Inisiasi, pertumbuhan, dan perkembangan kalus embriogenik tanaman stevia (Stevia rebaudiana)

The leaves of sweetener plant Stevia rebaudiana contain secondary metabolites of steviol glycosides which are very sweet, with no calorie and zero glycemic index. Propagation of stevia by seeds is ineffective due to its low germination rate and diverse progenies. The tissue culture of stevia can be used to mass propagate rapidly and is commonly conducted by shoot multiplication. Up to now, the technology of somatic embryogenesis (SE) in stevia has not been successful yet. SE is developed to increase the production scale, rejuvenate clonal-propagated plants, and plant genetic transformation. The research objective was to develop protocols for the initiation, proliferation, and development of embryogenic calli of stevia as potential materials for SE. The explants used were young leaves, nodes, and internodes of axenic plantlets of stevia BX clone. The explants were cultured on MS solid media containing different concentrations of auxin and cytokinin for callus initiation. Callus emerged after 2-3 weeks of culture. The calli obtained were proliferated by subculturing several times as material stocks for indirect SE. MS solid media added with 1 µM 3,4-D and 16 mM CaCl2 gave the highest callus multiplication rate (4.7 times in 3 weeks). The selection of embryogenic calli was made continuously to obtain a pure line of embryogenic calli. Three types of calli attained were friable, fast-growing, yellowish calli, shiny nodular calli, and greenish nodular calli. Histological studies revealed that cells of the nodular calli had been differentiated to potentially formed somatic embryos.

Optimization on Na and Ca bentonite activation using response surface method for increasing selectivity of stevioside in stevia extract

The demand for stevia extract consumption as an alternative sweetener that contains stevioside with zero-calorie is increasing. However, dark color and high tannin content from stevia leaf extract causes a disturbing aftertaste and reduces interest in consumption. Therefore, the purification process is a mandatory step to be done. Several studies on purification methods show the best approach by adsorption using bentonite. However, natural bentonite has limited adsorption capacity and low selectivity. An activation with acid and high temperature is expected to increase the adsorption capacity of color and its selectivity on maintaining the stevioside at the extract. This study aimed to obtain the optimum acid concentration and temperature for the activation using the Response Surface Method (RSM) experimental design and its application to the purification of stevia leaf extract. Based on the parameter of methylene blue number, the most optimum concentration of H2SO4 used for activation was 0.17 N for both natural bentonite. The heating temperature was 358°C for Na-bentonite and 481°C for Ca bentonite. The maximum adsorption capacities of activated Na and Ca-bentonite were increased from 15.65 and 38.23 mg g-1 to 197.72 and 169.52 mg g-1, respectively. The best adsorbent used for purification is Ca-activated, which increased extract clarification up to 81.37% at 655 nm and 86.64% at 410 nm compared to natural Ca bentonite. It also reduced tannin up to 97.46% and was more selective to recover 50.64% stevia content in the solution, which was higher than other previously reported studies.

Sintesis gliserol ester berbasis asam oleat sawit dan karakteristik sifat fisika kimia

Peningkatan kapasitas produksi biodiesel menyebabkan meningkatnya produksi gliserol. Salah satu cara alternatif untuk meningkatkan nilai ekonomi gliserol adalah melalui esterifikasi gliserol menjadi surfaktan, yaitu gliserol ester (GE). Penelitian ini bertujuan melakukan sintesis GE berbasis asam oleat sawit dengan waktu reaksi 180 menit menggunakan katalis p-toluenesulfonic acid (PTSA). Suhu sintesis yang digunakan, yaitu:140, 160, 180, dan 240°C. Hasil uji ANOVA dan Duncan (α = 0,05) menunjukkan bahwa suhu sintesis berpengaruh nyata pada rendemen, angka asam, dan viskositas. Proses sintesis GE optimum diperoleh pada suhu sintesis 160°C dengan nilai rendemen GE sebesar 95,66%, pH 7, nilai angka asam 11,28 mg KOH/g sampel, viskositas kinematis 75,76 cst, dan densitas 0,944 g cm-3. Suhu sintesis 160°C, 180°C, dan 240°C menghasilkan rendemen yang tinggi, berkisar 95,66-97,07% dan tidak berbeda nyata antara ketiganya. Analisis menggunakan metode Analytical Hierarchy Process(AHP) juga menghasilkan suhu terbaik untuk sintesis GE adalah 160°C. Produk GE yang terbentuk mengandung gugus ester, asam karboksilat, dan alkohol yang muncul pada 1240,41-1739,62 cm-1.[Kata kunci: biodiesel, esterifikasi, katalis PTSA, surfaktan]

Respons tanaman tebu (Saccharum officinarum L.) terhadap aplikasi konsorsium biostimulan di tiga tipologi lahan

