Evaluation of co-culture of cellulolytic fungi for enhanced cellulase and xylanase activity and saccharification of untreated lignocellulosic material.

Bioethanol production from lignocellulosic materials is hindered by the high costs of pretreatment and the enzymes. The present study aimed to evaluate whether co-cultivation of four selected cellulolytic fungi yields higher cellulase and xylanase activities compared to the monocultures and to investigate whether the enzymes from the co-cultures yield higher saccharification on selected plant materials without thermo-chemical pretreatment. The fungal isolates, Trichoderma reesei F118, Penicillium javanicum FS7, Talaromyces sp. F113, and Talaromyces pinophilus FM9, were grown as monocultures and binary co-cultures under submerged conditions for 7 days. The cellulase and xylanase activities of the culture filtrates were measured, and the culture filtrates were employed for the saccharification of sugarcane leaves, Guinea grass leaves, and water hyacinth stems and leaves. Total reducing sugars and individual sugars released from each plant material were quantified. The co-culture of Talaromyces sp. F113 with Penicillium javanicum FS7 and of T. reesei F118 with T. pinophilus FM9 produced significantly higher cellulase activities compared to the corresponding monocultures whereas no effect was observed on xylanase activities. Overall, the highest amounts of total reducing sugars and individual sugars were obtained from Guinea grass leaves saccharified with the co-culture of T. reesei F118 with T. pinophilus FM9, yielding 63.5% saccharification. Guinea grass leaves were found to be the most susceptible to enzymatic saccharification without pre-treatment, while water hyacinth stems and leaves were the least. Accordingly, the study suggests that fungal co-cultivation could be a promising approach for the saccharification of lignocellulosic materials for bioethanol production.

Biosynthesis and function of 7-deazaguanine derivatives in bacteria and phages.

SUMMARYDeazaguanine modifications play multifaceted roles in the molecular biology of DNA and tRNA, shaping diverse yet essential biological processes, including the nuanced fine-tuning of translation efficiency and the intricate modulation of codon-anticodon interactions. Beyond their roles in translation, deazaguanine modifications contribute to cellular stress resistance, self-nonself discrimination mechanisms, and host evasion defenses, directly modulating the adaptability of living organisms. Deazaguanine moieties extend beyond nucleic acid modifications, manifesting in the structural diversity of biologically active natural products. Their roles in fundamental cellular processes and their presence in biologically active natural products underscore their versatility and pivotal contributions to the intricate web of molecular interactions within living organisms. Here, we discuss the current understanding of the biosynthesis and multifaceted functions of deazaguanines, shedding light on their diverse and dynamic roles in the molecular landscape of life.

Queuosine Salvage in Bartonella henselae Houston 1: A Unique Evolutionary Path.

Queuosine (Q) stands out as the sole tRNA modification that can be synthesized via salvage pathways. Comparative genomic analyses identified specific bacteria that showed a discrepancy between the projected Q salvage route and the predicted substrate specificities of the two identified salvage proteins: 1) the distinctive enzyme tRNA guanine-34 transglycosylase (bacterial TGT, or bTGT), responsible for inserting precursor bases into target tRNAs; and 2) Queuosine Precursor Transporter (QPTR), a transporter protein that imports Q precursors. Organisms like the facultative intracellular pathogen Bartonella henselae, which possess only bTGT and QPTR but lack predicted enzymes for converting preQ1 to Q, would be expected to salvage the queuine (q) base, mirroring the scenario for the obligate intracellular pathogen Chlamydia trachomatis. However, sequence analyses indicate that the substrate-specificity residues of their bTGTs resemble those of enzymes inserting preQ1 rather than q. Intriguingly, mass spectrometry analyses of tRNA modification profiles in B. henselae reveal trace amounts of preQ1, previously not observed in a natural context. Complementation analysis demonstrates that B. henselae bTGT and QPTR not only utilize preQ1, akin to their Escherichia coli counterparts, but can also process q when provided at elevated concentrations. The experimental and phylogenomic analyses suggest that the Q pathway in B. henselae could represent an evolutionary transition among intracellular pathogens-from ancestors that synthesized Q de novo to a state prioritizing the salvage of q. Another possibility that will require further investigations is that the insertion of preQ1 has fitness advantages when B. henselae is growing outside a mammalian host.

Characterization of arrowroot (Maranta arundinacea) starch as a potential starch source for the food industry.

