Nanofibrillation of Bacterial Cellulose Using High-Pressure Homogenization and Its Films Characteristics

The microstructure of bacterial cellulose nanofibers(BCNs)film affects its characteristic.One of several means to engineer the microstructure is by changing the BCNs size and fiber distribution through a high-pressure homogenizer(HPH)process.This research aimed to find out the effects of repetition cycles on HPH process towards BCNs film characteristics.To prepare BCNs films,a pellicle from the fermentation of pineapple peels waste with Acetobacter xylinum(A.xylinum)was extracted,followed by crushing the pellicle with a high-speed blender,thereafter,homogenized using HPH at 150 bar pressure with variations of 5,10,15,and 20 cycles.The BCNs films were then formed through the casting process and drying in the oven at 60°C for 8 h followed by structural,morphological,and optical properties investigation using X-ray diffraction(XRD),scanning electron microscopy(SEM)and Fourier transform infrared(FTIR)spectrometer along with BCNs films porosity,tensile and roughness test.The research showed that the effect of HPH cycle on BCNs resulted in the highest film tensile strength by 109.15 MPa with the lowest surface roughness(Ra)of 0.93±0.10μm at 10 cycles.The HPH process is effective in controlling BCNs film porosity level.The HPH cycles influence the crystalline index and crystallite size,slightly.

Characterization of Nanocomposite Membrane Based Bacterial Cellulose Made of Pineapple Waste Reinforced by Graphite Nanoplatelets

Waste is the main problem for the environment.Handling waste for various useful applications has a benefit for the future.This work has been studied for handling pineapple peel waste to make composite film bacterial cellulose nanocomposite membrane(BCNM)with addition graphite nanoplatelet(GNP).The concentration of GNP in the membrane influence the membrane properties.The bacterial cellulose(BC)pellicle was synthesized by using media from pineapple peel waste extract.BC pellicle is cleaned with water and NaOH solution to be free from impactors.BCNM is synthesized through the mechanical disintegration stage.The results of disintegration using high pressure homogenizer at 150 bar and five cycles.BCNM/GNP is synthesized with varying addition of GNP of 2.5,5.0,10 and 100 wt%of dry bacterial nanocellulose(BNC).The BC and GNP solution were dried in an oven for 14 h at 80℃.BCNM morphology was observed using SEM.GNP is dispersed and distributed in the BC matrix as reinforcement.FTIR analysis shows many peaks of BNC less pronounced with increasing of GNP.The higher concentration of GNP,the rougher of BCNM.The optimum tensile strength of BCNM was achieved after addition GNP of 2.5 wt%.

Immunomolecular response of CD4^(+),CD8^(+),TNF-α and IFN-γ in Myxobolus-infected koi(Cyprinus carpio)treated with probiotics

A poor environment increases fish’s susceptibility to myxosporean infection that can cause the death of larval fish,especially for koi fish(Cyprinus carpio).This study aimed to determine the effect of probiotics,local anti-parasitic drugs(kutuklin),and the chemical compound diflubenzuron treatments on the koi immune response.This study used PCR with specific primer 18S SSU rDNA and DNA sequencing to detect Myxobulus phylogenetic.The treatments were divided into 5 groups:Treatment(A)(healthy koi without treatment),(B)(infected koi without treatment),(C)(infected koi with 0.55 mL/30 L probiotics),(D)(infected koi with 1μL/g of feed kutuklin),and(E)(infected koi with 0.02 mg/5 L dimilin).Myxospore has observed with Scanning Electron Microscopy(SEM)and 4′,6-diamidino-2-phenylindole(DAPI)fluorescence staining.The histological analysis using semi-quantitative scoring methods,and flow cytometry was conducted to analyse the immune response of Cluster of differentiation 4(CD4^(+)),Cluster of differentiation 8(CD8^(+)),Tumor Necrosis Factor-alpha(TNF-α),Interferon gamma(IFN-γ)cells in the gills.Results show that the histological analysis indicated edema,hyperplasia,lamella fusion,congestion,and hypertrophy lesions in infected koi.Treatment with probiotics shows the lowest damage(30.6%).The immune responses of CD4^(+)and CD8^(+)cells to dimilin treatment were 10.54%and 16.86%,respectively.The largest TNF-αand IFN-γresponse were for the kutuklin treatment(29.26%)and probiotics treatment(8.23%).

Thermogravimetric kinetic analysis of Nannochloropsis oculata combustion in air atmosphere

The thermal behavior of Nannochloropsis oculata combustion in air atmosphere were investigated by performing experiments on STA PT1600 Thermal Analyzer at heating rates of 10℃/min, 40℃/min and 70℃/min and range of temperatures from room tempera- ture to 1200℃. The kinetic parameters were evaluated by using Kissinger and Ozawa methods. The result showed that Nannochloropsis oculata combustion occurred in five stages. Started with initial devolatilization, the main thermal decomposition and combustion process, transition stage, the combustion of char and the last stage was the slow burning reaction of residual char. In line with increasing heating rate, the mass loss rate increased as well, but it delayed the thermal decomposition processes toward higher temperatures. The average activation energy at the main thermal decomposition stage and the stage of char combustion were approximately 251 kJ/mol and 178 kJ/mol, respectively.