The consortium biostimulant combines several types of biostimulant applied holistically, such as phytohormones to induce physiological processes, humic acid to improve nutrition intake and land fertility, and biofertilizer arbuscular mycorrhizal fungi to improve abiotic stress tolerance. The objectives of this research were to analyze the effect of application consortium biostimulant on the growth and productivity of Bululawang sugarcane variety planted in three land typologies, i.e. irrigated heavy soil with good drainage (BPL), irrigated heavy soil with poor drainage (BPJ), and rainfed light soil with good drainage (RHL). The research was conducted on plant cane (PC) sugarcane areal in Lumajang Regency, East Java, from July 2019 to September 2020. The treatment plot area was 1 ha for each land typologies, and the observation were conducted on 10 m plant row with ten times replications. Each treatment was replicated ten times. The results showed that the application of consortium biostimulant could induce faster growth of sugarcane shoots and better roots at one month after planting (MAP). Stalk height and diameter showed significantly different values between treatment and control at the plant age 6 to 12 MAP. In addition, the sugarcane stalk weight per meter row also increases by 13.72 – 28.57%. The growth performance of sugarcane on a commercial scale increased, also sugarcane productivity increased by 11.08 – 20.36%. The potential sugar yield increased by 15.05% in BPL land typology, 4.9% in BPJ land typology, and 9.7% in RHL land typology. The difference in land typologies affected the effectiveness of the consortium biostimulant application in increasing sugarcane productivity.

Peningkatan kadar capsaicin tanaman Capsicum annuum cv. Lado pada kondisi kekeringan menggunakan kitosan

AbstrakCabai merah (Capsicum annuum) merupakan jenis sayuran yang memiliki nilai ekonomi tinggi. Saat kekeringan, kemampuan bertahan hidup tanaman tersebut sering kali menurun, sehingga diperlukan upaya untuk meningkatkan ketahanannya. Kitosan dikenal sebagai elisitor ketahanan tanaman terhadap infeksi patogen melalui induksi sintesis metabolit sekunder senyawa golongan fenol seperti capsaicin. Penelitian ini bertujuan untuk mengetahui pengaruh aplikasi kitosan 1 mg mL-1 terhadap peningkatan kadar capsaicin dan ekspresi gen PAL1 tanaman cabai merah cv. Lado pada kondisi kekeringan. Serial perlakuan terdiri dari kitosan (Chi), kombinasi kitosan dan kekeringan (Chi-D), kekeringan (D) dan kontrol (C) yang diaplikasikan saat tanaman memasuki fase generatif. Parameter yang diamati meliputi analisis ekspresi gen PAL1, aktivitas enzim PAL dan kadar capsaicin. Hasil penelitian menunjukkan bahwa aplikasi kitosan 1 mg mL-1 saat kekeringan menurunkan level ekspresi gen PAL1 0,61 kali dan aktivitas enzim PAL 0,94 kali dibanding kontrol. Sebaliknya, kadar capsaicin meningkat 2,46 kali dibandingkan kontrol, sehingga aplikasi kitosan 1 mg mL-1 saat kekeringan diduga dapat meningkatkan ketahanan tanaman tersebut terhadap infeksi patogen.

Harnessing molasses as a low-cost carbon source for production of poly-hydroxy butyrate (PHB) using Burkholderia sp. B73 bacteria

Burkholderia sp. has been reported as a poly-hydroxy-butyrate (PHB) producer. PHB is a natural polyester class with a wide range of applications in foods, medicines, and biomedicines. However, the high production cost of PHB may limit its potential. Molasses, a by-product of the sugarcane industry available abundantly, may be used as an alternative carbon source of PHB production. In this research, we aimed to evaluate PHB production by Burkholderia sp. B73 in fermentation media using molasses as an alternative carbon source. Small-scale experiments were performed in Erlenmeyer flasks on a shaker at 150 rpm and 30 °C to evaluate the best initial C/N ratio for biomass accumulation and PHB production. A set of parameters including bacterial growth, dry cell weight, yield, and FTIR spectrum of PHB were observed. The results showed that molasses could be used to grow Burkholderia sp. B73 and the highest PHB production was obtained when a 20:1 C/N ratio of molasses was applied in the fermentation medium. In addition, when the initial pH was adjusted to 7.0, the highest PHB yield was also produced. More importantly, the use of molasses as a carbon source improved the PHB yield by nearly 2-fold compared with our previous report using a synthetic Ramsay’s minimal medium. In conclusion, the experiment results showed that molasses could be used as a low-cost carbon source for PHB production by Burkholderia sp. B73 bacteria.

The effect of inoculum and glucose addition on polyhydroxyalkanoate production by Brevibacterium sp. B45