Arrowroot is an underutilized tuber crop in Sri Lanka and the characterization of starch was done to identify its nutritional, physicochemical, and functional properties to evaluate its potential for use in the food industry. This study distinctly advances the field of arrowroot starch characterization by providing more characterization techniques for starch samples from Sri Lanka. Arrowroot starch colour was closely similar to colour of wheat flour indicating that the effect of colour is minimum when replacing wheat flour. Oval, spherical, and irregular globular shapes were the predominant starch granule shapes for arrowroot. The average length of starch granules was 44.99 ± 1.27 µm while the width of granules was 31.44 ± 0.58 µm. The least gelation concentration was 8.0% indicating its better gel-forming ability. The nutritional composition of arrowroot starch consisted of low crude protein (0.72 ± 0.02%), crude fat (0.26 ± 0.19%), and crude fiber (1.00 ± 0.09%) contents indicating the purity of starch. Sodium, Potassium, Calcium, Iron, and Zinc contents were 52.6 mg/kg, 4312.95 mg/kg, 382.67 mg/kg, 9.07 mg/kg, and 2.59 mg/kg, respectively. Results of flour densities demonstrated the potential of arrowroot starch to be used in the pharmaceutical industry. Arrowroot starch had high viscosity defining its potential as a thickener. The starch also had high swelling power and solubility indices while solubility was positively correlated with viscosity (0.679; P > 0.05). The low moisture absorbance indicates a longer shelf life of stored arrowroot starch. Onset temperature (To) of 75.02 °C, peak temperature (Tp) of 77.95 °C, and conclusion temperature (Tc) of 82.43 °C were resulted from DSC thermogram. Arrowroot was identified as an A-type starch from x-ray diffractometry and the FT-IR spectrum of arrowroot was identical to starch and presented the carbohydrate nature of starch. Thus, arrowroot starch has a high potential to be used in the food industry based on its functional properties.

Finite Element Analysis of Steel Plates with Rectangular Openings Subjected to Axial Stress.

Steel plates with openings are among the important ship structural components used in the ship's hull to withstand the hydrostatic forces of the ocean, which cause sagging and hogging moments at the ship's bottom. The existence of openings on plates can cause structural rupture, stress concentration and a decrease in ultimate strength. This research is aimed at investigating the influence of selected parameters on the ultimate capacity of steel plates with rectangular holes subjected to axial stress, using ANSYS finite element analysis (FEA) under its non-linear static structural programme. The main parameters investigated in this paper are the plate thickness, opening aspect ratio, number of openings, position of openings, and the boundary condition of the plate. The influence of these parameters on the stress of plates and their deformation was evaluated. The comparison of the numerical simulation with the well-established analytical method using the Navier solution and Roark's Formulas showed a good agreement.

Thin-Walled Cylindrical Shell Storage Tank under Blast Impacts: Finite Element Analysis.

Thin-walled cylindrical shell storage tanks are pressure vessels in which the walls of the vessel have a thickness that is much smaller than the overall size of the vessel. These types of structures have global applications in various industries, including oil refineries and petrochemical plants. However, these storage tanks are vulnerable to fire and explosions. Therefore, a parametric study using numerical simulation was carried out, considering the internal liquid level, wall thickness, material yield strength, constraint conditions, and blast intensity, with a diameter of 100 m and height of 22.5 m under different blast loads using the finite element analysis method. The thickness of the tank wall is varied as 10 mm, 20 mm, 30 mm, and 40 mm, while the fill level of internal fluid is varied as 25, 50, 75, and 100%. The blast simulation was conducted using LS-DYNA software. The numerical results are then compared with analytical results. The effects of blast intensity, standoff distance, wall thickness, and fill level of internal fluid on the structural behaviour of the storage tank were investigated and discussed.

Identification and culturing of cyanobacteria isolated from freshwater bodies of Sri Lanka for biodiesel production.

