic aquifer underlain by Recent confined aquifer followed by Tertiary confined aquifers. These systems were formed by the deposition of sediments under fluvio-marine and fluvial environment. The study of the hydrochemical and hydraulic properties of the three aquifer systems proved that these three systems are separate entities. The phreatic aquifers in the area have low hydraulic gradients and high rejected recharge. The Recent confined aquifer has very poor hydraulic characteristics and recharge to this aquifer is very low. The Tertiary aquifer system is the most potential fresh water aquifer system in the area and the groundwater flow in the aquifer is converging towards the central part of the study area (Alleppey town) due to large scale pumping of water for water supply from this aquifer system. Mixing of waters and anthropogenic interferences are the dominant processes modifying the hydrochemistry in phreatic aquifers. Whereas, leaching of salts and cation exchange are the dominant processes modifying the hydrochemistry of groundwater in the confined aquifer system of Recent alluvium. Two significant chemical reactions modifying the hydrochemistry in the Recent aquifers are oxidation of iron in ferruginous clays which contributes hydrogen ions and the decomposition of organic matter in the aquifer system which consumes hydrogen ions. The hydrochemical environment is entirely different in the Tertiary aquifers as the groundwater in this aquifer system are palaeo waters evolved during various marine transgressions and regressions and these waters are being modified by processes of leaching of salts, cation exchange and chemical reactions under strong reducing environment. It is proved that the salinity observed in the groundwaters of Tertiary aquifers are not due to seawater mixing or intrusion, but due to dissolution of salts from the clay formations and ion exchange processes. Fluoride contamination in this aquifer system lacks a regional pattern and is more or less site specific in natureThe lowering of piezometric heads in the Tertiary aquifer system has developed as consequence of large scale pumping over a long period. Hence, puping from this aquifer system is to be regulated as a groundwater management strategy. Pumping from the Tertiary aquifers with high capacity pumps leads to well failures and mixing of saline water from the brackish zones. Such mixing zones are noticed from the hydrochemical studies. This is the major aquifer contamination in the Tertiary aquifer system which requires immediate attention. Usage of pumps above 10 HP capacities in wells taping Tertiary aquifers should be discouraged for sustainable development of these aquifers. The recharge areas need to be identified precisely for recharging the aquifer systems throughartificial means.

Differential induction, isolation, physicochemical and molecular characterization of temperate phages of environmental Vibrio cholerae as evidence of phage mediated Horizontal Gene Transfer

The resurgence of the enteric pathogen Vibrio cholerae, the causative organism of epidemic cholera, remains a major health problem in many developing countries like India. The southern Indian state of Kerala is endemic to cholera. The outbreaks of cholera follow a seasonal pattern in regions of endemicity. Marine aquaculture settings and mangrove environments of Kerala serve as reservoirs for V. cholerae. The non-O1/non-O139 environmental isolates of V. cholerae with incomplete ‘virulence casette’ are to be dealt with caution as they constitute a major reservoir of diverse virulence genes in the marine environment and play a crucial role in pathogenicity and horizontal gene transfer. The genes coding cholera toxin are borne on, and can be infectiously transmitted by CTXΦ, a filamentous lysogenic vibriophages. Temperate phages can provide crucial virulence and fitness factors affecting cell metabolism, bacterial adhesion, colonization, immunity, antibiotic resistance and serum resistance. The present study was an attempt to screen the marine environments like aquafarms and mangroves of coastal areas of Alappuzha and Cochin, Kerala for the presence of lysogenic V. cholerae, to study their pathogenicity and also gene transfer potential. Phenotypic and molecular methods were used for identification of isolates as V. cholerae. The thirty one isolates which were Gram negative, oxidase positive, fermentative, with or without gas production on MOF media and which showed yellow coloured colonies on TCBS (Thiosulfate Citrate Bile salt Sucrose) agar were segregated as vibrios. Twenty two environmental V. cholerae strains of both O1 and non- O1/non-O139 serogroups on induction with mitomycin C showed the presence of lysogenic phages. They produced characteristic turbid plaques in double agar overlay assay using the indicator strain V. cholerae El Tor MAK 757. PCR based