Microbial interactions are necessarily associated with the development of polymicrobial oral biofilms. The objective of this study was to determine the coaggregation of eight strains of Candida albicans with Actinomyces naeslundii and Streptococcus mutans. In autoaggregation assays, C. albicans strains were grown in RPMI-1640 and artificial saliva medium (ASM) whereas bacteria were grown in heart infusion broth. C. albicans, A. naeslundii and S. mutans were suspended to give 10(6), 10(7) and 10(8) cells mL(-1) respectively, in coaggregation buffer followed by a 1 h incubation. The absorbance difference at 620 nm (ΔAbs) between 0 h and 1 h was recorded. To study coaggregation, the same protocol was used, except combinations of microorganisms were incubated together. The mean ΔAbs% of autoaggregation of the majority of RPMI-1640-grown C. albicans was higher than in ASM grown. Coaggregation of C. albicans with A. naeslundii and/or S. mutans was variable among C. albicans strains. Scanning electron microscopy images showed that A. naeslundii and S. mutans coaggregated with C. albicans in dual- and triculture. In conclusion, the coaggregation of C. albicans, A. naeslundii and S. mutans is C. albicans strain dependent.
Oral biofilms comprise of extracellular polysaccharides and polymicrobial microorganisms. The objective of this study was to determine the effect of polymicrobial interactions of Candida albicans, Actinomyces naeslundii, and Streptococcus mutans on biofilm formation with the hypotheses that biofilm biomass and metabolic activity are both C. albicans strain and growth medium dependent. To study monospecific biofilms, C. albicans, A. naeslundii, and S. mutans were inoculated into artificial saliva medium (ASM) and RPMI-1640 in separate vials, whereas to study polymicrobial biofilm formation, the inoculum containing microorganisms was prepared in the same vial prior inoculation into a 96-well plate followed by 72 hours incubation. Finally, biofilm biomass and metabolic activity were measured using crystal violet and XTT assays, respectively. Our results showed variability of monospecies and polymicrobial biofilm biomass between C. albicans strains and growth medium. Based on cut-offs, out of 32, seven RPMI-grown biofilms had high biofilm biomass (HBB), whereas, in ASM-grown biofilms, 14 out of 32 were HBB. Of the 32 biofilms grown in RPMI-1640, 21 were high metabolic activity (HMA), whereas in ASM, there was no biofilm had HMA. Significant differences were observed between ASM and RPMI-grown biofilms with respect to metabolic activity (P <01). In conclusion, biofilm biomass and metabolic activity were both C. albicans strain and growth medium dependent.
A series of some new bisadducts possessing five, six membered and coumarin subunits were synthesized by the condensation of heterocyclic aldehydes with active methylene compounds and characterized by IR, NMR and X-ray crystallographic studies and were assayed as antitubercular agents. Among the bisadducts, 4-hydroxy-3-[(4-hydroxy-2-oxo-2H-3-chromenyl)(3-thienyl)methyl]-2H-2-chromenone 3a was found to be the most promising compound, active against Mycobacterium tuberculosis (Mtb) H37Rv and isoniazid resistant Mycobacterium tuberculosis (INHR-Mtb) with minimum inhibitory concentration 5.22 and 8.34 microM, respectively.
