Effects of environmental and spatial gradients on Quercus-dominated Mountain forest communities in the Hindu-Kush ranges of Pakistan

Quercus-dominated forests are among the most important broad-leaved evergreen forests of the Hindu Kush ranges and are currently prone to drastic anthropogenic and climatic changes. The aim of this study was to provide basic data for the development of a regional oak forest ecosystem framework for ecological restoration and management plan development to maintain local peoples’ livelihoods. Hence, we analyzed distribution patterns and environmental factors that affect regional oak forests’ species composition and diversity. Ward’s Agglomerative clustering divided oak-dominated forest communities into three groups: i.e., Group I, dominated by Quercus baloot had an importance value index (IVI) of 89.87 ± 4.31, Group II, dominated by Quercus dilatata had an IVI of 32.16 ± 15.01, and Group III, dominated by Quercus oblongata had an IVI of 83.14 ± 4.67, respectively. The environmental factors which vary significantly within these communities were latitude, elevation, clay content and bulk density of the soil. Wilting point, saturation point, and electrical conductivity were also considered as ecosystem structural variables. Canonical correspondence analysis (CCA) indicated that community structure was affected by various environmental factors including precipitation, slope angle, elevation, clay content, and relative humidity.     

Risk factors associated with intestinal pathogenic parasites in schoolchildren

Diseases caused by intestinal parasites impose a substantial burden on population of middle income countries including Pakistan. This research was aimed to assess the risk factors for intestinal parasites in school children of Malakand, Pakistan. Two hundred and eighty eight students were enrolled between February and June 2016. Out of the total enrolled 184 were agreed to collect stool specimens. A questionnaire was also used to collect the data on socio-demographic and socio-economic characteristics of the participants. All the students were guided to collect at least 10gof their own stool specimens. Each of the stool specimens was diagnosed for the presence of any stage of helminth or protozoal parasites. Formal ether concentration method and wet mount techniques were applied. One way ANOVA was used for calculation of P value when it was less than 0.05 which was considered significant. Eighty two percent of the participants were found infected with one species of parasite while 69.9% of the participants were infected with more than one species of intestinal parasites. The most prevalent parasite was hook worm 33.4% (n = 99/296) followed by Taenia saginata 28.7% (n = 85/296), Ascaris lumbricoides 27.7% (n = 82/296), Hymenolepis nana 6.08% (n = 18/296), Entamoeba histolytica 3.37% (n = 10/296) and least for each Enterobius vermicularis and Fasciola hepatica 0.37% (n = 1/296). Previously used drugs, level in school, ages, weight and upper arm circumference were the most significantly (P < 0.05) related factors for the occurrence of intestinal parasite infection. Present research endorsed that risk factors play a key role in the transmission of parasitic diseases. Lack of safe water supply, using raw vegetables, animal keeping, which should be considered for sustainable strategies in the control of these infections preferably in remote parts of the world.     

Demonstration of aromatic l-amino acid decarboxylase activity in human brain with l-dopa and l-5-hydroxytryptophan as substrates by high-performance liquid chromatography with electrochemical detection

The enzymatic decarboxylations of l-DOPA and l-5-hydroxytryptophan (l-5-HTP) by aromatic l-amino acid decarboxylase (AADC) were measured with homogenates from human brain regions, caduate nucleus and hypothalamus, using our new and highly sensitive methods for l-DOPA decarboxylase and l-5-HTP decarboxylase by high-performance liquid chromatography with electrochemical detection (HPLC-ED). Dopamine formed from l-DOPA as substrate was measured for DOPA decarboxylase activity using d-DOPA for the blank. For 5-HTP decarboxylase activity, serotonin (5-HT) formed from l-5-HTP was measured, and the blank value in presence of NSD-1055 was subtracted. NSD-1055 inhibited 5-HTP decarboxylase activity completely at a concentration of 0.2 mM. In this study, the properties of l-5-HTP decarboxylase activity in human caudate nucleus were first examined. AADC activities in human brains were found to be widely variable for both l-DOPA and l-5-HTP as substrates. The ratio of the activities for l-DOPA and l-5-HTP were found to be significantly higher in hypothalamus than in caudate nucleus. AADC activity for l-DOPA in the brain was found to be linear up to 40 min of incubation, while that for l-5-HTP was found to be linear up to 240 min of incubation. The optimum pyridoxal phosphate concentration was found to be similar for both substrates and was between 0.01 and 0.1 mM. The optimum pH values were found to be 7.2 and 8.2 for l-DOPA decarboxylase and l-5-HTP decarboxylase, respectively. K_m and V_max values for a human caudate nucleus l-DOPA decarboxylase were found to be 414 μM and 482 pmol/min/g wet weight, respectively, while those for l-5-HTP decarboxylase were found to be 90 μM and 71 pmol/min/g wet weight, respectively.     

A New Cold-Adapted,Organic Solvent Stable Lipase from Mesophilic Staphylococcus epidermidis AT2

The gene encoding a cold-adapted, organic solvent stable lipase from a local soil-isolate, mesophilic Staphylococcus epidermidis AT2 was expressed in a prokaryotic system. A two-step purification of AT2 lipase was achieved using butyl sepharose and DEAE sepharose column chromatography. The final recovery and purification fold were 47.09 % and 3.45, respectively. The molecular mass of the purified lipase was estimated to be 43 kDa. AT2 lipase was found to be optimally active at pH 8 and stable at pH 6–9. Interestingly, this enzyme demonstrated remarkable stability at cold temperature (<30 °C) and exhibited optimal activity at a temperature of 25 °C. A significant enhancement of the lipolytic activity was observed in the presence of Ca²⁺, Tween 60 and Tween 80. Phenylmethylsulfonylfluoride, a well known serine inhibitor did not cause complete inhibition of the enzymatic activity. AT2 lipase exhibited excellent preferences towards long chain triglycerides and natural oils. The lipolytic activity was stimulated by dimethylsulfoxide and diethyl ether, while more than 50 % of its activity was retained in methanol, ethanol, acetone, toluene, and n-hexane. Taken together, AT2 lipase revealed highly attractive biochemical properties especially because of its stability at low temperature and in organic solvents.     

