Influence of fluorescent pigments on the spectral characteristics of luminous coated fabrics

In recent years, luminous coated fabrics based on SrAl2O4: Eu2+, Dy3+ luminescent materials have attracted more attention. However, due to the single emission color of SrAl2O4: Eu2+, Dy3+ luminescent materials, the application of prepared coated fabrics has certain liminations. Therefore, at present, there is a need to develop a kind of luminous coated fabric which has the capability of emitting multiple colors of light. In this work, fluorescent pigments and SrAl2O4: Eu2+, Dy3+ luminescent materials were added to a coating slurry and uniformly coated over a woven fabric substrate. The effects of adding fluorescent pigments on the spectral characteristics of luminous coated fabrics were evaluated. The blue fluorescent pigment causes a significant blue shift in the emission spectrum of the blue light-emitting coated fabric, whereas the emission spectra of the orange and red light-emitting coated fabrics exhibit a significant red shift. The yellow-green fluorescent pigments significantly affect the coated fabric. The emission spectrum shows no evident change and is similar to the emission spectrum of white (without any fluorescent pigment) luminescent coated fabric. The afterglow brightness of the colored luminous coated fabrics decreases exponentially with time. Adding blue fluorescent pigments has a greater impact on the brightness of the coated fabrics. The initial brightness is lower and the afterglow brightness loss is higher when using yellow-green fluorescence. The pigment has little effect on the brightness loss of coated fabrics, and the initial brightness of the coated fabric increases when adding yellow-green fluorescent pigments. Fluorescent pigments result in relatively low color purity for each colored coated fabric. However, the color rendering index is high, and the color rendering performance for the light source is excellent.

Characterisation of Pseudomonas syringae isolated from systemic infection of zucchini in Australia

Zucchini plants, with symptoms including twisted petioles, necrotic leaves, crown-rot and internal fruit-rot, were found in Bundaberg, Australia at a commercial field for the first time during late autumn 2016, resulting in direct yield losses of 70 to 80%. Three Pseudomonas syringae strains that isolated from symptomatic leaf (KL004-k1), crown (77-4C) and fruit (KFR003-1) were characterised and their pathogenicity evaluated on pumpkin, rockmelon, squash and zucchini. Biochemical assays showed typical results for P. syringae. The three isolates differed, however, in that two produced fluorescent pigment (KFR003-1 and 77-4C) whilst the third, KL004-k1, was non-florescent. Multi-locus sequence analysis classified the isolates to phylogroup 2b. The SNP analysis of core genome from the Australian and closely related international isolates of P. syringae showed two separate clusters. The Australian isolates were clustered based on fluorescent phenotype. Pathogenicity tests demonstrated all three isolates moved systemically within the inoculated plants and induced necrotic leaf symptoms in zucchini plants. Their identities were confirmed with specific PCR assays for P. syringae and phylogroup 2. Pathogenicity experiments also showed the Eva variety of zucchini was more susceptible than Rosa for all three isolates. Isolate KL004-k1 was more virulent than 77-4C on pumpkin, rockmelon, squash and zucchini. This study expands the knowledge of P. syringae isolates that infect cucurbits and provides useful information for growers about the relative susceptibility of a range of cucurbit species.

Pseudomonas capsici sp. nov., a plant-pathogenic bacterium isolated from pepper leaf in Georgia, USA

Three phytopathogenic bacterial strains (Pc19-1T, Pc19-2 and Pc19-3) were isolated from seedlings displaying water-soaked, dark brown-to-black, necrotic lesions on pepper (Capsicum annuum) leaves in Georgia, USA. Upon isolation on King’s medium B, light cream-coloured colonies were observed and a diffusible fluorescent pigment was visible under ultraviolet light. Analysis of their 16S rRNA gene sequences showed that they belonged to the genus Pseudomonas , with the highest similarity to Pseudomonas cichorii ATCC 10857T (99.7 %). The fatty acid analysis revealed that the majority of the fatty acids were summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c), C16 : 0 and summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c). Phylogenomic analyses based on whole genome sequences demonstrated that the pepper strains belonged to the Pseudomonas syringae complex with P. cichorii as their closest neighbour, and formed a separate monophyletic clade from other species. Between the pepper strains and P. cichorii , the average nucleotide identity values were 91.3 %. Furthermore, the digital DNA–DNA hybridization values of the pepper strains when compared to their closest relatives, including P. cichorii , were 45.2 % or less. In addition, biochemical and physiological features were examined in this study and the results indicate that the pepper strains represent a novel Pseudomonas species. Therefore, we propose a new species Pseudomonas capsici sp. nov., with Pc19-1T (=CFBP 8884T=LMG 32209T) as the type strain. The DNA G+C content of the strain Pc19-1T is 58.4 mol%.

