• Microbiology and Biotechnology Letters
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• v.12 no.4
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• pp.261-264
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• 1984

The optimal condition of the ethanol fermentation from raw cassava starch by simultaneous saccharification - fermentation (SSF) was studied using glucoamylase from Aspergillus sp. and a yeast strain. The rate and yield of ethanol production were optimum at pH 3.6 with shaking. The fine milling treatment was effective for both saccharification and SSF of raw cassava starch. The presaccharification at 6$0^{\circ}C$ for 1 hr before SSF increased the rate and yield of ethanol production, as well. To increase the ethanol concentration after fermentation the substrate concentration could be increased up to 2195 without the problem of viscosity. The use of high concentration ethanol tolerant yeast strains and high substrate concentration produced ethanol higher than 10%(W/V) after fermentation for 5 days.

• Microbiology and Biotechnology Letters
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• v.15 no.2
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• pp.75-79
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• 1987

The conventional alcohol fermentation method requires a large amount of energy for cooking the starchy raw materials prior to saccharification. The aim of this study was to compare the possibility of large scale alcohol fermentation from cassava slices were compared in low and high temperature cooking systems. The same amount of saccharifying and liquefying enzymes were used for cooking at low and high temperature. At low temperature cooking, conversion of glucose consumed in fermented mash to alcohol was 0.468g alcohol per g glucose of which was higher yield than that obtained at high temperature.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.75-81
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• 2007

The object of this study was to determine the influence of supplementation of concentrate containing high levels of cassava chip on rumen ecology, microbial protein and digestibility of nutrients. Four, rumen fistulated crossbred beef steers with initial body weight of 400${\pm}$10 kg were randomly assigned according to a 4${\times}$4 Latin square design. The dietary treatments were concentrate cassava chip based offering at 0, 1, 2 and 3% BW with urea-treated rice straw fed ad libitum. It was found that ruminal pH was significantly decreased with increase of concentrate. Volatile fatty acids (VFA) concentration in the rumen was significantly different among treatments. In addition, a molar proportion of propionate was higher in supplemented groups at 2 and 3% BW (p<0.05), leading to significantly decreased acetate:propionate ratio. Furthermore, microbial N supply was significantly improved and was highest at 2% BW supplementation. The efficiency of rumen microbial-N synthesis based on organic matter (OM) truly digested in the rumen was highest in level of concentrate supplementation at 2% BW (80% of cassava chip in diets). Moreover, bacterial populations such as amylolytic bacteria was linearly increased, while cellulolytic bacteria was linearly decreased (p<0.01) when cattle received concentrate supplementation in all levels. The total protozoal counts were significantly increased, while fungal zoospores were dramatically decreased in cattle receiving increased levels of concentrate. In conclusion, cassava chip can be use as energy source at 80% in concentrate and supplementation of concentrate at 2% BW with urea-treated rice straw as roughage could improve rumen fermentation efficiency in beef cattle.

• Environmental Engineering Research
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• v.21 no.2
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• pp.152-163
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• 2016

Present study investigates the potential of cassava peel and rubber tree bark for the removal of Cr (VI) from aqueous solution. Removal efficiency of more than 99% was obtained during the kinetic adsorption experiments with dosage of 3.5 g/L for cassava peel and 8 g/L for rubber tree bark. By comparing popular isotherm models and kinetic models for evaluating the kinetics of mass transfer, it was observed that Redlich-Peterson model and Langmuir model fitted well ($R^2$ > 0.99) resulting in maximum adsorption capacity as 79.37 mg/g and 43.86 mg/g for cassava peel and rubber tree bark respectively. Validation of pseudo-second order model and Elovich model indicated the possibility of chemisorption being the rate limiting step. The multi-linearity in the diffusion model was further addressed using multi-sites models (two-site series interface (TSSI) and two-site parallel interface (TSPI) models). Considering the influence of interface properties on the kinetic nature of sorption, TSSI model resulted in low mass transfer rate (5% for cassava peel and 10% for rubber tree bark) compared to TSPI model. The study highlights the employability of two-site sorption model for simultaneous representation of different stages of kinetic sorption for finding the rate-limiting process, compared to the separate equilibrium and kinetic modeling attempts.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.16-16
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• 2019