Matched MeSH terms: Mycobacterium tuberculosis/growth & development
Yield performance in wheat (Triticum aestivum) was compared under crop residue, tillage system and nitrogen rate treatments in cereal based cropping system. The experiments were conducted at Agronomy Research Farm, The University of Agriculture, Peshawar, in 2009-2010 and 2010-2011. Chopped crop residue on dry matter basis (5 t ha1-) of legume (Vigna unguicuata, var. Ebney) and cereal (Zea mays, var. Azam) was applied in main plots with no residue treatments and plowed with Mould Board (MB) and Cultivator as deep and shallow treatments, respectively. A month after the crop residue and tillage system treatments, field was uniformly plowed with cultivator and wheat was sown with drill in rows 25 cm apart in the month of November on both years. Both P2O55 and K2O (80 and 40 kg ha , respectively) were applied uniformly to all fields before sowing. Nitrogen as subplot treatment (0, 40, 80, 120 and 160 kg ha-1) was applied in two splits, half at 15 and the other half at 45 days after sowing with uniform cultural practices for crop growth and development. Compared to year 1, crop of year 2 showed better phenology with extended life cycle (LC). On two years average across tillage and N treatments, biological yield did not change (p<0.05) under the residue but did report lower at no-residue treatment. Nonetheless, grain yield showed a significant (p<0.05) change with the highest in legume followed by cereal and the lowest in no-residue treatments. A non-significant tiller number and significant variations in grain weight and spike m-2 were observed that influenced the grain and biological yield differently. Deep than shallow tillage resulted in better traits, which returned better biomass and grain yield. Nitrogen application from control to every increment showed a significant (p<0.05) improvement in all observations contributing in yield. The study confirms the significance of legume vs. cereal over no-crop residue incorporated through deep tillage system with optimum N (120 kg ha-1) in cereal-based cropping system for sustainable performance to sustain soil C:N for future production.
Determination of Length-weight Relationship (LWR) of any commercially important fish is crucial to validate the wild stock level, to predict their wellbeing in the natural habitat and for various sustainable fishery management practices. Liza subviridis (Valenciennes) is noted to be highly abundant along the coast of Parangipettai, South east coast of India. Hence, the present study was aimed to establish Length-weight relationship and condition factor of Greenback mullet, Liza subviridis (Valenciennes) occurring in Vellar estuary, Parangipettai (lat. 11 degrees 30' N, long. 79 degrees 46' E) using least square method. To determine the actual relationship between length and weight of L. subviridis exponent coefficient or equilibrium constant (b) and relative condition factor (Kn) analysis were adopted. The females were found to be heavier than males at similar length. The equilibrium constant 'b' was found to be 2.7106 in males and 2.8927 in females. The corresponding parabolic representation for male was W = 0.0462L(2.7106) and for female W = 0.0382L(2.8927). The equilibrium constant did not obey the cube law as it deviated significantly from 3 in the case of males. The relative condition factor around 1 and little over it revealed the well-being of L. subviridis in Parangipettai waters.
Matched MeSH terms: Smegmamorpha/growth & development
Rice is a staple and most important security food crop consumed by almost half of the world's population. More rice production is needed due to the rapid population growth in the world. Rice blast caused by the fungus, Magnaporthe oryzae is one of the most destructive diseases of this crop in different part of the world. Breakdown of blast resistance is the major cause of yield instability in several rice growing areas. There is a need to develop strategies providing long-lasting disease resistance against a broad spectrum of pathogens, giving protection for a long time over a broad geographic area, promising for sustainable rice production in the future. So far, molecular breeding approaches involving DNA markers, such as QTL mapping, marker-aided selection, gene pyramiding, allele mining and genetic transformation have been used to develop new resistant rice cultivars. Such techniques now are used as a low-cost, high-throughput alternative to conventional methods allowing rapid introgression of disease resistance genes into susceptible varieties as well as the incorporation of multiple genes into individual lines for more durable blast resistance. The paper briefly reviewed the progress of studies on this aspect to provide the interest information for rice disease resistance breeding. This review includes examples of how advanced molecular method have been used in breeding programs for improving blast resistance. New information and knowledge gained from previous research on the recent strategy and challenges towards improvement of blast disease such as pyramiding disease resistance gene for creating new rice varieties with high resistance against multiple diseases will undoubtedly provide new insights into the rice disease control.