PHOTO EFFECT AND BIO-AUTOGRAPHIC STUDIES OF INTRACELLULAR ORANGE FLUORESCENT PIGMENT PRODUCED BY Bacillus endophyticus

Present study has focused on the effect of chemical (solvents) and physical (photo) conditions on pigment production and its bioactivity of intracellular orange fluorescent pigment (IOFP) extracted from soil bacterium Bacillus endophyticus. Standardization of pigment and its colour stability was confirmed by using different solvents (70% & 100% ethanol, hexane, heptane, ethyl acetate, acetone, petroleum ether, chloroform, methanol and distilled water), photo conditions (Dark, U.V light and White light) on pigment production and its bio-activeness by antibacterial activity using agar cup plate method against gram-positive (Staphylococcus aureus, streptococcus pyogenes and Listeria monocytogenes) and gram-negative (Salmonella typhi, Vibrio cholera, Shigella Flexneri and E.coli) human pathogens and purification of pigment by TLC coupled with bio-autographic studies. Acetone is proved to be the best solvent for extraction and the pigment was stable in all solvents without changing its colour except heptane. When compared to control (dark incubation) antibacterial activity of IOFP produced in U.V and W. Light was effective against all tested pathogens with slight differences in their antibacterial activity. TLC bio-autographic studies reveal that the separated pure band shows clear zone of inhibition under red back ground of live cells stating that, the compound is active against human bacterial pathogens. Hence this study concludes that, the production and biological activity of the IOFP was independent of light incubation, and TLC guided bio-autographic approach offers a rapid detection technique that avoids the testing of purified fraction once again.

Facile fabrication of a stable fluorescent yellow X-10GFF/palygorskite hybrid pigment via semi-dry grinding

A hybrid fluorescent pigment composed of fluorescent yellow X-10GFF (FY-10G) and palygorskite (PLG) was prepared by semi-dry grinding. The effects of the physically adsorbed water content and grinding time on the environmental stability of FY-10G/PLG hybrid fluorescent pigments in terms of acid, ethanol and ultraviolet irradiation are discussed in detail. The incorporated FY-10 G molecules are mainly trapped on the external surface and the groove of PLG. Due to the host–guest interaction between PAL and FY-10G, the emission spectrum of the FY-10G/PLG hybrids shifts to a greater wavelength compared with that of FY-10G, but the physically adsorbed water content and grinding time have no effect on the position of the emission spectrum except for its intensity. A larger, physically adsorbed water content and appropriate grinding time may effectively prevent the aggregation and breakage of the bundles of PLG and facilitate FY-10 G molecules to enter into the groove of PAL. This increases the environmental stability of the as-prepared hybrid pigments.

CHARACTERIZATION OF BACTERIAL ISOLATES FOR SUSTAINABLE RICE BLAST CONTROL

ABSTRACT Rice blast (Magnaporthe oryzae) limits rice (Oryza sativa) grain yields worldwide. The objective of this investigation was to morphologically, biochemically, and molecularly characterize six bacterial isolates, BRM 32109, BRM 32110, BRM 32111, BRM 32112, BRM 32113, and BRM 32114, and to determine their potential as antagonists to M. oryzae. Morphological characterization was based on colony formation and color, Gram staining, and fluorescent pigment production. Biochemical studies were based on cellulase, chitinase, phosphatase, indoleacetic acid, and siderophore production, as well as biofilm formation. The molecular identification used specific primers for PCR amplification of the 16S rRNA region, followed by sequencing. The antagonism studies involved three experiments, which had randomized designs. Two of them were conducted in laboratory conditions, pairing bacterial colonies and M. oryzae, using bacterial filtrates, and the third was conducted in greenhouse conditions. BRM 32111 and BRM 32112 were identified as Pseudomonas sp., BRM 32113 as Burkholderia sp., BRM 32114 as Serratia sp., and BRM 32110 and BRM 32109 as Bacillus spp. BRM 32112, BRM 32111, and BRM 32113 inhibited the colony of M. oryzae by 68%, 65%, and 48%, respectively. The bacterial suspensions of the BRM 32111, BRM 32112, and BRM 3212 filtrates suppressed leaf blast by 81.0, 79.2, and 66.3%, respectively. BRM 32111 and BRM 32112 were determined to be antagonists of M. oryzae and were found to solubilize phosphate, produce siderophores and cellulose, form biofilms, and suppress leaf blast. These isolates should be further investigated as potential biological control agents for leaf blast control.