molecular typing with primers targeting specific conserved sequences in the bacterial genome, demonstrated genetic diversity among these lysogen containing non-O1 V. cholerae . Polymerase chain reaction was also employed as a rapid screening method to verify the presence of 9 virulence genes namely, ctxA, ctxB, ace, hlyA, toxR, zot,tcpA, ninT and nanH, using gene specific primers. The presence of tcpA gene in ALPVC3 was alarming, as it indicates the possibility of an epidemic by accepting the cholera. Differential induction studies used ΦALPVC3, ΦALPVC11, ΦALPVC12 and ΦEKM14, underlining the possibility of prophage induction in natural ecosystems, due to abiotic factors like antibiotics, pollutants, temperature and UV. The efficiency of induction of prophages varied considerably in response to the different induction agents. The growth curve of lysogenic V. cholerae used in the study drastically varied in the presence of strong prophage inducers like antibiotics and UV. Bacterial cell lysis was directly proportional to increase in phage number due to induction. Morphological characterization of vibriophages by Transmission Electron Microscopy revealed hexagonal heads for all the four phages. Vibriophage ΦALPVC3 exhibited isometric and contractile tails characteristic of family Myoviridae, while phages ΦALPVC11 and ΦALPVC12 demonstrated the typical hexagonal head and non-contractile tail of family Siphoviridae. ΦEKM14, the podophage was distinguished by short non-contractile tail and icosahedral head. This work demonstrated that environmental parameters can influence the viability and cell adsorption rates of V. cholerae phages. Adsorption studies showed 100% adsorption of ΦALPVC3 ΦALPVC11, ΦALPVC12 and ΦEKM14 after 25, 30, 40 and 35 minutes respectively. Exposure to high temperatures ranging from 50ºC to 100ºC drastically reduced phage viability. The optimum concentration of NaCl required for survival of vibriophages except ΦEKM14 was 0.5 M and that for ΦEKM14 was 1M NaCl. Survival of phage particles was maximum at pH 7-8. V. cholerae is assumed to have existed long before their human host and so the pathogenic clones may have evolved from aquatic forms which later colonized the human intestine by progressive acquisition of genes. This is supported by the fact that the vast majority of V. cholerae strains are still part of the natural aquatic environment. CTXΦ has played a critical role in the evolution of the pathogenicity of V. cholerae as it can transmit the ctxAB gene. The unusual transformation of V. cholerae strains associated with epidemics and the emergence of V. cholera O139 demonstrates the evolutionary success of the organism in attaining greater fitness. Genetic changes in pathogenic V. cholerae constitute a natural process for developing immunity within an endemically infected population. The alternative hosts and lysogenic environmental V. cholerae strains may potentially act as cofactors in promoting cholera phage ‘‘blooms’’ within aquatic environments, thereby influencing transmission of phage sensitive, pathogenic V. cholerae strains by aquatic vehicles. Differential induction of the phages is a clear indication of the impact of environmental pollution and global changes on phage induction. The development of molecular biology techniques offered an accessible gateway for investigating the molecular events leading to genetic diversity in the marine environment. Using nucleic acids as targets, the methods of fingerprinting like ERIC PCR and BOX PCR, revealed that the marine environment harbours potentially pathogenic group of bacteria with genetic diversity. The distribution of virulence associated genes in the environmental isolates of V. cholerae provides tangible material for further investigation. Nucleotide and protein sequence analysis alongwith protein structure prediction aids in better understanding of the variation inalleles of same gene in different ecological niche and its impact on the protein structure for attaining greater fitness of pathogens. The evidences of the co-evolution of virulence genes in toxigenic V. cholerae O1 from different lineages of environmental non-O1 strains is alarming. Transduction studies would indicate that the phenomenon of acquisition of these virulence genes by lateral gene transfer, although rare, is not quite uncommon amongst non-O1/non-O139 V. cholerae and it has a key role in diversification. All these considerations justify the need for an integrated approach towards the development of an effective surveillance system to monitor evolution of V. cholerae strains with epidemic potential. Results presented in this study, if considered together with the mechanism proposed as above, would strongly suggest that the bacteriophage also intervenes as a variable in shaping the cholera bacterium, which cannot be ignored and hinting at imminent future epidemics.