The Cassava (Manihot esculenta Crantz) is a perennial woody shrub cultivated mainly in the tropics for its starchy tuberous roots. It belongs to the family Euphorbiaceae which also includes rubber (Hevea brasiliensis) and castor bean (Ricinus communis). Among tropical crops, rice, sugarcane, maize and cassava are the most important sources of calories for human consumption. Problems in the propagation of cassava are virus diseases and low rates of seed germination. Thus, a study was undertaken to develop an efficient in vitro mass propagation protocol of Manihot esculenta Crantz. Young and actively growing stem segments were excised from adult plants of cassava. Samples were cut into a 3~4 cm nodal segments with single node after sterilization, and cultivated in the different medium supplemented with various plant growth regulators for 4 weeks. For shoot multiplication, single-node stem segments, approximately 1 cm in length, were taken from in vitro derived shoots and subcultured. After 4~6 weeks, the shoot generation rate was 55.6%, the shoot number and its length were 1.0/explant and 2.3 cm in the most favorable medium composition. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

• Journal of Plant Biotechnology
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• v.50
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• pp.11-18
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• 2023

Manihot esculenta Crantz, commonly known as cassava, is a staple aliment that is a significant source of revenue for farmers. The embryogenic callus is crucial in the genetic engineering of various crop species, including cassava. Four cultivar cassava landraces from East Java were assessed for their ability to produce friable embryogenic callus (FEC) for protoplast isolation. In this study, four cassava cultivars; (Kaspro, Kuning, Gajah, and Gendruwo); were used to obtain FEC, which involved the culture of immature leaf lobes (ILLs) and apical buds (ABs) media containing MS supplemented with 33 μM picloram and 2 μM of CuSO₄ (M1) or MS supplemented with 50 μM 2,4-D and 2 μM CuSO₄ (M2). The highest FEC induction efficiency ranged from 72% to 57%, and the highest FEC number ranged from 4.7 to 3.7 with AB explants in media containing MS + 33 μM pilocram and 2 μM CuSO₄ (M1). On the other hand, the efficiency of somatic embryogenesis induction ranged from 67% to 53%, and the number ranged from 4.4 to 3.4. The efficiencies of FEC induction ranged from 48% to 42%, and the number ranged from 3.1 to 2.6 with AB explants in media containing MS + 50 μM 2,4-D and 2 μM CuSO₄ (M2); the efficiency of FEC induction ranged from 56% to 50%, and the value ranged from 3.6 to 2.4 with ILL explants. The FEC induction of the Gendruwo cultivar, which was examined using AB and ILL explants, demonstrated the lowest efficiency. Nevertheless, all four cultivars showed the ability to generate FEC, even though their effectiveness differed depending on the explant genotype and the applied media.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.478-482
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• 2000

Whole cassava (Manihot esculenta, Crantz) crop was harvested about 10-15 cm above ground at 3 months after planting and sun dried for 1-3 days or until the leaves were crispy-dried and the branches and stems were mostly wilted to produce cassava hay. Cassava hay (CH) contained 86.3% DM, 8.9% ash, 23.6% CP, 44.3% NDF, 30.0% ADF, 5.8% ADL, 0.257% condensed tannin and 0.35 mg % HCN, respectively. In addition, CH contained relatively higher amino acid than alfalfa hay especially methionine, isoleucine, leucine and lysine. Ruminal fermentation of CH resulted in high concentrations of $C_2$, $C_3$, and $C_4$ at 72, 17 and 7 mol/100 mole, respectively. A feeding trial was conducted to study on effect of feeding of cassava hay in late lactating dairy cows fed on urea-treated rice straw during the dry season on their intake, ruminal pH, $NH_3$-N, milk yield and compositions. Thirty, Holstein-Friesian crossbred cows in their first lactation were randomly assigned in a randomized complete block design to receive five different dietary treatments: T1=supplementation of concentrate to milk yield at 1:2, T2=supplementation of concentrate to milk yield at 1:2+0.56 kg DM, T3=supplementation of concentrate to milk yield at 1:3+1.3 kg DM CH, T4=supplementation of concentrate to milk yield at 1:4+1.70 kg DM CH, T5=CH fed on ad libitum+small concentrate supplement. All cows received urea-treated rice straw as a roughage source throughout a 80 d feeding trial. The experiment revealed that cassava hay contained high level of protein and minimal level of tannin at 3 months of harvest. Tannin intake ranged from 1.44 to 13.36 g/hd/d and did not affect on urea-treated rice straw intake. Milk yield across treatments were similar (5.4-6.3 kg/hd/d) (p>0.05) but 3.5% FCM was highest in cows received CH at 1.70 kg/hd/d. Feeding of cassava hay resulted in increasing milk fat (4.0 to 4.6%) (p<0.05) and milk protein (3.8 to 5.3%) (p<0.05). Moreover, the use of CH could reduce concentrate supplementation to milk yield from 1:2 to 1:4, respectively, thus resulted in more milk income return.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.24-24
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• 2021