KARAKTERISASI Erwinia chrysanthemi PENYEBAB PENYAKIT BUSUK BAKTERI PADA DAUN LIDAH BUAYA (Aloe vera)

<p>Penyakit busuk (soft rot) pada daun tanaman lidah buaya (Aloe vera) disebabkan oleh F.rwima chrysanthemi pertama kali dilaporkan di Kcpulauan Kaibia tahun 1992. Pada awal tahun 2001, gejala pcnyakil busuk daun juga ditemukan pada tanaman lidah buaya di Semplak, Jawa Barat. Mengingat kerusakan yang ditimbulkan berupa pembusukan pada daun dan pangkal batang yang parah dalam waktu singkat, maka diduga penyebabnya cukup ganas dan dikhawatirkan dapat menjadi kendala pengembangan tanaman lidah buaya yang akhir-akhir ini sedang banyak diminati. Tujuan penelitian ini adalah mengidcntifikasi penyebab penyakit tersebut. Penelitian dilakukan di Laboratorium Bakteri Balai Penelitian Tanaman Rempah dan Obat, dari bulan April - Agustus 2001. Contoh daun lidah buaya sakit berasal dari kebun petani di Semplak, Bogor. Setelah melalui pengamatan gejala penyakit diikuti dengan prosedur isolasi dan pemumian patogen. maka diperoleh isolat kultur baktei yang bentuknya bulat dan pinggirnya tidak rata serta berwarna putih pada medium sukrosa pepton agar. Kultur baktei tersebut bersifat patogenik dan menimbulkan gejala penyakit sama seperti di lapangan, setelah diinokulasikan melalui pelukaan pada daun lidah buaya. Hasil karaktcrisasi morfologi, kultur dan biokimia isolat baktei tersebut menunjukkan sifat ncgatif untuk pewamaan Gram, pigmen fluorescn, oksidasc, dan produksi asam dari unsur karbon laktosa dan dulsitol. Sedangkan karaktcr positif diperoleh dai pengujian oksidasi/fermentasi, lesitinase, pembusukan jaringan umbi kentang, sensitivitas terhadap eitromisin, pertumbuhan pada suhu 37° C, NaCI 5%, serta menghasilkan asam pada medium mengandung manitol Inokulasi pada umbi ubi jalar menyebabkan pembusukan dalam waktu yang singkat. Berdasarkan data tersebut dapat disimpulkan bahwa penyebab penyakit busuk daun pada tanaman lidah buaya di Semplak adalah Erwinia chrysanthemi.</p><p>Kata kunci: Aloe vera, busuk daun, Erwinia chrysanthemi, Bogor</p><p> </p><p><strong>ABSTRACT </strong></p><p><strong>Characteristics o/Envinia chysanthemi causing bacterial soft rot ofAloe (Aloe VeraJ</strong></p><p>The bacterial sot rot of aloe, caused by Erwinia chrysanthemi, was first identified in Caibbean Island in 1992. In early 2001, similar symptoms were found on the aloe plants grown in Semplak, Bogor, West Java. Based on its symptom and progressively spread, especially on the leaf and basal stem, it appeared that the disease was serious and therefore threatened the current development of die plants. This study was conducted in the laboratory of the Research Institute for Spice and Medicinal Crops, Bogor, in April - August 2001. The objective of the study was identifying the cause of the sot rot disease of aloe in Semplak, Bogor. Diseased leaves of aloe were obtained from Semplak. Following the examination of the symptoms, isolation and purification of he causal agent, the bacteial isolates were found. They were round, white colony characteistics on sucrose peptone agar medium. The isolate was pathogenic and caused similar disease symptoms following the artificial inoculation on the wounded aloe leaf. Based on the morphological, cultural, and biochemical analyses of the isolates, it was found that the isolates gave negative reactions for die following characteistics: Gram staining, production of fluorescent pigment, oxidase, and production of acid reaction from lactose and dulcitol. The isolates, on the other hand, gave positive reaction from: oxidation/fermentation, IcciOiinase. and maceration of potato and sweet potato, sensitive to crythromycin, growth at 37 °C, and growth on agar medium containing NaCI 2%, as well as acid production from manmtol. Based on these data, it can be concluded that the pathogen causes sot rot of leaf of aloe in Semplak is Erwinia chrysanthemi. This is the irst repot on (he finding of die disease in Indonesia. More attention is required to stop the spread of the disease.</p><p>Key words: Aloe vera, sot rot. Erwinia chrysanthemi, Bogor</p>

Marking Drosophila suzukii (Diptera: Drosophilidae) with Fluorescent Dusts

The marking of Drosophila suzukii can be an important instrument for studying the ecology and behaviour of this economically important fruit pest, aiding the development of new Integrated Pest Management (IPM) tools or strategies. There is, however, a need for a cost-effective methodology that provides an easily detectable and stable mark. Whereas fluorescent pigment powders are often used in entomological research, the pigments (series, dyes), application techniques, or doses need to be evaluated for each studied species in terms of their efficacy and possible adverse effects on the performance of the insect. The effectiveness of different application techniques and dyes (RadGlo® TP-series) and their effect on the survival of adult D. suzukii were investigated in the laboratory. Furthermore, the influence of the marking on the behaviour of the flies was examined in laboratory trap assays (olfaction) and a field recapture study (general orientation). The persistence and detectability of the marks was evaluated both on living flies (for different application techniques) and dead flies under trapping/storage conditions. The use of fluorescent powders to mark D. suzukii flies yielded a clearly detectable and highly persistent mark, without any adverse effects on the survival and behaviour of the flies.