Influence of Growth Factors on Pigmentation of Chaetomium Cupreum SS-02 and the Antibacterial Efficacy of the Pigment against Ralstonia Solanacearum

An extracellular pigment-producing ascomycetous filamentous fungus Chaetomium was isolated from litter sample and identified as Chaetomium cupreum SS-02. The optimal growth conditions for high pigment yield and the invitro antagonistic activity of the pigment against Ralstonia solanacearum – a phytopathogenic bacterium, was investigated. The optimal culture conditions for pigment production were as follows; Dextrose 2%, Peptone + Yeast extract (0.4%), pH 6, temperature 35°C and inoculum age - 6 days old. The invitro screening of antibacterial activity of the pigment against five pathogenic strains of Ralstonia solanacearum was measured in terms of zone of inhibition. The highest activity was recorded against RS4 strain

Phytochemical Screening and in Vitro Assessment of Antimicrobial and Antioxidant Potential of Andrographis Serpyllifolia-An Endemic Medicinal Plant from South India

The current study was aimed to investigate the phytochemical composition, antibacterial and antioxidant activity of A. serpyllifolia plant extracts. Phytochemical screening revealed the presence of alkaloid, tannins, steroids, terpenoids, phlobatannin, anthraquinones flavonoids, saponins and phenolic compounds. Quantitative analysis revealed the presence of saponins (4.2%) in high concentration followed by tannins (4.12%), phenolics (1.4%), alkaloids (1.2%) and flavonoids (0.98%). This study will provide phytochemical information for preparation of concentrated and effective extract of A. serpyllifolia. Petroleum ether, chloroform, benzene and methanol extracts of shade dried plant parts of A. serpyllifolia were tested for antibacterial activity against six strains of bacterial species, viz., Bacillus subtilis, Escherichia coli, Proteus, Pseudomonas aeruginosa, Klebsiella sps and Staphylococcus aureus using the standard agar disk diffusion method. All the extracts have shown significant activity against tested microbes with the inhibition zone ranged of 5.7-16.8mm. Among various solvent extracts studied petroleum ether extract showed a highest antibacterial activity followed by methanol, benzene, chloroform. Antioxidant potential of methanol extracts was determined by DPPH and ABTS free radical scavenging assay. The extracts showed a very good antioxidant property and the IC50 value was found to 268.12ìg/ml for DPPH assay and 398.46ìg/ml for ABTS assay. Ascorbic acid taken as control showed highest antioxidant power in the present study. The results suggest that A. serpyllifolia has promising antioxidant activity and could serve as potential source of natural antioxidant

Induction of Systemic Resistance by Trichoderma Asperellum against Bacterial Wilt of Tomato Caused by Ralstonia Solanacearum

Trichoderma asperellum was used as a biological control agent against bacterial wilt disease caused by Ralstonia solanacearum. The present investigation is focused on the role of defense- related enzymes in imparting resistance to tomato against bacterial wilt pathogen Ralstonia solanacearum. Two isolates of Trichoderma asperellum (T4 and T8) exhibiting high antagonistic activity against a virulent strain of Ralstonia solanacearum (RS) were selected during screening for studies on several biocontrol mechanisms under greenhouse conditions. Seed treatment with T. asperellum isolates significantly improved the quality of seed germination and seedling vigor. Efficacy of T4 and T8 isolates, evaluated under greenhouse conditions exhibited suppression by about 50% in disease incidence of bacterial wilt and promoted growth in tomato plant. The isolates T4 and T8 were further tested for their ability to induce the production of defense-related enzymes in plants. The seed application with T4 and T8 isolates induced a significant increase in the activities of peroxidase (POX), Polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), and â.1, 3-glucanase in treated tomato plants. Increased activities of phenylalanine ammonia lyase, peroxidase, Polyphenol oxidase, â-1, 3-glucanase were observed in T4 and T8 pre-treated tomato plants challenged with Ralstonia solanacearum. Trichoderma asperellum treatment also triggered the defense related enzymes involved in synthesis of phenols. Higher accumulation of phenolics was noticed in plants pre-treated with T4 and T8 challenged with Ralstonia solanacearum. Native PAGE analysis of both peroxidase (POX) and Polyphenol oxidase (PPO) was carried out for the time course of enzyme activities. The present study shows that in addition to direct antagonism and plant growth promotion; induction and increased activity of defense related enzymes involved in the phenyl propanoid pathway collectively contributed to enhanced resistance against invasion of bacterial wilt in tomato caused by Ralstonia solanacearum

Optimization of physiological conditions for L-asparaginase production by endophytic fungi (Fusarium solani) isolated from Tinospora cordifolia (Willd.) Hook. F & Thomson