The Cassava (Manihot esculenta Crantz) is one of the major food crops in the tropical or subtropical regions. Recently, clean planting materials of improved cassava cultivars are in high demand. Problems in the propagation of cassava are virus vulnerable and low rates of seed germination. Thus, the study was undertaken to develop an efficient in vitro mass propagation protocol of Manihot esculenta Crantz. So we tried to optimize protocols for mass production from axillary buds of Cassava. Young and actively growing stem segments were excised from adult plants of cassava. Samples were cut into a 3~4 cm nodal segments with axillary buds, and cultivated in the different medium supplemented with various plant growth regulators for 4 weeks. For shoot multiplication, axillary buds approximately 1 cm in length were taken from in vitro derived shoots and subcultured. After 4~6 weeks, the shoot generation rate showed 55.6%. The shoot number and its length was 1.0/explant and 2.3 cm in the most favorable medium composition. The auxin β-indolebutyric acid(IBA) 0~2.0 mg/L was proved to be effective on root development. Plantlets with fibrous roots easily generated tuberous roots in vitro. The tuberous roots were induced only when both kinetin and IBA were used in combination. after 8 weeks, the root generation rate showed 100%. The root number and its length was 17.2/explant and 2.2 cm in the most promising medium composition. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.301-308
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• 2005

This study was carried out to investigate the effect of stem-cutting (SC) length and portion on the major agronomic characters related with dry matter production and accumulation, and to examine their relation­ships in cassava. When cassava was planted with longer SCs or with older portion SCs, major canopy or source characters like leaf number and leaf area index developed excessively, while tuber yields could be reduced due to the decrease of root/shoot ratio, relative growth rate, root dry weight, and harvest index, particularly in the bitter varieties (high cyanide-level varieties). It was considered that the sweet varieties (low cyanide-level varieties) be early­bulked with higher tuber yield when they are planted with the 25-30 cm long SCs or with the SCs from young type to semi-mature portions of mother stems, while the bitter varieties with the 15-20 cm long SCs or with the SCs from semi-mature to hardwood portions of mother stems, respectively. However, a significant interaction between length and portion of SC was not observed in all agronomic characters.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.45-54
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• 2005

This study was carried out to investigate the patterns of dry matter (DM) production and accumulation, and to screen the relationships between related major growth characters and DM accumulation in four cassava varieties in Bogor $(6^{\circ}19'-6^{\circ}47'S,\;106^{\circ}21'-107^{\circ}13'E)$, West Java, Indonesia. Gading and Adiral developed an enough source and canopy in short at the early growth phase and then translocated assimilates to storage roots with a higher partitioning rate, even these varieties were considered as early-bulking varieties, which have superior source and sink potentials in increasing yield and DM of tubers. The root/shoot ratio (R/SR), total dry weight (TDW), leaf area duration, leaf area index (LAI), and number of tubers showed higher positive correlations with the dry weight of roots (DWR), and the direct effects of TDW, R/SR, and LAI on the DWR were higher. These characters were considered to be useful target characters to screen cassava varieties with high yield potential and high DM in aspect of tuber production.