• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1127-1136
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• 2013

Four rumen-fistulated crossbred beef cattle (Brahman native) were randomly assigned according to a $4{\times}4$ Latin square design experiment to be fed plant herb supplements in their concentrate mixture. The treatments were: without herb supplementation (Control), lemongrass meal supplementation at 100 g/d (L), lemongrass meal supplementation at 100 g/d plus peppermint powder at 10 g/d (LP), and lemongrass meal supplementation at 100 g/d plus peppermint powder at 10 g/d with garlic powder 40 g/d (LPG), respectively. Based on the present study, the DMI and apparent digestibility of DM, OM, aNDF and ADF were not affected by dietary herb supplementation while CP digestibility tended to be decreased by herb supplement. Moreover, $NH_3$-N and BUN were decreased in all herb supplemented treatments and there was a tendency to an increase in ruminal pH in all herb supplemented groups. While there was no change in TVFA and C4 among lemongrass treatments, C2 was decreased in all herb supplemented treatments while C3 was increased. Methane production by calculation was the lowest in the LP and LPG groups. Population sizes of bacteria and protozoa were decreased in all herb supplemented groups, but not fungal zoospores. In all supplemented groups, total viable and proteolytic bacteria were decreased, while amylolytic and cellulolytic bacteria were similar. More importantly, in all herb supplemented groups, there were higher N balances, while there was no difference among treatments on purine derivative (PD) excretion or microbial N. Based on the results above, it could be concluded that there was no negative effect on ruminal fermentation characteristics and nutrient utilization by plant herb supplement, but protozoal population and $CH_4$ production were reduced. Thus, lemongrass alone or in combination with peppermint and garlic powder could be used as feed additives to improve rumen fermentation efficiency.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.11
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• pp.1583-1591
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• 2013

The objective of this study was to investigate microbial population in the rumen of dairy steers as influenced by supplementing with dietary condensed tannins and saponins and different roughage to concentrate ratios. Four, rumen fistulated dairy steers (Bos indicus) were used in a $2{\times}2$ factorial arrangement in a $4{\times}4$ Latin square design. The main factors were two roughage to concentrate ratios (R:C, 60:40 and 40:60) and two supplementations of rain tree pod meal (RPM) (0 and 60 g/kg of total DM intake). Chopped 30 g/kg urea treated rice straw was used as a roughage source. All animals received feed according to respective R:C ratios at 25 g/kg body weight. The RPM contained crude tannins and saponins at 84 and 143 g/kg of DM, respectively. It was found that ruminal pH decreased while ruminal temperature increased by a higher concentrate ratio (R:C 40:60) (p<0.05). In contrast, total bacterial, Ruminococus albus and viable proteolytic bacteria were not affected by dietary supplementation. Numbers of fungi, cellulolytic bacteria, Fibrobactor succinogenes and Ruminococus flavefaciens were higher while amylolytic bacteria was lower when steers were fed at 400 g/kg of concentrate. The population of Fibrobactor succinogenes, was found to be higher with RPM supplementation. In addition, the use of real-time PCR technique indicated that the population of protozoa and methanogens were decreased (p<0.05) with supplementation of RPM and with an increasing concentrate ratio. Supplementation of RPM and feeding different concentrate ratios resulted in changing the rumen microbes especially, when the animals were fed at 600 g/kg of concentrate and supplemented with RPM which significantly reduced the protozoa and methanogens population.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.181-186
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• 2017

