Lucrative pectinase production by novel strain Pseudozyma sp. SPJ with statistical optimization techniques using agro-industrial residues

Production of high titers of an alkaline, extracellular and thermo-tolerant pectinase by a newly isolated yeast Pseudozyma sp. SPJ was carried out under solid state fermentation. Citrus peel, the inexpensive agro-industrial residue used as substrate, was experienced to be unsurpassed. Response surface methodology was conducted to optimize the culture conditions for Pseudozyma sp. SPJ for hyper production of pectinase. Plackett Burman design was applied to identify the most effective culture variables. Out of nine variables studied, incubation time, moisture content and ammonium sulfate were detected as most important. A full factorial Central Composite Design was used to optimize the levels of these variables, which resulted in 17-fold increase （71.19 IU/g to 1215.66 IU/g dry substrate） in the enzyme yield. The results of analysis of variance and multiple regression analysis implies that the effect of incubation time （p 〈 0.000） and moisture content （p 〈 0.018） is more than ammonium sulfate. And also the interaction of moisture content with ammonium sulfate （p 〈 0.002） is more significant.     

Trans-spliced Heat Shock Protein 90 Modulates Encystation in Giardia lamblia

Background

Hsp90 from Giardia lamblia is expressed by splicing of two independently transcribed RNA molecules, coded by genes named HspN and HspC located 777 kb apart. The reasons underlying such unique trans-splicing based generation of GlHsp90 remain unclear.

Principle Finding

In this study using mass-spectrometry we identify the sequence of the unique, junctional peptide contributed by the 5′ UTR of HspC ORF. This peptide is critical for the catalytic function of Hsp90 as it harbours an essential “Arg” in its sequence. We also show that full length GlHsp90 possesses all the functional hall marks of a canonical Hsp90 including its ability to bind and hydrolyze ATP. Using qRT-PCR as well as western blotting approach we find the reconstructed Hsp90 to be induced in response to heat shock. On the contrary we find GlHsp90 to be down regulated during transition from proliferative trophozoites to environmentally resistant cysts. This down regulation of GlHsp90 appears to be mechanistically linked to the encystation process as we find pharmacological inhibition of GlHsp90 function to specifically induce encystation.

Significance

Our results implicate the trans-spliced GlHsp90 from Giardia lamblia to regulate an essential stage transition in the life cycle of this important human parasite.     

Combining drought and submergence tolerance in rice: marker-assisted breeding and QTL combination effects

TDK1 is a popular rice variety from the Lao PDR. Originally developed for irrigated conditions, this variety suffers a high decline in yield under drought conditions. Studies have identified three quantitative trait loci (QTLs) for grain yield under drought conditions, qDTY _3.1 , qDTY _6.1 , and qDTY _6.2 , that show a high effect in the background of this variety. We report here the pyramiding of these three QTLs with SUB1 that provides 2–3 weeks of tolerance to complete submergence, with the aim to develop drought- and submergence-tolerant near-isogenic lines (NILs) of TDK1. We used a tandem approach that combined marker-assisted backcross breeding with phenotypic selection to develop NILs with high yield under drought stress and non-stress conditions and preferred grain quality. The effect of different QTL combinations on yield and yield-related traits under drought stress and non-stress conditions is also reported. Our results show qDTY _3.1 to be the largest and most consistent QTL affecting yield under drought conditions, followed by qDTY _6.1 and qDTY _6.2 , respectively. QTL class analysis also showed that lines with a combination of qDTY _3.1 and qDTY _6.1 consistently showed a higher tolerance to drought than those in which one of these QTLs was missing. In countries such as Lao PDR, where large areas under rice cultivation suffer vegetative-stage submergence and reproductive-stage drought, these lines could ensure yield stability. These lines can also serve as valuable genetic material to be used for further breeding of high-yielding, drought- and submergence-tolerant varieties in local breeding programs.     

