Optimization of protease production from Bacillus halodurans under solid state fermentation using agrowastes

Marine microbes are potential source for novel metabolites. They are efficient in producing these metabolites utilizing agrowastes. Protease is one of the enzymes which find wide industrial applications. In the present study, protease producing bacteria was isolated from marine sediments and the organism was identified as Bacillus halodurans. The organism was subjected to protease production under solid state fermentation (SSF) using different agrowastes as substrates. Among the substrates used, wheat bran yielded maximum quantity of protease. The fermentation process was carried out under different cultural conditions to optimize the parameters influencing the enzyme production. The results of the stain removal studies by the enzyme revealed the increased efficiency of the microbial enzyme than the commercial detergent.     

Strict preparation and evaluation of water-soluble hat-stacked carbon nanofibers for biomedical application and their high biocompatibility: influence of nanofiber-surface functional groups on cytotoxicity

Water-soluble H-CNFs modified with a carboxyl group possessed the ability to induce TNF-alpha, whereas CHAPS-treated H-CNFs possessed significantly greater activity and were also found to activate NF-kappaB reporter activity, to a significantly greater level than H-CNFs; furthermore the functional group modified or coated on the surface of H-CNFs was a significant cytotoxic factor that affected cell activation.     

Two new black fly species of Simulium (Simulium) (Diptera: Simuliidae) from South India

Two new black fly species, Simulium (Simulium) pothigaiense sp. n. and Simulium (Simulium) valparaiense sp. n., are described based on females, males, pupae and larvae. Simulium (Simulium) pothigaiense sp. n. is characterized by a claw simple without subbasal tooth and the base of radial vein with hair tuft in the females, maxillary palp with small sensory vesicle in the males, pupal gill with 10 short slender filaments and very short common basal stalk in the pupae and 5 hypostomal bristles per side lying parallel to lateral margin in the larvae. Simulium (Simulium) valparaiense sp. n. is characterized by hind basitarsus 6.6 times as long as its greatest width and claw with small distinct subbasal tooth in the females, gonostyle in medial view 2.3 times longer than coxite in the males, common basal stalk of pupal gill 0.31 times as long as interspiracular trunk, and larval thoracic and abdominal cuticle with pair of dorsolateral protuberances. Taxonomic notes are given to distinguish these two new species from closely related species. www.zoobank.org/urn:lsid:zoobank.org:pub:7285F6BC-607D-4F76-B6EE-9CAC67CDE651     

A Pair of Ligation-Independent Escherichia coli Expression Vectors for Rapid Addition of a Polyhistidine Affinity Tag to the N- or C-Termini of Recombinant Proteins

6×His tag is one of the most widely used affinity fusion tags that facilitates detection and purification of recombinant proteins. However, the location of this tag within a particular type of protein may influence the expression, solubility, and bioactivity of the protein, and the optimal location needs to be determined experimentally. To provide a tool for rapid generation of 6× His tags at the N- or C-terminus of any recombinant protein, we have constructed a pair of Escherichia coli expression vectors—pLIC-NHis and pLIC-CHis—based on the pET30a vector, for ligation-independent cloning (LIC). Construction of this new pair of LIC vectors was accomplished by replacement of the multiple cloning site of pET30a with two specifically designed LIC cloning sites. A target gene derived by PCR with a pair of predesigned primers can be inserted into the LIC site of pLIC-NHis for expression of recombinant proteins fused with the N-terminal sequence MHHHHHHG or into that of pLIC-CHis for expression of recombinant proteins with the C-terminal sequence THHHHHH. Successful expression of two normal mammalian prion proteins and five bacterial proteins in E. coli using this pair of LIC vectors reveals that these vectors are valuable tools for the production of recombinant His-tagged proteins in E. coli.     

Absorption of molecular urea by rice under flooded and non-flooded soil conditions

A pot experiment was conducted with rice to study the relative absorption of urea in molecular form compared to the other forms of N produced in soil from the applied urea. A method involving application of ¹⁴C-labelled urea and ¹⁵N-labelled urea alternately in two splits was used to quantify the absorption of molecular urea and other forms of N formed from it. Biomass production and N uptake were greater in plants grown under flooded soil conditions than in plants grown under non-flooded (upland) conditions. Absorption of N by rice increased with increasing rate of urea application up to 250 mg pot⁻¹ and declined thereafter. The absorption of urea from the flooded soil constituted 9.4% of total N uptake from applied N compared to only 0.2% from the non-flooded. Under submerged conditions, absorption of urea from topdressing was about twice that from basal application at planting. High water solubility of the fertilizer and better developed rice root system might have enhanced the absorption of molecular urea by flooded rice, especially from topdressing. Thus, in the flooded rice system, the direct absorption of molecular urea from topdressing accounted for 6.3% of the total N uptake from added urea. Under upland condition, it was 0.12%. This revised version was published online in June 2006 with corrections to the Cover Date.     

Pyramided rice lines harbouring Allium sativum (asal) and Galanthus nivalis (gna) lectin genes impart enhanced resistance against major sap-sucking pests

We have developed transgene pyramided rice lines, endowed with enhanced resistance to major sap-sucking insects, through sexual crosses made between two stable transgenic rice lines containing Allium sativum (asal) and Galanthus nivalis (gna) lectin genes. Presence and expression of asal and gna genes in pyramided lines were confirmed by PCR and western blot analyses. Segregation analysis of F₂ progenies disclosed digenic (9:3:3:1) inheritance of the transgenes. Homozygous F₃ plants carrying asal and gna genes were identified employing genetic and molecular methods besides insect bioassays. Pyramided lines, infested with brown planthopper (BPH), green leafhopper (GLH) and whitebacked planthopper (WBPH), proved more effective in reducing insect survival, fecundity, feeding ability besides delayed development of insects as compared to the parental transgenics. Under infested conditions, pyramided lines were found superior to the parental transgenics in their seed yield potential. This study represents first report on pyramiding of two lectin genes into rice exhibiting enhanced resistance against major sucking pests. The pyramided lines appear promising and might serve as a novel genetic resource in rice breeding aimed at durable and broad based resistance against hoppers.     

Select pyrimidinones inhibit the propagation of the malarial parasite,Plasmodium falciparum

Plasmodium falciparum, the Apicomplexan parasite that is responsible for the most lethal forms of human malaria, is exposed to radically different environments and stress factors during its complex lifecycle. In any organism, Hsp70 chaperones are typically associated with tolerance to stress. We therefore reasoned that inhibition of P. falciparum Hsp70 chaperones would adversely affect parasite homeostasis. To test this hypothesis, we measured whether pyrimidinone-amides, a new class of Hsp70 modulators, could inhibit the replication of the pathogenic P. falciparum stages in human red blood cells. Nine compounds with IC₅₀ values from 30 nM to 1.6 μM were identified. Each compound also altered the ATPase activity of purified P. falciparum Hsp70 in single-turnover assays, although higher concentrations of agents were required than was necessary to inhibit P. falciparum replication. Varying effects of these compounds on Hsp70s from other organisms were also observed. Together, our data indicate that pyrimidinone-amides constitute a novel class of anti-malarial agents.