Studies on the control of enzymes for glyoxylate cycle inAspergillus terreus IRRL 16043

Current Microbiology - Complementation analysis of the 16 acetate nonutilizing (acu) mutants ofAspergillus terreus indicated that mutation with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) had...     

Enhancement of Catalytic Efficiencies of Xylanase, Pectinase and Cellulase by Microwave Pretreatment of their Substrates

Microwave pre-treatment of polygalacturonic acid, xylan and carboxymethylcellulose was found to improve the catalytic efficiencies of pectinase, xylanase and cellulase by 1.5, 2.3 and 1.6 fold, respectively. The microwave effect was distinguished from a pure thermal effect by irradiating at a constant temperature with the help of a non-contact infrared controller. The temperature and time of pre-treatment and substrate concentration during the pre-treatment were optimized by response surface methodology. Scanning electron microscopy revealed significant morphological changes in the substrate as a result of microwave pre-treatment. The time course of enzymatic hydrolysis in each case showed that the use of microwave pre-treated substrates gave higher catalytic rates. Also, a higher degree of bioconversion was observed in each case when microwave pre-treated substrates were used.     

Effect of (-)epicatechin on cAMP content, insulin release and conversion of proinsulin to insulin in immature and mature rat islets in vitro.

(-)Epicatechin, an active principle in the water extract of the bark of Pterocarpus marsupium increases the cAMP content of the islets which is associated with the increased insulin release, conversion of proinsulin to insulin and cathepsin B activity. The response of the islets to the (-)epicatechin stimulation is more pronounced in immature (one month old) than in mature (12 month old) rats.     

Maleic hydrazide induced changes in the physiology of Salvinia molesta mitch

Maleic hydrazide (MH) induced physiological changes in fronds of Salvinia molesta Mitch. in different durations of treatment up to 96 h. At 1000 and 5000 ppm, absorption of water, soluble proteins, reducing sugars and amylase activity were reduced; chlorophyll content and both protease and invertase activities were increased.     

Minimum Norm Invariant Quadratic Estimation of a Covariance Matrix in Linear Model

A general linear model with a known covariance structure is considered. The method of Minimum Norm Quadratic estimation extending RAO'S (1972) argument is outlined. This method is illustrated for a particular model where it is noted that MINQE used for estimating intraclass correlation coefficient yields the maximum likelihood estimate.