Petroleum-based plastics are the major cause of environmental pollution because the plastics need years to be degraded. The difficulties in handling waste of petroleum-based plastic have motivated researchers to produce environmentally friendly plastic materials that are biologically degradable; one of them is polyhydroxyalkanoate (PHA). Polyhydroxyalkanoate is natural biodegradable biopolymers produced by bacteria as an intracellular carbon and energy storage. This polymer is an alternative source of plastics with similar physical properties to petroleum-based plastic.It can be easily biodegraded aerobically and anaerobically. This study examined the potential of one superior isolate as PHA producers, i.e.,Brevibacterium sp. B45. Brevibacterium sp. B45 was cultivated in Ramsay’s minimal medium with inoculum concentrations were 1, 2, and 3% (v/v)and glucose concentrations were 1, 3, and 5% (w/v). The cultivation of Brevibacterium sp. B45 was carried out in a 500 mL Erlenmeyer flask on a shaker incubator with 150 rpm and 30 oC for 72 hours. PHA recovery was carried out by chloroform extraction and characterized by scanning electron microscopy (SEM), Fourier transformed infrared (FTIR), and differential scanning calorimetric (DSC) methods. The highest yield of dried biomass (2.92%) was obtained using 3% inoculum and 3% glucose. The melting temperature (Tm), enthalpy (ΔHf), and crystallinity (Xc) of the PHA product were 172.1 °C, 61.04 J g-1, and 41.08%, respectively. Data of SEM show that a porous surface characterized morphological of purified PHA grains. The functional units of purified PHA grains were C=O, CH3, C-O, C-O-C, C-C, C-H, and -OH. The purified PHA grains show a similar spectrum to the standard Poly-3-hydroxybutyrate (PHB). Therefore, it could be assumed that PHA produced by Brevibacterium sp. B45 was most likely PHB.

The role of calcium in drought stress response induced through antioxidant activity in oil palm (Elaeis guineensis Jacq.) seedlings

Oil palm productivity in Indonesia faces challenges related to drought that occur during the dry season. Calcium is an element that plays a role in determining the response of plant resistance to drought through biochemical activity. This study aims to determine the contribution of calcium in biochemical mechanisms involving various antioxidants. The treatment was arranged in factorial of 3 x 4 in a split-plot design. The first factor was calcium dosage, which consisted of 0 g (control/without calcium), 0.04 g, 0.08 g, and 0.12 g of calcium per plant. The second factor was the intensity of drought stress, referred as the Fraction of Transpirable Soil Water (FTSW) at 1 (control/field capacity), 0.35 (moderate drought), and 0.15 (severe drought) with a week duration of intensity. Calcium was applied in a ring placement on four-month-old seedlings planted in 40 x 40 cm polybags with alfisol soil planting medium and given drought treatment two months later for three weeks. The results showed that calcium could induce plant response to drought through the increase in superoxide dismutase (SOD) activity, the decrease in hydrogen peroxide (H₂O₂) concentration, and the decrease in malondialdehyde (MDA) concentration. The study concluded that calcium is an essential element used to reduce the effects of drought on oil palm seedlings through the change of biochemical activities regulated by enzymatic antioxidants.

Genetic relationships in Saccharum complex germplasm collections based on morphological and molecular markers

and is a cross-pollinator, so information about the genetic relationship between the accessions in germplasm collections is very important for selecting the prospective parent in crossbreeding. This research aims to determine the phylogenetic relationship of 24 Saccharum complex accessions and to verify the grouping of accessions using 37 morphological and three microsatellite molecular markers. Interpretation of morphological and molecular data was obtained from the analysis using the NTYSYpc-2.02i program. The results show that within the 24 accessions analyzed using morphological markers, some accessions did not cluster as the classification at the conservation time. This difference is due to the morphological markers, descriptions of characters that do not appear are considered as the same variables though in different morphological characters, so this increases the value of genetic similarity among accessions analyzed. In contrast, the grouping of molecular markers shows that each accession was grouped according to the classification at the conservation time. These accessions had a low genetic similarity of 0.20 with a broad genetic distance of 0.80. This broad genetic distance indicates that the twenty-four accessions have a distant genetic relationship with one another, so that the genetic diversity of these accessions is relatively high. The high genetic diversity in germplasm collections improves its potential as a crossing parent to obtain a high heterosis effect.

Fulvic acid – a small but powerful natural substance

Humic substances are defined as the result of the decomposition of any organic matter, and they consist mainly of humin, humic, and fulvic acids. Compared to humin, humic acids and fulvic acid (FA) are the most explored compounds. However, FAs are less studied than humic acids because of the usually small residual quantities. Considering that its potential for bioactivity is stronger than that of humic acids, the current review was performed to evaluate the effectiveness of FA application for crops and soils and its potential as an immuno-modulator for humans. The wide application of FA is challenged by two main factors affecting the quality and the effectiveness, i.e., the type of raw material and extraction method. Lignite, low-energy coal, is the most common material for FA production besides bog, peat, and compost. Fulvic acid extraction is done through several methods, i.e., hydrogen peroxide (H2O2), alkaline (NaOH/KOH), and/or water. The latest modified method shows that the combination of H2O2 with microwave power can recover a considerable amount of FA. However, it is still difficult to apply this method for industrial scale. Due to highly specified characteristics, FA showed a great potential to improve crop performances and soil health, making it strategic for supporting sustainable agriculture in the future through biotic and abiotic stress alleviations and sustainable yield achievement, including various plantation crops and biotechnological approach. For medicinal purposes, some studies have shown highly promising results, especially as an immuno-modulator and in combating neurodegenerative disorders as well as for cancer therapy and health food fortification, which might be in line with the new paradigm so-called One Health approach. The future market of FA is also estimated to grow in a very attractive economic value. However, as data are still limited, the wide range of potential use should encourage concerted and wide research and product development efforts to achieve sustainable agriculture and human health.