The present study was carried out to investigate cyanobacteria as a potential source for biodiesel production isolated from fresh water bodies of Sri Lanka. Semi mass culturing and mass culturing were carried out to obtain biomass for extracting total lipids. Fatty acid methyl ester (FAME) or biodiesel was produced from extracted lipid by trans-esterification reaction. FAME component was identified using gas chromatography (GC). Atotal of 74 uni-algal cultures were obtained from Biofuel and Bioenergy laboratory of the National Institute of Fundamental Studies (NIFS), Kandy, Sri Lanka. The total lipid content was recorded highest in Oscillatoria sp. (31.9 ±â€¯2.01% of dry biomass) followed by Synechococcus sp. (30.6 ±â€¯2.87%), Croococcidiopsis sp. (22.7 ±â€¯1.36%), Leptolyngbya sp. (21.15 ±â€¯1.99%), Limnothrixsp. (20.73 ±â€¯3.26%), Calothrix sp. (18.15 ±â€¯4.11%) and Nostoc sp. (15.43 ±â€¯3.89%), Cephalothrixsp. (13.95 ±â€¯4.27%), Cephalothrix Komarekiana (13.8 ±â€¯3.56%) and Westiellopsisprolifica (12.80 ±â€¯1.97%). FAME analysis showed cyanobacteria contain Methyl palmitoleate, Linolelaidic acid methyl ester, Cis-8,11,14-eicosatrienoic acid methyl ester, Cis-10-heptadecanoic acid methyl ester, Methyl myristate, Methyl pentadecanoate, Methyl octanoate, Methyl decanoate, Methyl laurate, Methyl tridecanoate, Methyl palmitoleate, Methyl pentadeconoate, Methyl heptadeconoate, Linolaidic acid methyl ester, Methyl erucate, Methyl myristate, Myristoloeic acid, Methyl palmitate, Cis-9-oleic acid methyl ester, Methyl arachidate and Cis-8,11,14-ecosatrieconoic acid methyl ester. The present study revealed that cyanobacteria isolated from Sri Lanka are potential source for biodiesel industry because of their high fatty acid content. Further studies are required to optimize the mass culture conditions to increase thelipid content from cyanobacterial biomass along with the research in the value addition to the remaining biomass.

Association between serum and adipose tissue resistin with dysglycemia in South Asian women.

BACKGROUND/OBJECTIVES: Mechanisms of obesity-associated insulin resistance and dysglycemia in South Asians remain relatively unknown. The objective of this study was to detect subcutaneous (SAT) vs. visceral (VAT) adipose tissue characteristics and adipocytokines associated with obesity, insulin resistance, and dysglycemia in South Asian women. SUBJECTS/METHODS: This was a hospital-based cross-sectional study conducted in Sri Lanka. Subjects comprised of 58 adult women who underwent routine abdominal surgeries. SAT and VAT were obtained from anterior abdominal wall and omentum, respectively. Measures of adiposity, serum insulin and glucose, SAT and VAT crown-like structures (CLS), macrophages, resistin by immunohistochemistry, mean adipocyte area (MAA), and serum adipocytokines were examined. RESULTS: The homeostatic model assessment for insulin resistance (HOMA-IR) score significantly correlated with age and waist circumference (WC), but not with body mass index (BMI). Although the number of CLS positively correlated with BMI, there were no significant differences between the number of CLS in women with normal fasting glucose (NFG) vs. those with impaired fasting glucose (IFG), indicating that adipose tissue macrophage infiltration is unlikely to be related to dysglycemia. In contrast, serum resistin level was on average 60% higher in women with IFG compared to ones with NFG (p < 0.05). Serum resistin levels correlated with age (r = 0.36, p < 0.05) and WC (r = 0.27, p < 0.05). There were no associations in serum levels of other adipocytokines with IFG. Adipose immunohistochemistry showed that women with IFG had a higher percentage of resistin positive adipocytes in SAT compared to ones with NFG. MAA of VAT, but not SAT, correlated with both BMI and WC. CONCLUSIONS: Resistin may be an important adipokine linking central adiposity and insulin resistance in South Asian women. Both systemic and adipose tissue resistin are linked to dysglycemia in these individuals and may be a potential biomarker for diabetes in this population.

Antioxidant properties in some selected cyanobacteria isolated from fresh water bodies of Sri Lanka.

Phytonutrients and pigments present in cyanobacteria act as antioxidants, which facilitate the formation of body's defense mechanism against free radical damage to cells. The aim of this investigation was to study the total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity, phycobiliproteins (PBPs), and active compounds in four cyanobacterial species, that is, Oscillatoria sp., Lyngbya sp., Microcystis sp., and Spirulina sp. isolated from fresh water bodies of Sri Lanka. In this study, Lyngbya sp., showed highest TPC (5.02 ± 0.20 mg/g), TFC (664.07 ± 19.76 mg/g), and total PBPs (127.01 mg/g) value. The ferric reducing antioxidant power (FRAP) was recorded highest in Oscillatoria sp. (39.63 ± 7.02), whereas the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was also reported the highest in Oscillatoria sp. (465.31 ± 25.76) followed by Lyngbya sp. (248.39 ± 11.97). In FTIR spectroscopy, Lyngbya sp. does not show any N-H stretching band which is ultimately responsible for the inhibition of antioxidant activity. The study revealed that Lyngbya sp. and Oscillatoria sp. can be an excellent source for food, pharmaceutical, and other industrial uses.

