Characterization of a novel cellobiase fromBacillus subtilis and expression of its structural gene inEscherichia coli

Summary A strain ofBacillus subtilis was found to produce a cellobiase resistant to catabolic repression by glucose. When the structural gene encoding cellobiase was cloned and expressed inEscherichia coli, the enzyme produced was resistant to repression by glucose.     

Genetic identity and diversity of Nigerian cacao genebank collections verified by single nucleotide polymorphisms (SNPs): a guide to field genebank management and utilization

Nigeria is the sixth largest cacao producer in the world. Field performance and quality of cacao hybrid families is largely dependent on the genetic integrity of parental clones obtained in field genebank collections. However, information on the impact of mislabeling on seed garden output in Nigeria is lacking. Using 63 single nucleotide polymorphism (SNP) markers, we analyzed 1457 cacao trees sampled from seven major field genebank plots in Nigeria to assess the genetic integrity in Nigerian cacao germplasm. The procedure of multilocus matching with known reference clones revealed up to 78% mislabeling in recently introduced international germplasm. A high rate of mislabeling was also revealed in the West African local selections and breeding lines, using Bayesian assignment test. The problem of mislabeling has been attributed to errors from the sources of introduction, pre-planting labeling errors, and rootstocks overtaking budded scions due to poor field management. The analysis of genetic diversity revealed a good representation of the available cacao germplasm groups in Nigerian field genebanks, indicating that the genetic base of Nigeria cacao germplasm has been significantly widened through germplasm introductions. However, only a small proportion of the available germplasm in the genebank have been utilized for variety development. This study proved the utility of SNP markers for cleaning up the genebanks and reducing offtypes; thereby providing a strong basis for improving the accuracy and efficiency in cacao genebank management and breeding, as well as for mobilizing improved varieties to cacao farmers in Nigeria.     

The Level of Toxic Elements in Edible Crops from Seleniferous Area (Punjab,India)

Biological Trace Element Research - The primary objective of the present study was to assess the level of selenium and toxic trace elements in wheat, rice, maize, and mustard from seleniferous...     

Microsatellite loci to assess genetic variation in Tor putitora

Seven polymorphic microsatellite DNA loci were identified in golden mahseer, Tor putitora, through cross‐species amplification. Thirty‐two primers developed for three cyprinid fishes were tested in the study. The genetic variation detected at each microsatellite locus in T. putitora specimens (n = 107), collected from three different rivers and one lake was assessed. The allele frequencies deviated significantly from that expected under Hardy–Weinberg equilibrium. The mean observed heterozygosity values ranged from 0.29 to 0.40. Significant genotype heterogeneity indicated that the samples were not drawn from the same gene pool. The results indicate that the identified microsatellite loci exhibit promise for use in fine scale population structure analyses of T. putitora.     

Development of an Ointment Formulation Using Hot-Melt Extrusion Technology

Ointments are generally prepared either by fusion or by levigation methods. The current study proposes the use of hot-melt extrusion (HME) processing for the preparation of a polyethylene glycol base ointment. Lidocaine was used as a model drug. A modified screw design was used in this process, and parameters such as feeding rate, barrel temperature, and screw speed were optimized to obtain a uniform product. The product characteristics were compared with an ointment of similar composition prepared by conventional fusion method. The rheological properties, drug release profile, and texture characteristics of the hot-melt extruded product were similar to the conventionally prepared product. This study demonstrates a novel application of the hot-melt extrusion process in the manufacturing of topical semi-solids.     

Two flavonoid glycosides from the bark of Prosopis juliflora

Two new glycosides, kaempferol 4′-methyl ether 3-O-β-d-galactopyranoside and retusin 7-O-neohesperidoside, have been characterized from the stem bark of Prosopis juliflora.     

Effect of water table depth and tillage methods on plant-water status and yield of rice

Summary Effects of water table depths on plant-water status, and on growth and yields of two rice varieties (TOS 78 and TOS 848) were studied in a lysimetric investigation. A field study was also conducted on a hydromorphic soil to investigate the effects of fluctuating water table on rice. The leaf-water potential of TOS 78 monitored at 1300 hours at 50% flowering stage was –17.5 and –23.0 bars for 0 and 60 cm water table depths, respectively. When grown under soil moisture stress, TOS 848 maintained higher leaf-water potential (–17.5 barvs –22.5 bar) and yielded more than TOS 78. Under hydromorphic soil conditions, no-tillage treatments yielded the same as conventionally tilled plots.     

The effects of insulin and tunicamycin on insulin receptors of cultured fibroblasts

The effect of down-regulation on the intracellular pool of insulin receptors and the role of glycosylation in recovery from down-regulation have been studied in fibroblastic cultures from the skin of non-diabetic mice. In control cultures, 55% of the total specific [¹²⁵I]insulin-binding activity was in the intracellular compartment. Insulin caused a time- and concentration-dependent decrease in the number of cell surface insulin receptors, with no significant change in total insulin receptors. This decrease in surface receptors was accompanied by an increase in the specific binding of [¹²⁵I]insulin in the intracellular compartment. Removal of insulin from down-regulated cells resulted in a time-dependent increase in the binding of [¹²⁵I]insulin to surface receptors, reaching 90% of that in controls by 12 h. The recovery of surface insulin receptors after removal of insulin was blocked by incubation of cultures with tunicamycin, but not by cycloheximide. These results indicate that down-regulation of surface insulin receptors by insulin is associated with translocation of receptors into the intracellular pool and suggest that protein glycosylation is important in insulin receptor recycling and externalization.