Asparaginase converts L-asparagine to L-aspartic acid and has received considerable attention in the recent years for its anti-carcinogenic potential. In the present investigation, the endophytic fungi isolated from T. cordifolia were screened for the production of extracellular L-asparaginase during their growth on Modified Czapekdox medium (MCD). The physical and nutritional conditions were optimized for maximum production of L-asparaginase by F. solani under submerged fermentation conditions (SmF). The fungi exhibited significant variations in the production of L-asparaginase under the influence of incubation period, temperature, pH, carbon and nitrogen sources. It was observed that maximum enzyme activity was recorded on the 6th day of incubation period at pH 7.0 with an incubation temperature of 30°C at 120 rpm. Sucrose (0.2%) was the best carbon source. Different nitrogen sources at concentrations ranging from 0.1% to 0.5% were assessed. Among them, ammonium nitrate (0.4%) and sodium nitrate (0.4%) showed maximum production of L- asparaginase

A Collision Avoidance Based Energy Efficient Medium Access Control Protocol for Clustered Underwater Wireless Sensor Networks

Underwater Wireless Sensor Networks (UWSNs) are typically deployed in energy constrained environments where recharging energy sources and replacing batteries are not viable. This makes energy efficiency in UWSNs a crucial directive to be followed during Medium Access Control (MAC) design. Multiplexing and scheduling based protocols are not ideal for UWSNs because of their strict synchronization requirements, longer latencies and constrained bandwidth.This paper presents the development and simulation analysis of a novel cross-layer communication based MAC protocol called Energy Efficient Collision Avoidance (EECA) MAC protocol. EECA-MAC protocol works on the principle of adaptive power control, controlling the transmission power based on the signal strength at the receiver. EECA-MAC enhances the conventional 4-way handshake to reduce carrier sensing by implementing an enhanced Request to Send (RTS) and Clear to Send (CTS) handshake and an improved back-off algorithm.Simulation analysis shows that the measures taken to achieve energy efficiency have a direct effect on the number of packet retransmissions. Compared to the Medium Access with Collision Avoidance (MACA) protocol, EECA-MAC shows a 40% reduction in the number of packets that are delivered after retransmissions. This reduction, coupled with the reduced signal interference, results in a 16% drop in the energy utilized by the nodes for data transmission

A Quality of Service Aware Source Routing Based Protocol for Underwater Wireless Sensor Networks

Underwater Wireless Sensor Networks (UWSNs) handle many underwater applications such as environment monitoring, surveillance and navigation. These applications generate varied types of traffic such as continuous bit rate, sporadic and different packet sizes, leading to additional QoS requirements that are traffic and application dependent. This paper presents the development of a Quality of Service Aware Source Routing (QASR) protocol. QASR discovers multiple paths from the sources to the sinks and selects the most QoS compatible route among them. QASR is distinctive because it incorporates multiple QoS parameters such as Signal to Noise Ratio (SNR), latency and residual energy. Depending on which of these parameters are chosen, QASR has three variants, namely, QASR-Latency (QASR-L), QASR-Residual Energy (QASR-RE) and QASR-Signal to Noise Ratio (QASR-SNR). The performance of QASR protocol is compared against traditional source routing protocols, with simulations showing a reduction of about 10% to 20% in latency and about 5% to 10% lesser energy consumption than source routing. QASR protocol exhibits comparable performance to classic source routing protocols while simultaneously adhering to the QoS requirements of the application. It is also worth noting that the performance profile of all the three variants of QASR do not have sudden and drastic variations, with the performance profiles showing consistent trend-lines

Efficacy of Trichoderma asperellum against Ralstonia solanacearum under greenhouse conditions

The rhizosphere soil samples of healthy tomato plants were used to isolate Trichoderma spp and identified based on morphological and molecular characterization as a Trichoderma koningii (T1) T. flavofuscum (T2), T. harzianum (T3), T. asperellum (T4), T. harzianum (T5 & T7), T. koningii (T6), T. asperellum (T8), T. harzianum (T9), T. viride (T10). The isolates screened for antagonistic activity against ten virulent strains of Ralstonia solanacearum (Rs). Two isolates of Trichoderma (T4 and T8) exhibiting high antagonistic activity (24-29mm and 20-27mm respectively) and also studied for several biocontrol mechanisms under greenhouse conditions. These strains were found to be positive to protease, β-1, 3-glucanase, Cellulase, Chitinase, Xylanase, Amylase, Pectinase and lipase activity. Germination percentage increased by 48% and 45% by Trichoderma with pathogen treated seeds and also increased root length, shoot length, fresh weight, dry weight and vigour index. Efficacy of T4 and T8 isolate were evaluated under green house conditions in suppressing disease and promoting tomato plant growth. The disease incidence was significantly reduced by about 50% in tomato plants raised under green house conditions