Blood cultures in acute surgical admissions.

INTRODUCTION: Obtaining blood cultures prior to the administration of antimicrobial therapy was a key recommendation of the 2012 UK Surviving Sepsis Campaign. Few studies have examined the effect blood cultures have on clinical management and there have been none on acute surgical admissions. This retrospective study sought to evaluate the effect of blood cultures on clinical management in acute surgical admissions. METHODS: Data on acute surgical patients admitted between 1 January and 31 December 2012 were extracted from hospital records. Patients given intravenous antibiotics within 24 hours of admission were identified. Data collected included antibiotics administered, blood culture results, admission observations and white blood cell count. Case notes were reviewed for patients with positive cultures to establish whether the result led to a change in management. RESULTS: Of 5,887 acute surgical admissions, 1,346 received intravenous antibiotics within 24 hours and 978 sets of blood cultures were taken in 690 patients. The recommended two sets of cultures were obtained in 246 patients (18%). Patients who had blood cultures taken had the same in-hospital mortality as those who had none taken (3.6% vs 3.5%, p=0.97). Blood cultures were positive in 80 cases (11.6%). The presence of systemic inflammatory response syndrome did not increase positivity rates (12.9% vs 10.3%, p=0.28). Overall, cultures altered management in two patients (0.3%). CONCLUSIONS: Blood cultures rarely affect clinical management. In order to assess the additional value that blood cultures bring to sepsis management in acute surgical admissions, a prospective randomised trial focusing on outcome is needed.

Shifting dominance of Shigella species in men who have sex with men.

Historically, Shigella sonnei has dominated other Shigella species infection in men who have sex with men (MSM) in Montréal. In early 2010, Toronto reported increased proportions of the more pathogenic S. flexneri, HIV co-infection and MSM in shigellosis cases since 2009. Analytical methods were used to assess whether S. flexneri had dominated Montréal's MSM cases since 2009 and whether changes had occurred in notifications in MSM and HIV-co-infected MSM. S. flexneri increased by 6·7% per month since 2007 and predominated in MSM since 2009 without changes in HIV co-infection or similar shifts in the general population. The results suggest that the surveillance of Shigella species in order to detect species shifts is beneficial for surveillance, given the potential for increased transmission and severity of S. flexneri in HIV-positive MSM.

Effects of cooking on the cell walls (dietary fiber) of 'Scarlet Warren' winter squash ( Cucurbita maxima ) studied by polysaccharide linkage analysis and solid-state (13)C NMR.

Cell wall polysaccharides of 'Scarlet Warren' winter squash ( Cucurbita maxima ) were investigated before and after thermal processing. Linkage analysis of polysaccharides was done by gas chromatography coupled to mass spectrometry (GC-MS). The linkage analysis showed the cell wall polysaccharide compositions of raw and cooked squash were similar. The total pectic polysaccharides (galacturonan, rhamnogalacturonan, arabinan, and arabinogalactan) contents of the cell walls of both raw and cooked squash were 39 mol %. The amounts of pectic polysaccharides and xyloglucan in the cell walls of squash showed little alteration on heating. The cellulose content of the raw and cooked cell walls was relatively high at 47 mol %, whereas the xyloglucan content was low at 4 mol %. Solid-state (13)C nuclear magnetic resonance (NMR) spectroscopy techniques were used to examine the molecular motion of the polysaccharides in the cell walls. The mobility of highly flexible galactan depends on the water content of the sample, but no difference was seen between raw and cooked samples. Likewise, the mobility of semimobile pectic polysaccharides was apparently unaltered by cooking. No change was detected in the rigid cellulose microfibrils on cooking.

Scale and tooth phenotypes in medaka with a mutated ectodysplasin-A receptor: implications for the evolutionary origin of oral and pharyngeal teeth.

