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Synthetic plastics are in great demand in society due to their diversified properties, but they cause environmental pollution due to their non-biodegradable nature. Therefore, synthetic plastics are in need to be replaced with biodegradable plastics. Polyhydroxyalkanoates (PHAs), bacterial biopolymers are natural alternative to synthetic plastics. These are present inside the bacterial cytoplasm in granular form. Presently, the production cost of PHA is high due to expensive carbon substrates used in its biosynthesis. Therefore, this study focuses on the cost-effective production of PHA using waste carbon sources. Rice bran and sugarcane molasses were used as the carbon source for PHA production from Bacillus subtilis, Bacillus cereus, Alcaligenes sp. and Pseudomonas aeruginosa. PHA production from these bacterial strains was confirmed through Sudan Black-B screening. With rice bran, as carbon source, the highest PHA yield obtained was for P. aeruginosa, which yielded 93.7% and lowest was 35.5% for B. cereus. Surprisingly, B. cereus produced the highest cell dry mass (0.045 g/L) but its extracted PHA contents were lowest being only 0.02 g/L. Alcaligenes sp. with 0.031 g/L CDM yielded 87.1% PHA. B. subtilis had a CDM 0.029 g/L, 0.02 g/L PHA content and a yield of 69.10%. In the case of sugarcane molasses, P. aeruginosa produced 95% PHA yield, 0.02 g/L CDM, and 0.019 g/L PHA content. Alcaligenes sp. yielded 90.9% PHA, 0.011 g/L CDM, and 0.01 g/L PHA content. B. subtilis produced 91.6% PHA yield, 0.012 g/L CDM, 0.011 g/L PHA content; B. cereus produced 80% PHA yield, 0.015 g/L CDM, 0.012 g/L PHA content at 37 °C, pH 7. Higher concentrations of carbon sources increased the CDM and decreased the PHA yield. The maximum yield of PHA was obtained from sugarcane molasses. 24–48 h of incubation was optimal for B. subtilis and B. cereus, while for Alcaligenes and P. aeruginosa incubation time of 48–96 h was desirable for higher PHA yield. The extracted biopolymers were analyzed by Fourier transform infrared spectroscopy (FTIR), which identified the extracted biopolymers as poly-3-hydroxybutyrate P(3HB). The thermal properties of the extracted biopolymers, such as melting temperatures, were analyzed by differential scanning calorimetry (DSC), which confirmed the thermal stability.

Fluorocarbon-based oil and water repellents are considered best in textile finishing due to their excellent performance. Although, long chain fluorocarbons are effective oil and water repellents but they are toxic and being banned. Therefore, the present study develops two fluorine-free water-repelling polymers for cotton fabrics using ecofriendly recipes containing bio-based stearic acid and formaldehyde-free succinic acid and itaconic acid. One optimized recipe was achieved through polymerization between bio-based stearic acid and succinic acid, and other optimized recipe was achieved through polymerization between stearic acid and itaconic acid. These two recipes were applied to cotton fabric, and treated fabric exhibited a water repellency rating of 4 and an oil repellency rating of 1. The proposed polymers exhibited good oil and water repellency and washing durability up to 10 washing cycles. However, after 20 washing cycles, the proposed polymers exhibited water repellency for ironed fabric and zero oil repellency. The proposed polymers exhibited comparable or better testing results than commercial C6-based fluorocarbon. The characterization of the two best recipes was carried out through H-NMR Spectroscopy, scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD).

Herein, silk fibroin (SF) extract was blended with silver nanoparticles (SNPs) to develop electrospun nanofibers whereas polyethylene oxide (PEO) mediated as a template to support the network. The electrospinning process was tuned to get beadles uniform nanofibers. The prepared SNPs and SF were characterized for z-average (mean hydrodynamic diameter), zeta potential, and UV-visible (vis.) absorbance; and the electrospun nanofibers for surface morphology, elemental analysis, crystalline properties, Fourier transform infrared spectroscopy (FTIR), surface wettability and thermal analysis. The results indicate that the z-average of SNPs was 50±5 nm with the polydispersity index (PDI) of 0.686 and that of SF as 450±20 nm with the PDI of 0.538, and respective zeta potential being -35±3 and -20±2 mV. The UV-vis. spectra expressed absorbance peaks for SNPs at 400 nm and SF at 279 nm. The surface morphology of composite nanofibers expressed an even mediation of SNPs within the composite nanofibers of uniform diameter. The FTIR results indicated weak intermolecular interactions between SF and the SNPs. The XRD patterns expressed that the crystallinity of resultant composite nanofibers increased on mediation with SNPs. The incorporation of SNPs made the nanofibrous network more hydrophobic and thermally stable.摘要在此, 丝素蛋白 (SF) 提取物与银纳米颗粒 (SNP) 混合以开发电纺纳米纤维, 而聚氧化乙烯 (PEO) 作为模板来支持网络.整静电纺丝工艺以获得均匀的纳米纤维。对制备的SNP和SF的z-平均值 (平均流体动力学直径) 、zeta电位和紫外-可见吸收率进行了表征; 以及用于表面形态、元素分析、结晶性能、傅里叶变换红外光谱 (FTIR) 、表面润湿性和热分析的电纺纳米纤维. 结果表明, SNP的z-平均值为50±5nm, 多分散指数 (PDI) 为0.686, SF的z-均值为450±20nm, PDI为0.538, 各自的zeta电位分别为-35±3和-20±2mV. 紫外可见光谱. 光谱表示400 nm处SNP和279 nm处SF的吸光度峰. 复合纳米纤维的表面形态表现出均匀直径的复合纳米纤维内SNP的均匀介导. FTIR结果表明SF和SNP之间的分子间相互作用较弱. XRD图谱表明, 在SNP的解下, 所得复合纳米纤维的结晶度增加. SNP的加入使纳米纤维网络更疏水和热稳定

