Volume 22, No. 1 (2021)

OVERVIEW OF WASTEWATER CHARACTERISTICS OF CARDBOARD INDUSTRY

S. Harif(*), M.A. Aboulhassan, L. Bammou

The purpose of this study is to characterize wastewater from the corrugated cardboard industry and to highlight the nature and sources of pollution. Wastewaters from the corrugator and printing processes as well as homogenization tank, which collects all effluents from industrial processes, were analysed using standard methods. The results indicate that these effluents had a significant pollution load. The wastewater from the homogenization tank had high concentration of COD (24243 ± 2374.6 mg∙L-1), BOD5 (413.33 ±17.14 mg∙L-1) and total solids (36.84 ± 10.62 g∙L-1). In addition, the biodegradability indices were less than 0.4, indicating that the effluents from the cardboard industry are not readily biodegradable. The printing process is the main source of liquid pollution in the cardboard industry facilities. The pollution load resulting from this process was much greater than that of the corrugator process wastewater. In accordance with current standards, these industrial effluents require treatment before discharge or re-use.

COMPUTATIONAL ANALYSIS AND EXPRESSION STUDY OF TREHALOSE 6-PHOSPHATE SYNTHASE (TPS) IN RICE (Oryza Sativa)

ABBAS SAIDI(*), ZOHREH HAJIBARAT

Trehalose-6-phosphate synthase is a key enzyme in trehalose biosynthesis. Trehalose has many applications in plant growth and development and in response to abiotic stresses. In this study, analysis of 11 sequences of OsTPS genes downloaded from NCBI was performed in Oryza sativa. The analysis of bioinformatics performed included co-expression network, gene expression, chromosomal map, analysis of cis element and phylogenetic relationships for the TPS gene in rice. Phylogenetic analysis showed that TPS genes were grouped into two classes. Class I and II included OsTPS1 and OsTPS2-11 genes, respectively. The gene network analysis showed that OsTPS formed the gene networks and are mostly active in nucleus and chloroplast. According to phylogeny tree, gene structure, and analysis of cis-elements, OsTPS1 gene was different from other TPS genes. Also, according to co-expressed network, OsTPS1 showed to be the central protein encoding protein trehalose-6-phosphate synthase. OsTPS1 has been suggested to play a key role in flowering initiation in rice. It has also been shown to have an important role in response to osmotic and abiotic stresses (low temperature, salinity and anoxia). Our findings can provide a better understanding of molecular mechanisms of OsTPS genes and their expression in response to various stresses.

FACTORS AFFECTING ANTIBIOFILM PROPERTIES OF MICROBIAL SURFACTANTS

TETIANA P. PIROG(1,2), LILIYA V. KLUCHKA(1), DARIA A. LYTSAI(1), VIKTOR P. STABNIKOV(1*)

Antibiofilm activity of surface-active substances (SAS) synthesized by Rhodococcus erythropolis, Acinetobacter calcoaceticus, or Nocardia vaccinia was studied. The strains were cultivated using carbon ethanol, glycerol, hexadecane, sunflower oil, and carbon-containing wastes from biodiesel production as carbon sources. Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and yeasts Candida albicans and Candida utilis were used as testing cultures. The antibiofilm activity of biosurfactants depended on the source and concentration of carbon source and duration of cultivation. The addition of calcium cations to media significantly increased antibiofilm activity. Replacement of pure sources of carbon for wastes provided the opportunity to receive biosurfactants with high antibiofilm properties on inexpensive substrates. Destruction of biofilms was the same in cases when supernatant or purified SAS was used.

PRELIMINARY INVESTIGATION OF BAKER’S YEAST FOR THE BIOSYNTHESIS OF METAL OXIDE NANOPARTICLES AND EVALUATION OF THEIR ANTIBACTERIAL ACTIVITY

DIANA RAKHMAWATY EDDY, IMAN RAHAYU, RETNA PUTRI FAUZIA, SAFRI ISHMAYANA(*)

The present study determined if metal ions (zinc sulphate, silver nitrate, copper sulphate, manganese sulphate and ferric chloride) can be used as precursors to prepare nanoparticles using a baker’s yeast culture medium. The particles were characterized using Fourier transform infrared (FTIR), scanning electron microscope‒energy-dispersive X-ray (SEM-EDX), transmission electron microscopy (TEM), and X-ray powder diffraction (XRD). The antibacterial activity against Escherichia coli and Streptococcus aureus was also evaluated. Saccharomyces cerevisiae strain A12 culture only synthesized nanoparticles using a silver nitrate solution. FTIR indicated that the protein might play a role in capping the nanoparticles, which formed large aggregates and contained silver, oxygen and a small amount of phosphorus. The nanoparticles were spherical, ranging in size from 9 to 85 nm, crystalline and characterized as Ag2O, however, they demonstrated weak antibacterial activity.