Ectodermal contribution to the induction of pharyngeal teeth that form in the endodermal territory of the oropharyngeal cavity in some teleost fishes has been a matter of considerable debate. To determine the role of ectodermal cell signaling in scale and tooth formation and thereby to gain insights in evolutionary origin of teeth, we analyzed scales and teeth in rs-3 medaka mutants characterized by reduced scale numbers due to aberrant splicing of the ectodysplasin-A receptor (edar). Current data show that, in addition to a loss of scales (83% reduction), a drastic loss of teeth occurred in both oral (43.5% reduction) and pharyngeal (73.5% reduction) dentitions in rs-3. The remaining scales of rs-3 were irregular in shape and nearly 3 times larger in size relative to those of the wild-type. In contrast, there was no abnormality in size and shape in the remaining teeth of rs-3. In wild-type medaka embryos, there was a direct contact between the surface ectoderm and rostral endoderm in pharyngeal regions before the onset of pharyngeal tooth formation. However, there was no sign of ectodermal cell migration in the pharyngeal endoderm and hence no direct evidence of any ectodermal contribution to pharyngeal odontogenesis. These data suggest differential roles for Eda-Edar signaling in the induction and growth of scales and teeth and support the intrinsic odontogenic competence of the rostral endoderm in medaka.

Alternative processing of Arabidopsis Hsp70 precursors during protein import into chloroplasts.

During protein import into chloroplasts, one of the Hsp70 proteins in pea (Hsp70-IAP), previously reported to localize in the intermembrane space of chloroplasts, was found to interact with the translocating precursor protein but the gene for Hsp70-IAP has not been identified yet. In an attempt to identify the Arabidopsis homolog of Hsp70-IAP, we employed an in vitro protein import assay to determine the localization of three Arabidopsis Hsp70 homologs (AtHsp70-6 through 8), predicted for chloroplast targeting. AtHsp70-6 and AtHsp70-7 were imported into chloroplasts and processed into similar-sized mature forms. In addition, a smaller-sized processed form of AtHsp70-6 was observed. All the processed forms of both AtHsp70 proteins were localized in the stroma. Organelle-free processing assays revealed that the larger processed forms of both AtHsp70-6 and AtHsp70-7 were cleaved by stromal processing peptidase, whereas the smaller processed form of AtHsp70-6 was produced by an unspecified peptidase.

Development and optimization of an in vitro chloroplastic protein import assay using recombinant proteins.

The in vitro protein import experiment is one of the most important techniques for determining protein localization. For chloroplastic proteins, proteins of interest are incubated with isolated chloroplasts in the presence of energy sources. Radio-labeled proteins synthesized either in vitro or in vivo have been widely used as substrate proteins. Here we report our development of the protein import assay system in which non-radio-labeled proteins, overexpressed in Escherichia coli, were applied. In this system, substrate proteins were designed to carry epitope-tags, thus allowing analysis of imported proteins by SDS-PAGE, followed by immunoblotting to detect these tags. Furthermore, the imported proteins were found to be incorporated into their native form. These observations indicated that recombinant proteins were imported into chloroplasts and folded correctly. Therefore, this assay system could represent another valuable tool for determining protein localization.

Dihydrochalcones with radical scavenging properties from the leaves of Syzygium jambos.

Chemical investigation of the dichloromethane extract of the leaves of Syzygium jambos furnished three dihydrochalcones, phloretin 4'-O-methyl ether (2',6'-dihydroxy-4'-methoxydihydrochalcone) (1), myrigalone G (2',6'-dihydroxy-4'-methoxy-3'-methyldihydrochalcone) (2), and myrigalone B (2',6'-dihydroxy-4'-methoxy-3,5'-dimethyldihydrochalcone) (3) with radical scavenging properties towards the DPPH radical by spectrophotometric method.

Microdosimetric model for the induction of cell killing through medium-borne signals.

Microbeam, medium-transfer and low-dose experiments have demonstrated that intercellular signals can initiate many of the same biological events and processes as direct exposure to ionizing radiation. These phenomena cast doubt on cell-autonomous modes of action and the linear, no-threshold carcinogenesis paradigm. To account for the effects of intercellular signals, new approaches are needed to relate dosimetric quantities to the emission and processing of signals by irradiated and unirradiated cells. In this paper, microdosimetric principles are used to develop a stochastic model to relate absorbed dose to the emission and processing of cell death signals by unirradiated cells. Our analyses of published results of medium transfer experiments performed using HPV-G human keratinocytes suggest that the emission of death signals is a bi-exponential function of dose with a distinct plateau in the 5- to 100-mGy range. However, the emission of death signals by HPV-G cells may not become fully saturated until the absorbed dose becomes larger than 0.6 Gy. Similar saturation effects have been observed in microbeam and medium-transfer experiments with other mammalian cell lines. The model predicts that the cell-killing effect of medium-borne death signals decreases exponentially as the absorbed dose becomes small compared to the frequency-mean specific energy per radiation event.