Abstract The response of two local maize (Zea mays L.) genotypes designated as Sahwal-2002 (salt-tolerant) and Sadaf (salt-sensitive) to salt stress was investigated under controlled growth conditions. The role of phenylalanine and seed priming under salt stress in maize with different morphological parameters were studied. The genotype Sadaf, being salt-tolerant, experienced more oxidative damage than the Sahiwall-2002 genotype under salt stress. The salinity affected both growth and physiological attributes of the maize species whereas the phenylalanine successfully increased the salinity tolerance in maize species at the seedling stage.

Herein, we report simple clean route for producing antibacterial knitted cellulose fabric. Silver nanoparticles (SNPs) were successfully synthesized and impregnated on the fabric by using starch as reducing and stabilizing agents under standard autoclave setup. The results expressed successful synthesis of SNPs with a mean diameter 25.72 ± 3.53 and corresponding zeta potential of −41 mV. The scanning electron microscopy analysis indicated that the surface of fabric was embedded with SNPs. The energy dispersive X-ray of SNPs-coated cotton fabric proved the incidence of SNPs. The SNPs impregnated knitted cellulose fabric expressed good broad spectrum antibacterial activity.

Herein, we report an investigation on an eco-compatible cross-linker, citric acid, to enhance multi-performance characteristics of knitted wool fabric. Citric acid reduced relaxation shrinkage after multiple washings as well as enhanced easy-care performance. Mediation of formic acid as swelling agent further improved cross-linking behavior of citric acid for wool. Shrinkage of wool in course and wale direction after one and five washes were observed, and found that presence of the highest concentration lowered the shrinkage. In addition, crease recovery angle 297°, moisture management 0.675, better dye ability with reactive and acid dye as well as antibacterial activity were achieved at 2% formic acid and 15% citric acid concentrations.

Abstract This study dealt with the fabrication and analysis of poly(lactic acid) (PLA) mediated chitosan nanocomposite. Such a novel nanobiocomposite may get future applications in drug delivery, and nanofinising of textile and polymer surfaces. Herein, this nanocomposite has been considered as an antibacterial finishing agent for a hydrophobic textile fabric like polyester. The prepared nanocomposite was characterized for zeta size and morphology, and subsequently applied on a woven polyester fabric though a coross linker. The treated polyester fabric was analyzed for textile functional characteristics as well asantibacterial activity. The spectral and optical properties demonstrated that the nanocomposite developed exhibited spherical morphologies with a mean nano particle size of ca. 88 nm. The treated fabric projected satisfactory antibacterial and fair fabric attributes. Hence, the nanofinished polyester fabric is a potential biocompatible candidate as medical and antibacterial textiles in addition to be used in antibacterial water filtration and materials packing.

The present paper envisages the multi-response optimization of certain process parameters like total sugars concentration, C/N ratio and incubation time on rhamnolipid yield, surface tension reduction, biomass formation and substrate utilization, in rhamnolipid production by a Pseudomonas aeruginosa mutant strain grown on clarified blackstrap molasses, under L9 orthogonal array in Taguchi design. The results have been analyzed by using grey relational analysis for the identification of an optimum level of process parameters. The validity of the results was checked though confirmation experiment, under grey relational analysis. Subsequently, the rhamnolipid yield improved from 1.45 to 1.50 g/L, substrate utilization reduced from 26 to 14% (w/v) and lesser biomass was formed. Moreover, the volumetric productivity of the process improved from 0.0086 to 0.0208 g/L/h by 142%. Furthermore, using analysis of variance method, significant contributions of process parameters were determined.

Tensioactive properties of rhamnolipids produced by a Pseudomonas aeruginosa strain were investigated in the presence or absence of Sr2+ or Pb2+. Surface and interfacial properties, and aggregate forming properties and morphologies were studied by various techniques including scanning electron microscopy. When the pH of a rhamnolipid aqueous solution (40 mg/l) was increased from 5 to 8, irregular vesicles gradually took the shape of oligo-vesicles, then regular vesicles and finally smaller spherical vesicles. Addition of metal ions controlled the aggregates’ morphology and stability, and influenced the surface and interfacial behavior of rhamnolipid solutions. [ABSTRACT FROM AUTHOR]