The study explores on upstream and downstream process in Microcystis aeruginosa for biodiesel production. The alga was isolated from temple tank, acclimatized and successfully mass cultivated in open raceway pond at semi-continuous mode. A two step combined process was designed and harvested 99.3% of biomass, the daily dry biomass productivity was recorded up to 28gm(-2)day(-1). The lipid extraction was optimized and achieved 21.3%; physicochemical properties were characterized and found 11.7% of FFA, iodine value 72% and 99.2% of ester content. The lipid was transesterified by a two step simultaneous process and produced 90.1% of biodiesel; the calorific value of the biodiesel was 38.8MJ/kg. Further, the physicochemical properties of biodiesel was characterized and found to be within the limits of American ASTM D6751. Based on the areal and volumetric biomass productivity estimation, M. aeruginosa can yield 84.1 tons of dry biomass ha(-1)year(-1).
Termites perform key ecological functions in tropical ecosystems, are strongly affected by variation in rainfall, and respond negatively to habitat disturbance. However, it is not known how the projected increase in frequency and severity of droughts in tropical rainforests will alter termite communities and the maintenance of ecosystem processes. Using a large-scale termite suppression experiment, we found that termite activity and abundance increased during drought in a Bornean forest. This increase resulted in accelerated litter decomposition, elevated soil moisture, greater soil nutrient heterogeneity, and higher seedling survival rates during the extreme El Niño drought of 2015-2016. Our work shows how an invertebrate group enhances ecosystem resistance to drought, providing evidence that the dual stressors of climate change and anthropogenic shifts in biotic communities will have various negative consequences for the maintenance of rainforest ecosystems.
Matched MeSH terms: Seedlings/growth & development
Considering the great potential of natural products as anticancer agents, the present study was designed to explore the molecular mechanisms responsible for anticancer activities of Mesua ferrea stem bark extract against human colorectal carcinoma. Based on MTT assay results, bioactive sub-fraction (SF-3) was selected for further studies using HCT 116 cells. Repeated column chromatography resulted in isolation of less active α-amyrin from SF-3, which was identified and characterized by GC-MS and HPLC methods. α-amyrin and betulinic acid contents of SF-3 were measured by HPLC methods. Fluorescent assays revealed characteristic apoptotic features, including cell shrinkage, nuclear condensation, and marked decrease in mitochondrial membrane potential in SF-3 treated cells. In addition, increased levels of caspases-9 and -3/7 levels were also observed in SF-3 treated cells. SF-3 showed promising antimetastatic properties in multiple in vitro assays. Multi-pathway analysis revealed significant down-regulation of WNT, HIF-1α, and EGFR with simultaneous up-regulation of p53, Myc/Max, and TGF-β signalling pathways in SF-3 treated cells. In addition, promising growth inhibitory effects were observed in SF-3 treated HCT 116 tumour spheroids, which give a hint about in vivo antitumor efficacy of SF-3 phytoconstituents. In conclusion, these results demonstrated that anticancer effects of SF-3 towards colon cancer are through modulation of multiple molecular pathways.
In this study, single, mix, multilayer Polyvinyl alcohol (PVA) electrospun nanofibers with epidermal growth factor (EGF) and fibroblast growth factor (FGF) were fabricated and characterized as a biological wound dressing scaffolds. The biological activities of the synthesized scaffolds have been verified by in vitro and in vivo studies. The chemical composition finding showed that the identified functional units within the produced nanofibers (O-H and N-H bonds) are attributed to both growth factors (GFs) in the PVA nanofiber membranes. Electrospun nanofibers' morphological features showed long protrusion and smooth morphology without beads and sprayed with an average range of 198-286 nm fiber diameter. The fiber diameters decrement and the improvement in wettability and surface roughness were recorded after GFs incorporated within the PVA Nanofibers, which indicated potential good adoption as biological dressing scaffolds due to the identified mechanical properties (Young's modulus) in between 18 and 20 MPa. The MTT assay indicated that the growth factor release from the PVA nanofibers has stimulated cell proliferation and promoted cell viability. In the cell attachment study, the GFs incorporated PVA nanofibers stimulated cell proliferation and adhered better than the PVA control sample and presented no cytotoxic effect. The in vivo studies showed that compared to the control and single PVA-GFs nanofiber, the mix and multilayer scaffolds gave a much more wound reduction at day 7 with better wound repair at day 14-21, which indicated to enhancing tissue regeneration, thus, could be a projected as a suitable burn wound dressing scaffold.
