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Biomedical subjects

I L Kothari

Publications and source records attributed to I L Kothari.

7 recordsLinked to original sources

Identification of an anonymous RFLP DNA probe through multiple arbitrary amplicon profiling and its use for strain differentiation in a field isolate of cellulose-degrading Aspergillus niger.

The genome of Aspergillus niger (MPS-002) was subjected to RAPD fingerprinting using none different random oligonucleotide primers. A 0.7 Kb PCR amplicon, generated by primer-3 could be used as a RFLP probe to differentiate A. niger (ATCC 16880) from A. niger (MPS-002). The probe revealed DNA polymorphism internal to two different EcoRI recognition sequences spaced apart at a distance of 0.4 Kb within a 4.0 Kb EcoRI fragment of the genome of both the strains. Localized genome mapping analysis further revealed that the 0.7 Kb RFLP probe was positioned at a distance of 2.7 Kb and 0.6 Kb from the two ends of a 4.0 Kb EcoRI fragment, respectively within the genome of the two strains of A. niger.

Aspergillus niger↗

Plant immunization.

Plant immunization is the process of activating natural defense system present in plant induced by biotic or abiotic factors. Plants are pre-treated with inducing agents stimulate plant defense responses that form chemical or physical barriers that are used against the pathogen invasion. Inducers used usually give the signals to rouse the plant defense genes ultimately resulting into induced systemic resistance. In many plant-pathogen interactions, R-Avr gene interactions results in localized acquired resistance or hypersensitive response and at distal ends of plant, a broad spectrum resistance is induced known as systemic acquired resistance (SAR). Various biotic or abiotic factors induce systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Some of the biotic or abiotic determinants induce systemic resistance in plants through salicylic acid (SA) dependent SAR pathway, others require jasmonic acid (JA) or ethylene. Host plant remains in induced condition for a period of time, and upon challenge inoculation, resistance responses are accelerated and enhanced. Induced systemic resistance (ISR) is effective under field conditions and offers a natural mechanism for biological control of plant disease.

Gene Expression Regulation, Plant↗

Culture filtrate of Lasiodiplodia theobromae restricts the development of natural resistance in Brassica nigra plants.

Culture filtrate of Lasiodiplodia theobromae increased respiration rate, phenylalanine ammonia lyase activity, and levels of hydrogen peroxide, lipid peroxides and salicylic acid in B. nigra plants. Salicylic acid (SA) level increased for 1 hr of interaction and reduced later. Development of systemic acquired resistance (SAR) was found restricted in plants infected with L. theobromae due to deficiency of SA, which is a major signal for development of SAR. Exogenously supplied SA did develop resistance and plant death was delayed. It was hypothesized that deficiency of SA could be due to jasmonic acid produced by fungus that inhibits SA biosynthesis.

Ascomycota↗

Plant defense induced in in vitro propagated banana (Musa paradisiaca) plantlets by Fusarium derived elicitors.

Perception of microbial signal molecules is part of the strategy evolved by plants to survive attacks by potential pathogens. To gain a more complete understanding of the early signaling events involved in these responses, we used fungal components of Fusarium under in vitro condition and checked the rise in signal molecule, salicylic acid (SA), and marker enzymes in defense reactions against the pathogen. SA level increased by 21 folds in elicitor treated plantlets as compared to that of control plantlets and there was marked increase in phenylalanine ammonia-lyase(PAL), peroxidase(POX), polyphenol oxidase(PPO) along with higher total phenolic content. Present results indicated that use of fungal components had successfully induced systemic resistance in in vitro cultured banana plantlets.

Catechol Oxidase↗

Infra-red spectroscopic analyses of banana waste degraded by oyster mushroom.

Carbon, hydrogen and nitrogen analyses of banana leaf and pseudostem biomass revealed their potentiality as substrates for microorganisms. Infra-red (IR) spectra of both biomass show presence of cellulose, xylan and lignin. IR spectra of leaf and pseudostem biomass degraded in solid state fermentation (SSF) by two Pleurotus species (P. sajor-caju and P. ostreatus) for 40 days showed the utilization of cellulose, xylan and lignin by these microbes. Dynamics of various lignocellulolytic enzymes of Pleurotus species and analyses of carbon, hydrogen and nitrogen contents of degraded biomass supported the same. Both the Pleurotus species exhibited lignin consumption ability on both the substrates.

Basidiomycota↗

Biotransformation of banana waste into protein by pleurotus sajor-caju.

Pseudostems and leaves from banana waste were used for biotransformation into protein by using P. sajor-caju, an oyster mushroom. Treatment of formalin (500 ppm) + carbendazim (12.5 ppm) of these substrates was found to favour relatively high percentage biological efficiency (BE) of P. sajor-caju.. Steam sterilization also exhibited comparable yield performance by P. sajor-caju. Fruiting bodies harvested from all the treatments had relatively higher protein contents. The spent substrate (steam sterilized) was found to be suitable as an ideal animal feed because of its rich nutritive composition.

Biodegradation, Environmental↗

Characterization of rpo-B mutant of a strain of Escherichia coli to confirm its suitability for routine work related to recombinant DNA technology.

Rifampicin resistant spontaneous mutant of a popular laboratory strain of Escherichia coli (DH5 alpha) was isolated and found to resist high level of the drug in growth medium. The growth of the isolate was found to be slower than its wild-type counterpart. Its ability to get transformed into drug-resistant state through transformation by chemical means as tested using plasmid DNA from three different size categories, was found to be at par with the wild type. Other properties, viz., alpha-complementation and ability to express foreign gene remained unaltered. The utility of the rifampicin-resistant phenotype as a potential chromosomal genetic marker was demonstrated in a typical conjugation experiment to establish the ability of the mutant to act as recipient strain for a recombinant, mobilizable plasmid DNA molecule with the advantage of drug-mediated, high efficiency selection. Substitution of the wild strain with the mutant for routine experimentations related to recombinant DNA technology was concluded to be appropriate and of advantage.

DNA, Recombinant↗