Improvement of Erythrose Reductase Activity,Deletion of By-products and Statistical Media Optimization for Enhanced Erythritol Production from Yarrowia lipolytica Mutant 49

The purpose of the present investigation was to produce erythritol by Yarrowia lipolytica mutant without any by-products. Mutants of Y. lipolytica were generated by ultra-violet for enhancing erythrose reductase (ER) activity and erythritol production. The mutants showing the highest ER activity were screened by triphenyl tetrazolium chloride agar plate assay. Productivity of samples was analyzed by thin-layer chromatography and high-performance liquid chromatography equipped with the refractive index detector. One of the mutants named as mutant 49 gave maximum erythritol production without any other by-products (particularly glycerol). Erythritol production and specific ER activity in mutant 49 increased to 1.65 and 1.47 times, respectively, in comparison with wild-type strain. The ER gene of wild and mutant strains was sequenced and analyzed. A general comparison of wild and mutant gene sequences showed the replacement of Asp²⁷⁰ with Glu²⁷⁰ in ER protein. In order to enhance erythritol production, we used a three component-three level-one response Box–Behnken of response surface methodology model. The optimum medium composition for erythritol production was found to be (g/l) glucose 279.49, ammonium sulfate 9.28, and pH 5.41 with 39.76 erythritol production.     

Phylogenetic relationships among Phytopythium species,and re-evaluation of Phytopythium fagopyri comb. nov., recovered from damped-off buckwheat seedlings in Japan

We examined the phylogenetic relationships among Phytopythium species using the rDNA ITS region, the LSU rDNA region, and the mitochondrial coxI and coxII genes. The genus was resolved into three monophyletic clades (1–3). Clade 1 was the largest clade, composed of 12 known species. Clades 2 contained two known and one new species candidate and clade 3 contained two known species. Three isolates in clade 2 (FP1, HonMa, and a strain designated as P. helicoides CBS293.35) formed a monophyletic group with high bootstrap support. This monophyletic group was distinct from P. helicoides sensu stricto. All three isolates came from damped-off buckwheat seedlings. The isolates were morphologically identical with one another and were characterized by globose, sub-globose, or pyriform sporangia with apical papillae; internally or internally nested proliferating sporangia; simple sympodia; coiling antheridial stalks; and wavy, sessile, or clavate antheridial cells. The isolates grew at temperatures between 15 °C and 40 °C, and the optimum temperature was 30 °C, with a radial growth rate of 20 mm/24 h. The phylogenetic and morphological analyses indicated that these isolates belong to a distinct species, which was previously under the genus Pythium, named here Phytopythium fagopyri comb. nov.     

Assembly of cyclic enterobacterial common antigen in Escherichia coli K-12

We describe here the purification and quantification of a water-soluble cyclic form of enterobacterial common antigen (ECA(CYC)) from Escherichia coli K-12 as well as information regarding its subcellular location and the genetic loci involved in its assembly. Structural characterization of purified ECA(CYC) molecules obtained from E. coli K-12 revealed that they uniformly contained four trisaccharide repeat units, and they were substituted with from zero to four O-acetyl groups. Cells from overnight cultures contained approximately 2 microg ECA(CYC) per milligram (dry weight), and cell fractionation studies revealed that these molecules were localized exclusively in the periplasm. The synthesis and assembly of ECA(CYC) were found to require the wzxE and wzyE genes of the wec gene cluster. These genes encode proteins involved in the transmembrane translocation of undecaprenylpyrophosphate-linked ECA trisaccharide repeat units and the polymerization of trisaccharide repeat units, respectively. Surprisingly, synthesis of ECA(CYC) was dependent on the wzzE gene, which is required for the modulation of the polysaccharide chain lengths of phosphoglyceride-linked ECA (ECA(PG)). The presence of ECA(CYC) in extracts of several other gram-negative enteric organisms was also demonstrated; however, it was not detected in cell extracts of Pseudomonas aeruginosa. These data suggest that in addition to ECA(PG), ECA(CYC) may be synthesized in many, if not all, members of the Enterobacteriaceae.     

Antagonistic potentiality of Trichoderma harzianum towards seed-borne fungal pathogens of winter wheat cv. Protiva in vitro and in vivo

The antagonistic effect of Trichoderma harzianum on a range of seed-borne fungal pathogens of wheat (viz. Fusarium graminearum, Bipolaris sorokiniana, Aspergillus spp., and Penicillium spp.) was assessed. The potential of T. harzianum as a biocontrol agent was tested in vitro and under field conditions. Coculture of the pathogens and Trichoderma under laboratory conditions clearly showed dominance of T. harzianum. Under natural conditions, biocontrol effects were also obtained against the test fungi. One month after sowing, field emergence (plant stand) was increased by 15.93% over that obtained with the control treatment, and seedling infection was reduced significantly. Leaf blight severity was decreased from 22 to 11 at the heading stage, 35 to 31 at the flowering stage, and 86 to 74 at the grain filling stage. At harvest, the number of tillers per plant was increased by 50%, the yield was increased by 31.58%, and the 1,000-seed weight was increased by 21%.