In this paper, a micropropagation protocol of sugar palm (Arenga pinnata Wurmb Merr) through callogenesis and somatic embryogenesis was examined. Callus induction frequency and somatic embryogenesis response were dependent on plant growth regulators (PGRs) and genotype. Semi-compact and compact embryogenic calluses were induced from excised immature zygotic embryo (IZE) cultured on semi-solid MS (Murashige & Skoog, 1962) medium supplemented with various concentration and combination of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyl aminopurine acid (BAP). MS medium supplemented with 0.4 mg/L 2,4-D and 0.5 mg/L BAP was found optimum to induce 100% rate of embryogenic calluses and maximum degree of callus formation after 8 and 12 weeks of culture. The incorporation of increased sucrose concentration (60.0 g/L) and 2.0 g/L casein hydrolysate (CH) to the culture medium with similar PGRs composition enhanced the induction of globular somatic embryos (SEs), while addition of silver nitrate (AgNO3) produced SEs of different stages. SEs maturated in MS medium containing 1.0 mg/L BAP and 1.0 mg/L naphthalene-acetic acid (NAA) formed cotyledon-stage embryos. Clonal roots regeneration was obtained on half-strength MS devoid of PGRs after 4 months of culture. Frequent subcultures increased embryogenesis rate favourably.
A biosurfactant-producing and hydrocarbon-utilizing bacterium, Pseudomonas aeruginosa USM-AR2, was used to assist conventional distillation. Batch cultivation in a bioreactor gave a biomass of 9.4 g L(-1) and rhamnolipid concentration of 2.4 g L(-1) achieved after 72 h. Biosurfactant activity (rhamnolipid) was detected by the orcinol assay, emulsification index and drop collapse test. Pretreatment of crude oil TK-1 and AG-2 with a culture of P. aeruginosa USM-AR2 that contains rhamnolipid was proven to facilitate the distillation process by reducing the duration without reducing the quality of petroleum distillate. It showed a potential in reducing the duration of the distillation process, with at least 2- to 3-fold decreases in distillation time. This is supported by GC-MS analysis of the distillate where there was no difference between compounds detected in distillate obtained from treated or untreated crude oil. Calorimetric tests showed the calorie value of the distillate remained the same with or without treatment. These two factors confirmed that the quality of the distillate was not compromised and the incubation process by the microbial culture did not over-degrade the oil. The rhamnolipid produced by this culture was the main factor that enhanced the distillation performance, which is related to the emulsification of hydrocarbon chains in the crude oil. This biotreatment may play an important role to improve the existing conventional refinery and distillation process. Reducing the distillation times by pretreating the crude oil with a natural biosynthetic product translates to energy and cost savings in producing petroleum products.
Matched MeSH terms: Pseudomonas aeruginosa/growth & development
Staphylococcus aureus biofilm associated infections remains a major clinical concern in patients with indwelling devices. Quantitative real-time PCR (qPCR) can be used to investigate the pathogenic role of such biofilms. We describe qPCRs for 12 adhesion and biofilm-related genes of four S. aureus isolates which were applied during in vitro biofilm development. An endogenous control (16S rRNA) was used for signal normalization. We compared the qPCR results with structural analysis using scanning electron microscopy (SEM). The SEM studies showed different cellular products surrounding the aggregated cells at different times of biofilm formation. Using qPCR, we found that expression levels of the gene encoding fibronectin binding protein A and B and clumping factor B (fnbA/B and clfB), which involves in primary adherence of S. aureus, were significantly increased at 24h and decreased slightly and variably at 48 h when all 4 isolates were considered. The elastin binding protein (ebps) RNA expression level was significantly enhanced more than 6-fold at 24 and 48 h compared to 12h. Similar results were obtained for the intercellular adhesion biofilm required genes type C (icaC). In addition, qPCR revealed a fluctuation in expression levels at different time points of biofilm growth of other genes, indicating that different parameter modes of growth processes are operating at different times.
