Imaging techniques for the detection of stored product pests

Stored grains are subject to deterioration and losses through various factors, but mainly insects and fungi. Various techniques are employed to detect stored product pests; however, there is an urgent need for an industrial-scale on-line detection technique. Near-infrared hyperspectroscopic imaging and soft X-rays have shown the potential for real-time application. These techniques are particularly effective for detecting internal infestations of stored grains. The digital images of the scanned objects are analyzed for various spectral and image features using statistical techniques such as complex multivariate tools. Classification accuracies as high as 80–100 % have been achieved for various pest and grain combinations. Dual-energy X-rays have been shown to detect the concealed eggs of stored product insect pests. The main threats to stored cereals come from Aspergillus spp., Penicillium spp., and Fusarium spp., which may produce mycotoxins. These imaging techniques have shown good results in the detection of fungal infections of stored grain.     

Sequence Analysis and Comparative Bioinformatics Study of Camelysin Gene (<Emphasis Type="Italic">calY</Emphasis>) Isolated from <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis>

Bacillus strains have been widely used for the production of fibrinolytic enzymes having role in the treatment of cardiovascular disorders. Purification and overproduction of such enzymes has increased their usage in medical fields including metalloproteinases with the ability to degrade extracellular matrix (ECM). Camelysin, a neutral metalloproteinase has been isolated from different species of bacteria like Bacillus cereus, Bacillus anthracis, and Bacillus thuringiensis with fibrinolytic, collagenolytic and actin degradation activity. This project successfully demonstrated the presence of 734-bp coding DNA sequence (CDS) encoding a 20.72331 kDa camelysin gene in local strain of Bacillus thuringiensis containing a signal peptide with cleavage site between residues 19 and 20. The sequence was submitted to GenBank (KT023597) and the sequence showed high homology with the camelysin protein of closely related Bacillus species. The alignment of related proteins through ClustalW displayed difference of four amino acids (“Q” replaced by “P” at position 169 and at position 182–184, “NQE” replaced by “HLK”) in the isolated protein. Comparison including structural and functional analysis of camelysin sequences isolated from different Bacillus species was carried out using different bioinformatics tools and software. The information would help in better understanding the properties of camelysin protein and its role in pathogenicity and clinical treatments.     

A steryl ester from Lepidium sativum

A new steryl ester isolated from the aerial parts of Lepidium sativumfy1>cf1>, has been identified as stigmast-5-en-3,β27-diol 27-benzoate on the basis of spectral data analyses and chemical reactions.     

Molecular Confirmation of Intraspecific Tomato (<Emphasis Type="Italic">Solanum lycopersicum)</Emphasis> Hybrids and Their Evaluation Against Late Blight and Cucumber Mosaic Virus

Tomato is one of the most consumed vegetables in the world. Diseases are the number one concern in the development of high-yield and disease-resistant tomato hybrids which is the foremost priority of breeders. Present study was conducted (1) to develop DNA-based markers for genetic confirmation of tomato F₁ hybrids, (2) to utilize sequenced characterized amplified region (SCAR) marker linked to the Ph-3 gene for Phytophthora infestans resistance in tomato and (3) to evaluate male and female parental genotypes and their F₁ hybrids against late blight (LB) and cucumber mosaic virus (CMV). For molecular studies, 58 previously reported markers including RAPDs (10), SCAR (01), EST-SSR (01) and SSR (46) were applied. The SCAR marker clearly differentiated the LB3 and LB4 from Roma and T-1359 and provided evidence for Ph-3 gene. The SCAR marker was able to confirm the Ph-3 gene in the hybrids Roma × LB4, Roma × LB3, Riogrande × LB2, Riogrande × LB3 and Roma × LB7. Out of several tested primers, SSR-22 proved useful for genetic confirmation of F₁ hybrid TMS1 × Money Maker (MM). For LB, tested hybrids/genotypes were ranked as susceptible to highly susceptible with different infection percentage (IP). However, the pace of symptom development was slower in hybrid Rio × LB2, 45% IP after 10 days of inoculation compared with 85% disease in one of the parent genotypes (Riogrande). None of the tested genotypes was found resistant; however, TMS1 responded as tolerant against CMV using mechanical inoculation. Under natural field conditions, TMS1 was found resistant while hybrids TMS1 × Naqeeb and TMS1 × MM were tolerant where as others were found to be susceptible. In conclusion, all tomato hybrids were genetically confirmed using DNA-based markers. SCAR marker was useful for marker-assisted confirmation of the Ph-3 gene in parental lines and hybrids; however, this gene was unable to provide protection against the local population of P. infestans.     