APPLICATION OF SILICA RICE HUSK ASH FOR CELLULASE IMMOBILIZED BY SOL-GEL ENTRAPMENT

ANTONIUS DIONOVTA R. P. MOLO(1), EVI SUSANTI(1), SURJANI WONORAHARDJO(*1,2)

Biosilica from rice husk ash can be used to immobilize enzyme by sol-gel entrapment method. Cellulase was chosen as the probe enzyme to test the feasibility of this material for such purpose. This research aimed to know the optimum condition of cellulase immobilization process by sol-gel entrapment, the optimum pH and temperature for immobilized enzyme, and the reusability of the immobilized enzyme, as concluded from its activity. The research was divided into 3 steps (1) sol-gel immobilization of cellulase, (2) protein and activity experiments to test immobilized enzyme by varying pH and temperature, and (3) reusability test. The result showed optimum condition gave 38.48 % recovery of enzyme activity with protein content of 0.42 mg·mL-1, the best pH and temperature were 7 and 55 0C respectively. The system could be reused for three times.

SYNTHESIS, CRYSTAL STRUCTURE AND CATALYTIC ACTIVITY OF A CU(II) COMPLEX WITH N-NICOTINOYLGLYCINE

XI-SHI TAI (1*), ZHEN REN(2), LI-LI LIU(1), LI-HUA WANG(3)

A new Cu(II) complex, [CuL2(H2O)2]·H2O (HL = N-nicotinoylglycine), has been obtained using N-nicotinoylglycine, copper(II) acetate monohydrate and NaOH as raw materials. The structure of the Cu(II) complex was characterized by elemental analysis and single crystal X-ray diffraction analysis. The Cu(II) ion is six-coordinated with two N atoms from two pyridine groups of L ligand and four O atoms of four coordinated H2O molecules. The Cu(II) complex forms a 2D layered structure and 3D network structure by the interaction of O-H···O hydrogen bonds. The catalytic activities of the Cu(II) complex catalyst for benzyl alcohol oxidation were determined with molecular oxygen as oxidant.

STUDY OF CHROMATOGRAPHIC FINGERPRINT OF FLAVONOID COMPOUNDS OF THE BUR-MARIGOLD HERB

ELINA E. KOTOVA(1*), SEMEN A. KOTOV(2), ANDRIY G. KOTOV(1)

The main aim of this work was to determine the possibility of reliable identification of phenolic compounds, in particular flavonoids, specific for very popular type of medicinal plant material Bidens (B. tripartita, B. frondosa, B. cernua), their qualitative and quantitative determination by various methods: TLC, HPLC and absorption spectrophotometry (UV method). TLC method was used to isolate a specific compound from B. cernua sample, and by using HPLC method this compound was identified as quercitrin in comparison with a reference sample. A study of 8 series of the bur-marigold herb has shown that the presence of significant amounts of quercitrin in the sample indicates an unacceptable impurity of B. cernua in the pharmacopeial samples of B. tripartita. The main components of B. tripartita were identified as: luteolin-7-glucoside, unidentified luteolin glycoside, luteolin, derivatives of caffeic acid, in particular chlorogenic acid, polyacetylenes, chalcones. The correlation between the results of quantitative determination of the sum of flavonoids by the UV method and the results of HPLC determination of main components was shown.

A THEORETICAL STUDY REGARDING THE INFLUENCE OF CARBON AMOUNT ON RESIDUAL STRESS DISTRIBUTION IN SURFACE LAYER

NICOLAE CATALIN TAMPU, RALUCA IOANA TAMPU(*), BOGDAN ALEXANDRU CHIRITA, EUGEN HERGHELEGIU

The aim of the present paper is to investigate the residual stress distribution generated in surface layers by machining. Experiments revealed that an increase of residual stress value in tensile zone (546 MPa) is connected with a high value of carbon percentage for up to 0.9 % from surface layer, while the decrease of residual stress value from approximately 550 to 300 MPa corresponded to a level 0.6 % of carbon. A theoretical investigation based on a finite element model (FEM) was carried out in order to check the influence of the carbon content on the residual stress distribution. Six types of materials containing various amounts of carbon (from 0.4 % C up to 0.96 % C) but with constant content for the other alloying elements were used in the simulations. The cutting parameters were kept constant in order to assess the influence of carbon presence over residual stress. From the FEM simulation a correlation between the carbon percentage and the distribution of the residual stresses in the surface layer was observed.

STUDY CONCERNING THE DAMPING OF PRESSURE WAVE PROPAGATION IN ADIABATIC EVOLUTION

LILIANA TOPLICEANU(1), CARMEN-VIOLETA MURARU(2), IULIAN FURDU(2), PETRU GABRIEL PUIU(1*)

The propagation of acoustic waves affects people’s daily life but especially the working conditions in certain industrial areas, including in the chemical and food sectors. In order to dampen noise and to improve the quality of the working environment, the phenomenon of pressure wave propagation must be studied. The paper analyzes the unidirectional pressure waves produced by a pneumatic machine operating at a constant speed. The hyperbolic equations with non-linear derivatives were studied using the method of finite difference and an original program was created to obtain the visualisation of the speed and pressure oscillations along the pipeline. The graphical representations of the oscillation speed and the pressure wave at different sections along the pipe have led to interesting conclusions that could be used to develop methodologies and systems for attenuating the pressure pulsation and therefore the noise.

DEVELOPING A RISK ASSESSMENT METHODOLOGY FOR THE PRODUCTION OF SEMI-SMOKED SAUSAGES

MIRA SERIKKYZY(1*), GULZIRA JUMABEKOVA(1), AINUR ZHELDYBAYEVA(1), AINUR MATIBAYEVA(2), ROZA OMIRBAY(1), DESISLAV BALEV(3)