Clinical information about genotypically different clones of biofilm-producing Staphylococcus aureus is largely unknown. We examined whether different clones of methicillin-sensitive and methicillin-resistant S. aureus (MSSA and MRSA) differ with respect to staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) in biofilm formation. The study used 60 different types of spa and determined the phenotypes, the prevalence of the 13 MSCRAMM, and biofilm genes for each clone. The current investigation was carried out using a modified Congo red agar (MCRA), a microtiter plate assay (MPA), polymerase chain reaction (PCR), and reverse transcriptase polymerase chain reaction (RT-PCR). Clones belonging to the same spa type were found to have similar properties in adheringto the polystyrene microtiter plate surface. However, their ability to produce slime on MCRA medium was different. PCR experiments showed that 60 clones of MSSA and MRSA were positive for 5 genes (out of 9 MSCRAMM genes). icaADBC genes were found to be present in all the 60 clones tested indicating a high prevalence, and these genes were equally distributed among the clones associated with MSSA and those with MRSA. The prevalence of other MSCRAMM genes among MSSA and MRSA clones was found to be variable. MRSA and MSSA gene expression (MSCRAMM and icaADBC) was confirmed by RT-PCR.
This study evaluated whether genotypically different clinical isolates of S. aureus have similar susceptibilities to individual antibiotics. It further aims to check the impact of biofilm on the in vitro activity of vancomycin, daptomycin, linezolid, and tigecycline against S. aureus clones. The study used a total of 60 different clinical MSSA and MRSA isolates. Susceptibilities were performed in planktonic cultures by macrobroth dilution and epsilon-test (E test) system. Biofilm production was determined using an adherent plate assay. The efficacy of antimicrobial activities against biofilms formation was checked using confocal laser scanning microscopy (CLSM). The study found that similar and different spa, MLST, and SCCmec types displayed high variation in their susceptibilities to antibiotics with tigecycline and daptomycin being the most effective. The biofilms were found resistant to high concentrations of most antibiotics tested with daptomycin being the most effective drug used in adhesive biofilms. A considerable difference exists among similar and various clone types against antibiotics tested. This variation could have contributed to the degree of virulence even within the same clonal genotype and enhanced heterogeneity in the infection potential. Thus, the development of a rapid and precise identification profile for each clone in human infections is important.
Light quality and the intensity are key factors which render microalgae as a potential source of biodiesel. In this study the effects of various intensities of blue light and its photoperiods on the growth and lipid content of Chlorella vulgaris were investigated by using LED (Light Emitting Diode) in batch culture. C. vulgaris was grown for 13 days at three different light intensities (100, 200 and 300 μmol m(-2)s(-1)). Effect of three different light and dark regimes (12:12, 16:08 and 24:00 h Light:Dark) were investigated for each light intensity at 25°C culture temperature. Maximum lipid content (23.5%) was obtained due to high efficiency and deep penetration of 200 μmol m(-2)s(-1) of blue light (12:12 L:D) with improved specific growth (1.26 d(-1)) within reduced cultivation time of 8 days. White light could produce 20.9% lipid content in 10 days at 16:08 h L:D.
Septins belong to GTPases that are involved in vital cellular activities, including cytokinesis. Although present in many organisms, they are yet to be isolated from Aedes albopictus. This study reports for the first time on a serendipitous isolation of a partial septin sequence from Ae. albopictus and its developmental expression profile. The Ae. albopictus partial septin sequence contains 591 nucleotides encoding 197 amino acids. It shares homology with several insect septin genes and has a close phylogenetic relationship with Aedes aegypti and Culex quinquefasciatus septins. The Ae. albopictus septin fragment was differentially expressed in the mosquito's developmental stages, with an increased expression in the adults.
