Superior Orthonasal but Not Retronasal Olfactory Skills in Congenital Blindness

Sight is undoubtedly important for finding and appreciating food, and cooking. Blind individuals are strongly impaired in finding food, limiting the variety of flavours they are exposed to. We have shown before that compared to sighted controls, congenitally blind individuals have enhanced olfactory but reduced taste perception. In this study we tested the hypothesis that congenitally blind subjects have enhanced orthonasal but not retronasal olfactory skills. Twelve congenitally blind and 14 sighted control subjects, matched in age, gender and body mass index, were asked to identify odours using grocery-available food powders. Results showed that blind subjects were significantly faster and tended to be better at identifying odours presented orthonasally. This was not the case when odorants were presented retronasally. We also found a significant group x route interaction, showing that although both groups performed better for retronasally compared to orthonasally presented odours, this gain was less pronounced for blind subjects. Finally, our data revealed that blind subjects were more familiar with the orthonasal odorants and used the retronasal odorants less often for cooking than their sighted counterparts. These results confirm that orthonasal but not retronasal olfactory perception is enhanced in congenital blindness, a result that is concordant with the reduced food variety exposure in this group.     

Distribution and function of prophage phiRv1 and phiRv2 among Mycobacterium tuberculosis complex

Mycobacterium tuberculosis complex (MTBC) is notorious for causing diseases, such as tuberculosis. Tuberculosis caused by M. tuberculosis remains a global public health concern. Two prophages, phiRv1 and phiRv2, can be found among most MTBC genomes. However, no precise functions have been assigned for the two prophages. In this paper, to find out the function of these two prophages, the distribution and function of phiRv1 and phiRv2 in MTBC genomes were analyzed from multiple omics data. We found that complex insertion, deletion, and reorganization appeared on the locus of two prophages in MTBC genomes; some genes of the two prophages can be translated and are functional from proteomic data; the expression of other prophage genes, such as Rv1577c, Rv2650c, Rv2652c, Rv2659c, and Rv2658c, can vary with environmental stresses and might enhance the fitness of MTBC. These data will facilitate our in-depth understanding of their function.     

Substrate docking and molecular dynamic simulation for prediction of fungal enzymes from Trichoderma species-assisted extraction of nanocellulose from oil palm leaves

Abstract

Fungi of the Trichoderma species are valued industrial enzymes in support of the ‘zero-waste’ technology to convert agro-industrial biomass into valuable products, i.e. nanocellulose (NC). In this study, an in silico approach using substrate docking and molecular dynamic (MD) simulation was used to predict the order of which the multilayers of cellulosic polymers, i.e. lignin, hemicellulose and cellulose in oil palm leaves (OPL) are degraded by fungal enzymes, endocellulase and exocellulase. The study aimed to establish the catalytic tendencies of the enzymes to optimally degrade the cellulosic components of OPL for high yield production of NC. Energy minimized endocellulase and exocellulase models revealed satisfactory scores of PROCHECK (90.0% and 91.2%), Verify3D (97.23% and 98.85%) and ERRAT (95.24% and 91.00%) assessments. Active site prediction by blind docking, COACH meta-server and multiple sequence alignment indicated the catalytic triads for endocellulase and exocellulase were Ser116–His205–Glu249 and Ser382–Arg124–Asp385, respectively. Binding energy of endocellulase docked with hemicellulose (?6.0 ? kcal mol^?1) was the most favourable followed by lignin (?5.6 ? kcal mol^?1) and cellulose (?4.4 ? kcal mol^?1). Exocellulase, contrarily, bonded favorably with lignin (?8.7 ? kcal mol^?1), closely followed by cellulose (?8.5 ? kcal mol^?1) and hemicellulose (?8.4 ? kcal mol^?1). MDs simulations showed that interactions of complexes, endocellulase–hemicellulose and the exocellulase–cellulose being the most stable. Thus, the findings of the study successfully identified the specific actions of sugar-acting enzymes for NC production.

Communicated by Ramaswamy H. Sarma     

Influence of Precocene II on the estimated changes within the haemocyte population of parasitized spodoptera littoralis larvae by microplitis rufiventris

Series of experiments were undertaken to investigate whether application of Precocene II (PII) to parasitized S. littoralis larvae can influence their THCs and DHCs. PII was applied in single dose treatments (70μg/5 μl/dose). Haemolymph samples were taken at daily intervals from day 3 to day 8 post‐treatments. Two distinct alterations were noted; first, PII‐treatments caused significant decrease in THCs. Once the parasitoid larvae emerge from either treated or untreated hosts, a sharp decline in THCs was observed. The second effect was changes in DHCs of S. littoralis larvae. In controls, haemocyte types could be arranged in descending order due to their relative occurrence into plasmatocytes (PLs), prohaemocytes (PRs), spherule cells (SPs), granular cells (GRs) and oenocytoids (OEs). This order changed in treated hosts to PLs, GRs, PRs, SPs and OEs, i.e., GRs that were less prevalent in the haemolymph of control larvae increased significantly in PII‐treated hosts. In the latters, sharp rise in GRs levels followed parasitoid emergence. OEs cells were scarce in both treated and untreated hosts. No significant difference was observed between the overall means of PLs in both types of host larvae. But GRs‐PRs was markedly altered in treated larvae.     