Induction of Systemic Resistance in Tomato against Ralstonia Solanacearum By Pseudomonas Fluorescens

The biological control agent Pseudomonasfluorescens was used against the bacterial wilt causing Ralstoniasolanacearum. The present investigation focuses on the role of defenserelated enzymes in imparting resistance in tomato against R. solanacearum. A total of ten rhizobacterial isolates werescreened against R. solanacearum, ofwhich three isolates (Pf3, Pf5 & Pf8) showed a maximum inhibition againstthe pathogen and were further identified as P.fluorescens by 16S rRNA analysis. Seedling treatment with P. fluorescens isolates significantlyenhanced the quality of seed germination and seedling vigor. The three P. fluorescens strains were furthertested for their ability to induce the production of defense-related enzymes inplants. Involvement of defense related enzymes in bacterial wilt pathogenesiswas studied in susceptible tomato cultivar (Arka Meghali). Root dip inoculationwas performed with bacterial suspensions of R.solanacearum and P. fluorescens (1× 108 cfu/ml) on ten days old seedlings and harvested at differenttime intervals (0, 3, 6, 9, 12, 15, etc. up to 72 h) and assayed for thedefense related enzyme activity. The seedling treatment of P. fluorescens isolatesinduced a significant increase in the activities of peroxidase (POX), Polyphenoloxidase (PPO), phenylalanine ammonia lyase (PAL), and β-1, 3-glucanase in treated tomato plants and the same trend ofincrease in enzyme activity was observed in P.fluorescens treated tomato seedlings challenged with R. solanacearum. The activities of the enzymes PAL, POX, PPO and β-1, 3-glucanase reached maximum at 24,18, 24 and 24 h after inoculation respectively. Higher accumulation ofphenolics was noticed in plants pre-treated with P. fluorescens and challenge inoculated with R. solanacearum. Native PAGE analysis of both Peroxidase (POX) andPolyphenol oxidase (PPO) was carried out for the time course of enzymeactivities and the isoforms of POX and PPO were examined

End-uses of electricity in households of Karnataka state, India

This paper describes the results of a survey of electricity consumption in a sample consisting of 1,165 households in four districts of Karnataka state in India. The survey revealed the patterns of consumption of electricity in AEH[1] and non-AEH[2] households, the stock of electrical appliances used by the households, the differences in the consumption of electricity in urban and rural areas, the use of other sources of energy for domestic purposes, and the degree of penetration of energy-efficient appliances/devices. The analysis of electricity consumption of appliances in AEH households showed that the consumption of electricity is mainly due to lighting, air circulation, water-heating and cooking. In non-AEH households, the end-uses accounting for most of the consumption of electricity are lighting, entertainment and air circulation. The survey also yielded the appliance elasticities and the degree of penetration of energy-efficient devices. As a result policy-makers can take corrective actions by promoting efficiency improvements in certain end-use devices so that increases in the penetration of these devices would not significantly affect the overall electricity requirement for the domestic sector

ALDEHYDE EMISSIONS FROM TWO-STROKE AND FOUR-STROKE SPARK IGNITION ENGINES WITH CATALYTIC CONVERTER RUNING ON GASOHOL

Rad donosi rezultate ispitivanja emisije aldehida iz dvotaktnog i četverotaktnog jednocilindričnog motora na paljenje svjećicama koji koristi mješavinu benzina (80 vol. %) i alkohola (20 vol.); motor je prevučen bakrom (sloj debljine 300 μm na klipu i na unutarnjoj strani glave cilindra) i opremljen katalizatorom od spužvastog željeza. Rezultati su uspoređeni s konvencionalnim benzinskim motorom na paljenje svjećicama. Motor prevučen bakrom pokazuje smanjenje emisije aldehida u odnosu na konvencionalni motor za oba ispitna goriva. Katalitički pretvornik s ubrizgavanjem zraka značajno smanjuje štetne emisije kod oba ispitna goriva i kod obje konfiguracije motora.This paper reports aldehyde emissions from two-stroke and four-stroke, single cylinder spark ignition (SI) engines with gasohol (80 vol. % gasoline, 20 vol. % ethanol) having copper coated engine (copper-coated thickness, 300 μm) on piston crown and inner side of cylinder head) provided with catalytic converter with sponge iron as catalyst and compared with conventional SI engine with gasoline operation. Copper-coated engine showed reduction in aldehyde emissions when compared with conventional engine with both test fuels. Catalytic converter with air injection significantly reduced emissions with both test fuels on both configurations of the engine