• Korean Chemical Engineering Research
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• 제46권5호
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• pp.858-862
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• 2008

분리 당화발효(Separate Hydrolysis and Fermentation, SHF)는 당화와 발효공정을 따로 수행하는 방법으로 최종 생성물인 글루코오스에 의해 억제 영향을 받기 때문에 반응에 진행됨에 따라 축적된 글루코오스의 농도가 높아지면 반응이 종결되는 단점이 있다. 이를 극복하기 위해 효소의 양을 늘리는 방법이 있지만, 효소의 생산비용이 비싸기 때문에 경제적인 방법이 될 수 없다. 이러한 분리 당화발효 공정의 단점을 극복하기 위해서 동시당화발효 공정(Simultaneous Saccharification and Fermentation, SSF)은 하나의 반응기에서 당화와 발효를 동시에 수행한다. 동시당화발효 공정에서는 당화과정에서 글루코오스가 생성되자마자 효모가 발효과정을 통해 글루코오스를 바로 제거하기 때문에 반응기내에서 당의 축적을 최소화할 수 있다. 따라서 동시당화발효 공정은 최종 생성물의 억제 작용을 방지할 수 있고, 효소의 가수분해 반응을 향상시킬 수 있다. 본 연구에서는 동시당화발효에서 에탄올의 수율에 관여하는 조건들(pH, 반응온도, 효소 투입량, 반응시간)의 최적 조건을 찾는 연구를 수행하였다. 기질로는 감자전분을 사용하였고, 효소는 glucoamylase, 균주는 Saccharomyces cerevisiae가 각각 사용되었다. 동시당화발효의 최적의 조건은 pH 4, 온도 38로 나타났다. 최적의 조건으로 감자전분을 동시당화발효하였을 때 반응 18시간 후에 에탄올은 최대 수율 86%에 도달하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권1호
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• pp.103-109
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• 2019

Objective: Ensiling of tannin-rich fruit byproducts (FB) involves quantitative and qualitative changes in the tannins, which would consequently change the rumen fermentation characteristics. This study aimed to evaluate whether ensiled FBs are effective in mitigating methane emission from ruminants by conducting in vitro assessments. Methods: Fruit byproducts (grape pomace, wild grape pomace, and persimmon skin) were collected and subjected to four-week ensiling by Lactobacillus buchneri inoculant. A defined feed component with or without FB samples (both fresh and ensiled material) were subjected to in vitro anaerobic culturing using rumen fluid sampled from beef cattle, and the fermentation parameters and microbial populations were monitored. Results: Reduced methane production and a proportional change in total volatile fatty acids (especially enhanced propionate proportion) was noted in bottles containing the FBs compared with that in the control (without FB). In addition, we found lower gene copy number of archaeal 16S rRNA and considerably higher levels of one of the major fibrolytic bacteria (Fibrobacter succinogenes) in the bottles containing FBs than in the control, particularly, when it was included in a forage-based feed. However, in the following cultivation experiment, we observed that FBs failed to exhibit a significant difference in methane production with or without polyethylene glycol, implying that tannins in the FBs may not be responsible for the mitigation of methane generation. Conclusion: The results of the in vitro cultivation experiments indicated that not only the composition but also ensiling of FBs affected rumen fermentation patterns and the degree of methane generation. This is primarily because of the compositional changes in the fibrous fraction during ensiling as well as the presence of readily fermented substrates, whereas tannins in these FBs seemed to have little effect on the ruminal fermentation kinetics.

• Animal Bioscience
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• 제34권2호
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• pp.205-212
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• 2021