Objective: Leucaena leucocephala (Leucaena) is a perennial tropical legume that can be directly grazed or harvested and offered to ruminants as hay, silage, or fresh. However, Leucaena contain phenolic compounds, which are considered anti-nutritional factors as these may reduce intake, digestibility and thus animal performance. Therefore, the objective of this experiment was to determine effects of Leucaena silage (LS) feeding levels on rumen microbial populations, N-balance and microbial protein synthesis in dairy steers. Methods: Four, rumen fistulated dairy steers with initial weight of $167{\pm}12kg$ were randomly assigned to receive dietary treatments according to a $4{\times}4$ Latin square design. Treatments were as followings: T1 = untreated rice straw (RS; Control), T2 = 70% RS+30% LS, T3 = 40% RS+60% LS, and T4 = 100% LS. Dairy steers were fed rice straw and LS ad libitum and supplemented with concentrate at 0.2% of body weight/d. Results: Results revealed that the rumen microbial population, especially cellulolytic, proteolytic bacteria and fungal zoospores were enhanced in steers that received 60% of LS (p<0.05), whereas the amylolytic bacteria population was not affected by treatments (p>0.05). Protozoal population was linearly decreased with increasing level of LS (p<0.05). Moreover, N-balance and microbial protein synthesis were enhanced by LS feeding (p<0.05) and were the highest in 60% LS group. Conclusion: Based on this study, it could be concluded that replacement of RS with 60% LS significantly improved microbial population and microbial protein synthesis in diary steers.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.2
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• pp.171-180
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• 2017

Objective: This study investigated the association of enzyme-producing microbes and their enzymes with starch and hemicellulose degradation during fermentation of total mixed ration (TMR) silage. Methods: The TMRs were prepared with soybean curd residue, alfalfa hay (ATMR) or Leymus chinensis hay (LTMR), corn meal, soybean meal, vitamin-mineral supplements, and salt at a ratio of 25:40:30:4:0.5:0.5 on a dry matter basis. Laboratory-scale bag silos were randomly opened after 1, 3, 7, 14, 28, and 56 days of ensiling and subjected to analyses of fermentation quality, carbohydrates loss, microbial amylase and hemicellulase activities, succession of dominant amylolytic or hemicellulolytic microbes, and their microbial and enzymatic properties. Results: Both ATMR and LTMR silages were well preserved, with low pH and high lactic acid concentrations. In addition to the substantial loss of water soluble carbohydrates, loss of starch and hemicellulose was also observed in both TMR silages with prolonged ensiling. The microbial amylase activity remained detectable throughout the ensiling in both TMR silages, whereas the microbial hemicellulase activity progressively decreased until it was inactive at day 14 post-ensiling in both TMR silages. During the early stage of fermentation, the main amylase-producing microbes were Bacillus amyloliquefaciens (B. amyloliquefaciens), B. cereus, B. licheniformis, and B. subtilis in ATMR silage and B. flexus, B. licheniformis, and Paenibacillus xylanexedens (P. xylanexedens) in LTMR silage, whereas Enterococcus faecium was closely associated with starch hydrolysis at the later stage of fermentation in both TMR silages. B. amyloliquefaciens, B. licheniformis, and B. subtilis and B. licheniformis, B. pumilus, and P. xylanexedens were the main source of microbial hemicellulase during the early stage of fermentation in ATMR and LTMR silages, respectively. Conclusion: The microbial amylase contributes to starch hydrolysis during the ensiling process in both TMR silages, whereas the microbial hemicellulase participates in the hemicellulose degradation only at the early stage of ensiling.

• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.51-55
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• 1983

It was investigated under several cultural conditions to produce biomass directly from starch by an strictly aerobic and amylolytic yeast, Sporobolomyces holsaticus FRI Y-5. Its optimal temperature and initial pH of medium for growth were $23^{\circ}C$ and 6.9, respectively. Activation energy, Ea, for growth was calculated to be 17.33 Kcal/mole from the Arrhenius relationship. When each of 13 nitrogen sources was added to the basal medium, $(NH_2)_2CO$ had the best effect, on which concentration of cell after 3 day incubation was 10.6 g/l and cell yield was 0.451. The yeast growth was affected by $MgSO_4,\;K_2SO_4\;and\;ZnSO_4$ as a mineral source and was best on the medium containing all of them. The addition of yeast extract (5g/l) could enhance the production of biomass and cell yield to 77% and 32%, respectively.