A study was conducted to investigate the effects of feeding low-protein diets fortified with individual non-essential amino acids (NEAA) on growth performance, serum metabolites (uric acid, UA; triglycerides, TG; total protein, TP; and albumin, Alb), organ weight, breast yield, and abdominal fat weight in broiler chicks raised under the hot and humid tropical climate. Eight isocaloric (3,017 kcal/kg) experimental diets were formulated and fed to male broiler chicks from d 1-21 as follows: 1) 22.2% crude protein (CP) (positive control; PC); 2) 16.2% CP + mixture essential amino acids (EAA) to meet or exceed the National Research Council (1994) recommendations (negative control; NC); 3) NC + glycine (Gly) to equal the total glycine + serine level in the PC; diets 4 through 7 were obtained by supplementing NC diet with individual glutamic acid, proline, alanine, or aspartic acid (Glu, Pro, Ala, or Asp, respectively); 8) NC + NEAA (Gly + Glu + Pro + Ala + Asp) to equal the total level of these NEAA in the PC. Fortifying NC diet with mixture NEAA resulted in a similar growth performance as PC. However, fortification of low-CP diet with individual NEAA failed to improve body weight (BW) (P < 0.0001), feed intake (FI) (P = 0.0001), and feed conversion ratio (FCR) (P = 0.0001). Serum uric acid (UA) was lower (P = 0.0356) in NC birds and NC diet supplemented with individual NEAA birds, whereas serum triglyceride (TG) (P = 0.007) and relative weight of abdominal fat (P = 0.001) were higher in these birds. In conclusion, no single NEAA fortification may compensate the depressed growth performance attributed to a low-CP diet. However, fortification with Gly may improve FCR. There is a possibility that broilers raised under the hot and humid climate require higher Gly fortification than the level used in this study.
1. This study was undertaken to examine the effect of feeding glycine (Gly)-fortified low protein (LP) diets on the growth performance, duodenal morphology and caecal microbial populations of broiler chickens raised under unheated, cyclic or constant heat stress environmental conditions. 2. From d 1 to 21 (starter phase), an equivalent number of birds were fed either a normal protein (NP) diet or a LP diet fortified with Gly. From d 22 to 42 (grower phase), an equivalent number of birds from each starter diet were distributed to one of the following dietary groups: (i) an NP diet during the starter and grower phases (NPNP), (ii) an NP diet during the starter phase and a LP diet during the grower phase (NPLP), (iii) an LP diet during the starter phase and an NP diet during the grower phase (LPNP) or (iv) LP diets during both phases (LPLP). 3. Commencing from d 22, an equivalent number of birds from each dietary group were exposed to (i) 23 ± 1°C throughout (unheated), (ii) 34 ± 1°C for 7 h each day from 10:00 to 17:00 (cyclic heat) or (iii) 34 ± 1°C throughout (constant heat). 4. Feeding the LP diet during the starter phase resulted in feed intake (FI), weight gain (WG), feed conversion ratios (FCR) and energy efficiency ratios (EER) similar to those for the NP diet. The birds fed the LP diet had a significantly higher protein efficiency ratio (PER) compared with the birds fed the NP diet. 5. During the grower phase, there were significant diet × temperature interactions for F, WG, FCR, PER, EER, villus height, crypt depth and caecal Clostridia. The birds fed the NPLP and LPLP diets had lower FI, WG and EER, higher FCR, shorter villus height and crypt depth and higher caecal Clostridia compared with the birds fed LPNP and NPNP diets under constant heat stress. However, feeding birds the NPLP and LPLP diets resulted in FI, WG, EER, FCR, morphology parameters and caecal Clostridia equivalent to the birds fed LPNP and NPNP diets, as well as improved PER, under unheated and cyclic heat stress conditions. 6. In conclusion, our results indicate that Gly-fortified LP diets can be fed to broilers under normal and acute heat stress environmental conditions without any adverse effects on performance. However, the use of such LP diets can be detrimental to broilers under chronic heat stress conditions.