One of the potential sources for bioenergy and biochemical products is Haematococcus pluvialis. However, these microalgae are vulnerable to chytrid infection when the cells are transitioning from the green flagellates’ stage to the resting stage. As a result, the productivity of their biomass is low. The objective of this research was to evaluate the effects of hydrogen peroxide as the fungicide, including those which were combined with fluazinam, on the growth of H. pluvialis. The variables used in this research were the dose of H2O2, the combination with fluazinam, and the frequency of H2O2 treatment. The initial cell number of H. pluvialis was 5 × 104 cells/mL culture medium. The 5 different treatments were done, i.e., (1) 0.028 mL H2O2/L liquid culture dosed every day; (2) 0.028 mL H2O2/L liquid culture dosed every day for only 3 days and then every two days combined with single dose 0.5 ppm of fluazinam on the first day; (3) same as (2) but without combination with fluazinam; (4) 0.035 mL H2O2/L liquid culture dosed every day for 3 days then every two days combined with single dose 0.5 ppm of fluazinam on the first day; (5) same as (4) but without combination with fluazinam. As a comparison, there was also a culture without any treatment as a control. The culture which was treated with hydrogen peroxide 0.028 mL H2O2/L liquid culture dosed every day for only 3 days and then every two days at the 7th day showed the highest cell number (45 × 104 cells mL−1 ∼ 9 fold from the initial cell number), even compared to the culture without any treatment. In conclusion, the treatment with hydrogen peroxide is effective against chytrid infection. The combination with fluazinam does not affect more to the effectiveness of H2O2 as a fungicide. It looks that by adding fluazinam, the H. pluvial growth is depressed.

The extraction of Canna edulis Ker. starch from its rhizome was performed using 2 different types of press (hydraulic press and screw press) and with the addition of Na-metabisulphite and NaOH (in the range of concentration 100 -5000 ppm each). The optimum condition for this process was determined by Central Composite Design of experiment and the statistical calculation was solved by Design-Expert 7.0.0. The targets of the observed responses were high starch yield, low ash, low fiber, and high carbohydrate content. The results showed that the starch yield and the reduction of fiber were only influenced by the physical treatment whereas ash content in the product was influenced by both the NaOH concentration and physical treatment. The carbohydrate content in the extraction product was affected by NaOH, by the interaction between the concentrations of NaOH and Na 2 S 2 O 5 and also by the physical treatment. The hydraulic press gives much better responses compared to the screw press. But in the selected range of additives concentrations, the screw press gives a higher starch yield (30% -52%).

ABSTRAKMunculnya makanan cepat saji dan polusi udara mendatangkan kerusakan tubuh akibat radikal bebas. Untuk melawan radikal bebas, antioksidan menjadi semakin populer di berbagai kalangan dan salah satunya astaxanthin. Haematococcus pluvialis merupakan sumber astaxanthin alami tertinggi. Tujuan penelitian ini untuk mempelajari pertumbuhan H. Pluvialis. Sebagai variabel dalam penelitian ini adalah (1) konsentrasi inoculum awal yang berbeda (yaitu 10%-v/v dan 20%-v/v) terhadap kepadatan dan jumlah sel; (2) penambahan garam NaCl dan induksi cahaya terhadap rasio karotenoid dan klorofil. Mikroalga H. pluvialis secara fotoautotrof selama sembilan hari. Karotenogenesis diinduksi oleh penambahan NaCl 0,8%-b/v, diikuti oleh induksi di bawah intensitas cahaya tinggi. Kadar klorofil dan total karotenoid dianalisis dengan menggunakan spektrofotometer. Hasil penelitian menunjukkan bahwa pertumbuhan H. pluvialis lebih baik dikulturkan dengan konsentrasi inokulum 10% dan diperoleh jumlah 70 x 105 sel/mL. Penambahan garam NaCl 0,8%-b/v disertai induksi intensitas cahaya tinggi dapat meningkatkan rasio kadar karotenoid terhadap klorofil sebesar 28,9%.Kata kunci:,Haematococcus pluvialis, induksi cahaya, karotenoid, klorofil, mikroalga.ABSTRACTFast food and air pollution lead to the production of free radicals in our body. To fight those, it is needed anti-oxidant. That is the reason why antioxidant become a popular supplement for many people and one of them is astaxanthin. Haematococcus pluvialis is the highest source of natural astaxanthin. The goal of this study is to observe the cell growth of H. pluvialis. The variables used in this research are (1) a different initial inoculum concentrations (i.e. 10%-v/v and 20%-v/v) to the density and number of cells; (2) the addition of salt NaCl and light induction to the ratio of carotenoids to chlorophyll. Microalgae H. pluvialis was cultured in batch mode and photoautotrophic cultivation for nine days. The carotenogenesis was induced by addition of NaCl 0.8%-b/v, followed by induction under high-light intensity. Chlorophyll levels and total carotenoids were analyzed using a spectrophotometer. It was observed that growth of H. pluvialis was preferable cultured with 10% inoculum concentration and obtained 70 x 105 cells/mL. The addition of NaCl 0.8%-b/v salt followed by high light intensity induction could increase the ratio of carotenoids to chlorophyll levels by 28.9%.Keywords: carotenoid, chlorophyll, Haematococcus pluvialis, light induction, microalgae.

Tomato is a fruit that does not last long (perishable), so it is necessary to find another alternative to increase its economic value. One of those alternatives that can be done is by making a fermented product called nata de tomato. Nata de tomato contains microbial cellulose which is formed by the bacteria Acetobacter xylinum. This microbial cellulose has some advantages over the typical cellulose found in common plants. Thus, it potentially could be further developed in the papermaking. This research was conducted to study the effects of combining microbial cellulose pulp from nata de tomato with tomato powder on paper quality, such as water content, grammage and water absorbency. In this research, the tomato filtrate was used as a growth medium for Acetobacter xylinum to produce nata de tomato. Then, nata de tomato was shredded into pulp, while its waste was dried into tomato powder and used as additional material for the pulp. This research was designed using a single factor experiment with variation in the addition of tomato powder by 0, 1, 3 and 5 % (w/w). The effects of this variation observed using variance analysis and significant test using the LSD (Least Significant Difference) method.

The technology development in many industries nowadays, such as electronic industry produces heavy metal wastes which may pollute our environment. The use of adsorbent as a heavy metal removal from soil and water is one of the efficient process which can be considered to be used. In addition the release of the adsorbate becomes an important way as well because usually those heavy metals still have a high value. The objective of this research is to develop adsorbent based on cassava starch. So, the release process will become easier and will not produce another waste. The adsorbent was produced through the grafting of acrylic acid onto cassava starch by using Fenton initiator. To construct a stable 3-D network, the crosslinker (CL) N,N'-methylenebisacrylamide was added. The variable observed were the amount of CL added (0.5%; 1.5%; 2.5% and 3.5%) and the treatment of generating more pores on starch copolymer. The treatments on starch copolymer observed were single freezing, second freezing, and citric acid modification and carbonization methods. Analysis performed on the adsorbent was % add-on, water absorption and metal adsorption (especially Cu 2+ ion) capacity. The result showed that the used of 2.5% CL produced the highest add-on (47.66 %), the highest water absorption capacity and the highest metal adsorption capacity (0.29g Cu 2+ /g adsorbent) The citric acid modification also produced the highest pores on the adsorbent.