The role of the pseudo-disaccharide neamine as an intermediate in the biosynthesis of neomycin.

By using wild-type and deoxystreptamine-negative mutants of Streptomyces fradiae grown in media containing [6(-3)H]glucose or [U-14C]glucose, and by subsequent hydrolysis of the labelled neomycin produced, neamines labelled with 3H in both rings I and II, but with 14C in ring I only, were prepared. A mixture of these two forms of neamine was converted by deoxystreptamine-negative Streptomyces rimosus forma paromomycinus into neomycin (not paromomycin) with a 30% yield. The3H: 14C ratio in this neomycin was the same as the measured in neamine produced by hydrolysis of the neomycin, and in unused neamine reisolated from the incubation medium. The 3H:14C ratio in the neomycin was not affected by the presence of unlabelled deoxystreptamine during the incubation. The radioactivity in the neomycin was associated with rings I and II only. It is concluded that the added neamine is incorporated into antibiotic intact, without initial hydrolysis, and that the probable first step in the subunit assembly of neomycin is the formation of neamine.     

Phosphoinositide 3-kinase mediated signalling contributes to development of diabetes-induced abnormal vascular reactivity of rat carotid artery

Diabetes mellitus is associated with vascular complications, including an impairment of vascular function and alterations in the reactivity of blood vessels to vasoactive agents. Phosphatidylinositol 3-kinase (PI3K) is a signalling enzyme that plays key roles in vascular growth, proliferation and cellular apoptosis and is implicated in modulating vascular smooth muscle contractility. The aim of this study was to determine whether PI3K plays a role in development of diabetes-induced altered vascular reactivity to selected vasoconstrictors and vasodilators. The effect of 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), a selective PI3K inhibitor, on isolated segments of carotid arteries from streptozotocin (STZ)-diabetic rats was investigated. Ring segments of the isolated carotid arteries were mounted in organ baths to measure changes in isometric tension. Our results showed that STZ treatment produced an increase in the vasoconstrictor response to norepinephrine (NE), angiotensin II (Ang II) and endothelin-1 (ET-1) and an attenuated vasodilator response to carbachol and histamine in the isolated carotid arteries from STZ-diabetic animals. Diabetes-induced impaired vascular responsiveness to the vasoactive agonists was prevented by chronic inhibition of PI3K by LY294002 even though blood glucose levels remained high. This is the first study to show that selective inhibition of PI3K can attenuate the development of diabetes-induced abnormal vascular reactivity in the isolated carotid arteries of diabetic rats.     

Lipase Induction in Mucor hiemalis

The influence on lipase induction in Mucor hiemalis of different types of triglycerides containing mainly oleic acid (olive oil), erucic acid (mustard oil), or saturated fatty acids of 8 to 16 carbons (coconut oil) was studied. The fungus was grown in shake flasks in a fermentation medium containing peptone, minerals, and glucose or one of the oils as the carbon source. Maximum lipase was produced when the initial pH of the fermentation medium was kept at 4.0. Addition of Ca²⁺ to the medium did not increase lipase production. The optimum pH for activity of both the mycelial and extracellular lipases was found to be 7.0. The fungus produced a significant amount of lipase in the presence of glucose, but the lipase activity increased markedly when olive oil was added to the medium at the beginning of the fermentation. Addition of olive oil at a later stage did not induce as much enzyme. Studies with washed mycelia showed that a greater amount of lipase was released when olive oil was present than when glucose was present. Among the various types of triglycerides used as the carbon source, olive oil was found to be most effective in inducing the lipase. Olive oil and mustard oil fatty acids inhibited the lipase more than those of coconut oil. The lipase induced by a particular type of triglyceride did not seem to be specific for the same triglyceride, nor was it inhibited specifically by it. Irrespective of the triglyceride used in the fermentation medium, the lipase produced was most active against coconut oil triglyceride, and this specificity, as shown by lipase activities in an n-heptane system, was not found to be due to a better emulsification of this oil. The lipase of M. hiemalis can be considered to be both constitutive and inducible.