Objective: The purpose of present study was to investigate the effects of condensed molasses fermentation solubles (CMS) on lactation performance, rumen fermentation, nutrient digestibility, and serum parameters of dairy cows. Methods: A total of 75 healthy Holstein cows with the same parity (milk production = 35±2.5 kg, body weight = 570±28 kg) were randomly selected and divided into 5 groups. One group served as control group (CON; no CMS), whereas the other 4 groups were CMS1 (accounted for 1% of the diet), CMS2 (2%), CMS3 (3%), and CMS4 (4%). All cows were fed regularly three times each day at 0800, 1600, and 2400 h. Cows received diet and water ad libitum. The experiment lasted for 60 days. Results: Results showed that the dry matter intake, milk yield, and protein of CMS2 were maximum and higher (p<0.05) than CMS4. The ruminal pH was observed less than 6 in CMS3 and CMS4 groups. No noticeable difference of microbial protein was found between CON and CMS2 groups, while the microbial protein in these groups was higher (p<0.05) than CMS3 and CMS4 groups. The apparent digestibility of dry matter, organic matter, and crude protein in CMS2 group was higher (p<0.05) than CMS3 and CMS4 groups. Compared to CMS3 and CMS4 groups, the CMS2 group increased (p<0.05) the serum concentrations of immunoglobulin G and immunoglobulin M on d 60. Conclusion: Therefore, it is practicable that CMS substitutes for a part of concentrates in lactating cows' diets, but higher addition of CMS (more than 3% of the diet) could decrease production performance of dairy cows as seen in the present study.

• Animal Bioscience
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• 제35권1호
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• pp.39-46
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• 2022

Objective: The fermentation profile and silage quality of 3 Italian ryegrass (Lolium multiflorum Lam.) cultivars (cvs. Devis, Hellen, and Trinova) treated with 5 nitrogen doses (0, 50, 100, 150, and 200 kg/ha) were evaluated. Methods: The experiment was laid out in split plot in randomized complete block design with three replications. Annual ryegrass cultivars used in this study have been commonly grown in Turkey. Nitrogen doses were set in main plot and cultivars in split plot in the field. Plants were harvested at full-flowering stage with dry matter content about 220 g/kg for first cutting and 260 g/kg for second cutting. Harvested plants were chopped theoretically into 2 to 3 cm lengths for ensiling. Chopped fresh materials were ensilaged by compressing in 2 L plastic jars about 3±0.1 kg. Results: Effects of N doses on dry matter, neutral detergent fiber, acid detergent fiber, dry matter digestibility, relative feed value, crude protein, pH, ammonia nitrogen, lactic acid, acetic acid, and lactic acid/acetic acid were statistically significant while water soluble carbohydrate, ash and organic matter were not statistically different. Ammonia nitrogen, crude protein, ash, organic matter, lactic acid, and lactic acid/acetic acid were affected by cultivars, but the other parameters were not. Increasing nitrogen applications positively affected the chemical composition of annual ryegrass silage. The significant increase in protein content was remarkable, however, silage fermentation properties were adversely affected by the increasing nitrogen dose. Conclusion: It can be recommended 150 kg/ha nitrogen dose for annual ryegrass harvested at full blooming stage. Even though the silage fermentation properties of the used cultivars were similar, cv. Devis gave better results than the others in terms of silage pH and relative feed value.

• Animal Bioscience
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• 제37권4호
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• pp.655-667
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• 2024

Objective: This study aimed to assess the impact of a hydroethanolic extract of walnut green husks (WGH) on rumen fermentation and the diversity of bacteria, methanogenic archaea, and fungi in sheep fed a high-concentrate diet. Methods: Five healthy small-tailed Han ewes with permanent rumen fistula were selected and housed in individual pens. This study adopted a self-controlled and crossover design with a control period and an experimental period. During the control period, the animals were fed a basal diet (with a ratio of concentrate to roughage of 65:35), while during the treatment period, the animals were fed the basal diet supplemented with 0.5% hydroethanolic extract of WGH. Fermentation parameters, digestive enzyme activities, and microbial diversity in rumen fluid were analyzed. Results: Supplementation of hydroethanolic extract of WGH had no significant effect on feed intake, concentrations of total volatile fatty acids, isovalerate, ammonia nitrogen, and microbial protein (p>0.05). However, the ruminal pH, concentrations of acetate, butyrate and isobutyrate, the ratio of acetate to propionate, protozoa count, and the activities of filter paper cellulase and cellobiase were significantly increased (p<0.05), while concentrations of propionate and valerate were significantly decreased (p<0.05). Moreover, 16S rRNA gene sequencing revealed that the relative abundance of rumen bacteria Christensenellaceae R7 group, Saccharofermentans, and Ruminococcaceae NK4A214 group were significantly increased, while Ruminococcus gauvreauii group, Prevotella 7 were significantly decreased (p<0.05). The relative abundance of the fungus Pseudomonas significantly increased, while Basidiomycota, Fusarium, and Alternaria significantly decreased (p<0.05). However, there was no significant change in the community structure of methanogenic archaea. Conclusion: Supplementation of hydroethanolic extract of WGH to a high-concentrate diet improved the ruminal fermentation, altered the structure of ruminal bacterial and fungal communities, and exhibited beneficial effects in alleviating subacute rumen acidosis of sheep.