• Korean Journal of Microbiology
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• v.27 no.3
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• pp.216-220
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• 1989

As the bsic study about protoplast fusion of amylolytic fungus Aspergillus oryze and nonamyloytic sugar fermenter, Saccaromyces cerevsisae, the intraspecific protoplast fusion of A. oryzae was carried out and the properties of the obtained fusants were investigated. For protoplast fomation from mycellia of auxotrophs, Novozyme 234 as lytic enzyme was the most effective and optimal pH was determined to be pH 5.5-6.0. When the two types of protoplasts were treated with a fusogen including 30% PEG4000, they fused effectively and most of fusants were heterokaryons. Protoplasts aggregated with 30% PEG4000 after fusion treatment were observed by the microscope. Protoplast regeneration frequency was 1.46 to 13.8% and complementation frequency of fusion was 0.12 to 0.16. Fusant strains had a 1.5-fold DNA content compared to that of parent strain. And amylase activity was intermediate between those of parent strains.

• Applied Biological Chemistry
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• v.24 no.4
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• pp.245-251
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• 1981

A study was conducted on the conversion of starch in sweet potatoes to sugar by the amylolytic enzymes during baking. Sugars were extracted with ethanol from the raw and baked sweet potatoes at the temperature of $55{\sim}57$, $70{\sim}75$, and $90{\sim}95^{\circ}C$. The individual sugars in the extracts was identified by thin-layer chromatography- and the individual sugar content was determined by high -performance liquid chromatographic analysis. Sugars identified from the raw and baked sweet potatoes at the temperature of $55{\sim}57^{\circ}C$ are glucose, fructose, and sucrose. Sucrose, maltose, glucose, and fructose were identified is the baked sweet potatoes at tile temperature of $70{\sim}75$ and $90{\sim}95^{\circ}C$. There was no significant increase in glucose, fructose and sucrose content during baking. Maltose was formed only above the gelatinization temperature.

• Korean journal of food and cookery science
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• v.27 no.2
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• pp.19-29
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• 2011

Sweet potato powders made from eight Korean varieties, including purple-fleshed, orange-fleshed, and commercial dry type sweet potatoes, were investigated for physicochemical and pasting properties to develop processed food. Crude protein and lipid contents of Shinjami and Borami were higher than those of other varieties. The lightness value of raw sweet potato flesh was the highest value in Shinchunmi, and the lowest in Shinjami. Using the color difference (${\Delta}E$), color similarities compared to the white plate occurred in the following order; purple-fleshed > orange-fleshed > commercial dry type sweet potatoes. Total and damaged starch contents were significantly different (p<0.05). Total starch content of sweet potatoes was higher in commercial dry sweet potatoes (61.89-70.46%), particularly Shinchunmi (70.46%) but lower in orange-fleshed sweet potato (48.87 and 49.53%, respectively). Water binding capacity of Yeonwhangmi, swelling power and solubility of Shinyulmi were the highest values (174.70, 25.54 and 87.49%, respectively) among them (p<0.05). But oil absorptions of Shinyulmi and Shinchunmi showed lower values (97.08 and 97.54%, respectively). All sweet potato powders had an A type x-ray diffraction pattern. The initial pasting temperatures of sweet potato powders ranged from 69.50 to $75.95^{\circ}C$ and the amylolytic enzyme in sweet potato powder lowered pasting viscosity.

• Korean Journal of Food Science and Technology
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• v.23 no.6
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• pp.739-744
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• 1991

A palatable paste-type lactic fermented rice (LFR) was prepared by lactic acid fermentation after liquefaction and saccharification of cooked rice. A mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus (1 : 1) produced the LFR of the best quality. A great improvement in quality of the LFR was achieved by 0.02% each ${\alpha}-amylase$ and glucoamylase treatment during the fermentation (simultaneous saccharification and fermentation), which resulted from the increased sourness and sweetness and the decreased size of solid particles contained in the LFR. The resulted LFR was superior in quality. Physical and chemical properties of the LFR were evaluated.