Characterization of A units released from the poly(A) tract of rabbit globin mRNA during protein synthesis: possible role of the released ATP in synthesizing protein

1. Rabbit globin mRNA poly(A) was translated in two cell-free synthesizing systems, rabbit reticulocyte lysate and wheat germ extract, to characterize the product released from the poly(A) tract during globin synthesis. 2. Kinetic studies indicate that the size of the cleaved nucleotide proves to be a monomer, as revealed by column chromatography on Sephadex G-100 or G-25. 3. Characterization of the monomer was accomplished by chromatography on DEAE-cellulose. Initially, 5 min post-translation, the monomer was ATP only; however, at later times ATP, ADP, AMP and adenosine were detected. 4. The two synthesizing systems differed in that globin mRNA poly(A) was translated at a faster rate in the wheat germ extract as revealed by the appearance of ATP, whereas AMP was detected sooner in the rabbit reticulocyte lysate. 5. The results indicate that the A unit released from the poly(A) tract during mRNA poly(A) translation is a monomer, and that these metabolites may play a role in controlling protein initiation via the released ATP.     

Toxic and deterrent effects of two volatile oils against cowpea weevil,Callosobruchus chinensis (Coleoptera: Bruchidae)

The fumigant effect of Mentha piperita and Ocimum basilicum oils and their mixture against adults and eggs of Callosobruchus chinensis (L.) was evaluated. Bioassay experiments showed that Ocimum basilicum oil was significantly effective against adult and egg stage which was the least effective. However, in the fumigant toxicity experiments against adult stage, Ocimum basilicum oil at a dose of 1.0 μl/38.5 ml air caused 100% mortality (LC₅₀ = 1.88), the mixture of both oils at a dose of 6.0 μl/38.5 ml air caused 100% mortality (LC₅₀ = 10.3) and Mentha piperita oil at a dose of 80.0 μl/38.5 ml air caused 80.0% mortality (LC₅₀ = 41.224) during a one day exposure period. Regarding the oviposition deterrent activity, Ocimum basilicum oil achieved 100% oviposition deterrent (at a dose of 0.5 μl/38.5 ml air) followed by the mixture of Mentha piperita and Ocimum basilicum oils, which achieved 71.22% oviposition deterrent (at a dose of 1.0 μl/38.5 ml air) and Mentha piperita oil, which achieved 39.6% oviposition deterrent (at a dose of 5.0 μl/38.5 ml air). The essential oils and their mixtures studied here determined a significant decrease in the number of eggs hatched and in the emergence of adults. The eggs failed to hatch on using Ocimum basilicum oil at a dose of 0.6 μl/38.5 ml air. However, the number of eggs hatched decreased to 7.4 on using a mixture of oils at a dose of 2.0 μl/38.5 ml air and 14.0 with Mentha piperita oil at a dose of 80.0 μl/38.5 ml air compared with 25.0 eggs hatched in the control experiments. On the other hand, the percentage reduction in emerging adults were 100% for Ocimum basilicum oil, 90.9% for a mixture of the two oils and 72.7% for Mentha piperita oil. Results showed that Ocimum basilicum oil and Ocimum basilicum oils plus Mentha piperita oils in blend are potential alternatives to synthetic fumigants in the treatment of durable agricultural products. Successful adoption of plant oils in the protection of food commodities promises an eco-friendly option compatible with international biosafety regulations.     

Potency of Bacillus thuringiensis and Bacillus subtilis against the cotton leafworm,Spodoptera littoralis (Bosid.) Larvae

The biological activities of two species of bacteria isolated from soil of cotton fields identified as Bacillus subtilis strain NRC313 (BS NRC313) and Bacillus thuringiensis strain NRC335 (BT NRC335) were evaluated against the third larval instar of the cotton leafworm, Spodoptera littoralis (Boisd.). The different entomopathogenic bacteria of BS NRC313and BT NRC335 contained 10 × 10⁸ cell/ml, and caused mortality of 100 and 97.3% for the above mentioned strains, respectively. Concentrations of 2.5 × 10⁸ to 10 × 10⁸ cell/ml of strains BS NRC313 and BT NRC335 were applied to the larvae: LC₅₀ were 3.3 × 10⁸ and 3.9 × 10⁸ cell/ml respectively. The influence of exposure to toxin concentrations manifested in terms of decreasing the adult emergence and prolongation of the generation period. The percentage of larvae that survived and succeeded to pupate increased by decreasing the concentration. The longevity of adult emergence that resulted from larvae treated with Bacillus subtilis were 6.0 ± 0.51 and 9.0 ± 0.63 days at 5 × 10⁸ and 2.5 × 10⁸ cell/ml, respectively compared with 9.8 ± 0.47 in control. The results indicated that Bacillus subtilis was more potent than Bacillus thuringiensis. Field applications of B. thuringiensis, B. subtilis and Reldan achieved 55.6, 67.4 and 89.4% reduction of the cotton leafworm larvae Spodoptera littoralis in clover plants under field conditions.