• 한국미생물·생명공학회지
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• 제51권4호
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• pp.449-456
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• 2023

Sugar or dextrose increases the cost of production of xanthan gum by Xanthomonas campestris. Brewers' Spent Grain (BSG) was chosen as a source of fermentable sugars. BSG is a significant industrial by-product generated in large quantities from the breweries. Primarily used as animal feed due to its high fiber and protein content, BSG holds great potential as an economically and ecologically sustainable substrate for fermenting biomolecules. This study explores BSG's potential as a cost-effective carbon source for producing xanthan, utilizing Xanthomonas campestris NCIM 2961. An aqueous extract was prepared from BSG and inoculated with the bacterium under standard fermentation conditions. After fermentation, xanthan gum was purified using a standard protocol. The xanthan yield from BSG media was compared to that from MGYP media (control). The fermentation parameters, including pH, temperature, agitation and duration were optimized for maximum xanthan gum yield by varying them at different levels. Following fermentation, the xanthan gum was purified from the broth by alcoholic precipitation and then dried. The weight of the dried gum was measured. The obtained xanthan from BSG under standard conditions and commercial food-grade xanthan were characterized using FTIR. The highest xanthan yields were achieved at 32 ℃, pH 6.0, and 72 h of fermentation at 200 rpm using BSG media. The FTIR spectra of xanthan from BSG media closely resembled that of commercial food-grade xanthan. The results confirm the potential of BSG as a cost-effective alternative carbon source for xanthan production, thereby reducing production costs and solid waste.

• 한국식품저장유통학회지
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• 제18권1호
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• pp.91-97
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• 2011

상업적 복합균주와 효모를 sourdough starter로 사용하여V5가지의 시료를 다음과 같이 준비하였다. 제빵용 효모만을V사용한 control군, 상업용 복합균주를 사용한 LAB 1군, 상업용 복합균주와 효모로 각각 발효한 후 합친 LAB 2군, 상업용 복합균주와 효모를 함께 사용하여 발효한 LAB 3군, 상업용 복합균주와 효모를 사용하여 각각 발효하여 합친 후 다시 10시간 발효한 LAB 4군을 사용하여 제조한 발효식빵의 제빵특성은 다음과 같다. CrumbScan에 의한 영상분석의 결과로 LAB 4의 부피가 2,140 cc로 가장 큰 것으로 발효율이 가장 높았던 LAB 4의 부피가 가장 크게 나타났다. 기공의 조밀도는 부피가 가장 큰 LAB 4가 806로 가장 낮게 나타났고, 기공의 찌그러짐 정도는 기공의 조밀도가 가장 높았던 LAB 1이 1.56으로 가장 높은 것으로 나타났다. 껍질의 두께는 대조구가 가장 얇았고 LAB 4가 가장 두껍게 나타나 유의적인 차이를 보였다. Sourdough bread의 비용적의 측정결과는 발효율이 가장 높았던 LAB 4의 비용적은 5.14 mL/g으로 가장 높게 나타났다. Firmness 측정결과는 93.2 g인 대조구에 비해 LAB 2, LAB 3과 LAB 4에서의 firmness 측정치는 각각 113.67, 111.97, 113.50 g로 높게 나타났다. 관능검사 결과에서 식빵의 내부색은 전반적으로 밝게 평가되었으며, LAB 4의 기공이 가장 균일한 것으로 나타났고 촉감도 가장 부드러운 것으로 평가되었고, 전체적인 품질평가에서도 3.7을 나타내어 가장 선호하는 것으로 나타났다. 결과적으로 대부분의 평가항목에서 LAB 4로 만든 sourdough bread를 선호하는 것으로 나타났다.

