Foraminifera-walled Schaubcylindrichnus coronus Frey and Howard, 1981, from the Middle Eocene,Kachchh, Western India

Bioclast lined tubes of Schaubcylindrichnus coronus are not much reported around the world. As of now only two reports are available. Interestingly in both these reports and in the current find, tests of foraminifers are used as tube building material. Current report of Schaubcylindrichnus is from the subtidal deposits of the Naredi Formation (Ypresian) of Kachchh Basin, Western India. As the host rock here abounds in the tests of larger benthic foraminifera, concentration of same is noticed within the tubes. The natural selection of lighter and larger calcitic grains of tests over the heavier mineral grains is the main reason for presence of the tests in tube building; moreover, presence of inner smooth wall of tube also indicates organisms’ preference for comfort within their burrow.     

The effect of polyamines on leaf senescence in two diverse rose species

Polyamines (PAs) retarded the senescence of leaf discs of two diverse speciesof rose viz., Rosa bourboniana andRosa damascena, while polyamine biosynthetic inhibitorsdifluoromethylornithine (DFMO), difluoromethylarginine (DFMA), methylglyoxal-bis(guanylhydrazone) (MGBG) and abscisic acid (ABA) promoted senescence. Sperminewas significantly the most effective polyamine in retarding senescence inR. bourboniana while MGBG and DFMA were more prominent inaccelerating senescence in R. damascena and R.bourboniana respectively. Protein and RNA content were significantlyhigher in polyamine treated leaf discs compared to those treated with polyaminebiosynthetic inhibitors and ABA. Total and reducing sugars decreased under alltreatments while the starch content increased significantly only in polyaminetreated leaf discs. Peroxidase and cellulase activities were retarded bypolyamine treatments and accelerated by polyamine biosynthetic inhibitors andABA. The role of PAs is discussed in relation to senescence.     

Role of ultrasound in assisted fermentation technologies for process enhancements

Abstract

Biological molecules are widely produced by fermentation technology using bacteria, fungi or yeast. Fermentation is a biochemical process wherein the rate of bioconversion is governed by the organisms involved. The growth of the organism is mainly limited by mass transfer rates of nutrients and gases that directly affect the product formation in fermentation. Attempts have been made to enhance the growth rate and yield using mutational, recombinant strain development approach at microbial level as well as fed batch and continuous processing approach at bioprocess level in the past. The growth rate of microbes can be accelerated by increased mass transfer rates and cell wall permeability with the use of controlled low frequency ultrasound irradiation. The present review provides insights into the application of acoustic cavitation in process intensification of fermentation approaches and the role of various factors involved are highlighted with typical examples.     

A Computer Simulation of the Adsorption and Diffusion of Benzene and Toluene in the Zeolites Theta-1 and Silicalite

Abstract

The influence of the framework geometries of zeolites on the adsorption and diffusion of benzene and toluene molecules has been studied through computer simulations. The behaviours of the uni- and bi-dimensional pore zeolites, theta-1 and silicalite, respectively, have been compared.