Glutamine synthetase,glutamate synthase and glutamate dehydrogenase in Rhizobium japonicum strains grown in cultures and in bacteroids from root nodules of Glycine max

The growth yields of three strains of Rhizobium japonicum (CB 1809, CC 723, CC 705) in culture solutions containing L-glutamate were about twice those grown with ammonium. The activities of glutamine synthetase (GS; EC 6.3.1.2) and glutamate dehydrogenase (GDH; EC 1.4.1.4) were dependent on the nitrogen source in the medium and also varied with growth. Both NADPH-and NADH-dependent glutamate synthase (GOGAT; EC 1.4.1.13) and NADPH-dependent GDH were found in strains grown with either glutamate or ammonium but NADH-linked GDH was only detected in glutamate-grown cells. Glutamine synthetase was adenylylated in cells grown with NH ₄ ⁺ (90%) and to lesser extent in those grown with L-glutamate (50%). In root nodules produced by the three strains in Glycine max (L.) Merr., the bulk of GS was located in the nodule cytosol (60–85%). The enzyme was adenylylated in bacteroids (43–75%) and in the nodule tissues (52–68%). The enzyme in cell-free extracts of Rh. japonicum (CC 705) grown in culture solutions containing glutamate and in bacteroids (CC 705) was deadenylylated by snake-venom phosphodiesterase. L-methionine-DL-sulfoximine restricted the incoporation of ¹⁵N-labelled (NH₄)₂SO₄ into cells of strains CB 1809 and CC 705, as well as in bacteroids of strain CC 705. It is noteworthy that appreciable activities for GDH were found in the free-living rhizobia grown on glutamate. Thus the presence of an enzyme does not necessarily imply that a particular pathway is operative in assimilating ammonium into cell nitrogen. Based on ¹⁵N studies, the GS-GOGAT pathway of rhizobia (strains CB 1809 and CC 705) is important when grown in culture solutions as well as in bacteroids from root nodules of G. max.     

Vitamin B12 and Folic Acid Improve Gross Motor and Problem-Solving Skills in Young North Indian Children: A Randomized Placebo-Controlled Trial

Objectives

Deficiencies of vitamin B12 and folate are associated with delayed development and neurological manifestations. The objective of this study was to measure the effect of daily supplementation of vitamin B12 and/or folic acid on development in young North Indian children.

Methods

In a randomized, double blind trial, children aged six to 30 months, received supplement with placebo or vitamin B12 and/or folic acid for six months. Children were allocated in a 1:1:1:1 ratio in a factorial design and in blocks of 16. We measured development in 422 children by the Ages and Stages Questionnaire 3rd ed. at the end of the intervention.

Results

Compared to placebo, children who received both vitamin B12 and folic acid had 0.45 (95% CI 0.19, 0.73) and 0.28 (95% CI 0.02, 0.54) higher SD-units in the domains of gross motor and problem solving functioning, respectively. The effect was highest in susceptible subgroups consisting of stunted children, those with high plasma homocysteine (> 10 μmol/L) or in those who were younger than 24 at end study. With the exception of a significant improvement on gross motor scores by vitamin B12 alone, supplementation of either vitamin alone had no effect on any of the outcomes.

Conclusion

Our findings suggest that supplementation of vitamin B12 and folic acid benefit development in North Indian Children.

Trial Registration

ClinicalTrials.gov NCT00717730     

Effect of Chronic Treatment with D2 Allosteric Modulator PAOPA on the Expression of Cerebral Dopamine Neurotrophic Factor (CDNF) in Select Brain Regions

International Journal of Peptide Research and Therapeutics - Impairment in dopaminergic pathways has been implicated in several detrimental neuropsychiatric and neurodegenerative disorders,...     

