The chitosan from shell of crabs (Portunus sanginolentus L.) waste was produced from deproteinization, demineralization, depigmentation,and deacetylation steps. This process was obtained 22.66% chitosan which identified by FTIR spectrophotometry and had 65.47% degree ofdeacetylation. This chitosan was used to adsorb methylene blue dye which fit to the Langmuir isotherm with 0.0312 l mg -1 equilibriumconstant of adsorption (K) and 4.20 mg g -1 maximum capacity of adsorption (q m).

This study aimed to determine the formation rate of silver nanoparticles synthesized using leaf extract of Ficus variegata and characterize their physical, chemical, and antibacterial properties against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. For the formation rate determination, an empirical exponential model was proposed and used to fit the absorbance vs. time data (kinetics data). The surface plasmon resonance wavelength was measured using UV-Vis spectroscopy for physical and chemical characterization. The shape and size of the silver nanoparticles were characterized by transmission electron microscopy (TEM), and organic materials on the surface of the particles were identified by characterizing the associated chemical bonding using FTIR spectroscopy. For antibacterial assays, disc diffusion and spectrophotometric methods were used. The formation rates of the silver nanoparticles were 0.036 per hour or 1.0 x 10-5 s-1 (slower rate) and 0.767 per hour or 2.1 x 10-4 s-1 (faster rate). UV-Vis absorption spectrum indicated the surface plasmon resonance peak at 415 nm. Silver nanoparticles formed mainly were spherical, with a mean diameter of 26.5±0.7 nm. The FTIR spectrum indicated the presence of organic materials on the surface of the silver nanoparticles, which indicated the involvement of the extract as a reducing agent in particles formation. Antibacterial assay showed that synthesized silver nanoparticles inhibited the growth of both S. aureus and E. coli. The results from the disc diffusion method imply that the particles inhibited the growth of E. coli more effectively than S. aureus.

Abstract:Background: Chitosan, a hydrophilic biopolymer industrially obtained by N-deacetylation of chitin, which allow for a wide scope of applications and can be applied as an antimicrobial agent.Theaim of this study was to determine theconcentration of chitosan compound in which it can play an active role in inhibiting the growth of bacteria and also absorb the fatty acid /cholesterol in the smoked fish meat. Method: The research method used in this study wastheRandomized Block Design (RBD) factorial. There were two treatments in this study, namely: Treatment A (fish was dipped in a chitosan solution and then smoked), Treatment B (fish was smoked and then dipped in a 1%, 2% and 3% chitosan solution) and one control, in which the fish was smoked without being dipped in chitosan solution and then stored for five days. Results: The results showed that the chitosan concentration (1%, 2%, 3%) significantly affected the growth of bacteria that occurred on day 3 (p = 0,00) and day 5 (p = 0,000), while day 1 did not differ significantly. There was a difference in the levels of fatty acids between the control and A (p = 0,00) and the control with B (p = 0,000), with the best concentration of chitosan was 3%. Conclusion: Fifteen saturated fatty acids and eleven unsaturated fatty acids were found in fish smoked with coconut shells.

Nowadays, the rivers are often used by residents around the river as the final disposal of domestic wastewater that causes the rivers to become polluted. Biodegradation is an alternative to wastewater treatment as an effort to solve water pollution which is often carried out using bacteria that have the potential to decomposers in the biodegradation process, especially indigenous bacteria. This study aims to identify and obtain isolates, combinations, and characteristics of the indigenous bacteria isolate that have the potential as a biodegradation agent for polluted river caused by domestic wastewater in the Way Tomu watershed, Ambon City. In this study, isolates of indigenous bacteria that were isolated and purified were tested for protease and amylase enzyme activity to select isolates to be used in the biodegradation process testing consisting of parameters pH, COD, and TSS as indicators of the biodegradation. Afterward, the isolates that have the best potential as biodegradation agents will be characterized and biochemical tests will be carried out to identify the general characteristics of these isolates. The results showed that the combination of Genus Aeromonas, Bacillus, and Pseudomonas as isolates of indigenous bacteria that has the best potential as an agent for the biodegradation of polluted river caused by domestic wastewater. The benefit of this research is as initial information and consideration for alternative treatment of polluted rivers caused by domestic wastewater using indigenous bacteria isolates as an effort to resolve river pollution, especially the rivers in Ambon City.

Basil and lime leaf extracts have chemical compounds that function to inhibit the growth of Staphylococcus aureus and total bacteria on the palms of the hands. The purpose of this study was to determine the antibacterial activity of basil and lime leaf extracts against Staphylococcus aureus total bacteria on the palms of the hands. This experimental laboratory research used basil and lime leaves which were extracted using the partial maceration method. The formulation of the hand sanitizer spray combination of basil leaf extract with lime leaves is 1:2, 2:1, and 2:2. The formulation was tested for an antibacterial effect on Staphylococcus aureus and total bacteria on the palms. Data analysis used descriptive quantitative. The results showed that the extracts of basil leaves and lime leaves had an antibacterial activity of Staphylococcus aureus and total bacteria. Formulation 2:2 is the best formulation with bactericidal power of formula is 0 CFU/ml and total bacteria with antiseptic power of formula are 7 CFU. The study concluded that basil and lime leaf extracts were effective in killing Staphylococcus aureus and total bacteria on the palms of the hands.