• Journal of Animal Science and Technology
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• 제62권2호
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• pp.227-238
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• 2020

Use of raw feedstuffs for livestock is limited by low digestibility. Recently, fermentation of feedstuffs has been highlighted as a new way to improve nutrient absorption through the production of organic acids using inoculated microorganisms, which can also play a probiotic role. However, standard procedures for feedstuff fermentation have not been clearly defined because the process is influenced by climatic variation, and an analytical standard for fermented feedstuffs is lacking. This study aimed to evaluate the microbiological and biochemical changes of feedstuffs during fermentation at temperatures corresponding to different seasons (10℃, 20℃, 30℃, and 40℃). We also investigated the effects of yeast, lactic acid bacteria (LAB), and Bacillus spp. on fermentation and determined the results of their interactions during fermentation. The viable cells were observed within 8 days in single-strain fermentation. However, when feedstuffs were inoculated with a culture of mixed strains, LAB were predominant at low temperatures (10℃ and 20℃), while Bacillus spp. was predominant at high temperatures (30℃ and 40℃). A significant drop in pH from 6.5 to 4.3 was observed when LAB was the dominant strain in the culture, which correlated with the concentrations of lactic acid. Slight ethanol production was detected above 20℃ regardless of the incubation temperature, suggesting active metabolism of yeast, despite this organism making up a marginal portion of the microbes in the mixed culture. These results suggested that fermentation temperature significantly affects microbiological profiles and biochemical parameters, such as pH and the lactic acid concentration, of fermented feedstuffs. Our data provide valuable information for the determination of industrial standards for fermented feedstuffs.

• Animal Bioscience
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• 제36권8호
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• pp.1190-1198
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• 2023

Objective: To our knowledge, there are few studies on the correlation between internal structure of fermented products and nutrient delivery from by-products from coffee processing in the ruminant system. The objective of this project was to use advanced mid-infrared vibrational spectroscopic technique (ATR-FT/IR) to reveal interactive correlation between protein internal structure and ruminant-relevant protein and energy metabolic profiles of by-products from coffee processing affected by added-microorganism fermentation duration. Methods: The by-products from coffee processing were fermented using commercial fermentation product, called Saus Burger Pakan, consisting of various microorganisms: cellulolytic, lactic acid, amylolytic, proteolytic, and xylanolytic microbes, for 0, 7, 14, 21, and 28 days. Protein chemical profiles, Cornell Net Carbohydrate and Protein System crude protein and CHO subfractions, and ruminal degradation and intestinal digestion of protein were evaluated. The attenuated total reflectance-Ft/IR (ATR-FTIR) spectroscopy was used to study protein structural features of spectra that were affected by added microorganism fermentation duration. The molecular spectral analyses were carried using OMNIC software. Molecular spectral analysis parameters in fermented and non-fermented by-products from coffee processing included: Amide I area (AIA), Amide II (AIIA) area, Amide I heigh (AIH), Amide II height (AIIH), α-helix height (αH), β-sheet height (βH), AIA to AIIA ratio, AIH to AIIH ratio, and αH to βH ratio. The relationship between protein structure spectral profiles of by-products from coffee processing and protein related metabolic features in ruminant were also investigated. Results: Fermentation decreased rumen degradable protein and increased rumen undegradable protein of by-products from coffee processing (p<0.05), indicating more protein entering from rumen to the small intestine for animal use. The fermentation duration significantly impacted (p<0.05) protein structure spectral features. Fermentation tended to increase (p<0.10) AIA and AIH as well as β-sheet height which all are significantly related to the protein level. Conclusion: Protein structure spectral profiles of by-product form coffee processing could be utilized as potential evaluators to estimate protein related chemical profile and protein metabolic characteristics in ruminant system.

• Food Science and Biotechnology
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• 제17권5호
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• pp.904-911
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• 2008

Covalent cross-links between a number of proteins and peptides explain why transglutaminase may be widely used by food processing industries. The objective of this work was optimization of the fermentation process to produce transglutaminase from a new microbial source, the Streptomyces sp. P20. The strategy adopted to modify the usual literature media was: (1) fractional factorial design (FFD) to elucidate the key medium ingredients, (2) central composite design (CCD) to optimise the concentration of the key components. Optimization of the medium resulted in not only an 86% increase in microbial transglutaminase activity as compared to the media cited in the literature, but also a reduction in the production cost. Optimal fermentation conditions - namely temperature and agitation rate - were also studied, using CCD methodology. Usual conditions of $30^{\circ}C$ and 100 rpm were within the optimal area. All other parameters for enzyme production were experimentally proven to be optimum fermentation conditions.