Molecular characterization and differential expression studies of an oxidosqualene cyclase (OSC) gene of Brahmi (Bacopa monniera)

Triterpenoid saponins are the class of secondary metabolites, synthesized via isoprenoid pathway. Oxidosqualene cyclases (OSCs) catalyzes the cyclization of 2, 3-oxidosqualene to various triterpene skeletons, the first committed step in triterpenoid biosynthesis. A full-length oxidosqualene cyclase cDNA from Bacopa monniera (BmOSC) was isolated and characterized. The open reading frame (ORF) of BmOSC consists of 2,292 bp, encoding 764 amino acid residues with an apparent molecular mass of 87.62 kDa and theoretical pI 6.21. It contained four QxxxxxW motifs, one Asp-Cys-Thr-Ala-Glu (DCTAE) motif which is highly conserved among the triterpene synthases and another MWCYCR motif involved in the formation of triterpenoid skeletons. The deduced amino acid sequence of BmOSC shares 80.5 % & 71.8 % identity and 89.7 % & 83.5 % similarity with Olea europaea mixed amyrin synthase and Panax notoginseng dammarenediol synthase respectively. Phylogenetic analysis revealed that BmOSC is closely related with other plant OSCs. Quantitative real-time PCR (qRT-PCR) data showed that BmOSC is expressed in all tissues examined with higher expression in stem and leaves as compared to roots and floral parts.     

Impact of In-Situ CO2 Nano-Bubbles Generation on Freezing Parameters of Selected Liquid Foods

The impact of in-situ CO₂ nano-bubbles generation on the freezing properties of soft serve, milk, and apple juice was investigated. Carbonated (0, 1000, and 2000 ppm) liquid foods contained in a tube were submerged and cooled for 90 min in a pre-set ethylene glycol bath (−15 °C). Before the enclosed liquid reached 0 °C, the vibration was discharged through ultrasound in the bath to create nano-bubbles within the carbonated food samples, and the changes in temperature for 90 min of each food were recorded as a freezing curve. The time for onset of nucleation of control soft serve mix was halved in samples with 2000-ppm CO₂ due to the presence of nano-bubbles. Likewise, the nucleation time for milk with and without nano-bubbles at the same CO₂ concentration of 2000 ppm was 7.9 ± 0.1 and 2.8 ± 0.8 min_, respectively. The generation of CO₂ nano-bubbles from 2000-ppm CO₂ level in 10 ^oBx apple juice displayed −9.3 ± 0.3 °C nucleation temperature while the control one had −11.7 ± 0.9 °C.

     

Maresin Conjugates in Tissue Regeneration 1 improves alveolar fluid clearance by up‐regulating alveolar ENaC,Na, K‐ATPase in lipopolysaccharide‐induced acute lung injury

Maresin Conjugates in Tissue Regeneration 1 (MCTR1) is a newly identified macrophage‐derived sulfido‐conjugated mediator that stimulates the resolution of inflammation. This study assessed the role of MCTR1 in alveolar fluid clearance (AFC) in a rat model of acute lung injury (ALI) induced by lipopolysaccharide (LPS). Rats were intravenously injected with MCTR1 at a dose of 200 ng/rat, 8 hours after administration of 14 mg/kg LPS. The level of AFC was then determined in live rats. Primary rat ATII (Alveolar Type II) epithelial cells were also treated with MCTR1 (100 nmol/L) in a culture medium containing LPS for 8 hours. MCTR1 treatment improved AFC (18.85 ± 2.07 vs 10.11 ± 1.08, P < .0001) and ameliorated ALI in rats. MCTR1 also significantly promoted AFC by up‐regulating epithelial sodium channel (ENaC) and Na⁺‐K⁺‐adenosine triphosphatase (Na, K‐ATPase) expressions in vivo. MCTR1 also activated Na, K‐ATPase and elevated phosphorylated‐Akt (P‐Akt) by up‐regulating the expression of phosphorylated Nedd4‐2 (P‐Nedd4‐2) in vivo and in vitro. However, BOC‐2 (ALX inhibitor), KH7 (cAMP inhibitor) and LY294002 (PI3K inhibitor) abrogated the improved AFC induced by MCTR1. Based on the findings of this study, MCTR1 may be a novel therapeutic approach to improve reabsorption of pulmonary oedema during ALI/acute respiratory distress syndrome (ARDS).